Research On The Influence Of Interruptible Load On The Long-term Reliability Of Grid In Power Market

Many large blackouts happened in recent years in the world lead to huge economic losses. How to predict power outages accidents and how to suppress the chain fault have become a hotspot. Along with the development of the reform of the electric power system and the electric power market, how to establish the long-term reliability model of the power system in electricity market and the research of the influence of mechanism of power market on the long-term reliability of power system have been an important research topic.There are two parts in this thesis. The first part is to set up the model of the mechanism of electric power market and determine the initial state of power system before chain fault operation state. The initial state of power system is determined by the day-ahead power market and the real-time power market. Considering the security constraints of power grid, the Independent System Operator (ISO) determines the initial trade plan on the basis of the load forecast curve and generators’offer in day-ahead market. In real-time power market, adjustments of generator’s output and shedding interruptible load are used to balance the power imbalance that caused by load fluctuation. Moreover, the interruptible load is selected in order to eliminate transmission congestion and the heavy load line. Eliminating the heavy load lines can save some transmission capacity to undertake the power flow transferred from the transmission lines that fall to fault initially. So this can prevent the chain fault. The second part is to establish long-term reliability model of the power system. A better power system cascading blackout model is proposed based on the idea of self-organized criticality. Two circulations are used to simulate the development process of power system, including30000cycles amount to eighty years’development. The outside circulation describes the process of continued growth of load, the expansion of generators and the expansion of transmission line. And the inner circulation describes the chain fault and the process of outage line.The IEEE30node test system is used to simulate the long-term reliability of grid in power market. Interruptible loads and adjustment of generators are taken to eliminate heavy load transmission lines so as to restrain the chain fault effectively.