초록 ▼

A method and apparatus for determining the critical dwell time required between firing pulses generated by a PWM inverter to eliminate greater than twice overvoltage on motor supply lines. Critical dwell time is correlated with line parameters including inductance and resistance per unit length and

A method and apparatus for determining the critical dwell time required between firing pulses generated by a PWM inverter to eliminate greater than twice overvoltage on motor supply lines. Critical dwell time is correlated with line parameters including inductance and resistance per unit length and is then provided to a controller to alter voltages provided to a motor to eliminate overvoltage.

대표청구항 ▼

[ We claim:] [1.] A method for determining a critical dwell time for use by a motor controller, the controller including a signal generator, a PWM controller and an inverter, the generator providing modulating waveforms to the PWM controller which compares the modulating waveforms with a carrier sig

[ We claim:] [1.] A method for determining a critical dwell time for use by a motor controller, the controller including a signal generator, a PWM controller and an inverter, the generator providing modulating waveforms to the PWM controller which compares the modulating waveforms with a carrier signal to generate firing pulses which control the inverter, the inverter providing exciting voltage to a motor via supply lines, the exciting voltage corresponding to the firing pulses and having a maximum intended amplitude, the controller substantially eliminating exciting motor voltage greater than twice the maximum intended amplitude by generating the firing pulses such that periods between consecutive firing pulses are equal to or greater than the critical dwell time, the controller providing at least one motor parameter which can be used to determine the critical dwell time, the method comprising the steps of:receiving the motor parameter;using the motor parameter to determine the critical dwell time; andusing the critical dwell time to modify the modulating waveforms thereby modifying the firing pulses.