级联电池储能系统待机状态电位与电压分布特性

Potential and Voltage Distribution Characteristics of Cascade Battery Energy Storage System in Standby State

受电缆对地分布电容和电池簇对地分布电容的影响,待机状态下CHB-BESS主电路中流过的电流为较微弱的容性漏电流,回路阻抗大,其储能单元对地电位和交流侧出口电压分布与运行状态有很大不同。靠近并网点的储能单元交流侧电压为矩形波,有效值高;随着与并网点距离的增加,储能单元交流侧电压趋向于正弦波,且电压有效值逐渐减小。测量装置的输入阻抗对CHB-BESS待机状态的电位分布和交流侧出口电压分布也会产生严重影响,需要针对性地对相关设备或电路在待机状态的适应性进行评估方可保证安全。

Due to the influence of cable to ground distributed capacitance and battery cluster to ground distributed capacitance,the current flowing in CHB-BESS main circuit in standby mode is weak capacitive leakage current with large loop impedance.The distribution of energy storage unit to ground potential and AC side outlet voltage is very different from the operating state.The AC side voltage of the energy storage unit close to the grid connection point is rectangular wave,and the effective value is high.As the distance from the grid connection point increases,the AC side voltage of the energy storage unit tends to be sine wave,and the effective value of the voltage gradually decreases.The input impedance of the measuring device also has a serious impact on the potential distribution of the CHB-BESS standby state and the AC side outlet voltage distribution.It is necessary to evaluate the adaptability of related equipment or circuits in the standby state to ensure safety.