Determining the fault location using conventional impedance based distance relay in the presence of FACTS controllers is a challenging task in a transmission line. A new distance protection method is developed to loca...Determining the fault location using conventional impedance based distance relay in the presence of FACTS controllers is a challenging task in a transmission line. A new distance protection method is developed to locate the fault in a transmission line compensated with STATCOM with simple calculations. The proposed protection method considers the STATCOM injected/absorbed current to correct the fault loop apparent impedance and accordingly calculates the actual distance to the fault location. The comprehensive equations needed for apparent impedance calculation are also outlined and the performance is evaluated and tested with a typical 400 KV transmission system for different fault types and locations using MATLAB/SIMULINK software. The evaluation results indicate that the new protection method effectively estimates the exact fault location by mitigating the impact of STATCOM on distance relay performance with error less than 0.3%.展开更多
Distance relays are prone to symmetrical power swing phenomenon.To mitigate this issue,a dynamic threshold-supported algorithm is proposed.A single logic is not supposed to be secure for all cases.Thus,a supervisory a...Distance relays are prone to symmetrical power swing phenomenon.To mitigate this issue,a dynamic threshold-supported algorithm is proposed.A single logic is not supposed to be secure for all cases.Thus,a supervisory algorithm,as proposed in this study,can aid in the improvement of the immunity of the relay during swing cases and be sensitive to symmetrical faults.In the developed stages,a three-phase power signal was used and processed in two different steps:(i)extraction of the effective intrinsic mode function(IMF)selected from the Kurtosis analysis using the wavelet synchro-squeezing transform,and(ii)estimation of the average Euclidean distance index using the absolute values of the decomposed IMF’s.The adaptive threshold facilitated resistance to swing situations.At the onset of a symmetrical fault,the proposed algorithm efficiently discriminated among events using a dynamic threshold.The IEEE 39-bus test system and Indian Eastern Power Grid networks were modelled using PSCAD software,and cases were generated to test the efficacy of the method.The impact of the proposed method on a large-scale wind farm was also evaluated.A comparative analysis with other existing methods revealed the security and dependability of the proposed method.展开更多
Power swing is an undesirable variation in power flow. This can be caused by large disturbances in demand load, switching, disconnection or reclosing lines. This phenomenon may enter the zones of distance relays and c...Power swing is an undesirable variation in power flow. This can be caused by large disturbances in demand load, switching, disconnection or reclosing lines. This phenomenon may enter the zones of distance relays and cause relay malfunction leading to the disconnection of healthy lines and undermining network reliability. Accordingly, this paper presents a new power swing detection method based on the prediction of current signal with a GMDH (Group Method of Data Handling) artificial neural network. The main advantage of the proposed method over its counterparts is the immunity to noise effect in signals. In addition, the proposed method can detect stable, unstable, and multi-mode power swings and is capable of distinguishing them from the variety of permanent faults occurring simultaneously. The method is tested for different types of power swings and simultaneous faults using DIgSILENT and MATLAB, and compared with some latest power swing detection methods. The results demonstrate the superiority of the proposed method in terms of response time, the ability to detect power swings of different varieties, and the ability to detect different faults that may occur simultaneously with power swings.展开更多
文摘Determining the fault location using conventional impedance based distance relay in the presence of FACTS controllers is a challenging task in a transmission line. A new distance protection method is developed to locate the fault in a transmission line compensated with STATCOM with simple calculations. The proposed protection method considers the STATCOM injected/absorbed current to correct the fault loop apparent impedance and accordingly calculates the actual distance to the fault location. The comprehensive equations needed for apparent impedance calculation are also outlined and the performance is evaluated and tested with a typical 400 KV transmission system for different fault types and locations using MATLAB/SIMULINK software. The evaluation results indicate that the new protection method effectively estimates the exact fault location by mitigating the impact of STATCOM on distance relay performance with error less than 0.3%.
文摘Distance relays are prone to symmetrical power swing phenomenon.To mitigate this issue,a dynamic threshold-supported algorithm is proposed.A single logic is not supposed to be secure for all cases.Thus,a supervisory algorithm,as proposed in this study,can aid in the improvement of the immunity of the relay during swing cases and be sensitive to symmetrical faults.In the developed stages,a three-phase power signal was used and processed in two different steps:(i)extraction of the effective intrinsic mode function(IMF)selected from the Kurtosis analysis using the wavelet synchro-squeezing transform,and(ii)estimation of the average Euclidean distance index using the absolute values of the decomposed IMF’s.The adaptive threshold facilitated resistance to swing situations.At the onset of a symmetrical fault,the proposed algorithm efficiently discriminated among events using a dynamic threshold.The IEEE 39-bus test system and Indian Eastern Power Grid networks were modelled using PSCAD software,and cases were generated to test the efficacy of the method.The impact of the proposed method on a large-scale wind farm was also evaluated.A comparative analysis with other existing methods revealed the security and dependability of the proposed method.
文摘Power swing is an undesirable variation in power flow. This can be caused by large disturbances in demand load, switching, disconnection or reclosing lines. This phenomenon may enter the zones of distance relays and cause relay malfunction leading to the disconnection of healthy lines and undermining network reliability. Accordingly, this paper presents a new power swing detection method based on the prediction of current signal with a GMDH (Group Method of Data Handling) artificial neural network. The main advantage of the proposed method over its counterparts is the immunity to noise effect in signals. In addition, the proposed method can detect stable, unstable, and multi-mode power swings and is capable of distinguishing them from the variety of permanent faults occurring simultaneously. The method is tested for different types of power swings and simultaneous faults using DIgSILENT and MATLAB, and compared with some latest power swing detection methods. The results demonstrate the superiority of the proposed method in terms of response time, the ability to detect power swings of different varieties, and the ability to detect different faults that may occur simultaneously with power swings.
