Overcurrent Protection Circuit for Sensor Range Limits
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing protection circuits for electrical power systems face challenges in accurately measuring and responding to both nominal and peak currents, especially when handling multiple output voltages and frequencies, leading to potential false trips and inadequate protection.
Innovation Solution
A protection circuit with a current sensor, rectifying module, superimposing module, low-pass filters, and logic module that generates an expanded signal to track or replace current sensor outputs beyond its dynamic range, allowing adjustable current-time characteristics for safe operation across varying voltages and currents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the current sensor measurement range is limited to nominal current, then measurement precision is improved, but peak current measurement capability is lost
Solution Approach 1:
The patent adds a temporal dimension to current measurement by implementing time-based signal processing. Instead of merely extending the amplitude range, the system uses temporal characteristics (duration, rate of change, waveform shape) to interpret current magnitude. This allows the same sensor to accurately represent both nominal and peak currents by analyzing the time-profile of the signal rather than relying solely on instantaneous amplitude.
Solution Approach 2:
The invention introduces software processing as an intermediary between the current sensor and the tripping decision. This intermediary layer processes the sensor output through algorithms that can infer peak current conditions from nominal current measurements by analyzing temporal patterns, waveform characteristics, and duration of current excursions, effectively bridging the gap between limited sensor range and comprehensive protection needs.
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
Ensures reliable overcurrent protection by accurately detecting and responding to both nominal and peak currents, preventing damage while allowing for flexible operation across different voltage domains.
Implementation Method 1
a current sensor (20) configured to generate an electric signal (38) by measuring an AC current (36) flowing via the electrical power system (12)
Implementation Method 2
a rectifying module (22) configured to generate a pulsating DC signal (40) in response to the electric signal (38)
Data Source
Figure 1
Figure 2~4
Figure 5~7
AI summary
The present teachings relate to a protection circuit for protecting an electrical power system, comprising: a current sensor (20) configured to generate an electric signal wherein the current sensor has a measurement dynamic range; a rectifying module (22) configured to generate a pulsating DC signal; a superimposing module (24) configured to generate an expanded signal; a low-pass filter (26a) configured to shape the expanded signal to generate a band-limited signal; a logic module (28) configured to generate a trip signal when the band-limited signal violates a predetermined threshold; wherein the trip signal is usable for cutting off the flow of the AC current. The present teachings also relate to related methods and software products.