Crest factor correction circuit

摘要

A crest factor correction circuit for an ac inverter receives inputs including a full-wave rectified output of the ac inverter having a fixed period and a periodic sequence of phase signals that divide each fixed period into predetermined phase intervals. An amplitude and crest factor signal circuit responds to the absolute value signal to provide an amplitude control signal proportional to the negative integral of the difference between the absolute value signal and a set reference voltage. The amplitude and crest factor signal circuit also provides a crest control signal proportional to the negative integral of the difference between the filtered peak value of the absolute value signal and a given reference voltage times a predetermined gain. A series resistor network responds to the amplitude control signal and to the crest control signal and provides a series of tap signals. Each tap signal is proportional to a respective predetermined ratio of the amplitude control signal. The series resistor network also provides a series of crest tap signals. Each crest tap signal is proportional to a respective predetermined ratio of the crest control signal. A multiplexer responds to the predetermined periodic series of phase signals, to the periodic series of tap signals and to the periodic series of crest tap signals to sequentially coupling a sequence of the tap signals followed by coupling a sequence of crest tap signals. The periodic sequence of tap signals and crest tap signals form the composite control signal for controlling the ac inverter.