Abstract: A method of generating low voltage auxiliary power forms for electric or hybrid vehicle use by tapping power from the traction motor primary winding with a secondary winding and rectifier.

Abstract: A control scheme for an surface-mounted permanent-magnet synchronous (SMPMS) drive uses a combination of an open-loop magnetizing current reference calculation and a stabilizing feedback term, which speeds-up the torque transient response. The feedback term increases the stability margin during torque transients by increasing the available voltage margin for current control. The magnetizing current reference calculation takes into account the saturation effects in the SMPMS drive, which occur at peak torque points, and compensates for them. By taking into account saturation effects, stable operation at high speed is achieved, thereby increasing the speed range of the SMPMS drive.

Abstract: A control scheme for an surface-mounted permanent-magnet synchronous (SMPMS) drive uses a combination of an open-loop magnetizing current reference calculation and a stabilizing feedback term, which speeds-up the torque transient response. The feedback term increases the stability margin during torque transients by increasing the available voltage margin for current control. The magnetizing current reference calculation takes into account the saturation effects in the SMPMS drive, which occur at peak torque points, and compensates for them. By taking into account saturation effects, stable operation at high speed is achieved, thereby increasing the speed range of the SMPMS drive.

Abstract: A control system and method for use in controlling a torque-controlled permanent magnet synchronous motor drive. A slew-rate limiter processes an input torque command to produce a modified torque command that is input to the motor drive. A controller is coupled to the slew-rate limiter and the motor drive for dynamically limiting the input torque command applied to the motor drive and its rate of increase. The slew rate limiter processes an applied torque command to output a modified torque command that is applied to the motor drive. Current control error signals are output by the motor drive. The RMS value of the current control error signals is computed. The RMS value is compared to low and high thresholds. If the RMS value is greater than the high threshold, the modified torque command is reduced until the RMS value is less than the high threshold.

Abstract: A control system and method for controlling an inverter used in an electric vehicle. The control system and method measures an average DC bus voltage and compares it to low voltage and high voltage thresholds defining predetermined conditions. If the voltage conditions are satisfied, the six-step mode is enabled based upon an applied torque command. Thus, if the torque command is higher than a high torque threshold, the six-step mode indefinitely enabled, and if the torque command is below the high torque threshold, the six-step mode is enabled for a limited time duration, and then disabled.

Abstract: A surface-mounted permanent magnet synchronous machine drive and a method of controlling the machine drive. Flux weakening and current regulating loops cooperate to provide automatic transition to the flux weakening mode (operation above base speed), regardless of DC bus voltage, load or other operating conditions. The modulation index (d) is used as a condition for automatic start of flux weakening operation is very useful because this point can be easily changed by software when necessary, regardless of the value of DC bus voltage. This feature provides significant performance improvement. No look-up tables are used in the flux weakening loop. The on-set point for flux weakening is automatically adjusted, and may be changed through software. An appropriate d-axis current component is injected over the entire speed range, providing the maximum available torque (which corresponds to the q-axis current component).

Abstract: An electric power system for an electric vehicle includes an electric drive motor, a high voltage bus for supplying operating power to energize the drive motor, and an inverter including power switching devices and having an inverter output. The inverter is coupled between the high voltage bus and the electric drive motor and a controller is coupled to the inverter and provides motor control signals and high frequency injection signals to the inverter. An auxiliary power unit is coupled to the inverter output and has a DC output for supplying DC operating power. The auxiliary power unit supplies DC power in response to the high frequency injection signals. The electric drive motor operates in response to the motor control signals and is substantially unaffected by the high frequency injection signals.

Abstract: A control algorithm or method for use in controlling a voltage-fed induction machine. The control algorithm includes the following steps. The DC link voltage supplied to an inverter driving the induction machine is monitored. When the DC link voltage is high enough, the algorithm controls the amount of current supplied to the induction machine to provide current controlled operation of the induction machine. When the DC link voltage is not high enough to control the current under transient conditions, the induction machine is controlled by imposing the maximum possible phase voltage and optimal slip angle on the machine to provide maximal torque per ampere operation of the induction machine. The maximal torque per ampere operation is performed when either of the following conditions is met: a) the torque level required by the induction machine is such that efficiency optimization cannot be performed, or b) current regulators approach saturation.

Abstract: Power-generating apparatus and a voltage generation method employing null vector modulation for use with an electric vehicle. A DC power supply voltage is provided or generated from a power source and is inverted by a three-phase inverter to generate three phase AC that is supplied to an AC motor or load. One phase of the three phase AC is filtered and transformed by a DC rejection capacitor and single phase transformer of an auxiliary power supply to generate an AC voltage. The AC voltage is rectified and filtered by a rectifier and low pass filter of the auxiliary power supply to produce a DC output voltage. The one phase of the three phase AC and the DC output voltage are processed by a controller to control frequencies of null line-to-line zero voltage vectors during inversion so that the transformed AC voltage does not affect or is not seen by the AC motor or load. This allows for independent control of the voltage at the output of the auxiliary power supply.

Abstract: A surface-mounted permanent magnet synchronous machine drive 10 and a method 30 of controlling the machine drive. Flux weakening and current regulating loops 70, 60 cooperate to provide automatic transition to the flux weakening mode (operation above base speed), regardless of DC bus voltage, load or other operating conditions. This feature provides significant performance improvement. No look-up tables are used in the flux weakening loop. The on-set point for flux weakening is automatically adjusted, and may be changed through software. An appropriate d-axis current component is injected over the entire speed range, providing the maximum available torque (which corresponds to the q-axis current component). The control method works with fixed frequency current compensators.