Study Of Wind Power Forecasting And Impact On Power Grid Operation

With the depletion of non-renewable resources, renewable resources have attracted the attention of the world. As the high maturity of wind power technology, it has been developed on quite a large scale. Wind power is recyclable and non-polluting, so that it can be a substitution of fossil fuels and improve the resource composition of power grid. However, the stochastic volatility of wind power makes power grid operation more difficult and even a threat to power grid security sometimes. How to allocate the reserve capacity with wind power integration has become the focus of research.After wind power integration, there are two issues for power balance and operation quality. The first is fluctuation regularity of wind power and the other is reserve capacity allocation. In the current situation, the research on coordination of security and economy in power grid operation has important theoretical and practical value.In this thesis, an exploratory study on optimal operation of power grid with wind power integration is carried out, which is based on mathematical optimization theory. The main works and innovative achievements of the thesis are as follows:1. Considering the regional grid with several wind farms integrated, the total wind power has a better regularity comparing to single wind farm. A ultra-short term forecasting method of wind farms is proposed in this paper, which is based on the correlation of total power and wind farms. The Least-Square Support Vector Machine and Kalman filter are adopted respectively to forecast total wind power and distribution factors recursively, so that the good regularity of total wind power could be restored to wind farms and the short power forecasting system of wind farms is established indirectly.2. The stochastic property of wind power leads to great error on forecasting result, and a fluctuation interval analysis of forecasting result is required for security operation. In this paper, an interval analysis model of wind power built based on quantile regression is proposed. After selection of regression function by support vector machine, the model of quantile regression is established for wind power. The interior point is adopted here to solve the model, then the analysis result of wind power fluctuation interval ahead consisting of a series of quantiles is obtained. The case study shows that the methodology proposed in this paper could provide a reliable interval analysis result for the power dispatching center which is beneficial to security operation, risk Assessment and the reserve capacity reduction.3. Analysis of impact on power grid operation risk by wind power integration is the key issue to maintaining the security level. Based on regularity of wind power fluctuation, the probability distribution of wind power can be combined with capacity outage probability table and the impact of wind power on power grid operation risk is specified. For further study on the influence to power grid scheduling, cumulative capacity outage probability table is introduced into Unit Commitment. The power grid in Yantai is study and the influence on operation cost and reserve capacity allocation is analyzed in detail.4. As the installed capacity of wind power in power grids reach a certain scale. the dispatching schedule becomes more complex for high efficiency utilization of wind power. In a power grid with wind power, there is a contradiction between fuel cost and effective utilization in the scheduling process. In this paper, the fuel cost saved is taken as the value of wind power. A scheduling method considering wind power receptiveness is proposed so that a fluctuation range can be calculated to coordinate the fuel cost and wind power receptiveness. Case study shows that the method proposed is appropriate for power grid scheduling considering renewable energy with uncertainty and accords with the principle of energy conservation.5. The project "Study of Impact on Power Grid operation in Shandong by Wind Power Integration" is introduced briefly. With analysis on power flow, Short-circuit capacity, static stability and reliability, the impact on Power Grid operation in Yantai by wind power integration is specified and measures of impact improvement are proposed.