DC Residual Current Monitoring With Single Hall Sensor Cutoff
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Solution Overview
Problem
Existing DC switching devices for coupling DC loads to DC sources lack efficient fault current monitoring systems that require a minimal number of components, particularly failing to detect low-impedance earth fault currents effectively.
Innovation Solution
A method and device for fault current monitoring using a single Hall effect sensor to detect the magnetic field around positive and negative conductors, comparing it with a threshold value, and activating a switching element to decouple the DC load when the threshold is exceeded, utilizing a ferrite core and evaluation device to manage current flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple sensors are used to detect fault currents in DC circuits, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent combines the detection of both conductors (positive and negative) into a single sensor arrangement. The sensor detects the magnetic field generated by the current difference between the two conductors, effectively merging what would traditionally require separate detection systems into one unified sensor that monitors the residual current by measuring the magnetic field around both conductors simultaneously.
Solution Approach 2:
The single sensor serves multiple functions: it detects earth fault currents, monitors residual current, and provides fault location information. By making the sensor multi-functional, the patent eliminates the need for separate detection systems for different types of faults, thereby reducing device complexity while maintaining comprehensive monitoring capability.
2Reliability
If traditional fault current monitoring methods are used, then reliability is improved, but device complexity increases
Solution Approach 1:
The patent merges the sensor, evaluation device, and switching element into an integrated monitoring system. The sensor detects the magnetic field, the evaluation device processes the signal to determine if a fault condition exists, and the switching element acts to disconnect the conductor - all working together as a unified system that maintains high reliability through coordinated operation of integrated components.
Solution Approach 2:
The monitoring system is designed to be self-acting: when the sensor detects a residual current exceeding the threshold, the evaluation device automatically triggers the switching element to open the circuit. This self-service mechanism eliminates the need for external intervention or complex control systems, maintaining reliability through automatic protection while simplifying the overall device architecture.
3Device complexity
If a single sensor is used to detect fault currents, then device complexity is reduced, but measurement precision deteriorates
Solution Approach 1:
The patent introduces a magnetic field as an intermediary between the current-carrying conductors and the sensor. Instead of directly measuring current, the sensor detects the magnetic field generated by the current difference between conductors. This intermediary approach allows a single sensor to accurately measure residual current by detecting the magnetic field signature, maintaining measurement precision while reducing the number of sensors required.
Solution Approach 2:
The patent replaces direct electrical current measurement with magnetic field detection. By using a magnetic sensor to detect the magnetic field generated by residual current, the system achieves accurate fault detection without requiring multiple electrical sensors. This substitution of measurement methodology maintains precision while simplifying the sensor configuration to a single device.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables efficient detection of fault currents with minimal components, preventing dangerous earth fault currents and ensuring safe operation by decoupling the DC load, while accommodating tolerable current fluctuations and losses.
Implementation Method 1
the sensor, in particular a Hall effect sensor, is designed to detect a magnetic field forming overall around the positive conductor and the negative conductor
Implementation Method 2
utilizing a ferrite core and evaluation device to manage current flow
Data Source
Figure 1
Figure 2
Figure 3a~3b
AI summary
The invention relates to a method for residual current monitoring when electrically coupling a DC voltage load (200) to a DC voltage source (4) via a positive conductor (8) and a negative conductor (10). The invention relates in particular to a DC voltage switching device (100) for coupling a DC voltage load (200) to a DC voltage source (4) via a positive conductor (8) and a negative conductor (10). The positive conductor (8) and the negative conductor (10) are guided through the DC voltage switching device (100, 100a), which comprises a switching element (101, 106) for coupling and decoupling the DC voltage load (200) and comprises a sensor (116), in particular a Hall effect sensor, which is designed to detect a magnetic field that forms around the entirety of the positive conductor (8) and the negative conductor (10); and an evaluation apparatus (118) which is connected to the sensor (116) and the switching element (101, 106) and is designed to compare the detected magnetic field to a threshold value and to activate the switching element (101, 106) in order to decouple the DC voltage load when the threshold value is crossed.