Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
223 words
An AC voltage integrating circuit, useful for forming an electric voltage signal proportional to a flux component in a rotating field machine from a voltage which is proportional to a Y voltage corresponding to the flux component and which contains a DC component, comprising: an integrator having an input to which the voltage proportional to the Y voltage is fed and an output at which the signal voltage proportional to the flux component in the machine is taken off; a summing point at the input of the integrator; a zero-controller for suppressing the DC component comprising a P-controller and an I-controller, each having an output fed to the summing point and each having an input; first means having a first input coupled to the output of the integrator, a second input to which a signal having a value between zero and one which is proportional to the frequency of the machine is coupled, and providing an output signal coupled to the P-controller which is proportional to the frequency of the machine; and second means having a first input coupled to the output of the integrator and a second input to which the signal which is proportional to the frequency of the machine is coupled and providing a signal to the I-controller which is proportional to the square of the frequency of the machine.
Claim 2
Dependent Claim
223 words
An AC voltage integrating circuit, useful for forming an electric voltage signal proportional to a flux component in a rotating field machine from a voltage which is proportional to a Y voltage corresponding to the flux component and which contains a DC component, comprising: an integrator having an input to which the voltage proportional to the Y voltage is fed and an output at which the signal voltage proportional to the flux component in the machine is taken off; a summing point at the input of the integrator; a zero-controller for suppressing the DC component comprising a P-controller and an I-controller, each having an output fed to the summing point and each having an input; first means having a first input coupled to the output of the integrator, a second input to which a signal having a value between zero and one which is proportional to the frequency of the machine is coupled, and providing an output signal coupled to the P-controller which is proportional to the frequency of the machine; and second means having a first input coupled to the output of the integrator and a second input to which the signal which is proportional to the frequency of the machine is coupled and providing a signal to the I-controller which is proportional to the square of the frequency of the machine.
Claim 3
Dependent Claim
35 words
A circuit according to claim 1 in which the first means comprises a first multiplier and the second means comprises a second multiplier having the output of the first multiplier coupled to its first input.
Claim 4
Dependent Claim
31 words
A circuit according to claim 2 in which the first and second multipliers comprise pulse-width multipliers and further comprising: a smoothing member connected to the intput of the second pulse-width multiplier.
Claim 5
Dependent Claim
55 words
A circuit according to claim 3, and further comprising: an inverting amplifier coupling the output of the first pulse-width multiplier to the input of the P-controller and to the input of the second multiplier, the inverting amplifier having a feedback resistor, and in which the smoothing member comprises a capacitor coupled across the feedback resistor.
Claim 6
Dependent Claim
45 words
A circuit according to claim 4 in which the I-controller includes a capacitor for determining the time constant and in which the capacitance of the smoothing capacitor is very small in comparison to that of the capacitor which determines the time constant of the I-controller.
Claim 7
Dependent Claim
58 words
A circuit according to any one of claims 3 to 5 in which each pulse-width multiplier comprises an FET switch having a control input and further comprising: a clock generator having a duty cycle proportional to the frequency of the rotating field machine, the clock generator having an output fed to the control input of each FET switch.
Claim 8
Dependent Claim
35 words
A circuit according to claim 6 in which the clock generator is adjustable, as to pulse frequency, below a transition frequency of the rotating field machine and, as to pulse width, above the transition frequency.
Claim 9
Dependent Claim
69 words
A circuit according to one of claims 2 to 7 and further comprising: means for feeding a signal proportional to the ohmic stator voltage drop of the rotating field machine to the summing point at the input of the integrator; a second summing point at the output of the integrator; and means for feeding a signal proportional to the integral of the reactive voltage to the second summing point.