| 摘要 |
PURPOSE:To perform high-accuracy control without increasing the memory capacity of an ROM, by a method wherein the output in a function generator sending a function signal corresponding to an electrical angle command signal and an amplitude command signal are compared and a pulse width modulation control signal is obtained. CONSTITUTION:An amplitude command signal generator circuit 10 generates a signal instructing the amplitude value by the feed back signal of output voltage and on the other hand, an electrical angle command signal generator circuit 11 generates a signal instructing the switching electrical angle of an inverter and the signal is fed into an ROM25 in which an optimum switching pattern has been written, to generate a corresponding function signal. And these signals are compared by a comparator 26 to form a constant-voltage and constant-frequency inverter by supplying the signals to a switching element through an OR circuit 27 and latch circuits 28. Therefore, the inverter can be controlled with high accuracy without increasing the memory capacity of the ROM in PWM control using the ROM. |
