Abstract
The integration of a modular multilevel converter-based high-voltage direct current (MMC-HVDC) transmission system in power networks has led to a high requirement for the rapidity of fault recognition. This study focused on the rapid fault diagnosis of an alternating current (AC) line fault in a back-to-back (BTB) MMC-HVDC system via fault detection and classification. Discrete wavelet transform and modulus maxima were applied to extract the fault features. Phase-mode transformation and normalization were adopted to widen the application range. Simulation and calculation results indicated that the proposed method can detect all fault types in an AC transmission line on the basis of single-side fault information within 1 ms under different values of transition resistance, fault inception angle, and fault distance. The BTB MMC-HVDC model was built using real-time laboratory (RT-LAB) based on the matrix laboratory (MATLAB) software platform, and the fault diagnosis algorithm was performed in MATLAB.
Highlights
Owing to the weakness of electronic devices in modular multilevel converter-based high-voltage direct current (MMC-HVDC) transmission systems, the required fault detection time is considerably lower in these systems than in alternating current (AC) transmission systems to prevent damage to electronic components caused by overcurrent scenarios
The single-line grounded (SLG) fault was simulated in the BTB-HVDC model built using real-time laboratory (RT-LAB) (11.0) and matrix laboratory (MATLAB) (2011b)
The feasibility of the proposed method is verified by performing numerous simulation tests, which revealed that such a method can detect faults within 0.2 ms and classify AC line fault types within 1 ms
Summary
Owing to the weakness of electronic devices in modular multilevel converter-based high-voltage direct current (MMC-HVDC) transmission systems, the required fault detection time is considerably lower in these systems than in AC transmission systems to prevent damage to electronic components caused by overcurrent scenarios. Several mitigation schemes, such as increasing the bridge inductance and changing the circuit structure, have been proposed to save extra time for the fault relay. Fault diagnosis, as the first step in fault protection in the MMC-HVDC, still requires a faster method than existing detection methods.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
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 call
