An improved single-terminal fault location method for inverter grid-connected system based on active control

Single-terminal fault location methods are easily affected by fault resistance and system parameters, and they always utilize iterative algorithm to solve fault distance. To improve their performance, an improved single-terminal fault location method for inverter system based on active control is proposed in this article, which can be used for symmetrical and asymmetrical faults. First, the problem that influences the performance of fault location method is analyzed. And to solve it, a control strategy that can create two fault statuses during fault stage is proposed. Then, using the electrical quantities under the different fault stages, two irrelevant equation groups can be established, and fault distance can be solved by single-terminal data. The PSCAD/EMTDC results demonstrate that the method can achieve fault location accurately, which just requires a small amount of calculation. And it is less affected by fault resistance and system parameters.