SINGLE-CYCLE POWER FACTOR CORRECTION CONTROL METHOD Russian patent published in 2023 - IPC G05F1/70 H02M1/42 

FIELD: converter electrical equipment.

SUBSTANCE: invention is related in particular to methods for controlling pulsed power converters that correct the input power factor and can find application in systems for converting and transmitting electrical energy. The method of single-cycle control of power factor correction includes the rectifier made in form of a three-phase semiconductor rectifier, the control circuit of the switching transistor made in form of an output divider voltage, sawtooth voltage generator, comparator, delay unit, current sensor with a buffer follower each, current converter, two drivers and an amplification circuit in form of a voltage error amplifier and a second amplifier in each of four modules containing two switching transistors connected in parallel at the input and outputs and forming a half-bridge with a rated current of up to 400 A. In each of the phases of the semiconductor rectifier, the completion of the soft start is identified, the difference between the reference voltage signal and the feedback voltage signal is sent to the input of the corresponding error amplifier, at the output of which a signal is generated, which, arriving at the corresponding sawtooth voltage generators, sets the same frequency of 50 kHz and the amplitude of the output sawtooth voltage for all three phases of the semiconductor rectifier. The input currents of the phases are supplied to the inputs of the corresponding comparators of each phase, which perform the function of pulse-width modulation of the modulators. Pulse-width modulation signal is generated at the output of the corresponding comparators. The pulse-width modulation signal enters the corresponding delay unit, where two signals are generated to control two drivers that control the gates of the corresponding two switching transistors, connected according to a half-bridge circuit in the corresponding switching transistor module. The switching transistor on time for driving the corresponding switching transistor is identified with a relative time shift of the two corresponding switching transistors to reduce the high frequency component of the currents flowing through the four smoothing capacitors, and optimized to reduce the current surge caused by the reverse recovery of their antiparallel diodes by slowing down the time of switching of the corresponding transistors by means of a resistor and diode installed in parallel into the corresponding driver circuits.

EFFECT: increasing the accuracy of power factor correction and the reliability of control of a three-phase semiconductor rectifier with an increase in the power transmitted by the three-phase semiconductor rectifier.

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