Design Of Interleaved Flyback Grid Connected Micro Inverter

In recent years, environmental pollution and energy shortage has become a common problem faced by all countries in the world. The international community at the Paris climate conference in France, including the Paris agreement and the relevant decisions of the Paris results in 2015. The agreement will further define the concept of Global Climate Governance for low-carbon green development, which marks the global economy from fossil energy to the development of clean green economic evolution. Solar power generation industry is an important part of the development and utilization of clean energy.Low power micro inverter will reduce the cost of photovoltaic power generation, improve the popularity of solar power generation. The research of micro inverter is currently towards miniaturization, digital and integrated development, however, there is still a lot of research room in its stability,controllability, service life and conversion efficiency.This paper describes the reasons for the selection of the interleaved flyback topology after comparing the contrast of the interleaved flyback and the double flyback micro inverter system; The power decoupling is carried out to solve the power fluctuation of input power of PV module, at the same time, we adopt film capacitor to instead of traditional aluminum electrolytic capacitor, which not only absorbs the disturbance voltage, but also improves the service life of the micro inverter; we adopt the active clamp converter to absorb the leakage energy and the input current of high frequency chopper to solve the problem of low conversion efficiency caused by large switching loss of photovoltaic grid connected micro inverter, which also achieves zero voltage switching tube; The maximum power point tracking is realized by using the BOOST boost step to boost the DC bus voltage, making two perturbation to improve tracking accuracy and speed based on variable step disturbance observation method; we studied the grid connected control strategy and compared the control effects of PI and PR controller to improve the waveform quality and reduce the harmonic interference.At last, we designed interleaved flyback photovoltaic micro inverter based on the DSPIC2812 which maximum output power is 235 W, and analyzed the experimental results.The simulation results and the experimental results show that the grid connected current waveform is good,harmonic interference is low, the prototype conversion efficiency is high.Experimental current and grid voltage is in the same frequency and phase.