High-power direct current/square wave changing circuit and control method therefor

Abstract

The invention discloses a high-power direct current / square wave changing circuit and a control method for the high-power direct current / square wave changing circuit. The high-power direct current / square wave changing circuit comprises four switch tubes, two fast-recovery diode modules and two capacitor modules, wherein the first switch tube and the third switch tube are connected in series to form a first side bridge arm of an H bridge, and the connecting position is an output end; a high end of the first switch tube is connected with an cathode of a first fast-recovery diode, the second capacitor is connected with an output end of a second side bridge arm at the connecting position; the second switch tube and the fourth switch tube are connected in series to form the second bridge arm, and the connecting position is an output end; a high end of the second switch tube is connected with a cathode of a second fast-recovery diode, and a first capacitor is connected with an output end of the first side bridge arm at the connecting position; and anodes of the two fast-recovery diodes are connected with a direct-current bus, and low ends of the third switch tube and the fourth switch tube are connected with a cathode of the direct-current bus. The control method is simple, the width, the frequency and the amplitude of output square-wave pulses can be regulated, and therefore, the output square-wave pulse has the advantages that the range of the duty ratio is large, the switching speed of a positive pulse and a negative pulse is high, etc.

Description

technical field [0001] The invention relates to a high-frequency pulse power supply for multiple industries and purposes, in particular to a high-power DC / square wave conversion circuit and a control method thereof. Background technique [0002] Pulse power supply is widely used in electroplating gold, silver, tin, alloys, etc., and plays a very important role in improving the coating. The electroplating of double-pulse power supply is more detailed and smoother than that of single-pulse power supply, and some special electroplating needs special voltage waveforms, such as positive and negative asymmetrical pulses. In order to meet the requirements of this special voltage waveform, most of the current domestic pulse power supply output part adopts H-bridge circuit structure. In order to improve the waveform, absorb voltage spikes, and protect the switching tube, it is usually necessary to increase the capacity capacitor on the busbar of the H-bridge. However, due to the cha...

AI Technical Summary

Problems solved by technology

However, due to the charging and discharging effect of the large capacitor on the bus, the output voltage has a large rise time delay and a large fall time delay, and cannot output a pulse voltage waveform with a large asymmetrical voltage difference or a small duty ratio. duty cycle is limited

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