Research On The Testing Technology For The Performance Of Photovoltaic Grid-Connected Inverter

Energy crisis and environmental pollution is a great challenge to human beings, in order to adjust the energy structure, realize sustainable development, and vigorously developing renewable energy power generation technology is an inevitable trend. Photovoltaic power generation system is an important part of renewable energy, grid connected inverter which plays an important role in energy conversion is usually used as the interface between the photovoltaic power generation unit and power grid. The performance of grid connected inverter directly affects the stability of power equipment and personnel, as well as the stability of the entire power generation system and the power grid, so how to verify and test the performance of PV grid connected inverter is one of the technical challenges of large-scale promotion of photovoltaic power generation system, In order to solve this problem, this paper takes the grid connected inverter as the research object, and focuses on the detection technology of the grid connected inverter.The most mature inverter topology and control strategy is researched, and as a model to study the detection technology of photovoltaic grid connected inverter. The mathematical model of the photovoltaic power generation unit is established, the working principle of the power electronic converter is analyzed, and the control block diagram of the forward and back stage converter are given. The intermittent reactive current disturbance detection method is studied, the fault detection blind area is analyzed, and the control block diagram of the realization of the isolated island detection is given.The hardware detection platform of grid connected photovoltaic inverter is built, the test project of PV inverter is proposed, The calculation methods and test procedure of the electrical performance and protection performance are given depending on the detection technology of PV grid connected inverter. The simulation model of the 30kW PV grid connected inverter is established, and the conversion efficiency、power factor、harmonic current、AC over/under voltage、AC over/under frequency、island protection of the system are tested and analyzed, and the theoretical basis is provided for the outdoor detection of the inverter. Through the outdoor performance detection of grid connected inverter, the illumination intensity of four seasons of a year and the photovoltaic output power data were extracted, and the conversion efficiency, power factor, current harmonics, and grid and off-grid voltage current shock were analyzed and tested. Test results show that the detection platform can realize the detection and analysis of PV inverter performance index, equipment configuration is reasonable, inverter detection technology is correct.