Patent ID: 9742319
Date: 2017-08-22
CPC Classifications: H02P

Claim:
1. A control system for an electric machine comprising a current sensor and a current controller, wherein the current controller comprises an input, an output, a threshold generator and a comparator, wherein the threshold generator stores a scaling factor and comprises a PWM module that operates on a reference voltage to generate a threshold voltage, the duty cycle of the PWM module being defined by the scaling factor, and the comparator compares a voltage at the input against the threshold voltage and causes a signal to be generated at the output of the comparator when the voltage at the input exceeds the threshold voltage, and wherein the current sensor outputs a voltage that is sensitive to a current in the electric machine, the output of the current sensor is delivered to the input of the current controller, the signal at the output of the comparator is generated whenever the current exceeds a current threshold, and the scaling factor is set such that the effect of component tolerances on the current threshold is trimmed.