Commutation Failures Caused by DC Line Faults in Double-Circuit LCC-HVDC Transmission Lines

2018 ◽  
Author(s):  
Yanjun MA ◽  
Haifeng LI ◽  
Gang Wang
Keyword(s):  
Transmission Lines ◽  
Hvdc Transmission ◽  
Hvdc Transmission Lines ◽  
Dc Line

scholarly journals A Novel Pilot Protection Principle Based on Modulus Traveling-Wave Currents for Voltage-Sourced Converter Based High Voltage Direct Current (VSC-HVDC) Transmission Lines

Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2395 ◽  
Author(s):  
Xiangyu Pei ◽  
Guangfu Tang ◽  
Shengmei Zhang
Keyword(s):  
High Voltage ◽  
Direct Current ◽  
Transmission Lines ◽  
Traveling Wave ◽  
Hvdc Transmission ◽  
High Voltage Direct Current ◽  
Hvdc Transmission Lines ◽  
Dc Line ◽  
Voltage Sourced Converter ◽  
Pilot Protection

Protection for transmission lines is one of crucial problems that urgently to be solved in constructing the future high-voltage and large-capacity voltage-sourced converter based high voltage direct current (VSC-HVDC) systems. In order to prevent the DC line fault from deteriorating further due to the failure of main protection, a novel pilot protection principle for VSC-HVDC transmission lines is proposed in this paper. The proposed protection principle is based on characteristics of modulus traveling-wave (TW) currents. Firstly, the protection starting-up criterion is constructed by using the absolute value of the 1-mode TW current gradient. Secondly, the fault section identification is realized by comparing the polarities of wavelet transform modulus maxima (WTMM) of 1-mode initial TW currents acquired from both terminals of the DC line. Then, the selection of fault line is actualized according to the polarity of WTMM of local 0-mode initial reverse TW current. A four-terminal VSC-based DC grid electromagnetic transient model based on the actual engineering parameters is built to assess the performance of the proposed pilot protection principle. Simulation results for different cases prove that the proposed pilot protection principle is excellent in reliability, selectivity, and robustness. Moreover, the data synchronization is not required seriously. Therefore, the proposed novel pilot protection principle can be used as a relatively perfect backup protection for VSC-HVDC transmission lines.

scholarly journals Locating Faults in Thyristor-Based LCC-HVDC Transmission Lines Using Single End Measurements and Boosting Ensemble

Electronics ◽  
2022 ◽  
Vol 11 (2) ◽  
pp. 186
Author(s):  
Aleena Swetapadma ◽  
Shobha Agarwal ◽  
Satarupa Chakrabarti ◽  
Soham Chakrabarti ◽  
Adel El-Shahat ◽  
...  
Keyword(s):  
Direct Current ◽  
Transmission Lines ◽  
Fault Location ◽  
Ensemble Method ◽  
Percentage Error ◽  
Communication Link ◽  
Half Cycle ◽  
Optimal Method ◽  
Hvdc Transmission ◽  
Hvdc Transmission Lines

Most of the fault location methods in high voltage direct current (HVDC) transmission lines usemethods which require signals from both ends. It will be difficult to estimate fault location if the signal recorded is not correct due to communication problems.Hence a robust method is required which can locate fault with minimum error. In this work, faults are located using boosting ensembles in HVDC transmission lines based on single terminal direct current (DC) signals. The signals are processed to obtain input features that vary with the fault distance. These input features are obtained by taking maximum of half cycle current signals after fault and minimum of half cycle voltage signals after fault from the root mean square of DC signals. The input features are input to a boosting ensemble for estimating the location of fault. Boosting ensemble method attempts to correct the errors from the previous models and find outputs by combining all models. The boosting ensemble method has been also compared with the decision tree method and thebagging-based ensemble method. Fault locations are estimated using three methods and compared to obtain an optimal method. The boosting ensemble method has better performance than all the other methods in locating the faults. It also validated varying fault resistance, smoothing reactors, boundary faults, pole to ground faults and pole to pole faults. The advantage of the method is that no communication link is needed. Another advantage is that it allowsreach setting up to 99.9% and does not exhibitthe problem of over-fitting. Another advantage is that the percentage error in locating faults is within 1% and has a low realization cost. The proposed method can be implemented in HVDC transmission lines effectively as an alternative to overcome the drawbacks of traveling wave methods.

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