Electric Appliance Monitor Using Complex Load Current Coordinates
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Solution Overview
Problem
Existing electric appliance monitoring systems fail to accurately detect abnormal states and aging conditions, leading to potential unnoticed failures and further damages, as they rely solely on scalar parameters like power, voltage, and current, which do not effectively capture the impedance changes indicative of appliance health.
Innovation Solution
The method and system utilize a reflection coefficient of the electric appliance's properties to determine abnormal states and aging conditions by calculating and displaying the real and imaginary parts of the load current on a real-imaginary current coordinate system, allowing for timely intervention and maintenance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If scalar parameters (power, voltage, current) are used for monitoring, then the monitoring system is simple to implement, but the detection precision of abnormal states and aging conditions is insufficient
Solution Approach 1:
The patent transforms scalar electrical parameters (power, voltage, current) into complex impedance parameters with real and imaginary components. By calculating the real part (active impedance) and imaginary part (reactive impedance) of the load current, the system captures both magnitude and phase information, enabling detection of impedance changes that indicate aging or abnormal states without requiring complex additional hardware
Solution Approach 2:
The patent adds a dimensional transformation by representing the load current in a two-dimensional complex plane with real and imaginary axes. This dimensional expansion from scalar to complex representation allows the system to detect subtle changes in electrical characteristics that are invisible in single-dimensional scalar measurements, thereby improving detection precision while maintaining implementation simplicity
2Reliability
If traditional monitoring methods are used, then the system is easy to operate, but the reliability of detecting aging conditions is low
Solution Approach 1:
The patent establishes a feedback mechanism where the calculated real and imaginary parts of the load current continuously monitor the appliance's electrical characteristics. By comparing these parameters against threshold values or historical data, the system provides feedback on the appliance's health status, enabling reliable detection of aging conditions through automated analysis rather than manual inspection
Solution Approach 2:
The monitoring system performs self-service by automatically calculating complex impedance parameters and detecting abnormal states without requiring user intervention. The system autonomously processes the electrical parameters, identifies aging conditions, and can trigger protection mechanisms, making the reliable detection of aging conditions accessible through simple operation
3Measurement precision
If complex impedance parameters are calculated and displayed, then the detection accuracy of abnormal states improves, but the device complexity increases
Solution Approach 1:
The patent extracts only the essential components needed for aging detection from the full complex impedance spectrum. By focusing specifically on the real part (active impedance) and imaginary part (reactive impedance) of the load current, the system isolates the most relevant parameters for detecting aging conditions, avoiding the complexity of analyzing the entire impedance spectrum while maintaining high detection accuracy
Data Source
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AI summary
An electric appliance monitor method and an monitor system are provided. The method includes the following steps. In a sampling period, data of an electric appliance is transmitted to a cloud server, and a load boundary is determined. The electric appliance is detected to obtain a measured power factor, a measured root-mean-square voltage and a measured power. Further, a supply frequency of an electric supply is recognized. Based on the measured data, a real part and an imaginary part of the load current related to a reflection coefficient of the electric appliance during the current usage state is calculated. On a real-imaginary current coordinate system, the load boundary and a coordinated point representing to the real part and imaginary part of the load current are displayed. Whether to execute a protection process is determined according to the load boundary, the real part and the imaginary part of the load current.