Investigation of operating differences between wind and photovoltaic assisted by coal-fired power plant

Abstract

ABSTRACT This paper investigates an integrated energy system combining wind/photovoltaic (PV) power and a coal-fired power plant (CFPP). It is found that there are significant differences in the integrated energy system of wind-coal and PV-coal due to the influence of natural conditions on wind and PV. The integrated energy system is analyzed from two aspects: the grid side and the power supply side. On the grid side, the power supply capacity of the system is evaluated by load evaluation. It is found that the load evaluation qualified rate of the wind-coal and PV-coal integrated energy system is 14.2% and 5.3% lower than the grid side standard, respectively. The greater volatility of wind power increases the regulating difficulty of CFPP. Through optimization, the optimal storage capacities of the wind-coal-storage and PV-coal-storage systems are 5.5MWh and 3.2MWh respectively, enabling the integrated energy system power supply to reach grid-side demand levels. On the supply side, the operating depth of CFPP in wind-coal-storage and PV-coal-storage increased by an average of 3.11% and 4.23% per month, respectively. In both combined modes of operation, CFPP combined with wind power has more frequent load regulation, with an average daily regulation frequency of 10.8% higher, while CFPP combined with PV has a higher operating depth of up to 49.84%. This study reveals different aspects of the operational characteristics of wind/PV when supplying power directly in conjunction with CFPP. The results show that the combined supply with wind/PV places higher demands on the operation of CFPP.