Twelve pulse AC motor drive

摘要

A single microcomputer controls the firing time determination for two independent current regulators for two six pulse AC/DC converters which are part of a twelve pulse parallel controlled current inverter (CCI) AC motor drive. A very short high priority interrupt occurs when a motor channel source converter thyristor fires. This interrupt calls a longer, low priority current regulator interrupt informing it that a master channel source converter thyristor has just been fired. The current regulator causes a count to be loaded into a master fire counter and also loads a firing mask into a hardware latch or buffer. When the master fire counter times out the next thyristor pair of the master channel source converter is fired directly out of hardware. Similarly, there is a separate slave channel fire counter loaded after the current regulator is called by a short high priority interrupt when a thyristor in the slave channel source converter fires.