Abstract
This paper presents a novel fault location scheme of DC line in modular multilevel converter (MMC)-based multi-terminal DC (MTDC) grids. Considering the low-inertia characteristics and the meshed topology, the scheme, based on traveling-wave principle, is divided into three steps, namely, faulty pole identification, faulty segment determination and fault-distance calculation. With accurate amplitude, polarities and arrival times of the first arrival current traveling waves (FACTWs) collected from time-synchronized measurements taken just at the converter stations, the proposed scheme can correctly determine the faulty pole, the faulty segment and the precise fault location. The continuous wavelet transform (CWT) is deployed to extract the required features of the input signals at the DC lines. Since the scheme merely needs the features of FACTWs, the practical difficulties of detecting subsequent traveling waves are avoided. A four-terminal MMC-based high voltage direct current (HVDC) grid was built in PSCAD/EMTDC software to evaluate the performance of the fault-location scheme. Simulation results for different cases demonstrate that the proposed fault-location scheme has high accuracy, good adaptability and reliability. Furthermore, the algorithm can be used for a MMC-MTDC grid with any number of meshes.
Highlights
Voltage source converter (VSC)-based high voltage direct current (HVDC) technology has become a focus for scholars all over the world, because the technology has the advantages of controlling active and reactive power independently, reversing power flow without changing voltage polarity, supplying power for passive networks, etc. [1,2]
Since modular multilevel converter (MMC) has the advantages of higher quality of output waveform, lower switching frequency and power loss and higher reliability, it has been regarded as an excellent choice for bulk power transmission, especially for multi-terminal direct current (MTDC) grid
The fault location method based on the distributed parameter model proposed in [12] has a good applicability to the two-terminal MMC-HVDC transmission line, and the accuracy of fault location is high, but it is difficult to extend to the multi-terminal MMC-based MTDC grid
Summary
Voltage source converter (VSC)-based high voltage direct current (HVDC) technology has become a focus for scholars all over the world, because the technology has the advantages of controlling active and reactive power independently, reversing power flow without changing voltage polarity, supplying power for passive networks, etc. [1,2]. The fault location method based on the distributed parameter model proposed in [12] has a good applicability to the two-terminal MMC-HVDC transmission line, and the accuracy of fault location is high, but it is difficult to extend to the multi-terminal MMC-based MTDC grid. It is able to figure out the exact fault location The method uses both voltage and current measurements obtained at the converter stations to identify the faulty line for protection purposes.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
