A protection method for multi-terminal HVDC system based on fuzzy approach

This paper presents a Fuzzy Inference System (FIS)-based method to detect a fault, identify the faulty section, and recognize the faulty pole in the Voltage Source Converter (VSC)-based Multi-Terminal High Voltage Direct Current (MT-HVDC) system. The method uses only rectifier end measurements of voltage and current signals. To achieve complete protection of the MT-HVDC system, three separate frameworks of FIS modules have been developed. The FIS-1 detects the presence of fault in either AC or DC segments. The FIS-2 identifies the fault section and eventually, the FIS-3 recognizes the faulty pole. The proposed method provides a rapid fault detection and it does not require any communication media as it is based on the rectifier-end measurements only. The efficacy of the implemented FIS-based method is evaluated in an MT-HVDC system simulated in MATLAB environment. Important highlights of this method are:-: • FIS-based method is deployed using simple if-then rules, therefore very easy to implement. • Effortless means to exploit one end measurements of MTDC system in an environment accustomed to power engineer. • Proposed method provides a rapid fault detection and it does not require any communication link.