Research On Reactive Power Disturbance Islanding Detection Of Three Phase Grid-Connected Inverter

The conventional energy crisis becomes more sharper day by day, so the new energy has been the new focus thing that can promote the development of energy ecosystem. The combination of distributed generation system with grid has been affirmed the major method and the new development direction of electric industry by some specialists of energy and electric power which can reduce investment outlay, lower the consumption of energy, improve the system safety and flexibility. When the distributed generation system connected to located grid by grid connected inverter can generate a series questions, thereinto the islanding question is one of the most important questions.The paper researches the definition, harm, and the possible reason of islanding. Researching several kinds of primary ialanding detection methods. Analysing communication method between the grid and PV inverter; primary passive inverter-resident method; primary active inverter-resident method. Compare the characteristic of these methods.Deeply researches the non detection zones of grid connected inverter with constant power contral and constant current contral, those are in the over/ under-voltage and over/under-frequency protection.In the article has given under the dq coordinate system the digital phase-locked loop mathematical model, and has conducted the simulation research. Completed the three-phase digitized software phase-locked loop experiment. The phase-lock control has been able to guarantee the invertor output current and the grid voltage frequency synchronism.In this paper, three-phase voltage source inverter current control programs that focus on improving the current disturbance method, proposed that the intermittent reactive current disturbance islanding detection method, has carry out the simulation analysis, has given this method procedure flow. The Simulation results show that the method is can be achieved no non-detection zone examination. The use of TMS320F2812 DSP chip as the control, used the C language to complete the DSP programming and to carry on the experiment prototype debug. The experiments show that the use of over-voltage or under-voltage and over-frequency or under-frequency due to the protection of passive detection isolated island examination method and with intermittent reactive current disturbance islanding detection method be able to power grid at a rapid blockade of the output pulse, when the grid failure the rapid blockade output pulse, realizes invertor's reliable shutdown.