Control of PWM inverter by commands to final control element of pulse pattern generator for three=phase motor

摘要

A procedure for controlling a PWM inverter through commands to the final control element of a pulse pattern generator PMG has asynchronous pulse patterns supplied in low frequency operation and a frequency-dependent switchover for predetermined optimised synchronous pulse patterns in high frequency operation, the patterns being filed in the PMG. This guarantees a high dynamic range. The PMG evaluates during the generation of a synchronous pulse pattern, the temporal mean of the next pulse and gives this time point as the next sampling angle for the controlled variable to the control unit, working at discrete time intervals. Likewise the next switching angle for controlling the inverter is determined by linear interpolation from the predetermined angles for maximum level.