Five-level high-power shore power supply system with low harmonic wave and high performance

Abstract

The invention provides a five-level high-power shore power supply system with low harmonic wave and high performance. The five-level high-power shore power supply system comprises a 36-pulse-wave rectification phase-shifting transformer, a rectification circuit and a double-layer cascade H-bridge inverter circuit. Six three-phase windings on the secondary side of the transformer all need to be subjected to phase shifting, the phase difference of phase shifting angles is 60 degrees / 6 = 10 degrees, 36 pulse wave rectification is formed in total, the grid side current waveform is greatly improved, power grid harmonic pollution is eliminated, the power factor is improved, and therefore the input side and the output side of the transformer do not need to be provided with filtering devices. The rectification circuit adopts an IGBT controllable rectification circuit or a diode uncontrolled rectification circuit and provides a direct-current power supply for the inverter circuit; the inverter circuit adopts a double-layer cascade H-bridge circuit, the output phase voltage is five levels, the output voltage harmonic wave of the inverter can be reduced, the switching frequency can be reduced, and the system has wide engineering application value.

Description

technical field [0001] The invention relates to all high-power inverter power supply fields such as high-power medium and low-voltage frequency converters, test power supplies, and shore power supplies, and in particular to a five-level high-power shore power supply system with low harmonics and high performance. Background technique [0002] In the application field of high-power inverter power supply, a transformer is generally used to supply power to the power unit. If there are 6 three-phase output power units in total, the secondary side of the transformer generally has two layers, a total of 6 three-phase windings, and 6 power units respectively. power supply. In order to reduce the harmonic pollution of the rectifier module to the grid side, the existing solutions mostly adopt the method of adding filters or using phase-shifting transformers. The three three-phase windings on each layer do not perform phase shifting, but only perform phase shifting between the two la...

AI Technical Summary

Problems solved by technology

In order to reduce the harmonic pollution of the rectifier module to the grid side, the existing solutions mostly adopt the method of adding filters or using phase-shifting transformers. The three three-phase windings on each layer do not perform phase shifting, but only perform phase shifting between the two layers. The phase difference of the phase shifting angle is 60° / 2=30°, forming a total of 12 pulse rectifications, and there are still 11 times on the grid side. Harmonics of the above order, the current harmonic pollution is large, and the power factor is low

In addition, if the inverter circuit adopts a single-layer structure, there are disadvantages such as low output voltage level and large harmonics.

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