Frequency conversion system

Claim 2

A frequency conversion system comprising a power source producing a voltage having an indeterminate varying frequency, a plurality of switching devices coupled to said power source to receive said voltage, said switching devices being actuated into conductivity upon the application of switching signals thereto, a reference frequency source, modulating means coupled to said power source and said reference frequency source, said modulating means including a plurality of control means, each of said control means being actuated into conduction at times controlled by the combined voltage outputs of said power source and said reference frequency source to produce said switching signals, means coupling said switching signals to each of said switching devices, and combining means coupled to said switching devices for combining the outputs therefrom to produce an output having the frequency of said reference frequency source.

Claim 3

A frequency conversion system comprising a power source producing an indeterminate varying frequency, a first group of switching devices respectively actuated into conductivity upon the application thereto of switching signals and the output from said power source of one polarity, a second group of switching devices respectively actuated into conductivity upon the application thereto of switching signals and the output from said power source of the opposite polarity, a reference frequency source, the frequency of said reference frequency source being less than the lowest frequency of said power source, modulating means coupled to said power source and said reference frequency source, said modulating means including a plurality of control means, each of said control means being actuated into conduction at times controlled by the combined outputs of said power source and said reference frequency source to produce said switching signals, means coupling each of said control means to corresponding ones of said switching devices, and combining means coupled to said switching devices to combine the outputs therefrom to produce a powEr output having the frequency of said reference frequency source.

Claim 4

A frequency conversion system comprising a power source producing an indeterminate varying frequency, a first group of switching devices respectively actuated into conductivity upon the application thereto of switching signals and the output from said power source of one polarity, a second group of switching devices respectively actuated into conductivity upon the application thereto of switching signals and the output from said power source of the opposite polarity, a reference frequency source, the frequency of said reference frequency source being less than the lowest frequency of said power source, modulating means coupled to said power source and said reference frequency source, said modulating means including a plurality of control means, each of said control means being actuated into conduction at times controlled by the combined outputs of said power source and said reference frequency source to produce said switching signals, means coupling each of said control means to corresponding ones of said switching devices, and combining means coupled to said switching devices to combine the outputs therefrom to produce a powEr output having the frequency of said reference frequency source.

Claim 5

A system as recited in claim 2 wherein each of said control means is a magnetic amplifier having a gate winding coupled to said power source and a control winding coupled to said reference frequency source.

Claim 6

A frequency conversion system comprising the indeterminate varying frequency power source having a number of balanced phase outputs, at least one frequency conversion means, each frequency conversion means comprising first and second groups of switching devices, each of the switching devices of said first group being actuated into conductivity upon the application thereto of a switching signal and an output from said power source of one polarity, each of the switching devices of said second group being actuated into conductivity upon the application thereto of a switching signal and an output from said power source of the opposite polarity, a reference frequency source producing a number of phase displaced outputs equal to the number of frequency conversion means, the frequency of said reference frequency source being less than the lowest frequency of said power source, modulating means equal in number to the number of frequency conversion means, each modulating means being coupled to said power source and to the associated phase output reference frequency source, each of said modulating means being coupled to an associated frequency conversion means, each modulating means including a plurality of control means, each of said control means being actuated into conduction at times controlled by the combined outputs of said power source and said reference frequency source to produce said switching signals, means coupling each of said control means to corresponding ones switching devices, and means coupled to each of said frequency conversion means to combine the outputs of the switching devices therein so as to produce a number of balanced phase outputs equal to the number of frequency conversion means and having the frequency of said reference frequency source.

Claim 7

A frequency conversion system comprising the indeterminate varying frequency power source having a number of balanced phase outputs, at least one frequency conversion means, each frequency conversion means comprising first and second groups of switching devices, each of the switching devices of said first group being actuated into conductivity upon the application thereto of a switching signal and an output from said power source of one polarity, each of the switching devices of said second group being actuated into conductivity upon the application thereto of a switching signal and an output from said power source of the opposite polarity, a reference frequency source producing a number of phase displaced outputs equal to the number of frequency conversion means, the frequency of said reference frequency source being less than the lowest frequency of said power source, modulating means equal in number to the number of frequency conversion means, each modulating means being coupled to said power source and to the associated phase output reference frequency source, each of said modulating means being coupled to an associated frequency conversion means, each modulating means including a plurality of control means, each of said control means being actuated into conduction at times controlled by the combined outputs of said power source and said reference frequency source to produce said switching signals, means coupling each of said control means to corresponding ones switching devices, and means coupled to each of said frequency conversion means to combine the outputs of the switching devices therein so as to produce a number of balanced phase outputs equal to the number of frequency conversion means and having the frequency of said reference frequency source.

Claim 8

A system as recited in claim 4 wherein each of said control means is a magnetic amplifier having a gate winding coupled to one of the outputs of said power source and a control winding coupled to the associated output of said reference frequency source.

Claim 9

A frequency conversion system comprising an indeterminate varying frequency power source having a plurality of balanced phase outputs, a number of frequency conversion means equal to the number of system phase outputs desired, each frequency conversion means comprising first and second groups of switching devices, each of the switching devices of said first group being actuated into conductivity upon the application thereto of a switching signal and an output from said power source of one polarity, each of the switching devices of said second group being actuated into conductivity upon the application thereto of a switching signal and an output from said power source of the opposite polarity, a reference frequency source producing a number of phase displaced outputs equal to the number of system phase outputs desired, the frequency of said reference frequency source being less than the lowest frequency of said power source, modulating means equal in number to the number of system phase outputs desired, each modulating means being coupled to the outputs of said power source and the associated phase output of said reference frequency source, each modulating means being coupled to the associated frequency conversion means, said modulating means each including a number of control means equal to the number of switching devices within the associated frequency conversion means, each of said control means being actuated into conduction at times controlled by the combined outputs of said power source and said reference frequency source to produce said switching signals, means coupling each of said control means to corresponding ones of said switching devices, and combining means coupled to each Frequency conversion means to combine the outputs of the switching devices therein so as to produce the desired number of balanced phase system outputs of the frequency of said reference frequency source.

Claim 10

A frequency conversion system comprising an indeterminate varying frequency power source having a plurality of balanced phase outputs, a number of frequency conversion means equal to the number of system phase outputs desired, each frequency conversion means comprising first and second groups of switching devices, each of the switching devices of said first group being actuated into conductivity upon the application thereto of a switching signal and an output from said power source of one polarity, each of the switching devices of said second group being actuated into conductivity upon the application thereto of a switching signal and an output from said power source of the opposite polarity, a reference frequency source producing a number of phase displaced outputs equal to the number of system phase outputs desired, the frequency of said reference frequency source being less than the lowest frequency of said power source, modulating means equal in number to the number of system phase outputs desired, each modulating means being coupled to the outputs of said power source and the associated phase output of said reference frequency source, each modulating means being coupled to the associated frequency conversion means, said modulating means each including a number of control means equal to the number of switching devices within the associated frequency conversion means, each of said control means being actuated into conduction at times controlled by the combined outputs of said power source and said reference frequency source to produce said switching signals, means coupling each of said control means to corresponding ones of said switching devices, and combining means coupled to each Frequency conversion means to combine the outputs of the switching devices therein so as to produce the desired number of balanced phase system outputs of the frequency of said reference frequency source.

Claim 11

A system as recited in claim 6 wherein each of said control means is a magnetic amplifier having a gate winding coupled to one of the outputs of said power source and a control winding coupled to the associated output of said reference frequency source.

Claim 12

A system as recited in claim 7 wherein each of said switching devices has an anode, a cathode, and a switching electrode, each switching device of said first group of switching devices has its anode coupled to one of the outputs from said power source, its cathode coupled to said combining means, and its switching electrode coupled to the corresponding one of said control means in the associated modulating means, and each switching device of said second group of switching devices has its cathode coupled to one of the outputs from said power source, its anode coupled to said combining means, and its switching electrode coupled to the corresponding one of said control means in the associated modulating means.

Claim 13

In combination with a varying frequency power source having a number of balanced phase outputs, at least one frequency conversion means, each frequency conversion means comprising first and second groups of devices which are rendered conductive upon the supplying of switching signals respectively thereto, each of said devices comprising an anode, a cathode and a switching electrode, the anode of each of said first devices being coupled to one of said power source outputs, the cathode of each of said second devices being coupled to one of said power source outputs, a reference frequency source having a number of phase displaced outputs equal to the number of frequency conversion means, the frequency of said reference frequency source being less than the lowest frequency of the output from said power source, modulating means equal in number to the number of frequency conversion means, each modulating means being coupled to the outputs of said power source and the associated phase output of said reference frequency source to mix said power source outputs with the output of said reference frequency source, means for applying the respective outputs of said modulating means to the switching electrodes of the devices within corresponding frequency conversion means, combining means coupled to each frequency conversion means for combining the outputs of the devices therein to produce a number of balanced phase outputs equal to the number of frequency conversion means and having the frequency of said reference frequency source, and inhibit means responsive to the outputs from said combining means for supplying a signal to each of said modulating means for preventing the switching into conductivity of one group of said devices while current is flowing in the other group of said devices.

Claim 14

In combination with a varying frequency power source having a number of balanced phase outputs, at least one frequency conversion means, each frequency conversion means comprising first and second groups of devices which are rendered conductive upon the supplying of switching signals respectively thereto, each of said devices comprising an anode, a cathode and a switching electrode, the anode of each of said first devices being coupled to one of said power source outputs, the cathode of each of said second devices being coupled to one of said power source outputs, a reference frequency source having a number of phase displaced outputs equal to the number of frequency conversion means, the frequency of said reference frequency source being less than the lowest frequency of the output from said power source, modulating means equal in number to the number of frequency conversion means, each modulating means being coupled to the outputs of said power source and the associated phase output of said reference frequency source to mix said power source outputs with the output of said reference frequency source, means for applying the respective outputs of said modulating means to the switching electrodes of the devices within corresponding frequency conversion means, combining means coupled to each frequency conversion means for combining the outputs of the devices therein to produce a number of balanced phase outputs equal to the number of frequency conversion means and having the frequency of said reference frequency source, and inhibit means responsive to the outputs from said combining means for supplying a signal to each of said modulating means for preventing the switching into conductivity of one group of said devices while current is flowing in the other group of said devices.

Claim 15

In combination with a varying frequency power source having a number of balanced phase outputs, at least one frequency conversion means, each frequency conversion means comprising first and second groups of silicon-controlled rectifiers, each of said silicon-controlled rectifiers comprising an anode, a cathode, and a gate electrode, the anode of each of the silicon-controlled rectifiers in said first group being coupled to one of said power source outputs, the cathodes of each of the silicon-controlled rectifiers in said second group being coupled to one of said power source outputs, a reference frequency source having a number of phase displaced outputs equal to the number of frequency conversion means, the frequency of said reference frequency source being less than the lowest frequency of the outputs of said power source, modulating means equal in number to the number of frequency conversion means, each modulating means being coupled to the outputs of said power source and the associated phase output of said reference voltage souRce for mixing said power source outputs with the output from said reference frequency source, means for applying the respective outputs of each modulating means to the gate electrodes of the silicon-controlled rectifiers within the corresponding frequency conversion means, combining means coupled to each frequency conversion means for combining the outputs of the silicon-controlled rectifiers therein to provide a number of balanced phase outputs equal to the number of frequency conversion means and having the frequency of said reference frequency source, the cathodes of the silicon-controlled rectifiers in said first group and the anodes of the silicon-controlled rectifiers in said second group being coupled to said combining means, filter means coupled to the outputs of said combining means for removing those components having frequencies other than the frequency of said reference frequency source, and inhibit means responsive to the current in the outputs from said combining means for preventing the switching into conductivity of one group of silicon-controlled rectifiers while current is still flowing in the other group of silicon-controlled rectifiers.

Claim 16

In combination with a varying frequency power source having a number of balanced phase outputs, at least one frequency conversion means, each frequency conversion means comprising first and second groups of silicon-controlled rectifiers, each of said silicon-controlled rectifiers comprising an anode, a cathode, and a gate electrode, the anode of each of the silicon-controlled rectifiers in said first group being coupled to one of said power source outputs, the cathodes of each of the silicon-controlled rectifiers in said second group being coupled to one of said power source outputs, a reference frequency source having a number of phase displaced outputs equal to the number of frequency conversion means, the frequency of said reference frequency source being less than the lowest frequency of the outputs of said power source, modulating means equal in number to the number of frequency conversion means, each modulating means being coupled to the outputs of said power source and the associated phase output of said reference voltage souRce for mixing said power source outputs with the output from said reference frequency source, means for applying the respective outputs of each modulating means to the gate electrodes of the silicon-controlled rectifiers within the corresponding frequency conversion means, combining means coupled to each frequency conversion means for combining the outputs of the silicon-controlled rectifiers therein to provide a number of balanced phase outputs equal to the number of frequency conversion means and having the frequency of said reference frequency source, the cathodes of the silicon-controlled rectifiers in said first group and the anodes of the silicon-controlled rectifiers in said second group being coupled to said combining means, filter means coupled to the outputs of said combining means for removing those components having frequencies other than the frequency of said reference frequency source, and inhibit means responsive to the current in the outputs from said combining means for preventing the switching into conductivity of one group of silicon-controlled rectifiers while current is still flowing in the other group of silicon-controlled rectifiers.

Claim 17

The combination defined in claim 10 wherein said reference frequency source comprises an oscillator having a determinable range of frequencies and a phase shifter for producing said phase displaced outputs from the output of said oscillator, and wherein there is further included sensing means in circuit with the outputs of said filter means for sensing an out-of-balance phase relationship between the outputs therefrom, the output of said sensing means being applied to said phase shifter as a correction signal.

Claim 18

The combination recited in claim 10 further including voltage regulating means responsive to the output of said filter means and coupled to said modulating means for comparing the voltage of the output of said filter means with the voltage of a predetermined value included in said regulating means, the output of said voltage regulating means being applied to said modulating means to control the time of the switching into conductivity of said silicon-controlled rectifiers.

Claim 19

The combination defined in claim 12 wherein each modulating means comprises a plurality of magnetic amplifiers, each of said magnetic amplifiers comprising a gate winding to which there is applied a power source output, a first control winding to which there is applied the output of said voltage regulating means and a second control winding to which there is applied the associated output of said reference frequency source, the output of a magnetic amplifier being applied to the gate electrode of an operatively associated silicon-controlled rectifier.

Claim 20

The combination defined in claim 13 wherein the output of a magnetic amplifier is applied to a gate electrode of a silicon-controlled rectifier through a transformer and wherein the output of said inhibit means is applied to these transformers in such polarities as to prevent the switching into conductivity of one of said groups of silicon-controlled rectifiers when the current in the outputs of said combining means is other than at the zero crossover point.

Claim 21

In combination, a rotary input source having an indeterminate variable speed, electrical generating means responsive to the application of said rotary input thereto for producing a number of balanced phase outputs of an indeterminate variable frequency directly proportional to said indeterminate variable speed, at least one frequency conversion means, each frequency conversion means comprising first and second groups of devices which are rendered conductive upon the supplying of switching signals respectively thereto, each of said devices comprising an anode, a cathode, and a switching electrode, the anode of each of the devices in said first group being coupled to one of the outputs of said electrical generating means, the cathode of each of the devices in said second group being coupled to one of the outputs of Said generating means, a reference frequency source producing a number of phase displaced outputs equal to the number of frequency conversion means, the frequency of said reference frequency source being less than the lowest frequency of the outputs from said electrical generating means, modulating means equal in number to the number of frequency conversion means, each modulating means being coupled to the outputs of said generating means and the associated phase output of said reference frequency source for mixing said generating means outputs with the output of said reference frequency source, means for applying the respective outputs of said each modulating means to the switching electrodes of the devices within the corresponding frequency conversion means, combining means coupled to each frequency conversion means for combining the outputs of the devices therein to provide a number of balanced phase outputs equal to the number of frequency conversion means and having the frequency of said reference frequency source, and disabling means in circuit with said combining means and said electrical generating means for disabling said combination when the voltage of an output of said combining means substantially differs from a selected voltage value and when the frequency of an output of said combining means substantially differs from the frequency of said reference frequency source.

Claim 22

In combination, a rotary input source having an indeterminate variable speed, electrical generating means responsive to the application of said rotary input thereto for producing a number of balanced phase outputs of an indeterminate variable frequency directly proportional to said indeterminate variable speed, at least one frequency conversion means, each frequency conversion means comprising first and second groups of devices which are rendered conductive upon the supplying of switching signals respectively thereto, each of said devices comprising an anode, a cathode, and a switching electrode, the anode of each of the devices in said first group being coupled to one of the outputs of said electrical generating means, the cathode of each of the devices in said second group being coupled to one of the outputs of Said generating means, a reference frequency source producing a number of phase displaced outputs equal to the number of frequency conversion means, the frequency of said reference frequency source being less than the lowest frequency of the outputs from said electrical generating means, modulating means equal in number to the number of frequency conversion means, each modulating means being coupled to the outputs of said generating means and the associated phase output of said reference frequency source for mixing said generating means outputs with the output of said reference frequency source, means for applying the respective outputs of said each modulating means to the switching electrodes of the devices within the corresponding frequency conversion means, combining means coupled to each frequency conversion means for combining the outputs of the devices therein to provide a number of balanced phase outputs equal to the number of frequency conversion means and having the frequency of said reference frequency source, and disabling means in circuit with said combining means and said electrical generating means for disabling said combination when the voltage of an output of said combining means substantially differs from a selected voltage value and when the frequency of an output of said combining means substantially differs from the frequency of said reference frequency source.

Claim 23

The combination defined in claim 15 further including auxiliary electrical generating means operably associated with said rotary input source for providing operating supply voltages for said combination.

Claim 24

The combination defined in claim 16 wherein said auxiliary electrical generating means is a permanent magnet generator and wherein there is further included means responsive to the rotational speed of said rotary input source for controlling the electrical actuation of said combination, the last-recited means enabling said actuation only when said speed attains a predetermined level.

Claim 25

The combination defined in claim 15 wherein said disabling means comprises means coupled to the outputs of said combining means for disabling the operation of said combination when the voltage of one of the last-named outputs exceeds a first selected voltage and when the voltage of one of the last-named outputs is less than a second selected voltage.

Claim 26

The combination defined in claim 15 wherein said disabling means includes means coupled to the outputs of said combining means for disabling said combination when the frequency of one of the last-named outputs exceeds a first prescribed frequency and when the frequency of one of the last-named outputs is less than a second prescribed frequency.

Claim 27

The combination defined in claim 15 wherein said disabling means includes means coupled to said electrical generating means to disable said combination in response to a feeder fault in said electrical generating means.

Claim 28

In a multiple electrical generating system parallel arrangement, each system comprising a power source having an indeterminate varying frequency and having a number of balanced phase outputs, at least one frequency conversion means, each frequency conversion means comprising first and second groups of devices which are rendered conductive upon the supplying of switching signals respectively thereto, each of said devices comprising an anode, a cathode, and a switching electrode, the anode of each of the devices in said first group being coupled to one of the outputs of said power source, the cathodes of each of the devices in said second group being coupled to one of the outputs of said power source, a reference oscillator having a frequency which is less than the lowest frequency of the outputs of said power source, phase shifting means coupled to said oscillator for producing a number of phase displaced outputs equal to the number of frequency conversion means, modulating means equal in number to the number of frequency conversion means, each modulating means being coupled to the ouTputs of said power source and an associated output of said phase-shifting means for mixing said power source outputs with the phase-shifted output of said reference oscillator, means for applying the respective outputs of said each modulating means to the switching electrodes of the devices within the corresponding frequency conversion means, combining means coupled to each frequency conversion means for combining the outputs of the devices therein to provide a number of balanced phase outputs equal in number to said frequency conversion means and having the frequency of said reference oscillator, regulating means coupled to the output of each combining means and including a reference voltage and means for applying the difference between the voltage of an output of said combining means and said reference voltage as an input to the associated modulating means to control the time of switching of the devices in the corresponding frequency conversion means, means respectively coupled to each combining means and responsive to the outputs the corresponding combining means in the other systems in said parallel arrangement for deriving real load division control signals, means for applying one real load division signal as a correction signal to said phase shifting means, means respectively coupled to each combining means and responsive to the outputs of corresponding combining means in the other systems in said parallel arrangement for deriving reactive load division signals, one reactive load division signal being applied as a correction signal to said regulating means.

Claim 29

In a multiple electrical generating system parallel arrangement, each system comprising a power source having an indeterminate varying frequency and having a number of balanced phase outputs, at least one frequency conversion means, each frequency conversion means comprising first and second groups of devices which are rendered conductive upon the supplying of switching signals respectively thereto, each of said devices comprising an anode, a cathode, and a switching electrode, the anode of each of the devices in said first group being coupled to one of the outputs of said power source, the cathodes of each of the devices in said second group being coupled to one of the outputs of said power source, a reference oscillator having a frequency which is less than the lowest frequency of the outputs of said power source, phase shifting means coupled to said oscillator for producing a number of phase displaced outputs equal to the number of frequency conversion means, modulating means equal in number to the number of frequency conversion means, each modulating means being coupled to the ouTputs of said power source and an associated output of said phase-shifting means for mixing said power source outputs with the phase-shifted output of said reference oscillator, means for applying the respective outputs of said each modulating means to the switching electrodes of the devices within the corresponding frequency conversion means, combining means coupled to each frequency conversion means for combining the outputs of the devices therein to provide a number of balanced phase outputs equal in number to said frequency conversion means and having the frequency of said reference oscillator, regulating means coupled to the output of each combining means and including a reference voltage and means for applying the difference between the voltage of an output of said combining means and said reference voltage as an input to the associated modulating means to control the time of switching of the devices in the corresponding frequency conversion means, means respectively coupled to each combining means and responsive to the outputs the corresponding combining means in the other systems in said parallel arrangement for deriving real load division control signals, means for applying one real load division signal as a correction signal to said phase shifting means, means respectively coupled to each combining means and responsive to the outputs of corresponding combining means in the other systems in said parallel arrangement for deriving reactive load division signals, one reactive load division signal being applied as a correction signal to said regulating means.

Claim 30

The arrangement defined in claim 21 further including means for summing the real load division signals derived from the combining means in a system and for applying the resultant of said summed signals to said oscillator as a correction signal.

Claim 31

The arrangement defined in claim 21 further including protective means associated with each of said systems, said protective means being coupled to said combining means, said protective means comprising overvoltage means responsive to an output of said combining means having a voltage greater than a first selected value for disabling said system, undervoltage means responsive to an output of said combining means having a voltage less than a second selected value for disabling said system, overfrequency means responsive to an output of said combining means having a frequency greater than a first prescribed frequency for disabling said system, underfrequency means responsive to an output of said combining means having a frequency less than a second prescribed frequency for disabling said system, means responsive to the outputs of said combining means for deriving a first bias signal which is proportional to the difference between the reactive current supplied by the outputs of said combining means and the average of all the outputs of the combining means of said parallel arrangement, said first bias signal being applied to said overvoltage and undervoltage means and means responsive to the outputs of said combining means for deriving a second bias signal which is proportional to the difference between the real current supplied by the outputs of said combining means and the average of all the outputs of the combining means of said parallel arrangement, said second bias signal being applied to said overfrequency and underfrequency means.

Claim 32

The arrangement defined in claim 23 wherein means are coupled to each of said power sources for regulating the voltage of the output thereof.

Claim 33

In a multiple electrical generating system parallel arrangement, each system comprising a power source having an indeterminate varying frequency and having a plurality of balanced phase outputs, a number of frequency conversion means equal to the number of system phase outputs desired, each frequency conversion means comprising a first group of switching devices which are actuated into conductivity upon the application thereto of switching signals and the outputs from said power source of a positive polarity, and a second group of switching devices which are actuated into conductivity upon the application thereto of switching signals and the outputs from said power source of a negative polarity, a reference frequency source producing a number of phase displaced outputs equal to the number of system phase outputs desired, the frequency of the reference frequency source being less than the lowest frequency of said power source, modulating means equal in number to the number of system phase outputs desired, each modulating means being coupled to the outputs of said power source and the associated phase output of said reference frequency source for mixing said power source outputs with the output from said reference frequency source, means for applying the respective outputs of each modulating means as switching signals to the switching devices in the corresponding frequency conversion means, combining means coupled to each frequency conversion means for combining the outputs of the switching devices therein to produce the desired number of balanced phase system outputs having the frequency of said reference frequency source, means respectively coupled to each combining means and responsive to the outputs of the other systems in said parallel arrangement for deriving a real load division signal, means for applying said real load division signal as a correction signal to control the time of switching the switching devices in said frequency conversion means, means respectively in circuit with each combining means and responsive to the outputs of the other systems in said parallel arrangement for deriving a reactive load division signal, and means for applying said reactive load division signal as a correction signal to control the time of switching the switching devices in said frequency conversion means.

Claim 34

In a multiple electrical generating system parallel arrangement, each system comprising a power source having an indeterminate varying frequency and having a plurality of balanced phase outputs, a number of frequency conversion means equal to the number of system phase outputs desired, each frequency conversion means comprising a first group of switching devices which are actuated into conductivity upon the application thereto of switching signals and the outputs from said power source of a positive polarity, and a second group of switching devices which are actuated into conductivity upon the application thereto of switching signals and the outputs from said power source of a negative polarity, a reference frequency source producing a number of phase displaced outputs equal to the number of system phase outputs desired, the frequency of the reference frequency source being less than the lowest frequency of said power source, modulating means equal in number to the number of system phase outputs desired, each modulating means being coupled to the outputs of said power source and the associated phase output of said reference frequency source for mixing said power source outputs with the output from said reference frequency source, means for applying the respective outputs of each modulating means as switching signals to the switching devices in the corresponding frequency conversion means, combining means coupled to each frequency conversion means for combining the outputs of the switching devices therein to produce the desired number of balanced phase system outputs having the frequency of said reference frequency source, means respectively coupled to each combining means and responsive to the outputs of the other systems in said parallel arrangement for deriving a real load division signal, means for applying said real load division signal as a correction signal to control the time of switching the switching devices in said frequency conversion means, means respectively in circuit with each combining means and responsive to the outputs of the other systems in said parallel arrangement for deriving a reactive load division signal, and means for applying said reactive load division signal as a correction signal to control the time of switching the switching devices in said frequency conversion means.

Claim 35

A frequency conversion system as recited in claim 2 further including inhibit means supplying a signal to said modulating means in response to the power output form said combining means to prevent the actuation into conductivity of one group of said switching devices while current is flowing in the other group of said switching devices.

Claim 36

A frequency conversion system comprising an indeterminate varying frequency power source, a load, a number of frequency conversion means equal to the number of system phase outputs desired, each frequency conversion means comprising a switching device for each phase output of said power source of one polarity and a switching device for each phase output of said power source of the opposite polarity, each switching device being triggered into conduction to couple said power source to said load when said switching device is forward biased by the output of said power source and a switching signal is applied thereto, a reference frequency source producing a number of phase displaced outputs equal to the number of system phase outputs desired, a number of modulating means equal to the number of system phase outputs desired, each modulating means being coupled to receive the power source output and one phase output of said reference frequency source, each modulating means being coupled to one frequency conversion means, each modulating means including a control means for each switching device within the associated frequency conversion means, each control means within a given modulating means being coupled to the phase output of said power source that is coupled to its corresponding switching device and to the associated one phase output of said reference frequency source, each control means being triggered into conductivity by the half cycle of said power source output that forward biases the switching device coupled thereto to produce the switching signal for said switching device, the point of triggering within a half cycle being determined by the output from said reference frequency source, and means coupled to the switching devices in each frequency conversion means for combining the outputs therefrom to produce the desired number of balanced phase system outputs for said load having the frequency of said reference frequency source.

Claim 37

A frequency conversion system comprising an indeterminate varying frequency power source, a load, a number of frequency conversion means equal to the number of system phase outputs desired, each frequency conversion means comprising a switching device for each phase output of said power source of one polarity and a switching device for each phase output of said power source of the opposite polarity, each switching device being triggered into conduction to couple said power source to said load when said switching device is forward biased by the output of said power source and a switching signal is applied thereto, a reference frequency source producing a number of phase displaced outputs equal to the number of system phase outputs desired, a number of modulating means equal to the number of system phase outputs desired, each modulating means being coupled to receive the power source output and one phase output of said reference frequency source, each modulating means being coupled to one frequency conversion means, each modulating means including a control means for each switching device within the associated frequency conversion means, each control means within a given modulating means being coupled to the phase output of said power source that is coupled to its corresponding switching device and to the associated one phase output of said reference frequency source, each control means being triggered into conductivity by the half cycle of said power source output that forward biases the switching device coupled thereto to produce the switching signal for said switching device, the point of triggering within a half cycle being determined by the output from said reference frequency source, and means coupled to the switching devices in each frequency conversion means for combining the outputs therefrom to produce the desired number of balanced phase system outputs for said load having the frequency of said reference frequency source.

Claim 38

A frequency conversion system as recited in claim 27 wherein each control means is a magnetic amplifier having a gate winding coupled to one phase output of said power source and a control winding coupled to one phase output of said reference frequency source.

Claim 39

In an electrical power generating system including a system output terminal and a power source producing output power of varying frequency, converter apparatus for changing the source output power into system output power of predetermined lower, constant frequency, the converter apparatus comprising: means for generating a reference frequency signal having a constant frequency lower than the power source output frequency; means coupled to the power source and to the generating means for producing trigger pulses during successive half cycles of the power source output voltage in response to the reference signal and a portion of source output power; and controllable conductive means connected between the power source and the system output terminal and selectively controllable in response to applied trigger pulses to pass to the system output terminal portions of the positive half cycles of power source output voltage occurring during a period equal to one half cycle of the reference signal, and to pass to the system output terminal portions of the negative half cycles of power source output voltage occurring during a period equal to the next half cycle of the reference signal.

Claim 40

In an electrical power generating system including a system output terminal and a power source producing output power of varying frequency, converter apparatus for changing the source output power into system output power of predetermined lower, constant frequency, the converter apparatus comprising: means for generating a reference frequency signal having a constant frequency lower than the power source output frequency; means coupled to the power source and to the generating means for producing trigger pulses during successive half cycles of the power source output voltage in response to the reference signal and a portion of source output power; and controllable conductive means connected between the power source and the system output terminal and selectively controllable in response to applied trigger pulses to pass to the system output terminal portions of the positive half cycles of power source output voltage occurring during a period equal to one half cycle of the reference signal, and to pass to the system output terminal portions of the negative half cycles of power source output voltage occurring during a period equal to the next half cycle of the reference signal.

Claim 41

In an electrical power generating system, converter apparatus as represented in claim 29 further including filtering means connected to the output of the controllable conductive means for smoothing said portions of the power source output voltage passed by the controllable conductive means.

Claim 42

In an electrical power generating system including a system output terminal and a power source producing output voltage and current of varying frequency, converter apparatus for changing the variable-frequency source output power into system output voltage and current equal in frequency to the lower, constant frequency of a reference signal, the converter apparatus comprising: means for generating a reference signal of constant frequency lower than the variable output frequency of the power source; and first and second controllable conductive means connected between the power source and the system output terminal and having a control terminal responsive to signals originated by the reference signal generating means for selectively conducting portions of the positive half cycles of power source output current during a period equal to one half cycle of the reference signal, and for conducting portions of the negative half cycles of power source output current during a period equal to the next half cycle of the reference signal.

Claim 43

In an electrical power generating system including a system output terminal and a power source producing output voltage and current of varying frequency, converter apparatus for changing the variable-frequency source output power into system output voltage and current equal in frequency to the lower, constant frequency of a reference signal, the converter apparatus comprising: means for generating a reference signal of constant frequency lower than the variable output frequency of the power source; and first and second controllable conductive means connected between the power source and the system output terminal and having a control terminal responsive to signals originated by the reference signal generating means for selectively conducting portions of the positive half cycles of power source output current during a period equal to one half cycle of the reference signal, and for conducting portions of the negative half cycles of power source output current during a period equal to the next half cycle of the reference signal.

Claim 44

In an electrical power generating system, converter apparatus as represented in claim 31 further comprising filtering means connected to receive the portions selectively conducted by the controllable conductive means for smoothing the waveform presented at said system output terminal.

Claim 45

In an electrical power generating system including a system output terminal and a power source producing output power of varying frequency, converter apparatus for changing the frequency of the source output power to a predetermined lower, constant frequency, the converter apparatus comprising: a first controllable, unidirectionally conductive device having a control terminal, an anode coupled to the power source, and a cathode; a second controllable, unidirectionally conductive device having a cathode coupled to the power source, a control terminal, and an anode; means for generating a reference signal at said predetermined lower, constant frequency; first means coupled to the power source, the reference signal generator, and the control terminal one of tHe first and second devices for controlling the latter to conduct during a period equal to one half cycle of the reference signal, a series of positive components of source power for use in forming the positive half cycles of the system output current; second means coupled to the power source, the reference signal generator, and the control terminal of the other of the first and second devices for controlling the latter to conduct, during a period equal to an alternate one half cycle of the reference signal, a series of negative components of source power for use in forming the negative half cycles of the system output current; and filtering means coupled to the cathode of the first device, the anode of the second device and the system output terminal for smoothing the positive and negative components of alternating power to form an approximate sine waveform of system output voltage and current equal in frequency to the reference signal.

Claim 46

In an electrical power generating system including a system output terminal and a power source producing output power of varying frequency, converter apparatus for changing the frequency of the source output power to a predetermined lower, constant frequency, the converter apparatus comprising: a first controllable, unidirectionally conductive device having a control terminal, an anode coupled to the power source, and a cathode; a second controllable, unidirectionally conductive device having a cathode coupled to the power source, a control terminal, and an anode; means for generating a reference signal at said predetermined lower, constant frequency; first means coupled to the power source, the reference signal generator, and the control terminal one of tHe first and second devices for controlling the latter to conduct during a period equal to one half cycle of the reference signal, a series of positive components of source power for use in forming the positive half cycles of the system output current; second means coupled to the power source, the reference signal generator, and the control terminal of the other of the first and second devices for controlling the latter to conduct, during a period equal to an alternate one half cycle of the reference signal, a series of negative components of source power for use in forming the negative half cycles of the system output current; and filtering means coupled to the cathode of the first device, the anode of the second device and the system output terminal for smoothing the positive and negative components of alternating power to form an approximate sine waveform of system output voltage and current equal in frequency to the reference signal.

Claim 47

In an electrical power generating system including a system output terminal and a power source producing output voltage and current of varying frequency, converter apparatus for changing the variable-frequency source output power into system output voltage and current equal in frequency to the lower, constant frequency of a reference signal, the converter apparatus comprising: means for generating a reference signal of constant frequency lower than the variable output frequency of the power source; means coupled to the power source and to the system output terminal for conducting portions at least of the positive half cycles of power source output current during a period equal to one half cycle of the reference signal, and for conducting portions at least of the negative half cycles of power source output current during a period equal to the next half cycle of the reference signal; means coupled to the power source, to the reference signal generator, and to the conducting means for predetermining the conduction periods of the latter; and means coupled to the conduction means and the system output terminal for synthesizing from the conducted portions of source output power continuous waveforms of system output voltage and current.

Claim 48

In an electrical power generating system including a system output terminal and a power source producing output voltage and current of varying frequency, converter apparatus for changing the variable-frequency source output power into system output voltage and current equal in frequency to the lower, constant frequency of a reference signal, the converter apparatus comprising: means for generating a reference signal of constant frequency lower than the variable output frequency of the power source; means coupled to the power source and to the system output terminal for conducting portions at least of the positive half cycles of power source output current during a period equal to one half cycle of the reference signal, and for conducting portions at least of the negative half cycles of power source output current during a period equal to the next half cycle of the reference signal; means coupled to the power source, to the reference signal generator, and to the conducting means for predetermining the conduction periods of the latter; and means coupled to the conduction means and the system output terminal for synthesizing from the conducted portions of source output power continuous waveforms of system output voltage and current.

Claim 49

In an electrical power generating system including a system output terminal and a power source producing output voltage and current of varying frequency, converter apparatus for changing the variable-frequency source output power into system output voltage and current equal in frequency to the lower, constant frequency of a reference signal, the converter apparatus comprising: means for generating a reference signal of constant frequency lower than the variable output frequency of the power source; means coupled to the power source and to the system output terminal for conducting portions at least of the positive half cycles of power source output current during a period equal to one half cycle of the reference signal, and for conducting portions at least of the negative half cycles of power source output current during a period equal to the next half cycle of the reference signal; means coupled to the power source, to the reference signal generator, and to the conducting means for determining respective lengths of the conduction periods of the latter in accordance with a function at least approximating the desired waveform of the system output voltage and current; and means coupled between the conduction means and the system output terminal for synthesizing from the conducted portions of source output power continuous waveforms of system output voltage and current.

Claim 50

In an electrical power generating system including a system output terminal and a power source producing output voltage and current of varying frequency, converter apparatus for changing the variable-frequency source output power into system output voltage and current equal in frequency to the lower, constant frequency of a reference signal, the converter apparatus comprising: means for generating a reference signal of constant frequency lower than the variable output frequency of the power source; means coupled to the power source and to the system output terminal for conducting portions at least of the positive half cycles of power source output current during a period equal to one half cycle of the reference signal, and for conducting portions at least of the negative half cycles of power source output current during a period equal to the next half cycle of the reference signal; means coupled to the power source, to the reference signal generator, and to the conducting means for determining respective lengths of the conduction periods of the latter in accordance with a function at least approximating the desired waveform of the system output voltage and current; and means coupled between the conduction means and the system output terminal for synthesizing from the conducted portions of source output power continuous waveforms of system output voltage and current.

Claim 51

In an electrical power generating system, converter apparatus as represented in claim 35 wherein the predetermining means comprises means for predetermining the respective lengths of the conduction periods of the conducting means in accordance with the amplitude of said reference signal.