Research Of The Isolated Push-pull Forward DC/DC Converter To Pv System

As an important part of the energy development strategy in the world, Solar energy is an inexhaustible green energy, therefore, photovoltaic power generation technology has been developing rapidly. Combined with advances in power electronics and photovoltaic cells, critical the balance device-DC/DC converter of photovoltaic power generation system requirs increasingly performance.Push-pull Forward has a great advantage in the low-voltage high-current output voltage, wide range of occasions. The push-pull forward converter is selected as the main topology of the system.of the Push-pull Forward circuit works, as well as clamp capacitance and leakage inductance circuit is analyzed in great detail. It will face a dilemma on converter design:If the system achieve high output voltage, high power output, it will cause the switch tube to withstand the relatively high current, large rectifier diode withstand the voltage stress and the reverse recovery problem a long time, while the system device selection may be limited. To solve these problems, this paper presents a program which named IPOS modular converter of two push-pull forward DC/DC converter module input parallel output series, satisfying the effect of boost isolated output, high power and high voltage.Then, analysis the IPOS of combination converter parameters effect on the voltage balance. If you want to guarantee the normal work of the system, output voltage sharing among the modules of IPOS converter should be ensured. This paper analysis the relationship between the input current sharing and the output voltage sharing of the modules in IPOS converter, that the output voltage sharing can ensure the input current sharing, opposite also established. The system uses a modular voltage sharing control strategy, and is eatablished IPOS the modular converters modular voltage sharing control model.Finally, based on DSP TMS320F2812digital control, experimental platform is established by the IPOS modular DC/DC converter,which consists of two push-pull forward circuit. By experiment and simulation to verify the correctness of a single module work process, as well as two modules the IPOS modular converter voltage sharing control strategy is feasible, and the design requirments are met.