Leakage Current Protection Device Using Digital Signal Processing
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Solution Overview
Problem
Conventional electronic protection devices against earth leakage currents in low-voltage electric lines face challenges such as high power consumption, large dimensions, limited flexibility, and increased production costs due to complex algorithms and the need for high-performance microcontrollers, which also result in longer tripping times for high leakage currents.
Innovation Solution
The electronic protection device employs digital processing means with a microcontroller to acquire and process residual current samples, using concise and straightforward procedures to generate a control logic signal, reducing the need for high calculation power and allowing for flexible adaptation to installation requirements, thereby minimizing power consumption and overall size while simplifying manufacturing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If complex algorithms are used to process residual current samples, then measurement precision is improved, but device complexity and power consumption increase
Solution Approach 1:
The processing algorithm is segmented into distinct functional stages: signal acquisition from current sensor, analog-to-digital conversion, threshold comparison logic, and tripping signal generation. Each stage performs a specific function with simple, deterministic operations rather than complex continuous calculations.
Solution Approach 2:
The patent extracts only the essential information from the residual current signal by comparing it against predetermined thresholds, rather than performing comprehensive analysis. This extraction approach focuses solely on detecting whether leakage current exceeds safe levels, eliminating unnecessary computational complexity.
2Reliability
If high-performance microcontrollers are used to ensure optimal performance, then reliability is improved, but power consumption and cost increase
Solution Approach 1:
The patent employs a low-performance, cost-effective microcontroller that consumes minimal power, accepting that it has limited computational capabilities. This approach trades computational performance for energy efficiency and cost reduction, which is appropriate given the relatively simple processing requirements of the protection device.
Solution Approach 2:
The patent changes the operational parameters of the microcontroller by implementing sleep modes and activating processing only when necessary (when residual current exceeds thresholds). This reduces average power consumption while maintaining reliability during critical detection periods.
3Measurement precision
If complex processing algorithms are implemented, then measurement precision is improved, but tripping time increases
Solution Approach 1:
The patent performs preliminary actions by continuously monitoring residual current and pre-calculating threshold values before actual leakage events occur. When leakage current exceeds predetermined thresholds, the system can immediately trigger tripping without requiring complex real-time calculations, thus reducing tripping time.
Solution Approach 2:
The patent implements a streamlined processing path that skips unnecessary computational steps. When residual current exceeds thresholds, the system rushes through the minimal necessary operations (comparison and signal generation) to achieve rapid tripping, rather than performing comprehensive analysis.
4Adaptability or versatility
If dedicated product lines are created for each functionality, then adaptability is improved, but manufacturing cost increases
Solution Approach 1:
The patent implements a universal electronic protection device platform that can perform multiple functions through software configuration rather than hardware differentiation. The same microcontroller and processing architecture can be programmed to provide different tripping characteristics, auxiliary functionalities, and adaptation to various installation requirements, eliminating the need for separate dedicated product lines for each function.
Data Source
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AI summary
The present invention relates to an electronic protection device (1) against earth leakage currents for a low-voltage electric line (5). The electronic protection device comprises an electronic stage complete with digital data processing means (30). These digital data processing means implement a processing procedure (10) on a series (ID) of samples (VN), indicative of the residual current detected between two conductors on said electric line. Said processing procedure enables information (11) to be obtained on the period of said series of samples (ID) and on the amplitude dynamics of said series of samples (ID) by comparison with a preset reference value (ID0). Said processing means generate a control logic signal (IC) based on said information acquired by means of said processing procedure. In a further aspect, the present invention also refers to a procedure for detecting earth leakage currents for an electronic protection device.