1. Multiterminal DC Fault Identification for MMC-HVDC Systems Based on Modal Analysis—A Localized Protection Scheme
- Author
-
Nougain, Vaibhav, Mishra, Sukumar, Misyris, George S., and Chatzivasileiadis, Spyros
- Subjects
DC fault ,Computer science ,business.industry ,Modal analysis ,Energy Engineering and Power Technology ,High voltage ,Hardware_PERFORMANCEANDRELIABILITY ,Modular design ,Fault (power engineering) ,Localized protection ,Power (physics) ,Fault identification ,Robustness (computer science) ,Control theory ,Electrical and Electronic Engineering ,MMC-HVDC ,business ,Voltage ,Current limiting reactor - Abstract
For the purpose of DC fault identification in multi-terminal modular multilevel converter (MMC) high voltage DC (HVDC) systems, the proposed work addresses the issues of localized protection schemes. The proposed work is focused on selectivity issues such as differentiating between forward external and internal faults, and classification of type of fault contingency i.e., pole to pole (PTP) or pole to ground (PTG) in the system. The scheme uses equivalent network of multi-terminal MMC-HVDC systems for DC fault identification. Modal transformation is used to analyse line-mode and zero-mode voltage across the current limiting reactor (CLR) for different possible contingencies in the system. A maloperation region has been defined to address the issue of selectivity of internal HIFs and external low impedance faults (LIFs). Rate of change of DC voltage (dUdc/dt) is used as the mitigation technique to differentiate a HIF as high as 1000Ω. Further, a sensitivity function is formulated which gives the variation of decisive parameters i.e., line-mode voltage and zero-mode voltage with respect to change in fault resistance and value of current limiting reactor. PSCAD/EMTDC based simulations are used to validate the performance of the proposed scheme. The scheme is validated in terms of detection time, robustness to WGN in measurement, security for AC faults, DC circuit breakers (DCCB) operation, power reversal (load transients).
- Published
- 2021