Single-Ended Fault Location Using Zero Sequence Phase Angle
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Solution Overview
Problem
Conventional fault location techniques in electric power transmission systems, especially those involving inverter-based renewable resources, face challenges in accuracy due to non-homogeneous impedance calculations during faults, particularly for resistive faults, and require measurements from both ends of the line, which is not always feasible.
Innovation Solution
A data processing system that determines fault location using single-ended measurements by processing zero sequence fault current and phase angles, allowing for accurate fault location determination even when measurements from the remote end are not available, and accounting for inverter-based resources without requiring their settings or parameters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional impedance-based fault location techniques are used, then fault location accuracy is improved for short lines, but measurement complexity and system configuration requirements increase
Solution Approach 1:
The patent extracts and utilizes only the near-end measurements (voltage and current at one end of the transmission line) to determine fault location, eliminating the need for remote-end measurements. This single-ended approach simplifies the measurement configuration while maintaining adequate accuracy for fault location, directly resolving the contradiction between measurement precision and device complexity.
Solution Approach 2:
The patent introduces an intermediary calculation approach using the relationship between near-end voltage, current, and fault current to bridge the gap between single-ended measurements and accurate fault location. By using the equation that relates these quantities, the system can determine fault location without direct remote measurements, thus reducing complexity while maintaining precision.
2Device complexity
If single-ended fault location methods are implemented, then device complexity is reduced, but fault location accuracy deteriorates due to non-homogeneous impedance calculations
Solution Approach 1:
The patent changes the approach by using the phase angle relationship between near-end voltage and current, combined with the fault current calculation, to account for impedance non-homogeneity effects. By transforming the problem into the phase angle domain and using the derived relationship equation, the system maintains accuracy despite the simplified single-ended measurement configuration.
3Productivity
If inverter-based renewable resources are integrated into the power system, then energy sustainability is improved, but fault location accuracy deteriorates due to controlled phase angle effects
Solution Approach 1:
The patent incorporates feedback by using the measured near-end voltage and current phasors to calculate the fault current and determine the phase angle relationship that accounts for IBR effects. The system continuously uses these measurements to adjust the fault location calculation, compensating for the controlled phase angle effects introduced by inverter-based resources, thus maintaining accuracy despite IBR integration.
Data Source
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AI summary
A data processing system (20) and method are operative to determine a fault location along a line (11) based on measurements performed at an end of the line. The data processing system (20) is operative to process the measurements to determine a zero sequence fault current and perform a fault location determination based on the zero sequence fault current. The zero sequence fault current has a zero sequence fault current phase angle. The fault location determination is performed based on the zero sequence fault current phase angle.