对称及不对称电网故障下的电池储能系统低电压穿越控制策略

摘要

为了兼顾储能系统（Energy Storage System, ESS）对称及不对称电压故障时低电压穿越（Low Voltage Ride Through， LVRT）需要，针对目前其PCS控制的一些不足，重点研究了其实现LVRT的控制方法。建立了PCS的正、负序复合数学模型，设计了双d-q不平衡控制策略实现正、负序电流的有效控制。在此基础上，通过指令切换来实现LVRT过程中的有功、无功电流的分配与限制。并用PSCAD对一84 kW的电池储能系统进行了仿真，仿真结果表明所建立的正负序复合模型以及控制方法能够满足电网电压对称及不对称故障时的LVRT要求。%In order to meet the requirement of low voltage ride through (LVRT) in the situation of both the balance and unbalance voltage fault in the energy storage system (ESS), considering the shortage of power conversion system (PCS), the LVRT control methods are studied, a positive-negative sequence composite mathematical model is built, a double d-q unbalance control strategy is designed and the positive-negative sequence current is controlled effectively. Based on that, the active and reactive current during the LVRT is distributed and limited through reference switching. At last simulation of a battery module (84 kW) in the case of grid fault based on the PSCAD is conducted, and the results show that the mathematical model built and the control method studied can meet the needs of the LVTR under both balance and unbalance grid fault. This work is supported by National Natural Science Foundation of China (No. 50807012).