Abstract: Disclosed examples include power conversion systems and methods to operate an inverter to drive a motor load through an intervening output filter, a transformer and a cable, including a current regulator to compute a command value according to a current reference value and a motor current feedback value, a cross-coupled feedforward component to compensate the command value by an estimated cross-coupled voltage value to compute a control output value, a cross-coupled object component to compute the motor current feedback value according to a voltage value using a plant transfer function representing the output filter, the transformer, the cable and the motor load, and a controller to provide the inverter switching control signals to control the inverter according to the control output value.

Abstract: Disclosed examples include power conversion systems, methods and computer readable mediums to operate an inverter to drive a motor load through an output filter, in which a control output value is computed according to a current reference value and a current feedback value using a proportional-integral (PI) current regulator, the control output value is filtered using a lag compensator filter to compute an inverter output command value, and the inverter is controlled according to the inverter output command value.

Abstract: Disclosed examples include motor drive power conversion systems with an inverter, as well as a controller methods to drive a motor in which output filter capacitor currents are computed and used to compensate the motor control in consideration of damping resistance values of an output filter.

Abstract: Disclosed examples include power conversion systems, methods and computer readable mediums to operate an inverter to drive a motor load through an output filter, in which a control output value is computed according to a current reference value and a current feedback value using a proportional-integral (PI) current regulator, the control output value is filtered using a lag compensator filter to compute an inverter output command value, and the inverter is controlled according to the inverter output command value.

Abstract: A method of estimating stator resistance of an induction motor is provided. The method includes applying voltage pulses through two phase paths of the motor for a plurality of electrical cycles to inject current in the motor, wherein the voltage pulses are applied until rotor flux of the motor is substantially stabilized and measuring stator voltage and stator current in response to the applied voltage pulses for each of the plurality of electrical cycles. The method also includes calculating the stator resistance based upon the measured stator voltages and the stator currents.

Abstract: Disclosed examples include power conversion systems, methods and computer readable mediums to operate an inverter to drive a motor load through an intervening filter, by computing a speed error value according to a speed reference value and a speed feedback value, computing a torque reference value according to the speed error value, computing a motor current reference value according to the torque reference value, compensating the motor current reference value according to capacitor currents of the output filter using a transfer function representing an output current to input current amplitude vs. frequency behavior of the output filter and the motor load, and controlling the inverter according to the inverter output current reference value.

Abstract: Disclosed examples include motor drive power conversion systems with an inverter, as well as a controller methods to drive a motor in which output filter capacitor currents are computed and used to compensate the motor control in consideration of damping resistance values of an output filter.

Abstract: Motor drives, methods and estimation systems are presented for estimating a rotor position of a motor load in which four sets of inverter output current samples obtained at four different sample times in a given inverter PWM cycle are converted into a corresponding stationary reference frame current value pairs, and the rotor position estimate is computed according to the stationary reference frame current values.

Abstract: Disclosed examples include power conversion systems, methods and computer readable mediums to operate an inverter to drive a motor load through an intervening filter, by computing a speed error value according to a speed reference value and a speed feedback value, computing a torque reference value according to the speed error value, computing a motor current reference value according to the torque reference value, compensating the motor current reference value according to capacitor currents of the output filter using a transfer function representing an output current to input current amplitude vs. frequency behavior of the output filter and the motor load, and controlling the inverter according to the inverter output current reference value.

Abstract: Motor drive control apparatus and methods are presented for speed reversal control for drives used with output filters and transformers using a high or maximal drive current command to facilitate dissipation of regenerative energy seen in this system during speed reversal with open loop control to reverse the spin direction of a driven motor while quickly transitioning through zero speed.

Abstract: Disclosed examples include power conversion systems and methods to operate an inverter to drive a motor load through an intervening output filter, a transformer and a cable, including a current regulator to compute a command value according to a current reference value and a motor current feedback value, a cross-coupled feedforward component to compensate the command value by an estimated cross-coupled voltage value to compute a control output value, a cross-coupled object component to compute the motor current feedback value according to a voltage value using a plant transfer function representing the output filter, the transformer, the cable and the motor load, and a controller to provide the inverter switching control signals to control the inverter according to the control output value.

Abstract: Cascade H-Bridge inverters and carrier-based level shift pulse width modulation techniques are presented for generating inverter stage switching control signals, in which carrier waveform levels are selectively shifted to control THD and to mitigate power distribution imbalances within multilevel inverter elements using either complementary carrier or complementary reference modulation techniques.

Abstract: Methods and systems are presented for closed loop motor speed and torque control without a sensor at the motor, in which configuration parameters are received from a user interface to define operating characteristics of a filter, a transformer, a cable, and the motor coupled with the output of a motor drive, and an object model of the motor drive is configured according to the filter, transformer, cable and motor configuration parameters to facilitate sensorless closed loop motor speed and/or torque control.

Abstract: Disclosed examples include methods, computer readable mediums and motor drive power conversion systems for sensorless speed control of a motor driven by an inverter through an intervening filter, a transformer and a motor cable, in which sensorless vector control is used to regulate the motor speed based on a speed feedback value computed according to voltage or current values associated with the motor drive using an observer having formulas and impedance parameters of the filter, the transformer, the motor cable and the motor.

Abstract: Motor drives, methods and estimation systems are presented for estimating a rotor position of a motor load in which four sets of inverter output current samples obtained at four different sample times in a given inverter PWM cycle are converted into a corresponding stationary reference frame current value pairs, and the rotor position estimate is computed according to the stationary reference frame current values.

Abstract: Motor drive control apparatus and methods are presented for speed reversal control for drives used with output filters and transformers using a high or maximal drive current command to facilitate dissipation of regenerative energy seen in this system during speed reversal with open loop control to reverse the spin direction of a driven motor while quickly transitioning through zero speed.

Abstract: Motor drive control apparatus and methods are presented for sensorless control of a driven motor using open loop current regulated control during low-speed operation and an EMF-based position observer for position estimation during higher speed operation, with zero feedback speed during low-speed open-loop operation and feedback speed estimated by the EMF-based observer during high-speed operation and with velocity mode control over the full speed range and mode control hysteresis for smooth transitions between open loop and EMF-based observer control.

Abstract: Disclosed examples include methods, computer readable mediums and motor drives power conversion systems for sensorless speed control of a motor driven by an inverter through an intervening filter, in which a controller computes motor current feedback values for a current control cycle according to inverter output current values, capacitance values representing capacitances of filter capacitors of the filter, filter output voltage values representing output voltages of the filter, and a speed feedback or reference value of a previous control cycle. The controller computes a speed feedback value for the current control cycle according to the motor current feedback values and the filter output voltage values, and controls the inverter to regulate the rotational speed of the motor at least partially according to the speed feedback or reference value using vector control.

Abstract: Disclosed examples include methods, computer readable mediums and motor drive power conversion systems for sensorless speed control of a motor driven by an inverter through an intervening filter, a transformer and a motor cable, in which sensorless vector control is used to regulate the motor speed based on a speed feedback value computed according to voltage or current values associated with the motor drive using an observer having formulas and impedance parameters of the filter, the transformer, the motor cable and the motor.

Abstract: A power converter, control apparatus and methods are presented for driving a permanent magnet motor or other load through a sine wave filter and a transformer, in which inverter output current is controlled using a current-frequency relationship to convert a desired frequency or speed value to a current setpoint, and the inverter output current is regulated to the current setpoint using a control algorithm with a bandwidth below the resonant frequency of the sine wave filter.