Abstract: A method and apparatus for deriving phase voltage control signals for use in controlling current flow to an induction motor. The method may comprise obtaining an error term; converting the error term into a commanded voltage value; transforming the commanded voltage value into a commanded voltage vector; and converting the commanded voltage vector into the phase voltage control signals via pulse width modulation control. The apparatus may comprise a Park vector converter for converting a first stator phase measurement and a second stator phase measurement into a stator phase current vector; a scalar operator for obtaining a stator phase current value; a summer for obtaining an error term; an error converter for converting the error term into a commanded voltage value; a voltage transformer for transforming the commanded voltage value into a commanded voltage vector, and pulse width modulation control for converting the commanded voltage vector into the phase voltage control signals.

Abstract: A system and method is provided for generating DC power using a synchronous reluctance machine (12) or a salient-pole synchronous machine (102) and a power converter (110). The present invention can be used to achieve power production for a synchronous reluctance machine (12), or can be used to achieve partial production of power from a traditional salient-pole synchronous machine/starter (102) in the case where the salient-pole synchronous machine/starter has degenerated into a synchronous reluctance machine due to, for example, a loss of excitation. In a power generation system, a control system and method can include a power converter (110), controlled by a voltage command and at least one of a measured DC link (120) voltage or DC link (120) current, for use with a synchronous reluctance machine armature winding (102A) and a prime mover (116), such that movement of the synchronous reluctance machine rotor of the synchronous reluctance machine can be used to produce at least partial DC power generation.

Abstract: A system and method is provided for generating AC power using a synchronous reluctance machine (12) or a salient-pole synchronous machine (102) and a power converter (110). The present invention can be used to achieve power production for a synchronous reluctance machine (12), or can be used to achieve AC power from a traditional salient-pole synchronous machine/starter (102) without dependence upon a rotor current which is subject to failure. In the power generation system, the control system and method can include a power converter (110), controlled by a voltage command and at least one of a measured AC bus (125) current and voltage, and a DC link (120) voltage, for use with a synchronous reluctance machine (102) and a prime mover (116), such that movement of the rotor of the synchronous reluctance machine (102) can be used to produce at least partial AC power generation on the AC bus (125).

Abstract: A system and method is provided for generating DC power using a synchronous reluctance machine (12) or a salient-pole synchronous machine (102) and a power converter (110). The present invention can be used to achieve power production for a synchronous reluctance machine (12), or can be used to achieve partial production of power from a traditional salient-pole synchronous machine/starter (102) in the case where the salient-pole synchronous machine/starter has degenerated into a synchronous reluctance machine due to, for example, a loss of excitation. In a power generation system, a control system and method can include a power converter (110), controlled by a voltage command and at least one of a measured DC link (120) voltage or DC link (120) current, for use with a synchronous reluctance machine armature winding (102A) and a prime mover (116), such that movement of the synchronous reluctance machine rotor of the synchronous reluctance machine can be used to produce at least partial DC power generation.

Abstract: A system and method is provided for generating AC power using a synchronous reluctance machine (12) or a salient-pole synchronous machine (102) and a power converter (110). The present invention can be used to achieve power production for a synchronous reluctance machine (12), or can be used to achieve AC power from a traditional salient-pole synchronous machine/starter (102) without dependence upon a rotor current which is subject to failure. In the power generation system, the control system and method can include a power converter (110), controlled by a voltage command and at least one of a measured AC bus (125) current and voltage, and a DC link (120) voltage, for use with a synchronous reluctance machine (102) and a prime mover (116), such that movement of the rotor of the synchronous reluctance machine (102) can be used to produce at least partial AC power generation on the AC bus (125).

Abstract: A system and method of controlling the power factor for providing either unity, leading or lagging results for the sensorless control of synchronous machines. The system and method provides an estimated angle of the phase current Park vector and uses a floating synchronous reference frame that is shifted from the estimated angle of the phase current Park vector by an angle ? to allow the active control and change of the power factor during operation for applications such as producing reluctance torque of a salient pole synchronous machine during Main Engine Start (MES), and field weakening for Environmental Control Systems (ECS) and MES applications.

Abstract: A method and system for controlling a power converter coupled to a polyphase power line. The method includes measuring at least two motor phase currents, obtaining a floating reference frame for the current Park vector, adjusting the reference frame based on an estimated rotor speed, and controlling the power converter via the floating reference frame to reinitiate power to a motor while a rotor is still moving.

Abstract: The present invention relates to a method of controlling a power converter (20) of a synchronous machine system (10), the method comprising sampling phase-current values between the power converter (20) and the synchronous machine (30); selecting a reference frame; regulating a current vector to align with the selected reference frame, the selected reference frame having a direct-axis component and a quadrature-axis component; estimating rotor speed and position as a function of instantaneous power; adjusting the selected reference frame, based on estimated rotor position, to synchronize the selected reference frame with a magnetic axis of the rotor, thereby generating a synchronized floating frame; and applying the synchronized floating frame to control the power converter (20). The present invention also related to a power converter controlling apparatus (100) for controlling a power converter (20) of a synchronous machine system (10) without use of a machine position sensor.

Abstract: A method and apparatus for deriving phase voltage control signals for use in controlling current flow to an induction motor. The method may comprise obtaining an error term; converting the error term into a commanded voltage value; transforming the commanded voltage value into a commanded voltage vector; and converting the commanded voltage vector into the phase voltage control signals via pulse width modulation control. The apparatus may comprise a Park vector converter for converting a first stator phase measurement and a second stator phase measurement into a stator phase current vector; a scalar operator for obtaining a stator phase current value; a summer for obtaining an error term; an error converter for converting the error term into a commanded voltage value; a voltage transformer for transforming the commanded voltage value into a commanded voltage vector, and pulse width modulation control for converting the commanded voltage vector into the phase voltage control signals.

Abstract: The present invention relates to a method of controlling a power converter (20) of a synchronous machine system (10), the method comprising sampling phase-current values between the power converter (20) and the synchronous machine (30); selecting a reference frame; regulating a current vector to align with the selected reference frame, the selected reference frame having a direct-axis component and a quadrature-axis component; estimating rotor speed and position as a function of instantaneous power; adjusting the selected reference frame, based on estimated rotor position, to synchronize the selected reference frame with a magnetic axis of the rotor, thereby generating a synchronized floating frame; and applying the synchronized floating frame to control the power converter (20). The present invention also related to a power converter controlling apparatus (100) for controlling a power converter (20) of a synchronous machine system (10) without use of a machine position sensor.

Abstract: A power distribution system includes an ac power source; a power bus connected to the ac power source; a capacitor bank shunt-connected to the power bus; and an active filter shunt-connected to the power bus. The active filter includes current sensors, an inverter and an inverter control. Each current sensor senses current flowing through a corresponding capacitor of the capacitor bank. The inverter control, in response to the current sensors, controls the inverter to inject harmonic currents into the power bus.

Abstract: A system and method for an autotransformer configuration including a plurality of windings which can be used to provide a substantial reduction in harmonics. The autotransformer includes a series of wye windings configured to provide a constant length voltage vector for any given input voltage, and a series of delta windings having a variable length voltage vector based upon turns ratio. The delta winding circuit is electrically coupled with the wye winding circuit to allow circulation of triplen harmonics, thereby reducing the effect on input current waveform such that total harmonic distortion (THD) is reduced, and producing an equivalent kVA rating that is lower than prior art applications, which results in savings in size, weight and cost.

Abstract: A dc offset compensator receives a three phase ac current signal as an input and provides a dc offset signal correction voltage as an output. The dc offset compensator comprises a processor configured to sample the ac current signal, generate a rotating vector (r) from the sample, extract a dc offset from the sample and to generate a dc offset signal correction voltage from the dc offset. A method of compensating for dc offset in a three phase ac current signal is also presented.

Abstract: An ac-to-ac power converter includes a source-side inverter that is operated in current mode and a drive side inverter that is operated in commutation mode. The source side inverter performs current regulation during a first portion of each modulating cycle and space vector modulation during a second portion of each modulating cycle.

Abstract: An electrical power distribution system includes permanent magnet generator, and an ac regulator. The ac regulator includes an inverter shunt-connected to the permanent magnet generator, and an inverter control for causing the inverter to regulate voltage at output terminals of the generator by providing reactive power (either leading or lagging) that circulates between the inverter and the generator.

Abstract: An electrical power system includes an electric power source providing AC power to a load. A wideband voltage controller provides a wideband control signal vector to the electric power source. A fundamental component removal module interfaces to the AC power, receiving a fundamental component Park vector of the AC voltage, and providing a resonant frequency content in Park vector format of the AC current. A narrow band voltage regulator uses a resonant component Park vector of the AC current and the resonant frequency content in Park vector format to provide a narrow band output vector signal. A dead band compensating circuit rotates narrow band output vector signal by a transport lag compensation angle to provide a compensated control signal vector to the electric power source. The wideband control signal vector and compensated control signal vector are used to regulate the AC power so that the resonant frequency content is attenuated.

Abstract: An electrical power system includes an electric power source, for example, an electrical machine, capable of supplying AC power to a load; a power converter connected to the electric power source; a position estimator for receiving a current feedback signal in Park vector format and providing a synchronous reference frame without the need, for example, of a rotor position sensor in the electrical machine; and a controller configured to provide a voltage command for controlling the power converter, the controller receiving the current feedback signal and a current reference in Park vector format and using the synchronous reference frame, the current feedback signal, and the current reference to produce the voltage command.

Abstract: An electrical power system includes a switched reluctance machine/inverter adapted for providing DC power to a load; a voltage controller, which provides a control angle &thgr;C to the switched reluctance machine/inverter; an extraction module having an interface to the DC power and providing a resonant frequency content in Park vector format of a resonant frequency content at the interface; a phase locked loop, which provides a transformation angle &thgr; from the resonant frequency content in Park vector format; a resonant frequency voltage controller, which uses the resonant frequency content in Park vector format and the transformation angle &thgr; to provide a control angle &Dgr;&thgr; to the switched reluctance machine/inverter so that the control angle &thgr;C and the control angle &Dgr;&thgr; can be used to regulate the DC power and the resonant frequency content is attenuated in regulating the DC power.

Abstract: An electrical power system includes an electric power source, for example, an electrical machine, capable of supplying AC power to a load; a power converter connected to the electric power source; a position estimator for receiving a current feedback signal in Park vector format and providing a synchronous reference frame without the need, for example, of a rotor position sensor in the electrical machine; and a controller configured to provide a voltage command for controlling the power converter, the controller receiving the current feedback signal and a current reference in Park vector format and using the synchronous reference frame, the current feedback signal, and the current reference to produce the voltage command.

Abstract: A dc offset compensator receives a three phase ac current signal as an input and provides a dc offset signal correction voltage as an output. The dc offset compensator comprises a processor configured to sample the ac current signal, generate a rotating vector (r) from the sample, extract a dc offset from the sample and to generate a dc offset signal correction voltage from the dc offset. A method of compensating for dc offset in a three phase ac current signal is also presented.