Research On Inverter For Independent Solar Energy System

In recent years, photovoltaic power technology has widespread application, along with our country new energy law enacted, photovoltaic power system will have broader development space in our country.Inverter is an important component in photovoltaic system, its performance has great influence on photovoltaic system application. At present, the domestic pure sine wave output inverter mainly uses 50HZ transformer for raising the output voltage, with large size, heavy weight and higher price, making it difficult to adapt to technological development and market demand.Therefore, this article developed an inverter by using the "push-pull circuit + high frequency transformer + single_phase full_bridge inverter" design proposal, which help to reduce system volume and increase system efficiency. The entire system consists of hardware and software designed, hardware divides into DC-DC part and DC-AC part. In DC-DC design part, this article uses the voltage feedback and current feedback , avoids the high-frequency transformer magnetic bias saturated question, at the same time increases the system stability and the dynamic speed of response. The controller is UC3846 current mode control chip. This paper also discusses the high-frequency transformer design, the filter components parameters choices in detail.In DC-AC design part, this article uses the Integrated Power Module, simplifies the drive circuit design. The system antijamming ability is increased because IPM has under_voltage protection and short circuit protection built_in. The control chip is inexpensive, superior performance arm7 series controller LPC2132, produces the SPWM wave and monitors system condition.In software design, this article uses the transient voltage feedback and the PI control algorithm, thus result high quality output voltage waveform, reduces the harmonics content of output voltage. The paper elaborates the overall framework of software design and produces subprogram code. Finally, the paper gives the experimental waveform of single-phase inverter prototype with 1.0KVA rated power.