Harmonic Current Pattern Matching for Non-Intrusive Load Disaggregation
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Solution Overview
Problem
Existing non-intrusive power load monitoring methods face challenges in accurately identifying appliance operating states, especially when current waveforms of different appliances are similar, leading to decreased disaggregation accuracy and incorrect identification results, particularly for appliances with multiple operating states or continuously variable power.
Innovation Solution
A harmonic-characteristics based current pattern matching method that establishes a load signature database and uses a table looking-up approach to optimize the matching of actual total load current patterns with estimated ones, reducing the need for high computing performance and enabling precise appliance state recognition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional intrusive load monitoring equips every appliance with one sensor to track its power state, then the monitoring accuracy is improved, but the installation cost and system complexity increase significantly
Solution Approach 1:
The patent extracts the monitoring function from individual appliances and consolidates it at the service access point. Instead of installing sensors in each appliance, the system monitors total current at the service entrance and uses signal processing to extract individual appliance information, thereby reducing device complexity while maintaining monitoring accuracy
Solution Approach 2:
The patent introduces an intermediary processing layer between the total current measurement and individual appliance identification. The current waveform analysis and feature extraction modules act as intermediaries that decompose the aggregate current signal into individual appliance signatures, enabling accurate monitoring without direct appliance-level sensors
2Adaptability or versatility
If a large number of sensors with digital communication are deployed for intrusive monitoring, then the monitoring coverage is improved, but the expenditure and system complexity increase
Solution Approach 1:
The patent creates a universal monitoring system at the service access point that can identify and track multiple different appliances simultaneously. The single monitoring infrastructure serves multiple functions by detecting various appliance types through their unique current signatures, eliminating the need for appliance-specific sensors and communication systems
3Adaptability or versatility
If event-based load monitoring methods are used to identify appliance states, then the monitoring capability is improved, but the accuracy decreases when current waveforms of different appliances are similar
Solution Approach 1:
The patent transforms the monitoring approach from event-based detection to continuous waveform parameter analysis. By extracting multiple parameters including harmonic content, RMS values, and waveform shape characteristics, the system can distinguish between appliances with similar operating patterns, thereby improving disaggregation accuracy while maintaining versatile monitoring capability
4Measurement precision
If optimization algorithms are used for current pattern matching to achieve accurate disaggregation, then the measurement precision is improved, but the computational requirements and microprocessor performance needs increase
Solution Approach 1:
The patent performs preliminary action by pre-calculating and storing appliance current signatures and characteristic parameters in a database before actual monitoring. During operation, the system matches measured waveforms against these pre-computed references using simpler comparison algorithms, achieving accurate disaggregation with reduced real-time computational requirements and lower microprocessor performance needs
Data Source
AI summary
A harmonic-characteristics based current pattern matching method for the non-intrusive power load monitoring and disaggregation is provided in this present invention, on the basis of establishing the load signature database, which comprises electrical appliance registration and load state word space initialization, data acquisition and data preprocessing, feasible state word space search based on table looking-up, the optimal matching of current pattern, and display and output of the monitoring and disaggregation results. The method improves the accuracy of disaggregation, and can achieves exact identification of operating states of appliances, and also can reduce the cost.