储能系统在风电场闪变抑制中的应用

摘要

并网风功率中含有的波动分量有可能会导致风电并网点的电压闪变.当风电接入低压配电网时,传统的基于无功补偿的闪变抑制方案具有一定的局限性.提出基于储能技术的风功率波动平抑方案,该方案采用超级电容器为储能元件,功率调节系统采用电压源型变流器VSC (voltage source converter)级联双向DC/DC变换器结构.将低通滤波器滤过的风功率作为控制目标,建立储能系统的控制策略,实现对有功功率的追踪.以考虑塔影效应和风剪切的风速模型作为输入,仿真比较了风电场采用储能调节有功功率前后的功率波动和闪变值.仿真结果验证了方案的正确性和控制策略的有效性.%A great deal of fluctuation contain in the integrated wind power generation, which will result in voltage flicker on the point of common coupling. When wind farms are integrated into low-voltage distributions, the traditional reactive-power-based methods of flicker mitigation show their limits. Consequently, a novel energy storage-based method for the flicker mitigation purpose was proposed in this paper, in which a supercapacitor was selected as a storage medium, and the structure of the voltage source converter cascade bidirectional DC/DC converter was used in power conditioning system. The wind power through a low-pass filter was considered as the control objective, and the control strategy of the energy storage system was established to track the active power. Regarding a wind model with wind shear and tower shadow effects as the input, power fluctuation and flicker values were compared before and after the installation of storage system. The effectiveness of the scheme and corresponding control strategy were justified by the simulation results.