DAB converter input end current oscillation suppression method and device

Abstract

The invention provides a DAB converter input end current oscillation suppression method and device. The method comprises the following steps of: establishing a system small signal model according to a circuit topology structure of a DAB converter; according to the established small signal model and the control mode of the DAB converter, determining a controller transfer function and a phase shift angle control signal; determining a transfer function between the port current and the phase shift angle of the DAB converter according to the controller transfer function and the topological structure of a DAB circuit; determining a damping link transfer function after an input end current damping link is added according to the transfer function between the port current and the phase shift angle of the DAB converter; and determining a phase shift angle signal according to the damping link transfer function, the input end current of the DAB converter, the parameters of the DAB converter and the determined phase shift angle control signal so as to carry out current oscillation suppression. According to the control method for suppressing the current oscillation of the input end of the DAB converter, the current oscillation of the input end is effectively suppressed on the premise of not increasing extra power loss, and the stability of a system is improved.

Description

technical field [0001] The invention relates to electric power technology, in particular to a method and device for suppressing current oscillation at the input end of a DAB converter. Background technique [0002] The stability of the system input voltage and current and the magnitude of its ripple play a vital role in the stable operation of the entire system. In order to filter the double frequency ripple and high frequency ripple at the input end of the power equipment, an inductance is sometimes added to the input side. At the same time, some power equipment itself has an inductor connected in series at the output end. This inductance resonates with the input filter capacitor of the post-stage converter, which causes the instability of the input current and voltage and affects the stability of the system. [0003] In view of the above problems, there are two solutions in the prior art: the first is to connect resistors in series with the branch where the input inducta...

AI Technical Summary

Problems solved by technology

This inductance resonates with the input filter capacitor of the post-stage converter, which causes the instability of the input current and voltage and affects the stability of the system.

[0003] In view of the above problems, there are two solutions in the prior art: the first is to connect resistors in series with the branch where the input inductance is located, which will cause additional power loss and affect the efficiency of the system; the other is to reduce the Control the bandwidth of the converter, and place the resonance point of the input LC below 0dB to avoid the influence of resonance on the system

However, after reducing the control bandwidth, it will have a negative impact on the dynamic response of the system

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