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.

主权项

1. A piezoelectric transformer power converter circuit comprising
a power stage including an amplifier with a controllable gain coupled to a piezoelectric transformer; a regulation control stage that generates a regulation control signal that is representative of the error between a desired electrical regulation set-point and a measured electrical parameter of the output of the power stage; a frequency control stage that generates a frequency control error signal that is representative of the error between a first and second measured operating parameter of the power stage; a voltage controlled oscillator generates a frequency control signal having a periodic wave with a frequency controlled by the frequency control error signal; wherein the amplifier generates a piezoelectric drive signal, that includes an amplitude that is controlled by the regulation control signal, and a frequency that is simultaneously controlled by the frequency control signal, thereby maintaining a desired drive condition for an electrical load.