The Research Of PV Grid-connected Micro-inverter Technology

Nowadays, due to the exploitation of fossil energy, Limited traditional energy sources begin to reduce, so people have to find a new type of renewable energy to replace the traditional energy, because of the solar energy is the most abundant renewable resource, in recent years, it is began to be used, in particular,using solar energy to generate power, not only can save the traditional energy, but also it is clean and reliable. Photovoltaic technology is begin to progress and development, photovoltaic power generation system scale is also in constant change from large power to the small scale, the traditional centralized power energy utilization ratio is low, because when there is part of the region with dark clouds, making the power output cannot reach the maximum, but the micro inverter can solve this problem.Firstly, a micro inverter topology classified research, comparison of various implementation principle of topological circuit, drawing the circuit structure of flyback is most suitable for micro inverter, which leads to the interleaved flyback micro inverter topology. A detailed analysis of the working principle, flyback circuit working patterns, and of several models are compared, and then illustrates the working principle of interleaved flyback micro inverter topology; in addition, a detailed analysis of the working process of the active clamp circuit, tells the story of the clamp circuit can realize zero voltage transition, obtained in the continuous mode of the primary and secondary current waveform; advantages and disadvantages compared with the traditional maximum power tracking algorithm, the shortcoming of traditional method, this paper puts forward a kind of improved MPPT algorithm, the method has high tracking accuracy, small vibration, the feasibility of t the improved MPPT algorithm through MATLAB simulation; through the comparison of the unipolar and bipolar SPWM technology, unipolar SPWM modulation used in expository texts; and then carried out a detailed research on the control strategy that used in this paper is the double closed loop control strategy; finally the system parameter calculation, hardware circuit design and software program flow through the simulation and experiment conclusion analysis.