基于主从逆变器的无感消弧有源接地补偿系统

Non-inductive arc-suppression and active grounding compensation system based on master-slave inverters

设计了一种基于主从逆变器的无感消弧有源接地补偿系统,由补偿接地故障电流的基波分量与有功分量的主逆变器以及补偿谐波分量的从逆变器组成。在电网正常时,通过恒频注入法和不对称电压法综合计算得到故障电流的基波分量与有功分量;在电网发生单相接地后,检测流过中性点的故障电流,利用快速傅里叶算法提取出谐波分量,然后迅速投入主从逆变器进行补偿输出,实现故障电流的全补偿,从而使得残流在总体上达到一个较低的水平。计算机仿真验证了以上设计的可行性和有效性。

A non-inductive arc-suppression and active grounding compensation system based on master-slave inverters is designed to effectively compensate the active-power and harmonic components of grounding fault current,which is composed of a master inverter for compensating the fundamental and active components and a slave inverter for compensating the harmonic components. During normal operation,both constant frequency injection method and asymmetric voltage method are used to respectively measure the fundamental and active component of grounding fault current. When single-phase grounding fault occurs,the fault current at neutral point is detected and its harmonic component is extracted by FFT algorithm. The master and slave inverters are then quickly switched on to completely compensate the grounding fault current and keep the residual current at a lower level. The feasibility and effectiveness of the designed system are verified by computer simulations.