考虑风电场随机波动性的变电站关口无功控制区间整定方法

针对分散式风电并网所导致的传统九区图自动电压控制策略中,关口无功控制区间整定方法无法适应风电场出力随机波动性的特点,分析了含分散式风电场接入的配电网有功损耗特性,定义了关口无功优化区间矩阵,并解释了矩阵中相关元素的具体物理含义及计算方法,即当风电场有功功率和功率因数为上、下边界值或中值时,根据系统总有功损耗与变电站关口无功的关联特性,在考虑主变高压侧电压限制的前提下,求得不同负荷水平下的关口无功优化区间并取交集得到相应的矩阵元素值,提出了分块定区间法,求得了与风电场运行工况相配合的变电站关口无功控制区间。算例证明,运用所提方法进行配电网无功控制,在节能降耗、减少设备动作次数及提高系统电压安全性方面均有优势,且易于工程实现。

Setting Method of Reactive Power Interval for Substation Gateway Considering Stochastic Volatility of Wind Farm

Since the control range of reactive power of substation gateway(RPSG)in traditional nine-zone automatic voltage control(AVC)strategy cannot adapt to output fluctuation of wind farm in a distribution network, the active loss characteristic of distribution network with distributed wind power integration is analyzed. An optimal interval matrix is defined, the physical meaning and calculation method of matrix elements are explained. To obtain the corresponding element value, the intersection of optimal intervals of RPSG under different load levels is set. The intervals are obtained and improved according to the correlation characteristic between the active loss and RPSG and the voltage limits when the wind power output changes. A block interval method is proposed to obtain the control interval which can adapt to the wind farm operation condition. The simulation shows that the setting methods are simple and practical in engineering, which realize the multi-objective of volt/var control such as saving energy, avoiding frequent regulation and improving voltage quality. This work is supported by National Natural Science Foundation of China(No. 51277070).