Single Rogowski Coil Current Sensing for Circuit Breakers
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Solution Overview
Problem
Existing circuit breaker systems require separate sensors for measuring operating currents and fault currents, leading to increased installation space, complexity, and cost.
Innovation Solution
A device using a single Rogowski coil to simultaneously measure operating and fault currents, with a protection circuit and measurement circuit configured to output fault and operating voltages based on voltages generated in the Rogowski coil.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If separate sensors are installed for measuring operating current and fault current, then measurement accuracy for both currents can be ensured, but installation space increases and system complexity increases
Solution Approach 1:
The Rogowski coil is designed to perform multiple functions: it measures both operating current and fault current using the same sensor structure. The coil's output is processed differently by two separate circuits (measurement circuit for operating current, protection circuit for fault current), allowing one sensor to serve dual purposes and eliminate the need for separate sensors.
Solution Approach 2:
The single Rogowski coil output signal is segmented into two separate measurement paths: one path processes the signal for operating current measurement with appropriate scaling, while the other path processes the same signal for fault current detection. This signal segmentation allows one physical sensor to provide information for multiple measurement purposes.
2Reliability
If separate sensors are installed for measuring operating current and fault current, then reliable measurement of both currents is achieved, but installation space increases
Solution Approach 1:
The Rogowski coil serves as a universal sensor for both operating current and fault current measurement. By designing the coil with appropriate characteristics and providing two processing circuits that operate in parallel from the same sensor output, the system achieves reliable measurement of both current types while using only one physical sensor, thereby reducing installation space requirements.
3Measurement precision
If separate sensors are installed for measuring operating current and fault current, then accurate measurement of both currents is possible, but manufacturing cost increases
Solution Approach 1:
The invention merges the function of two separate current sensors into a single Rogowski coil. Although two processing circuits are required (measurement circuit and protection circuit), they process signals from the same sensor, reducing the overall component count compared to using two independent sensors. This consolidation lowers manufacturing costs while maintaining measurement accuracy for both operating and fault currents.
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
The solution reduces installation space and manufacturing costs while maintaining accuracy and reliability for both operating and fault current measurements.
Implementation Method 1
A circuit breaker operating current/fault current measuring device using a single Rogowski coil according to the present invention includes a Rogowski coil installed to wrap around a current-carrying conductor, a protection circuit outputting a fault voltage based on a voltage generated from a tap installed on a portion of the Rogowski coil
Data Source
AI summary
The present invention relates to a circuit breaker operating current/fault current measuring device using a single Rogowski coil has an advantage of reducing an installation space and a manufacturing cost by simultaneously measuring an operating current and a fault current with the single Rogowski coil and has an advantage of improving reliability by simultaneously satisfying accuracy required for measurement of the operating current and the fault current. The circuit breaker operating current/fault current measuring device using a single Rogowski coil according to the present invention is configured with a Rogowski coil installed to wrap around a current-carrying conductor, a protection circuit outputting a fault voltage based on a voltage generated from a tap installed on a portion of the Rogowski coil, and a measurement circuit outputting an operating voltage based on a voltage generated in the entire coil of the Rogowski coil.