Study And Realization On Pv System For Experimental Platform And Control Strategy

Because the shortage and pollution problems of energy sources are trending to more and more serious, a kind of cleanly, reliable and renewable energy sources must be developed as soon as possible. Fortunately, the Photovoltaic generation is a conformable one for its merit of safety, no noise and no pollution, besides, for the fast development of power converter and Digital Signal Processor (DSP), the academia and the industry are dedicating their efforts to study the PV generation technology.Based on the analysis and study on usual topologies and control strategies of PV grid-connected generation, a 3kW PV system for experimental platform is set up. The main circuit chooses the two-stage structure with the Boost converter and full bridge DC/AC inverter, and the core control strategies including the new dual-mode fuzzy maximum power point tracing (MPPT) control algorithm, the deadbeat control algorithm and so on. This PV system for experimental platform not only meets the requirements of economic, reliable, simple structure and easy to implement, but also provides many opportunities to know and learn the circuit and structure of PV system, study and develop the PV generation control strategies.Firstly, aim to the disadvantage of traditional control algorithms in PV grid-connected system, in MPPT aspect, a dual-mode fuzzy control algorithm with regulating factor is designed to solve the conflict between fast tracing and accurate positioning and improve the efficiency of PV generation system. In grid-connected inverter controlling aspect, a deadbeat control algorithm based on digital filter is designed to filter the wrong sampled signals of the power system voltage, and then improves the control effect. In Phase-Locked Loop designing aspect, the Software Phase-Locked Loop is adopted to efficiently keep the output current of inverter and the power system voltage in the same pace. In islanding protection aspect, the Active Frequency Drift with Positive Feedback (AFDPF) is adopted to reduce the blind spot of detection and improve the reliability of islanding protection.Secondly, based on the electrical specifications of 3kW PV system for experimental platform, the detail design of main circuit including its component parameters and the external circuit of DSP TMS320F2812 such as auxiliary power supply circuit, signal detection circuit, protection circuit and drive circuit is finished.Finally, after the realization of software, the simulation model of controller is built in MATLAB/Simulink environment. Through the simulation and experiment, lots of results show that the output of PV system for experimental platform with new control algorithms has reduced the output current harmonics and provided better quality power energy than the one with traditional algorithms. Not only the design requirements are reached, but also both of its good stability and the availability are proved to be well.