Study On Power System Optimization Dispatch With Intermittent Source

With the intermittent source connected to the power system, how to optimize the source structure to meet the social sustainable development has been a vital problem which is of great significance. But, at the same time, the characteristics of volatility, uncertainty of wind power, photovoltaic and the other intermittent power, has brought a series of problems to the power grid, such as security and stability. How to analyse the characteristic of intermittent power supply and based on which to dispatch power system to improve the utilization level of intermittent source and ensure electricity benefit is the key problem to solve Chinese large-scale development of intermittent power supply consumption. The problem of the intermittent source system is studied taking the Jiangsu power grid intermittent power as the research background.(1) The characteristics of the intermittent source is reserached and analysed. The method to measure the intermittent source fluctuation characteristics of Jiangsu Yancheng network is put forward and an evaluating index is defined. At the same time according to the index the complementary characteristics between the intermittent source are analyzed. Above research provides a theoretical basis for the allocation and scheduling of with intermittent source system.(2) Because it is difficult to obtain accurate probability distribution function, this leads to a scheduling error. The non probabilistic uncertainty optimization theory and method of interval mathematics programming is discussed to solve the uncertainty of wind power optimization method to reduce the scheduling error. Using this method, the uncertainty optimization problem is transformed into a deterministic optimization problem. The unit output power range is obtained by the interval algorithm. The units output plan is made According to unit output range.(3) Wind power prediction has large error, volatility, which leads to units output deviating the planned output.In order to reflect "fair, open, justice" dispatch principle, a dispatch strategy to balance deviation of power output is put forward. The improved method takes the units output deviation square as the dispatch objective function, which further reduces the unit output deviation than the traditional dispatch method.(4) According to the difference dispatching jurisdiction of wind power, a coordinated scheduling scheme between provincial upper level and regional lower level with wind power on the grid is put forward. At the same time, concept of slack tie-line power and slack wind power is proposed. Slack tie-line power is used as interface of interactive scheduling to mitigate wind power fluctuation and maximum the utilization of available wind power. Due to the dispatch problem takes place between two different cost regions, two marginal cost methods are put forward to calculate the cost of the wind power and tie-line power. Economic comparison of two different marginal cost methods is discussed in the paper.(5) In order to reduce the number of simulation wind turbine and improve the efficiency of simulation, the wind farm equivalent method considering the difference of wind speed is proposed. This method provides an efficient and simple method for offline research on wind power.