Bidirectional direct current converter based on immittance network, and digital control system and method of bidirectional direct current converter

Abstract

The invention discloses a bidirectional direct current converter based on an immittance network, and a digital control system and a digital control method of the bidirectional direct current converter. The bidirectional direct current converter based on the immittance network comprises a storage battery, a low-voltage-side filter capacitor, a first active full-bridge circuit, the immittance network, a high-frequency transformer, a second active full-bridge circuit and a high-voltage-bus-side filter capacitor. The digital control system comprises a first voltage sensor, a second voltage sensor, a current sensor and a digital signal processing (DSP) digital controller, wherein the DSP digital controller comprises a BUCK controller, a BOOST controller, a signal conditioner, a first selective switch and a second selective switch. According to the basic characteristics of the immittance network, the two active full-bridge circuits in the bidirectional direct current converter can operate with high power factor, and the current stress of a switching tube can be greatly reduced. By the adoption of the system and the method, according to the characteristics of the immittance network, the zero-current turn on and zero-current turn off of all switching devices of a high-voltage-side active full-bridge circuit are realized, and the efficiency of the converter is improved.

Description

technical field [0001] The invention relates to a bidirectional DC converter based on an impedance network and its digital control system and method, belonging to the field of power electronic converters and their control. Background technique [0002] Because the bidirectional DC converter can realize the bidirectional flow of energy on the input and output sides of the circuit, which can reduce the weight, volume and cost of the converter, it has been widely valued. In the new energy power generation system with photovoltaic cells and wind turbines as the main energy source, in the island operation mode, when the power supplied by the new energy power generation is less than the power required by the local load, the insufficient energy is supplied by the storage device through the power converter; When the power supplied by the new energy is greater than the power required by the local load, the excess energy is stored in the storage device through the converter. Therefor...

AI Technical Summary

Problems solved by technology

At present, the immittance network has been widely used, such as constant current source power supply, capacitor charging, new inverter, etc., but there is no relevant literature on the application of the immittance network to the bidirectional DC converter.

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