Grid-connection adaptability testing system and method for photovoltaic power stations

Abstract

The invention relates to the field of test of the photovoltaic power generation system, in particular to grid-connection adaptability testing system and a method for photovoltaic power stations. The grid-connection adaptability testing system comprises a photovoltaic array, a direct-current switch and a photovoltaic inverter which are sequentially connected. A voltage acquiring port of the photovoltaic inverter is connected with a microcomputer relay protector and used for inputting voltage signals of the microcomputer relay protector into the photovoltaic inverter. An oscilloscope is respectively connected with the voltage acquiring port and an output contactor of the photovoltaic inverter and simultaneously monitors voltage signals of the microcomputer relay protector and on or off signals of the output contactor of the photovoltaic inverter, and grid-connection adaptability testing results are judged by processing and analyzing recorded waveforms through the oscilloscope. The grid-connection adaptability testing system and method have the advantages of simplicity in implementing, convenience in testing and high testing accuracy.

Description

technical field [0001] The invention relates to the field of photovoltaic power generation system testing, in particular to a photovoltaic power station grid-connected adaptability testing system and a testing method thereof. Background technique [0002] As large-scale photovoltaic power plants are connected to the grid, in order to ensure the safe and stable operation of new energy grid-connected, the country has issued technical standards for grid-connected photovoltaic inverters and grid adaptability of photovoltaic power plants. The standard stipulates that when the voltage amplitude or frequency of the grid is abnormal, the photovoltaic inverter should maintain normal grid-connected operation or disconnect the grid within a specified time to stop running. For the performance test of photovoltaic inverters, regardless of the type test in the laboratory or the field test of the photovoltaic power station, the common practice at home and abroad is to establish a correspon...

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Problems solved by technology

For the performance test of photovoltaic inverters, regardless of the type test in the laboratory or the field test of the photovoltaic power station, the common practice at home and abroad is to establish a corresponding power grid disturbance generating device, and the rated capacity of the device is usually the measured photovoltaic inverter. Three times the capacity of the inverter or grid-connected unit. The main body of this test method is to use a frequency converter composed of power electronic devices to simulate the abnormal voltage or frequency characteristics of the real power grid, so as to achieve the corresponding test purpose. The establishment of this test environment is not only expensive, but also The steps are complicated, and the test accuracy is not high due to the output resolution of the grid disturbance generator itself

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