基于自适应虚拟阻抗的交流微电网无功功率-电压控制策略

摘要

微电网作为分布式电源的有效载体,是分布式能源合理利用的有效途径.而在微电网中,由于物理线路阻抗不匹配等因素的影响,传统的下垂控制难以合理分配无功功率.为了改善无功分配的精度,提出一种基于自适应虚拟阻抗的微电网无功功率电压控制策略.该方案在传统的虚拟阻抗基础上叠加自适应项,从而修改电压参考值;同时,通过电压恢复机制来补偿由此造成的输出电压的降低.仿真和实验结果实现了负荷有功和无功功率的合理均分,从而验证了所提控制策略的可行性和有效性.%As an effective carrier of distributed generation,microgrid is an effective way to ensure the distributed power reasonable utilization.However,due to the mismatch of line impedance and other factors in microgrid,reactive power supplied by distributed generation units cannot be shared reasonably.In order to share the reactive power accurately,this paper proposes a reactive power-voltage control strategy based on adaptive virtual impedance.This method changes the voltage reference value by adding an adaptive term based on the traditional virtual impedance.Meanwhile,a voltage recovery mechanism is used to compensate the output voltage of distributed generator in the process.Simulations and experimental results show that the proposed controller can achieve reasonable sharing of active and reactive power of load,and the feasibility and effectiveness of the proposed control strategy are verified.