The Research Of Push-pull Full Bridge Bi-directional Converter Based On The PFF Control

Photovoltaic system can be divided into independent photovoltaic system andgrid-connected photovoltaic system. Independent photovoltaic system is an important wayto generate electricity because of the limited capability of photovoltaic system.Independent photovoltaic system can be used in some areas that power grid can not cover,such as remote rural areas, pastoral areas in the Midwest and islands. The bi-directionalDC-DC converter between the DC bus and battery in photovoltaic system can control theenergy, so it is important to design a resonable and effective control method. In this paper,proportional-feed-forward(PFF) control method can be used in push-pull full bridgebi-directional DC-DC converter. It can not only guarantee voltage stability in DC bus andbatter side, but also benefit to the battery charging and discharging.This paper introduces working principle of the push-pull full bridge bi-directionalDC-DC converter which can work in two ways. Mainly introducing the PFF controlmethod, making a contrast between the PFF control and PI control. PFF control has anadvantage over PI control in input disturbance and also has good dynamic characteristic toload disturbance. Synchronous rectification technology can be used based on the hardwareof the push-pull full bridge bi-directional DC-DC converter. This paper proposes a methodof booster soft-starter which can decide duty cycle by detecting inductance current.At last, building a1000W prototype based on the chip of DSP2812. The theory isverified by the simulation of MATLAB and experiment.