摘要:
Methods and systems are provided for controlling permanent magnet machines under varying loads. The method comprises generating a d-axis voltage command and a q-axis voltage command, producing a modified d-axis current command based on the q-axis voltage command and a d-axis current command, converting the modified d-axis current command to a modified d-axis voltage command, and transmitting the modified d-axis voltage command and the q-axis voltage command to the PM machine. The d-axis voltage command is based on a d-axis current command.
摘要:
A dynamic pulse width modulation (PWM) selection device automatically switches between discontinuous PWM (DPWM) control methods. The PWM selection device comprises a PWM control module. The PWM control module determines a desired pulse width of a switching control signal according to a desired output signal. The PWM control module controls an actual pulse width of the switching control signal according to the desired pulse width and a first PWM control method. A selection module determines whether the desired pulse width exceeds a pulse width threshold. The selection module selects a second PWM control method when the desired pulse width exceeds the pulse width threshold.
摘要:
A method of detecting a phase winding fault in a multi-phase electric machine is executable via a motor controller, and includes measuring feedback signals of the machine, including each phase current, and generating reference phase voltages for each phase. The method includes calculating a predetermined voltage value using the feedback signals and reference phase voltages, and comparing the voltage value to a corresponding threshold to determine the fault. A control action is executed when the voltage value exceeds the corresponding threshold. The voltage value is one or more of: a ratio of a normalized zero sequence voltage to a modulation index, an RMS voltage for each phase, and total harmonic distortion of each phase current. An apparatus detects the fault, and includes a motor controller and an algorithm as set forth above. The apparatus may include a voltage inverter for generating a multi-phase alternating current output for powering the machine.
摘要:
A control architecture for an electrical inverter includes a synchronous frame current regulator and a stationary frame current regulator. The stationary frame current regulator receives input currents that represent filtered versions of stationary frame currents that correspond to the inverter output currents. The control architecture employs an adaptive filter module that filters the stationary frame currents to remove the fundamental motor frequency component (and its related harmonics), thus extracting any low frequency harmonic components. The stationary frame current regulator processes the low frequency components, while the synchronous frame current regulator processes the fundamental frequency component, resulting in suppression of low frequency oscillations in the inverter output.
摘要:
A method for controlling an inverter uses sequences of predetermined states where each state uniquely corresponding to a set of control signals provided to the inverter that is coupled to a motor. The method includes repeatedly applying a first center null timing sequence of the states while monitoring a zero crossing condition and then changing the repeated application of the first center null timing sequence of the states into a repeated application of a second center null timing sequence of states when the monitoring detects a zero crossing condition. The repeated application of the first center null timing sequence sequentially provides the inverter with a first predetermined sequence of sets of control signals. The monitoring of a zero crossing condition monitors for a zero crossing condition in an electrical current flowing between the inverter and a terminal of the motor. The second center null timing sequence defines a second predetermined sequence of sets of control signals.
摘要:
A control architecture for an electrical inverter includes a command limiter that is realized as a circular voltage limiter. The command limiter includes a Cartesian-to-polar converter coupled to a command source such as a synchronous frame current regulator. The Cartesian-to-polar converter provides magnitude and phase components for d-q command voltages. The command limiter further includes a magnitude limiter that limits the magnitude component to the maximum fundamental voltage component of the inverter, and a polar-to-Cartesian converter that converts the limited magnitude component and the phase component into modified d-q command voltages.
摘要:
A method of detecting a phase winding fault in a multi-phase electric machine is executable via a motor controller, and includes measuring feedback signals of the machine, including each phase current, and generating reference phase voltages for each phase. The method includes calculating a predetermined voltage value using the feedback signals and reference phase voltages, and comparing the voltage value to a corresponding threshold to determine the fault. A control action is executed when the voltage value exceeds the corresponding threshold. The voltage value is one or more of: a ratio of a normalized negative sequence voltage to a modulation index, an RMS voltage for each phase, and total harmonic distortion of each phase current. An apparatus detects the fault, and includes a motor controller and an algorithm as set forth above. The apparatus may include a voltage inverter for generating a multi-phase alternating current output for powering the machine.
摘要:
A method for controlling an alternating current (AC) motor includes choosing a pulse sequence based on a ripple current in the AC motor at a sampling instant; and providing a voltage to the AC motor based on the pulse sequence.
摘要:
A control architecture for an electrical inverter includes a synchronous frame current regulator and a stationary frame current regulator. The stationary frame current regulator receives input currents that represent filtered versions of stationary frame currents that correspond to the inverter output currents. The control architecture employs an adaptive filter module that filters the stationary frame currents to remove the fundamental motor frequency component (and its related harmonics), thus extracting any low frequency harmonic components. The stationary frame current regulator processes the low frequency components, while the synchronous frame current regulator processes the fundamental frequency component, resulting in suppression of low frequency oscillations in the inverter output.
摘要:
A method for controlling an alternating current (AC) motor includes choosing a pulse sequence based on a ripple current in the AC motor at a sampling instant; and providing a voltage to the AC motor based on the pulse sequence.