Sensor Unit Fault Current Detection During Charging Phase
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Solution Overview
Problem
Current sensor units in energy supply networks cannot detect fault currents during the charging phase, leading to delayed fault detection and localization, especially in low-voltage networks, which hampers efficient network operation and customer safety.
Innovation Solution
A sensor unit with a current transformer, load resistor, energy buffer, and electronic unit that monitors and evaluates charging voltage to detect fault currents during both measuring and charging phases, allowing continuous monitoring and quick fault localization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the sensor unit uses a current transformer to charge the energy buffer during the charging phase, then the internal power supply is maintained, but fault currents cannot be detected during the charging phase
Solution Approach 1:
The patent divides the operational cycle into distinct measuring phases and charging phases. During measuring phases, the current transformer connects to the load resistor for fault current detection. During charging phases, the current transformer connects to the energy buffer for power supply recharging. This segmentation allows each phase to be optimized for its specific function while maintaining overall system reliability through continuous monitoring capability.
Solution Approach 2:
The patent implements dynamic switching between different operational modes using switching elements controlled by an electronic unit. The system can transition between measuring phases and charging phases based on energy buffer status and fault detection needs. This dynamic operation allows the sensor unit to maintain both power supply functionality and fault detection capability across different operational states.
2Loss of time
If the sensor unit operates in alternating measuring and charging phases, then energy self-sufficiency is achieved, but continuous fault monitoring is compromised
Solution Approach 1:
The electronic unit continuously monitors the energy buffer status and automatically controls the switching between measuring and charging phases. This feedback mechanism ensures that the system maintains optimal operational cycles without external intervention. The electronic unit adjusts the phase timing based on energy levels, ensuring continuous fault monitoring capability while maintaining energy self-sufficiency.
Solution Approach 2:
The sensor unit is designed to be self-sufficient by using the current transformer to recharge the energy buffer during charging phases. The system automatically manages its own power supply needs through the electronic unit, which monitors energy levels and switches phases accordingly. This self-service capability eliminates the need for external power sources or manual intervention, reducing operational complexity while maintaining continuous monitoring.
3Measurement precision
If fault detection is only possible during measuring phases, then the measurement precision is high, but the productivity of fault localization is reduced
Solution Approach 1:
The system performs preliminary fault detection during both measuring and charging phases. During charging phases, the electronic unit monitors energy buffer characteristics that can indicate fault conditions. This preliminary detection during charging phases allows the system to prepare for rapid fault localization when a measuring phase occurs, improving overall productivity without compromising measurement precision during dedicated measuring phases.
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 the detection of fault currents and de-energized conductors during the charging phase, facilitating rapid fault localization and minimizing disruptions, thus ensuring safety and reducing the impact on customers.
Implementation Method 1
a current transformer, which is used in a measuring phase to determine a current in the conductor to be monitored
Implementation Method 2
in the charging phase to charge an energy buffer for the internal power supply of the sensor unit
Data Source
Figure 1~2
Figure 3
AI summary
The invention relates to a sensor unit (SE) which enables identification of fault currents (I) or interference in a conductor (L) being monitored in a power supply network, and to a corresponding method. The sensor unit (SE) has a current converter (SW) which is used, in a measurement phase, to determine a current (I) in the conductor (L) being monitored in the power supply network via a load resistor (Rb) of the sensor unit (SE) and, in the charging phase, to charge an energy buffer (EB) for internally supplying power to the sensor unit (SE). To control the sensor unit (SE) and to analyse and transfer measurement results, an electronic unit (MMT) is provided, which is designed to monitor a charge voltage (LP) at the energy buffer (EB) and to compare same with an upper and lower limit value. The sensor unit (SE) also has two switch elements (S1, S2) which are controlled by the electronic unit (MMT) such that, when the charge voltage (LP) at the energy buffer (EB) reaches and/or exceeds the upper limit value, the sensor unit (SE) is put into the measurement phase by closing the first switch element (S1) and opening the second switch element (S2) and, when the charge voltage (LP) at the energy buffer (EB) reaches and/or falls below the lower limit value, the sensor unit (SE) is put into the charging phase by opening the first switch element (S1) and closing the second switch element (S2), and the charge voltage (LP) at the energy buffer (EB) is used for discharging the current (I) in the conductor being monitored.