Gate signal generation manner and device and PWM inverter device null of PWM

摘要

Disclosed is a PWM inverter apparatus used for driving an a.c. motor, comprising: an inverter including an output part connected to the a.c. motor and switching elements on-off controlled by a PWM signal; a part (10) for receiving, at an interval of a given sampling period, status command information specifying a desired status of a vector of a rotating magnetic flux in the a.c. motor; a part (10) for predicting, on the basis of at least the status command information received at each sampling time, the status of the vector of the rotating magnetic flux which will be produced at next sampling time; a part (22) for calculating the difference between the status of the vector of the rotating magnetic flux specified by the status command information received at current sampling time and the predicted status of the vector of the rotating magnetic flux which will be produced at next sampling time; a part (21, 23, 24) for synthesizing the difference vector using ones selected from among a plurality of predetermined reference voltage vectors; and a part (30) for generating a PWM signal for controlling the switching elements of the inverter so as to produce the selected reference voltage vectors.