Research Of10kW Photovoltaic Grid Inverter Control System

In recent years, with the energy crisis and environmental problems worsens increasingly, the development of a new energy is crunch time. Solar energy is becoming the focus of many countries to study, there are many forms of solar energy utilization, one of the most advanced and most promising is the photovoltaic power generation. This paper is mainly about the study on control system of lOkW photovoltaic grid connected inverter, focuses on the analysis of the structure of the grid connected inverter system and its control strategy, and conducted experiments with a prototype.Firstly, analysis the characteristics of photovoltaic cells, propose the model reference conductance increment method MPPT control strategy, improve the tracking speed and control precision, and track the maximum power point of the photovoltaic cells faster and more stable. Secondly, the main circuit structure of the grid connected power system is designed in detail, previous stage DC/DC boost section uses a dual Boost Boost chopper, the structure uses interleaving control technology, thus greatly reduce the current ripple amplitude, improve the switching frequency; DC/AC inverter part uses IPM module6MBP50RA120, it contains the three-phase full bridge inverting circuit, and controlled by virtual flux oriented control technology. The software and hardware of the inverter of the system is designed, mainly for the auxiliary power supply、a detection circuit and a control circuit, the control circuit adopts DSP2407to control the system real time; The system uses a positive feedback based on active frequency shift method to protect island, and its simulation analysis, validate the strategy to detect faster.Finally, relying on the existing10kW photovoltaic grid connected power system, through the analysis of the experimental waveform, feasibility and effectiveness of the proposed control strategy has been verified.