Patent ID: 6819070
Filing Date: 2004-11-16
Classification: H02M

Abstract:
A method to be used with a motor controller generating firing pulses to control an inverter, the inverter providing exciting voltage to a motor corresponding to the firing pulses, the voltage having a maximum intended amplitude, the method for substantially eliminating exciting voltage overvoltage by modifying the firing pulses, the method comprising the steps of:(a)identifying characteristics of an initial firing pulse; (b)comparing the initial pulse characteristics to an overvoltage characteristic set known to cause overvoltage; (c)where the initial pulse characteristics match the overvoltage characteristic set, altering the initial firing pulse such that the altered firing pulse does not cause overvoltage; (d)identifying an accumulated error corresponding to the modified firing pulse; (e)modifying the firing pulse following the altered firing pulse as a function of the accumulated error to generate a composite firing pulse; and (f)repeating steps (a) through (e) with the composite firing pulse as the initial firing pulse.