Brushless synchronous motor control system

Claim 2

In a brushless synchronous motor unit including a rotating motor winding, and a stationary motor winding, an exciter unit coupled to the motor unit including a rotating exciter winding and a stationary exciter winding, a control system for controlling the synchronous operation of the motor unit by controlling the applicatiOn of electrical energy from the exciter unit to the motor unit, said control system being fixedly supported relative to the stationary motor winding, and means for magnetically coupling said control system to one of said rotating windings.

Claim 3

The control system of claim 1 wherein said control system is magnetically coupled to sense motor operations through the airgap formed by the exciter unit windings.

Claim 4

The control system of claim 1 further including an exciter electrical energy supply system electrically connected to the exciter stationary winding, a synchronizer control sensor circuit for sensing preselected conditions of said synchronous motor unit, and switch means controlled by said sensor circuit for energizing said stationary winding from said energy supply system.

Claim 5

The control system of claim 3 wherein said control system is magnetically coupled to sense said preselected motor conditions magnetically through the airgap formed by the exciter unit windings.

Claim 6

In the synchronous motor unit of claim 4 wherein the motor unit is started rotating as an induction motor, the control system further including that said preselected conditions includes the slip frequency of the synchronous motor unit, and said synchronizer sensor circuit has means for preselecting a slip frequency and means for comparing the sensed slip frequency to the said preselected frequency.

Claim 7

The control system of claim 5 wherein said slip frequency is at least partially reflected through said airgap as a zero frequency signal for a period, said period being a function of one-half of the electrical cyclic operation of the motor unit.

Claim 8

The control system of claim 6 wherein said slip frequency is further reflected through said airgap as a plurality of pulses during another period, said another period being a function of the remaining half of the electrical cyclic operation, and said pulses being related to the numerical relationship between the number of exciter poles an motor poles.

Claim 9

In the synchronous motor unit of claim 5, a startup control circuit for controlling the flow path of energy in the rotating windings during the inductive startup means for forcing the flow of energy from the rotating motor winding to the rotating exciter winding during one portion of the cyclic operation of the motor unit and substantially shunting the flow of energy from the rotating motor winding to the rotating exciter winding during another portion of the cyclic operation.

Claim 10

The startup control circuit of claim 8 wherein said one portion is one-half electrical cycle of operation of said motor unit and said another portion is the other half cycle of operation.

Claim 11

In the synchronous motor and exciter unit of claim 1, a discharge impedance control circuit, said discharge impedance control circuit including impedance means and impedance control means for sensing startup of the motor unit, said impedance means being adapted to be switched into circuit with said motor rotating winding during startup of the motor unit in response to said impedance control means.

Claim 12

The control system of claim 1 further including a synchronizer control sensor circuit for sensing said motor operations, said motor operations including the speed of rotation of the rotating motor winding.

Claim 13

The control system of claim 11 wherein said motor operations includes the polarity of the induced field current due to the rotation of the rotating motor windings.

Claim 14

The control system of claim 11 further comprising adjustment control means including said synchronizer control sensor circuit for permitting adjustment of the operating conditions of the motor unit during rotation of the rotating motor winding.

Claim 17

The method of claim 14 wherein the step of magnetically coupling the control system to sense motor operations includes coupling the control system through the airgap formed by the exciter unit windings.

Claim 18

The method of claim 14 further including the step of electrically connecting an exciter electrical energy supply system to the exciter stationary winding, sensing preselected conditions of the synchronous motor unit, and energizing the exciter stationary winding from said energy supply system in response to said preselected conditions.

Claim 19

The method of claim 16 wherein said preselected motor conditions are sensed magnetically through the airgap formed by the exciter unit windings.

Claim 20

In the synchronous motor unit of claim 17, the method further including the steps of starting the motor unit rotating as an induction motor, sensing the slip frequency of the synchronous motor unit as a preselected condition, preselecting a slip frequency and comparing the sensed slip frequency to the said preselected frequency to energize the stationary exciter winding.

Claim 21

The method of claim 18 wherein said slip frequency is at least partially reflected through said airgap as a zero frequency signal for a period, said period being a function of one-half of the electrical cyclic operation of the motor unit.

Claim 22

The method of claim 19 wherein said slip frequency is further reflected through said airgap as a plurality of pulses during another period, said another period being a function of the remaining half of the electrical cyclic operation, and said pulses being related to the numerical relationship between the number of exciter poles and motor poles.

Claim 23

In the synchronous motor unit of claim 18, the method further including the step of controlling the flow path of energy in the rotating windings during the inductive startup means for forcing the flow of energy from the rotating motor winding to the rotating exciter winding during one portion of the cyclic operation of the motor unit and substantially shunting the flow of energy from the rotating motor winding to the rotating exciter winding during another portion of the cyclic operation.

Claim 24

The method of claim 21, wherein said one portion is one-half electrical cycle of operation of said motor unit and said another portion is the other half cycle of operation.

Claim 25

In the synchronous motor and exciter unit of claim 14, the method including providing a discharge impedance control circuit including impedance means and impedance control means for sensing startup of the motor unit, and switching said impedance means into circuit with said motor rotating winding during startup of the motor unit.

Claim 26

In a synchronous motor unit having a stationary winding, a rotating wind, and an exciter unit having a rotating winding electrically connected to the motor rotating winding and a stationary winding, the motor unit being adapted to be operated in a startup mode wherein electrical energy is fed from the motor rotating winding to the exciter rotating winding and a running mode wherein electrical energy is fed from the exciter rotating winding to the motor rotating winding, a synchronizer control circuit coupled to the motor rotating winding for controlling the application of electrical energy from the exciter unit to the motor unit during the startup mode, the motor unit generating a signal wave during the startup mode having a zero current characteristic which has a duration varying as a function of the slip frequency of the motor uniT during the startup mode and a second characteristic, a slip frequency sensing circuit having means for preselecting a comparison slip frequency reference and timing said zero current characteristic duration, said slip frequency sensing circuit generating a control signal when said sensed duration bears a preselected relationship to said preselected slip frequency reference and switching means for applying exciter energy to the motor unit in response to said control signal and said second characteristic, said second characteristic resetting said slip frequency sensing circuit when said duration is less than an amount selectable by said slip frequency reference.

Claim 27

In a synchronous motor unit having a stationary winding, a rotating wind, and an exciter unit having a rotating winding electrically connected to the motor rotating winding and a stationary winding, the motor unit being adapted to be operated in a startup mode wherein electrical energy is fed from the motor rotating winding to the exciter rotating winding and a running mode wherein electrical energy is fed from the exciter rotating winding to the motor rotating winding, a synchronizer control circuit coupled to the motor rotating winding for controlling the application of electrical energy from the exciter unit to the motor unit during the startup mode, the motor unit generating a signal wave during the startup mode having a zero current characteristic which has a duration varying as a function of the slip frequency of the motor uniT during the startup mode and a second characteristic, a slip frequency sensing circuit having means for preselecting a comparison slip frequency reference and timing said zero current characteristic duration, said slip frequency sensing circuit generating a control signal when said sensed duration bears a preselected relationship to said preselected slip frequency reference and switching means for applying exciter energy to the motor unit in response to said control signal and said second characteristic, said second characteristic resetting said slip frequency sensing circuit when said duration is less than an amount selectable by said slip frequency reference.

Claim 28

The synchronizer control circuit of claim 24 wherein said second characteristic includes at least one pulse differing in amplitude from said first characteristic.