Research On PV Grid Power Generation System And Mode Leakage Current Control Strategy

Along with the continuous development of economy and the improvement of life quality, thedemand for energy is increasing, but the fossil energy drying up, green, environmental protection,sustainable and harmonious renewable sources of energy to get the favor of people. Because the solarenergy resources widely, permanent, green energy, and not affected by geographical advantages isbecoming the new energy. Solar photovoltaic power generation namely became the various countries’energy research important direction, and gradually shows its good application prospect. Due to the solarenergy density low, covers an area of large, high cost of photovoltaic power generation system, andinfluenced by the climate and other restrictions make photovoltaic power generation efficiency is low.Therefore, to deepen the research and development of solar photovoltaic power generation system, improvethe efficiency of the photovoltaic power generation as a whole, in particular, to ease the human has theenergy crisis has very important significance.Among them, the solar cell is a major part of the photovoltaic power generation, so how toimprove the power efficiency of the battery is the research hot spot. Because of the photovoltaic cell is acomplicated nonlinear system, the input and output characteristics are influenced by the strong sunlight andbattery temperature. So all kinds of photovoltaic cells general simulation model were put forward．Andbecause pv cells general simulation model is complex and difficult problems, such as making aphotovoltaic cell simulation has great difficulty, greater restrictions on the actual experiment．This paperintroduces a new simulation model is simple and clear. Several important parameters in the model ofphotovoltaic cells for modular processing, makes the model can be clear for different temperature and lightintensity on the influence of photovoltaic battery parameters. And in combination with the new method oftracking MPPT, verify the correctness of the model.However, it is imminent that how to be more efficient, higher quality conversion become thepeople can direct use of electricity．No transformer grid inverter with high efficiency, small volume, lightquality and low cost advantage, quickly become a research hotspot of scientific research personnel. But thetransformer to eliminate the photovoltaic (PV) and grid formed between a larger common mode leakage current, conduction and radiation disturbance, increase the net harmonic current, and even endanger theequipment and personnel safety. So the leakage current of eliminating popularity and development ofphotovoltaic (pv) grid inverter without transformer is very important. Single-phase grid inverter based onthe analysis of leakage current, on the basis of mechanism was established considering the parasiticparameters of common mode resonant circuit equivalent model, through the leakage current excitationsource, with symmetrical and asymmetrical parameters were analyzed, and different switch modulationmethod, the power grid voltage, filtering inductance and stray capacitance on the influence of leakagecurrent. Beat by the end, current control of single phase photovoltaic (pv) grid inverter circuit, and putforward on the basis of the principle of no beat current control compared to compensate the compensationmethod. And through the system simulation and experimental data show the proposed method caneffectively eliminate the leakage current of inverter and the influence of MPPT stable current, can carry outhigh quality grid current output of the system and the maximum power of accurate tracking.Therefore, this paper puts forward a new type of battery simulation model, improve theunderstanding of the photovoltaic battery simulation model, so as to strengthen the operability of the actualexperiment. And by no beat current control of single-phase photovoltaic (pv) grid inverter circuit, theleakage current of inverter current and the influence of MPPT. To compensate the duty ratio and putsforward the compensation method, eliminate the leakage current of inverter and the influence of MPPTstable current, to achieve the high quality of system of grid current output and the maximum power ofaccurate tracking.