Study Of Multi-objective Load Optimal Dispatching For Grid And Thermal Power Plant

With the deepening of the process of electricity market, it is an important means for power system to change the current generation scheduling to carry out energy-saving generation dispatching to deal with energy conservation and ensure the sustainable development of power industry. Therefore, this paper conducted study of multi-objective load optimal dispatching for grid and thermal power plant.First, for the practical problem faced by thermal power plants, considering the cost of power generation, pollutant emissions and load adjustment time, a multi-objective optimal load distribution model based on economy, environmental protection and speediness was established. The classic multi-objective optimization methods ideal point method and target multiplication and division methods were applied to transforme multi-objective problem into single objective. Then adaptive immune vaccine algorithm was used to solve the model in order to achieve better optimization results, while increasing the simplicity of the optimization program.Second, A short-term optimal scheduling problem based on wind power prediction for wind-thermal power systems was considered. With thermal power units providing positive and negative spare capacity to cope with the volatility and random intermittent of wind power output, considering thermal power output limits, lifting load rate and the minimum start-stop time, system balance and reserve capacity as constaaits, the cost of electricity and environmental protection system as the objective function, a multi-objective optimal scheduling model was established. In response to the randomness of wind power output, the traditional method of unit priority order table was improved to considering the economy of thermal power units and the rate of load lifting. Heuristic search method was applied to determine the unit combination and proportional allocation method was used to allocate spare capacity. A new idea was provided for solving short-term optimal scheduling problem of wind-thermal power systems.Finally, with the increasing scale of wind power, the ability of thermal power will not be enough to make up for the randomness and volatility of wind power. Therefore the hydropower was introduced into wind-thermal power system and wind power-thermal power-hydropower joint optimization scheduling model was established. According to the principle of energy generation scheduling, joint optimization process system for wind-thermal-hydropower was designed. Different optimization scheduling policy were maked to adjust to the different operating characteristics of hydropower and pumped storage power plant. As a result, simulation experiments show that the strategies proposed can exert the advantage of hydropower, reduce the pressure for thermal power in response to fluctuations of wind power and peak load difference. The joint optimization problem of wind power, thermal power and hydropower was solved.