Multi-phase interleaving parallel DC-DC converter output current control method and system

Abstract

The invention discloses a multi-phase interleaving parallel DC-DC converter output current control method and system. The method comprises the steps of: setting interruption frequency fi=N*fs, wherein fs is the switching frequency; setting the triangular carrier frequency of a pulse width modulation register PWM to be fs, employing a counting mode adopting increase and decrease counting, and setting triangular carrier phases to be sequentially lagged by 360 degrees/N. The method further comprises the following steps of: S1, when triggering interruption occurs, reading current information of N-phase bridge arms, and calculating a duty ratio of a power switch tube of an Sth-phase bridge arm when the current of the Sth-phase bridge arm is just the average value current; S2, converting the duty ratio into a PWM signal; and S3, driving a power switch tube of the Sth-phase bridge arm by using the generated PWM signal. The system comprises a calculation module, a digital control module and a driving module, wherein the driving module is used for generating PWM signals and sequentially driving the power switch tubes of the N-phase bridge arms. According to the multi-phase interleaving parallel DC-DC converter output current control method, the problem of poor current control effect caused by relatively large current ripples of a multi-phase interleaving parallel DC-DC converter can be solved, meanwhile, good current sharing among phases can be realized, and the current control precision is improved.

Description

technical field [0001] The invention relates to the technical field of current control, in particular to a method and system for controlling output current of a multi-phase interleaved parallel DC-DC converter. Background technique [0002] Interleaved parallel DC-DC converters are widely used due to their advantages of small size, low cost and high efficiency. There are two key points in the implementation of this circuit topology: one is to solve the problem of current sharing between phases, and the other is to solve the problem of poor output current control. [0003] In response to these problems, different literatures have proposed a variety of control schemes to improve the performance of the DC-DC converter, and all control schemes need to sample the output current of the DC-DC converter as feedback to participate in the operation, so the sampling and control of the output current The method is crucial to the control effect of the DC-DC converter system. [0004] T...

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Problems solved by technology

[0006] In view of this, the purpose of the embodiments of the present invention is to provide a multi-phase interleaved parallel DC-DC converter output current control method and its system, which can solve the problem caused by the large current ripple of the multi-phase interleaved parallel DC-DC converter. The current control effect is not good, and at the same time, it can achieve good current sharing between the phases and improve the current control accuracy.

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