基于无功控制的光伏逆变器三相不平衡抑制方法

Three Phase Unbalance Suppression Method of Photovoltaic Inverter Based on RPC Control

随着分布式光伏的推广,配电网转变为多源荷共存网络,使得电网潮流与电压分布特征更为复杂,更易出现三相不平衡状况。为解决配电网三相不平衡状态下分布式光伏出力波动问题,提出了一种基于无功控制(reactive power control,RPC)的光伏逆变器三相不平衡抑制方法,实现配电网三相不平衡补偿与分布式光伏有功功率的输出稳定,由此保证光伏发电机组的连续运行,保障配电网可靠运行。在PSCAD/EMTDC平台搭建仿真模型,仿真结果表明,所提控制策略能有效地抑制三相不平衡,实现并网有功功率稳定。该策略的实施将保证光伏发电机组的连续运行,从而实现配电网和整个电网的安全可靠运行。

With the popularization of distributed photovoltaic,the power distribution network has been transformed into a multiple-source load coexistence network,which complicates the characteristics of power flow and voltage distribution and makes it prone to have three-phase imbalance.In order to solve the problem of distributed photovoltaic output fluctuation in the three-phase unbalanced distribution network,this paper proposes a three-phase imbalance suppression method for the photovoltaic inverter to realize the unbalanced three-phase compensation and the stable active power output of distributed photovoltaic,so as to ensure the continuous operation of photovoltaic generating units and the reliable operation of the distribution network.The effectiveness of the control strategy is verified by building a simulation model on the PSCAD/EMTDC platform.