Impact of wind and solar power plants on the reliability of the IPS

Abstract

One of the most promising areas in the development of the electric power industry is generally regarded to lie in expanding the share of renewable energy sources (RES) in the electric energy balance of power systems in the form of wind and solar power plants (WPP and SPP), the saving of organic fuel (coal, gas, fuel oil) and the reduction of environmentally harmful emissions into the atmosphere considered to be their most important advantages. However, the impact of RES on the controllability of the modes of operation of electric power systems and on the reliability of the IPS operation remains quite unexplored.Currently, the global energy industry uses 318 million kW of WPP and about 142.4 million kW of SPP, of which the major West European countries account for about 227 million kW, or 49.3%. On average, wind and solar power plants account for almost 30% of the total generating capacity in Western Europe, with Denmark having the largest share of WPP (47%) and Germany having the highest share of SPP (18.6%). However, an uncontrolled growth in the share of WPP and SPP in the structure of generating capacities of power systems begins to manifest itself in a sharp decline in the reliability of the power industry due to the fact that a number of negative properties of WPP and SPP have not been taken into account (at least, to a sufficient extent), which manifested themselves in practice in a system accident in the UK power system that occurred on August 09, 2019, when, as a result of an "ordinary" short circuit, a system accident occurred, with up to 1.1 million consumers with a total load of 1690 MW disconnected from the power supply system for a period of 15 to 45 minutes. This is estimated to have resulted in economic losses for consumers amounting to 12.3–15.0 million USD.The reason for this is that the high sensitivity of WPP, SPP, CCGT and gas piston units to voltage and frequency drops is not properly considered in conditions of insufficient capacity of the rotating (mobile) generation reserve. Damage can be prevented by increasing the rotating reserve within the available reserve of the power system, which will require an increase in funds for maintaining the same due to additional fuel consumption. The ratio of reduction of probable damage to consumers and the cost of additional fuel consumption for maintenance of a required rotating reserve in the power system allows to economically substantiate the strategy and scale of introduction of renewable energy sources to the power industry.