Stability judging method of grid-connected photovoltaic power station

Abstract

The invention provides a stability judging method of a grid-connected photovoltaic power station. The method comprises a procedure of establishing a stability judging criterion which comprises the following steps: photovoltaic power system components formation and topology structure analysis, photovoltaic cell array P-U power output characteristic analysis and a mathematical expression thereof, DC-AC converter control mode principle analysis and a mathematical expression thereof, and obtainment of a control mode of the grid-connected photovoltaic power station in constant power and a stability criteria under an MPPT power control mode. Voltage and power data at an outlet of a photovoltaic array are measured, and combined with the obtained criteria in the above steps, the stability of the grid-connected photovoltaic power station is obtained. According to the method, only through the measured voltage and power data at the outlet of the photovoltaic array, the stability of the grid-connected photovoltaic power station can be fully judged. The method has the advantages of simpleness, convenient realization of stability measurement and convenient engineering application. A foundation is provided for a control scheme of the grid-connected photovoltaic power station.

Description

technical field [0001] The invention relates to the technical field of grid-connected photovoltaic power plants, in particular to the stability judgment of grid-connected photovoltaic power plants. Background technique [0002] In recent years, China's photovoltaic power generation projects have shown a trend of rapid development. Vigorously promoting the development and utilization of new energy represented by photovoltaic power generation is an effective measure to solve the current energy shortage crisis and ease the pressure on environmental protection. Solar energy is transitioning from a supplementary energy source to an alternative energy source. Photovoltaic grid-connected power generation is the development trend of solar energy utilization. Large-scale photovoltaic grid-connected power stations and rooftop photovoltaic grid-connected power stations are gradually playing an important role in power system peak regulation, frequency regulation, and stability control....

AI Technical Summary

Problems solved by technology

[0005] 2) It is necessary to know the operating characteristic parameters of the photovoltaic power station. However, the operating characteristic parameters of the photovoltaic power station (such as the output P-U characteristic curve of photovoltaic cells) are affected by various uncontrollable factors such as radiation intensity, ambient temperature and wind speed, and have time-varying characteristics. and difficult to measure accurately;

[0006] 3) The role of the photovoltaic power plant control system is not considered

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