Microgrid Fault Localization Using Voltage-Current Classification
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Solution Overview
Problem
Existing power system protection schemes struggle to accurately detect and localize faults in microgrids with high penetration of distributed energy resources, particularly due to limited fault current contributions and intermittent behavior of renewable energy sources, leading to reliability and effectiveness issues.
Innovation Solution
The implementation of a device with a processor configured to use a classification model for fault detection and localization, leveraging real-time voltage and current measurements, and employing SVM-based classifiers to differentiate between upstream and downstream faults, along with hierarchical and distributed approaches for fault localization, ensuring timely and accurate fault identification and isolation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If pre-defined threshold protection schemes are used, then device complexity is reduced and ease of operation is improved, but measurement precision and reliability deteriorate due to reduced appropriateness with distributed energy resources
Solution Approach 1:
The patent transforms the protection scheme from using fixed pre-defined thresholds to using dynamic, learned parameters through machine learning classification models. The system extracts multiple features (positive sequence, negative sequence, zero sequence components) and uses learned decision boundaries instead of static thresholds, allowing the parameters to adapt to varying system conditions with distributed energy resources.
Solution Approach 2:
The patent replaces the traditional mechanical/electrical threshold-based protection mechanism with an intelligent software-based classification system. Instead of relying on hardware-defined fixed thresholds, the system uses machine learning models (such as support vector machines, neural networks) to perform classification and decision-making, substituting the mechanical threshold comparison with computational intelligence.
2Measurement precision
If machine learning classification models are implemented, then measurement precision and reliability are improved, but device complexity increases
Solution Approach 1:
The patent segments the complex protection problem into distinct feature extraction stages and classification stages. The system separately extracts positive sequence, negative sequence, and zero sequence features, then feeds these segmented features into classification models. This segmentation allows the complex task to be divided into manageable, modular components that can be implemented and maintained more easily.
Solution Approach 2:
The patent introduces feature extraction as an intermediary layer between raw measurements and final protection decisions. Instead of directly comparing raw signals to thresholds, the system first transforms measurements into meaningful features (sequence components, harmonics), then uses these intermediate representations for classification. This intermediary processing simplifies the overall system by creating a structured bridge between sensing and decision-making.
3Reliability
If fault localization using upstream/downstream classification is implemented, then reliability is improved through accurate fault identification, but loss of time increases due to additional processing requirements
Solution Approach 1:
The patent performs preliminary classification of fault direction (upstream or downstream) as part of the initial fault detection process. By determining the fault direction early in the protection scheme, the system enables faster fault localization without requiring additional sequential processing steps. This preliminary action on fault direction classification allows the system to quickly identify which side of a protective device the fault is on, reducing overall response time.
Data Source
AI summary
An example device includes at least one processor configured to determine, based on a value of a voltage and a value of a current at a location of an electrical power system, a plurality of voltage features and a plurality of current features corresponding to the location. The at least one processor may be further configured to determine, based on the plurality of voltage features and the plurality of current features, using a classification model, whether a fault has occurred in the electrical power system and responsive to determining that a fault has occurred, causing a protective device in the electrical power system to trip.


