A novel method of measuring the positive-sequence capacitance of T-connection transmission lines is proposed. The mathematical model of the new method is explained in detail. In order to obtain enough independent equa...A novel method of measuring the positive-sequence capacitance of T-connection transmission lines is proposed. The mathematical model of the new method is explained in detail. In order to obtain enough independent equations, three independent operation modes of T-connection transmission lines during the line measurement are introduced. The digital simulation results and field measurement results are shown. The simulation and measurement results have validated that the new method can meet the needs of measuring the positive-sequence capacitance of T-connection transmission lines. This method has been implemented in the newly developed measurement instrument.展开更多
The results of T-Line Traveling Wave Fault Location is easily influenced by the wave arrival time and traveling wave propagation velocity;it proposes that the traveling wave uses wavelet transform to extract the modul...The results of T-Line Traveling Wave Fault Location is easily influenced by the wave arrival time and traveling wave propagation velocity;it proposes that the traveling wave uses wavelet transform to extract the modulus maxima of breakdown voltage, to confirm the time of the traveling wave reaching the three-terminal line. The speed of the traveling wave reaching three terminals is confirmed by the structural parameters of the transmission line. We apply the arrival time and propagation velocity to the T-type traveling wave fault location algorithm. Different transmission line distance select the corresponding algorithm, excluding the impact of fault branches and in some cases ranging accuracy, the failure dead zone will not appear. After MATLAB simulation analysis, the algorithm analysis is clear;the range accuracy is high, so that it can meet the requirements of fault location.展开更多
The conjugate of T-connection in a Riemannian manifold is obtained, also some of its properties are studied. T-statistical manifold is defined and was considered. Finally a characteristic vector field of the deformati...The conjugate of T-connection in a Riemannian manifold is obtained, also some of its properties are studied. T-statistical manifold is defined and was considered. Finally a characteristic vector field of the deformation algebra （M, , ） is also obtained.展开更多
The integration of inverter-interfaced distributed generations(IIDGs)has modified the fault characteristics of active distribution networks(ADNs),substantially affecting the range,sensitivity,and reliability of conven...The integration of inverter-interfaced distributed generations(IIDGs)has modified the fault characteristics of active distribution networks(ADNs),substantially affecting the range,sensitivity,and reliability of conventional single-ended protection.Conventional current differential protection and existing waveform similarity-based protection methods suffer from poor tolerance to transition resistance and rely on simulations or field experiences for setting threshold values.To address these problems,this paper proposes a pilot protection method based on improved Fréchet distance by analyzing the differences in amplitude-phase characteristics of short-circuit currents during internal and external faults in ADNs with IIDGs.This method fully considers the physical significance of applying Fréchet distance to power-frequency current waveforms,offering a short operating time,high tolerance to transition resistance,and strong resistance to synchronization errors.Furthermore,a compensation criterion based on the positive-sequence current amplitude of the virtual T-connected branch is established to handle the impact of multiple unmeasurable T-connected branches.PSCAD simulations verify the effectiveness of the proposed method under different fault conditions and demonstrate its improvement over existing methods.Finally,a real-time digital simulator(RTDS)-based hardware test platform is used to further verify the developed differential relay prototypes based on the proposed method.展开更多
文摘A novel method of measuring the positive-sequence capacitance of T-connection transmission lines is proposed. The mathematical model of the new method is explained in detail. In order to obtain enough independent equations, three independent operation modes of T-connection transmission lines during the line measurement are introduced. The digital simulation results and field measurement results are shown. The simulation and measurement results have validated that the new method can meet the needs of measuring the positive-sequence capacitance of T-connection transmission lines. This method has been implemented in the newly developed measurement instrument.
文摘The results of T-Line Traveling Wave Fault Location is easily influenced by the wave arrival time and traveling wave propagation velocity;it proposes that the traveling wave uses wavelet transform to extract the modulus maxima of breakdown voltage, to confirm the time of the traveling wave reaching the three-terminal line. The speed of the traveling wave reaching three terminals is confirmed by the structural parameters of the transmission line. We apply the arrival time and propagation velocity to the T-type traveling wave fault location algorithm. Different transmission line distance select the corresponding algorithm, excluding the impact of fault branches and in some cases ranging accuracy, the failure dead zone will not appear. After MATLAB simulation analysis, the algorithm analysis is clear;the range accuracy is high, so that it can meet the requirements of fault location.
文摘The conjugate of T-connection in a Riemannian manifold is obtained, also some of its properties are studied. T-statistical manifold is defined and was considered. Finally a characteristic vector field of the deformation algebra （M, , ） is also obtained.
基金supported by the Natural Science Foundation of Shandong Province(No.ZR2025QC1158).
文摘The integration of inverter-interfaced distributed generations(IIDGs)has modified the fault characteristics of active distribution networks(ADNs),substantially affecting the range,sensitivity,and reliability of conventional single-ended protection.Conventional current differential protection and existing waveform similarity-based protection methods suffer from poor tolerance to transition resistance and rely on simulations or field experiences for setting threshold values.To address these problems,this paper proposes a pilot protection method based on improved Fréchet distance by analyzing the differences in amplitude-phase characteristics of short-circuit currents during internal and external faults in ADNs with IIDGs.This method fully considers the physical significance of applying Fréchet distance to power-frequency current waveforms,offering a short operating time,high tolerance to transition resistance,and strong resistance to synchronization errors.Furthermore,a compensation criterion based on the positive-sequence current amplitude of the virtual T-connected branch is established to handle the impact of multiple unmeasurable T-connected branches.PSCAD simulations verify the effectiveness of the proposed method under different fault conditions and demonstrate its improvement over existing methods.Finally,a real-time digital simulator(RTDS)-based hardware test platform is used to further verify the developed differential relay prototypes based on the proposed method.
