FREQUENCY TRACKING PIEZOELECTRIC TRANSFORMER POWER CONVERTER WITH SIMULTANEOUS TWO-PARAMETER CONTROL

摘要

The present invention is directed to a piezoelectric transformer based power converter that exhibits efficient operating point tracking ability while providing output regulation by means of simultaneous two-parameter control of the converter power stage. A regulation control stage provides the power stage a regulation control signal indicative of the difference between the measured output parameter and a set-point reference, therefore continuously controlling the gain of the converter to result in a stabilized, regulated output. Additionally, a frequency control stage simultaneously provides the power stage with a frequency control signal correlative to the difference between the current and desired operating points of the piezoelectric transformer. The power stage then translates the frequency control signal into an adjustment to the operational frequency of the input signal to the piezoelectric transformer, as to continuously drive the operating point to the desired position.