The Design Of 5KW Single-phase Photovoltaic (PV) Inverter

With China's socialist market economy is keeping a high speed growth, the development and using of new energy has been more and more paid attention by the people. Solar energy has been gradually used and developed which has clean, environmental protection, rich resources, arc。That has been an important direction in the new energy field in the least then years. PV inverter as the main energy conversion device in the energy utilization of solar is an important part of research and development at present, which the quality of the directly affects the level of solar energy utilization efficiency.In this context, we made a more deeply research about PV inverter, used energy of solar in a maximize, made pollution-free feedback power grid as a main aim, used current feedback control, and improved the main circuit of the traditional PV inverter, made the research about the theoretical and experimental of solar power generation system, which is important for the research of solar power generation system.In this paper, we made analysis and research on the techniques about circuit topology, current feedback control and islanding prevention of system.First, introduce about present and future of the using of solar energy resource, present the main of this study, analysis details about the main circuit and working principle of PV inverter. We proposed the calculation method of how to select the main components of PV inverter, and give it a proof by simulation and experiment.When analysis the main circuit, change some place on the basic structure of the main circuit for improving the circuit's output power. Use IGBT which has higher switching frequency and more pressure than IGBT, simply the circuit structure, slow down the lost of the power of the circuit and ensure output waveform well, the dynamic response quickly. Then, introduce the current feedback control method, give out adaptive FIR control method, and made the experiments to proof this method could reduced the system's response time interval, can make current which output from PV inverter the same as grid voltage and can attach to the aim which make power factor equals 1.Island effect must be protected in the grid-connected PV system. In this paper, give out an effective prevention methods about island effect, effect reduce the blind spot with checking island effect by the initiative and passive methods at same time.Finally, Describe the IGBT drive circuit, and designed in the signal acquisition circuit of voltage, current sampling circuit and overcurrent protection, thermal protection circuits, the power supply. Use TI Company's IC, TMS320F28027 DSP, which as the main control IC, to develop a 5KW PV inverter. Make a proof that use the methods which give out in this paper, the system could have a good run as safe, stable and efficient work.