Control method applied to bidirectional isolation full-bridge current transformer for battery energy storage

Abstract

The invention provides a control method applied to a bidirectional isolation full-bridge current transformer for battery energy storage, and aims at the current-voltage type bidirectional isolation full-bridge current transformer, a current-mode full bridge is connected at a battery side, and a voltage-mode full bridge is connected at an inverter side. According to pulse generation method of two H-bridges, the control of the bidirectional isolation full-bridge current transformer becomes simple. A current-mode H-bridge utilizes PWM (pulse-width modulation) to guarantee the current continuity of input inductance and control the transitive power; and a voltage-mode H-bridge utilizes phase shift control to match and finish the bidirectional flow of power. Phase shift between carriers of an original secondary side H-bridge is controlled, so that the power of the bidirectional isolation full-bridge current transformer is only related to the current-mode PWM duty cycle, and power control of the bidirectional isolation full-bridge current transformer can be finished only by using a single PI ring. The control method provided by the invention is simple and practical, and lays a basis for the application of the bidirectional isolation full-bridge current transformer in battery energy storage.

Description

technical field [0001] The invention relates to the technical field of electrical automation equipment, in particular to a control method for a bidirectional isolated full-bridge converter applied to battery energy storage. Background technique [0002] Due to its fast response, high energy density, good environmental conditions, and mature technology, battery energy storage systems have been widely used in various aspects of the power system, especially in load balancing, user-side power quality, reactive power compensation, and accommodation. Highlighting strengths in important issues such as renewable energy. [0003] Bidirectional isolated full-bridge converter is the development direction of high-power DC / DC converter in the future. Its structure and control are simple, and it can realize soft switching, reduce loss and improve efficiency. Under high-frequency operation, the volume of the isolation transformer can be very small, and it is easy to realize high-voltage i...

AI Technical Summary

Problems solved by technology

[0004] However, in the traditional bidirectional isolated full-bridge converter, whether it is single-phase-shift control or double-phase-shift control, the relationship between the transmitted power and the phase-shift angle is very complicated, and it cannot be realized by simple PI control.

Moreover, the primary and secondary sides of the traditional bidirectional isolated full-bridge converter are voltage-type H-bridges, which makes the current pulsation on the battery side very large, which is not conducive to the life and reliability of the battery.

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