Research And Realization Of Three Phase Grid-connected Inverter Based On Peak Current Feedback

The world’s energy crisis and environmental problems have been growing count-ries in the world are competing for the development of green renewable energy. Solar energy for its sustainable development and no pollution has been favored in all over the word. With advances in PV module prices decline and photovoltaic technology, so-lar photovoltaic power generation will become an important alternative energy sour-ces. Especially in recent years, the state’s promotion of distributed generation,photov-ol-taic power generation system to allow users access and tariff subsidies, and more top-romote the development of the photovoltaic industry, making the PV gridconnect-ed system has become a hot research. In this paper, the inverter control algorithm has been in-depth researched.The peak current feedback control algorithminto the design and implemengation of photovoltaic inverters.Peak current feedback control in inverter welding applicat-ion has been very mature, this article will apply to the photovoltaic grid inverter.Bas-ed on peak current feedback control inverter has many outstanding advantages:First, the peak current control inherent instantaneous peak current limiting function, to dete-ct the peak pulse current limiting and one by one, which has a strong transient protect-ion, in order to achieve or simplified overcurrent protection for power devices; seco-ndly, this control has fast dynamic response and the output current can be a good foll-ower to quantitative; In addition, the peak current control mode, enables multimodu-le parallel streams and is particularly suited High-power applications.Using FPGA peak current control. Peak current feedback control is necessary to detect the peak pulse individually, to deal with real-time system requirements are very high.DSP and microcontroller, such as the processor core can execute only one instr-uction,not achieve pesk current feedback control.In order to achieve peak current feedback,systems are built using analog components.However,this system is with po or anti-jamming performance, stable insufficient and costly.FPGA can execute instruc tions in parallel, can handle different tasks, to meet peak current feedback control system for real-time requirements. With the DSP as a secondary controller, the system can give full play to the advantages of digital signal processing on DSP, which greatly improves the performance of the system. The main circuit topology uses a three-level T-type structure. Successfully resolved the problem of the freewheeling after turning off the swich. Because of the T-type three-level topology has two clamping diodes less than neutral point clamped three-level topology, conduction loss is reduced. In addition, T-type three-level topology mainly consider to protect the two swiches of the main bridge. Therefore protection is more simple than neutral point clamped three-level topology.