High-power compensation type cascade diode H-bridge unit power factor rectifier

Abstract

The invention provides a high-power compensation type cascade diode H-bridge unit power factor rectifier which comprises various main power circuits which are formed by cascading a plurality of module units in a three-phase star connection, angle connection or double-star connection mode. Meanwhile, the invention further provides a small-capacity compensation device formed through serial connection or parallel connection or series-parallel connection, and unit power factor rectification can be easily achieved. The rectifier has the advantages that a low-voltage power switch tube can be used for large-power rectification conversion under high voltage, a power-frequency phase-shifting transformer which is large, heavy and complex in wiring does not need to be used, the topological structures of the main power circuits are simplified, the number of switching devices which are used is greatly reduced, loss of the circuits in work is reduced, work efficiency of a system is improved, the size is small, the weight is low and cost is low. Meanwhile, the power factor of the rectifier always keeps to be 1 on the situation that a load is changed. The rectifier has important application value in the application field such as high-voltage direct current transmission, high-power electric and electronic transformers, high-power medium-and-high-voltage AC-DC-AC converters.

Description

technical field [0001] The invention relates to a rectifier, in particular to a high-power compensation cascaded diode H-bridge unit power factor rectifier. Background technique [0002] With the rapid development of science and technology and industrial modernization and the requirement for energy conservation, medium and high voltage power electronic converters used in high-power applications play an increasingly important role. In recent years, multilevel power converters (Multilevel Converter) have been successfully applied in the fields of high-voltage and high-power frequency conversion speed regulation, active power filter devices, high-voltage direct current (HVDC) transmission systems, and reactive power compensation of power systems. The basic circuit topologies of multilevel converters mainly include diode clamping, flying capacitor, and power unit cascading circuits. Among them, the power unit cascaded multilevel converter has become the mainstream of the market...

AI Technical Summary

Problems solved by technology

However, since the input inductance of this scheme is located after diode rectification, the current in one or more inductors will pass through the switch tube and the corresponding diode rectifier bridge to form a circulating current during the rectification process, so that the AC side of these diode rectifier bridges The voltage is zero, which causes the diode rectifier bridge in other cascaded modules to bear all the power supply voltage, which loses the meaning of reducing the withstand voltage value of the diode through the cascaded diode

Images