Broken Conductor Detection Using Sequence Current Ratios
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing systems struggle to rapidly detect broken conductors in energized electric power systems, which can lead to hazardous conditions such as electrical arcs and fires, and require costly communication infrastructure for detection.
Innovation Solution
A method using local measurements of zero-sequence, negative-sequence, and positive-sequence currents to identify a broken conductor, employing a ratio of zero-sequence and negative-sequence currents to positive-sequence currents, and implementing protective actions based on this ratio to de-energize the conductor before it falls to the ground.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If communication infrastructure is used for broken conductor detection, then detection reliability is improved, but device complexity and implementation cost increase
Solution Approach 1:
The patent extracts the detection function from a communication-dependent system to a standalone local measurement system. By using sequence current measurements (zero-sequence, negative-sequence, and positive-sequence currents) that can be obtained locally without communication infrastructure, the system eliminates the need for complex communication channels while maintaining detection capability through the relationship I0 + I2 = -I1
Solution Approach 2:
The system uses locally available current measurements to perform self-diagnosis of broken conductors. Each terminal equipment independently measures sequence currents and determines broken conductors using the current relationship, without requiring external communication or assistance from other system components
2Speed
If rapid detection of broken conductors is implemented, then safety hazards are reduced, but measurement precision requirements increase
Solution Approach 1:
The system continuously monitors sequence currents and immediately processes measurements through the relationship I0 + I2 = -I1 to detect broken conductors. This real-time feedback mechanism enables rapid detection by continuously comparing measured values against the expected relationship, allowing quick identification when deviations occur
Solution Approach 2:
The patent transforms the detection problem from monitoring absolute current values to monitoring the relationship between sequence currents. By changing the parameter from individual current magnitudes to the algebraic relationship I0 + I2 + I1 = 0, the system achieves rapid detection through simple comparison operations on measured parameters
Data Source
AI summary
The present disclosure relates to systems and methods to detect a fault in an electric power system. One embodiment may detect a single phase broken conductor in a multi-phase electric power system. An intelligent electronic device (IED) may receive a plurality of measurements over time of a current through an electrical conductor in the electric power system. Based on the measurements of the current, a fault detection subsystem may determine a zero-sequence current, a negative-sequence current, and a positive-sequence current. The fault detection subsystem may determine a ratio of the zero-sequence current, the negative-sequence current, and the positive-sequence current, and may monitor the ratio over time. The fault detection subsystem may identify the broken conductor condition based on the ratio and a fault detection region. A protective action subsystem may implement a protective action based on identification of the broken conductor condition.