Fault Passage Indication Using Current-Only Power Delta Integration
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Solution Overview
Problem
Existing fault passage identification algorithms in AC distribution networks require costly modifications to substations for voltage measurements and have prolonged faulty section identification times.
Innovation Solution
A method that determines phase current delta values and calculates power delta values for each phase, integrating these over a time window to indicate a fault passage based on predetermined thresholds, without the need for voltage measurements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If voltage measurement together with current measurement is used for fault passage indication, then measurement precision is improved, but device complexity and cost increase due to required substation modifications
Solution Approach 1:
The patent extracts the voltage measurement requirement from the fault detection system, achieving accurate fault passage indication using only current measurements. By removing the voltage measurement component and deriving the necessary information from current delta values and power calculations, the system maintains measurement precision while eliminating complex substation modifications.
Solution Approach 2:
The patent introduces power delta values as an intermediary parameter that bridges the gap between simple current measurements and accurate fault detection. By calculating power delta from current measurements and integrating them over time windows, the system achieves voltage-level detection accuracy without requiring actual voltage measurements, thus resolving the contradiction between precision and complexity.
2Reliability
If existing fault passage identification algorithms are implemented, then fault detection capability is improved, but loss of time increases due to prolonged faulty section identification
Solution Approach 1:
The patent performs preliminary integration of power delta values over time windows continuously, so that when a fault occurs, the system can immediately compare the pre-calculated integrated values against thresholds. This preliminary preparation eliminates computational delays during actual fault detection, maintaining high reliability while reducing identification time.
Solution Approach 2:
The patent uses a streamlined algorithm that skips complex iterative computations by directly comparing integrated power delta values against predetermined thresholds. This approach rushes through the fault identification process by eliminating unnecessary calculation steps, thereby reducing loss of time while maintaining accurate fault detection capability.
3Measurement precision
If voltage measurement infrastructure is deployed in all substations, then measurement precision is improved, but loss of substance increases due to higher infrastructure costs
Solution Approach 1:
The patent replaces expensive, long-term infrastructure investments (voltage measurement equipment in all substations) with a computationally intensive but financially lightweight solution. By using existing current measurement infrastructure and processing data through software algorithms, the system achieves the same measurement precision without the substantial capital expenditure required for physical voltage measurement deployment.
Data Source
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Figure 2B
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AI summary
There is disclosed herein a method 100 for fault passage indication in a substation 20 of an alternating current, AC, distribution network 2 having a plurality of phases 2a-c. The method comprises determining 110 a phase current delta value for each phase and calculating 120 a power delta value for each phase based on the determined phase current delta values. The method further comprises integrating 130 each of the power delta values over a time window and determining 140 whether one of the integrated power delta values exceeds a predetermined threshold and the remaining integrated power delta values are below the predetermined threshold within said time window, and if so, indicating a fault passage. There is also disclosed herein a fault passage indicator device 10 and a feeder line 30.