BuckBoost circuit and control method thereof

Abstract

The invention provides a BuckBoost circuit and a control method thereof. The method comprises the steps that under the fixed-frequency width-modulation mode of the BuckBoost circuit, a controller calculates the modulation ratio M in real time according to an output voltage given value and an output voltage sampling value; the controller controls a Buck switching tube bypass relay and a Boost diodebypass relay according to the modulation ratio M respectively; the controller conducts bypass control on a Buck switching tube and a Boost diode through the bypass relays respectively, and a BuckBoost circuit working mode is controlled. The circuit comprises the Buck switching tube bypass relay which is used for conducting bypass on the Buck switching tube, the Boost diode bypass relay which is used for conducting bypass on the Boost diode, a flying-across relay which is arranged between the Buck switching tube and the Boost diode, and the controller. According to the BuckBoost circuit and the control method thereof, the circuit efficiency can be effectively improved, the cost is low, the circuit loss is reduced, the topological function of the circuit is not influenced, the circuit is safe and reliable in running, and the system performance and efficiency are optimized. Zone bits are controlled, so that the system is safe and reliable in running under topology.

Description

technical field [0001] The invention belongs to the technical field of power supplies and relates to BuckBoost circuit control, in particular to a BuckBoost circuit and a control method thereof. Background technique [0002] High efficiency is one of the important qualities of power supply products. There are three ways to improve its efficiency: [0003] 1) Reduce loss and improve efficiency by improving device performance; [0004] 2) Apply soft switching technology to reduce device loss; [0005] 3) Low impedance switching devices are used to bypass power devices to reduce system losses. [0006] These three approaches differ in terms of performance, cost, and ease of implementation. Among them, improving the performance of the device is the fundamental way to reduce the loss of the device, but the performance of the device is subject to the process, and with the improvement of the performance of the device, the cost of the device will increase exponentially; the soft ...

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Problems solved by technology

Therefore, when switching modes with the relay, its efficiency cannot meet the practical requirements, the operation is more complicated, and the efficiency of the power system is not high

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