Control method for bidirectional DC-DC converter based on Z source

Abstract

The invention discloses a control method for a bidirectional DC-DC converter based on a Z source, and aims to provide a method for controlling the voltage rising and dropping of the converter within a wide range, short-circuit protection, energy flow control and the switching of forward-reverse energy flow. The technical scheme adopted by the invention is that a control unit in the converter is improved, so that the control unit consists of a voltage calculating unit, a voltage deviation calculating unit, a voltage controller, a current calculating unit, a current deviation calculating unit, a current controller and a failure monitoring unit, and then a double parallel closed-loop control method for performing single closed-loop control on electric current and voltage is adopted to control the energy flow of the converter. According to the invention, the control of output voltage rising and dropping within a large range is realized; the independent control of the electric current and the voltage, and the decoupling control of variates are realized; the smooth switching of energy flow can be realized without stopping the converter; the short-circuit failures of input and output can be rapidly judged, and failure protection can be rapidly performed.

Description

technical field [0001] The invention belongs to the field of bidirectional high-power DC-DC conversion, in particular to a control method for a Z-source-based high-power DC-DC converter. Background technique [0002] Bidirectional high-power DC-DC converters have broad application prospects in distributed power generation, electric vehicles, energy storage systems, new energy power generation and other fields. [0003] The dual active full-bridge topology is the preferred topology in the field of isolated high-power bidirectional DC-DC converters due to its small current / voltage stress on power devices and higher power transmission by devices with the same capacity. [0004] In the main circuit of the Dual Active Bridge Bi-directional Converter (DABBC for short), the active bridge on the primary side is composed of four switching power transistors to form a full bridge circuit, which works in the inverter state. The turn-on and turn-off are controlled by a PWM (Pulse Width ...

AI Technical Summary

Problems solved by technology

[0009] However, the control method published in the document "Z source bidirectional DC-DC converter and its phase-shifted direct control strategy" is a multi-input variable, multi-output control method, and the control method is fuzzy and complicated; Self-shifting the phase angle and inserting the through zero vector to adjust the output voltage and output current, and changing the phase shifting angle and inserting the through zero

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