Research On Optimization Models In Power System Operation Based On Distributed Energy

With the increasing of intermittent wind power and photovoltaic power in distributed grid, stochastic volatility of power generation has brought risk to the operation of power grids. Therefore, we need alleviate the great challenges of distributed energy generation on the grid safe and reliable operation by optimizing the scheduling, dispatching, planning and other aspects from the grid. Operation optimization models of power system considering distributed energy is a large-scale, multi-objective, multi-constraint and nonlinear optimization problem, and control variables have the characteristics of mixed discrete and continuous phase. Therefore, optimization models of power system operation and their solution algorithm considering the distributed energy system have become an important research topic.According to analysis mentioned above and the importance of load forecasting to scheduling operations, short-term load forecasting model and optimization models of power system operation are analyzed in this paper, including closed-loop economic dispatch problem, network optimization problems considering wind power access and network planning problem considering distributed energy. Specific research topics are listed in the following:(1) Short-term load forecasting is an important basis for day-ahead economic dispatch, LS-SVM short-term load forecasting model based on GARCH error correction is proposed in this paper, using LS-SVM model to predict load data. GARCH model is applied to forecast error correction to improve the accuracy of prediction.(2) The day-ahead economic dispatch model based on closed-loop control is presented, linearizing a variety of constraints and taking into account the unit cost of start and stop, security constraints of power grid operation, including the power flow constraints, voltage security constraints as well as N-1security constraints. Prevention-correction method is employed for solving the unit commitment model and security-constrained economic dispatch model alternately.(3) A multi-objective power flow optimization model is established considering the wind power and system voltage stability margin simultaneously, including the minimum cost of power generation and maximum voltage stability margin. The problem was solved using the adaptive particle swarm optimization optimization algorithm.(4) Distributed network planning model based on varied-weight predictor-corrector interior point method is put forward to optimize the allocation of different types of renewable distributed generator. Minimum network losses is used as the objective function, taking into account the operation possibility of distributed generator. In order to improve the efficiency of the problem, the model applies power flow equations and constraints in rectangular coordinates.By modeling and solving the problem mentioned above, we can not only realize the basic requirements of power system on security, economics, environmental protection, but also can reduce costs of power generation and transmission, and coordinate the conflict between power plants and power grids. Therefore, research on operation optimization models of power system considering distributed energy has important theoretical value and practical significance.