The Research Of Reverse Power Detecting Method At The Grid-Connected Photovoltaic System Based On Transient Wave

As energy issues are becoming increasingly prominent, solar energy is being attached more importance with its clean, non-polluting, inexhaustible and other advantages. To use Photovoltaic power generation system to make solar reach the practical level, Grid-connected Photovoltaic System is being concerned. In this case, the problem of reverse power could be produced because of high-power load changes.Given that the problem of reverse power could be produced in the process of the Grid-connected Photovoltaic System, a new idea, characteristic wave detection and control using the transient process theory and transient protection theory in the power system is suggested. Namely, the transient wave can be captured when some loads change its current situation. By using its characteristics, the detection and control function can be achieved. In the small Grid-connected Photovoltaic test platform, sampling circuit and threshold value judging method are designed to capture the transient wave when one load changes its current situation. FFT algorithm is designed to analysis the sampling data. Matching and positioning algorithm based on statistical indicators is designed to establish model library. The model meets the requirements of system design when it is tested in the test platform. The method is going to apply into the area of small Grid-connected Photovoltaic System in order to avoid the problem of the reverse power and to achieve the safety of all the equipments fundamentally.