Thor Technology Corporation

John G Reichard

Joseph R Pottebaum

Jerome J Reichard

An AC power line current regeneration method and circuitry energizes an AC power line from a DC power source through pulse width modulated switch means. The method and circuitry involves sampling the required peak line regeneration current value from a previous PWM cycle, I(peak last), sampling line regeneration current value at turn-on of the switch means, I(turn-on), and calculating the required peak line regeneration current value for the present PWM cycle, I(peak present), from both I(peak last) and I(turn-on).

AC power line current regeneration

High speed fast response PWM current control regulation methodology and circuitry samples the required peak motor current value from a previous PWM cycle and calculates the required peak motor current value for the present PWM cycle and repeats the sampling and calculating every PWM cycle and updates the new required peak motor current value every PWM cycle. The required peak motor current value for the present PWM cycle is calculated according to the equation

Fast response motor current regulator

In a plural phase electric motor, a control system provides a variable commutation delay interval between commutations from state to state, during which delay interval all phases are unenergized, to minimize current spikes upon commutation. The duration of the delay interval is varied according to a given motor operating parameter during operation of the motor to optimize the delay interval for different operating conditions, to provide maximum delay when needed to eliminate current spikes, and to provide minimum delay when unneeded, to in turn provide maximum energization current to the phases. In one embodiment, motor speed is sensed, and the duration of the delay interval is varied in response thereto by shortening the delay interval with increasing motor speed. In another embodiment, DC bus current is sensed, and the duration of the delay interval is varied in response thereto by preventing termination of the delay interval until the level of DC bus current drops below a given value.

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Milwaukee, WI, United States of America

John G Reichard