Comprehensive Evaluation of Plant Power System Safety under Frequency Startup of Pumped Storage Power Station

Pumped storage power stations play an irreplaceable role in the power system by virtue of their advantages in peak shifting, frequency shifting and accident backup. From the current operation of the power plant, abnormalities and failures within the plant power system occur from time to time during the starting and pumping process of the unit, and the safety of the plant power system of the pumped storage power plant is related to the safe and reliable operation of the unit and even the whole power plant. Reasonable and scientific evaluation of the plant power system is an important condition to improve the level of risk prediction and increase the efficiency of operation and maintenance. Firstly, a safety evaluation index system covering the safety of power quality of plant bus, main transformer, excitation system and auxiliary equipment is constructed. Then, the subjective weights are obtained by applying the modified G1 method, the objective weights are obtained by using the coefficient of variation (CV) method, and the combined weights are obtained by applying the minimum information identification method, respectively. Finally, the approximate absolute ideal solution is introduced to form the generalized gray absolute correlation evaluation method, and an example is used to verify the effectiveness and scientificity of the comprehensive evaluation method of plant power system security. The results of the example show that the impact of the starting mode of the unit under different towing paths on the safety of the power plant is different, and the optimal towing path should be prioritized.

I. Introduction

With the rapid development of China's economy and the increasing demand for electricity, the peak-to-valley difference in the power grid has increased significantly, and the system peak adjustment problem has received widespread attention [1]–[3]. Pumped storage power station as an effective tool to regulate the stable operation of the power system, the impact of the system, to improve the level of safe and stable operation of the power system, improve the economy of grid operation and security and reliability plays a very important role [4]–[5].