Solid State Breaker Fault Diagnosis for Fast Switching Reliability
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Solution Overview
Problem
Solid state circuit breakers have a high failure rate during operation, leading to potential power grid accidents and significant economic losses due to the lack of effective fault diagnosis capabilities.
Innovation Solution
A solid state circuit breaker with a fault self-diagnosing function, incorporating a solid state switch, inductor, fly-wheel diode, and a fault detection circuit that uses voltage measurements and switching control signals to identify faults such as overheat, short circuit, and open circuit through a field programmable gate array (FPGA) and logic gate circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a solid state circuit breaker is used to achieve fast switching speed and microsecond-level action, then the switching performance is improved, but the failure rate increases leading to higher risk of power grid accidents
Solution Approach 1:
The fault detection circuit continuously monitors the circuit breaker's operational status before actual failure occurs. By detecting abnormal conditions such as overcurrent, overtemperature, and insulation degradation in advance, the system can trigger protective actions or alert operators before the circuit breaker fails, thus maintaining high reliability while preserving the fast switching capability.
Solution Approach 2:
The patent implements a feedback mechanism where the fault detection circuit continuously monitors parameters like current, temperature, and voltage across the circuit breaker components. This real-time feedback allows the system to detect degradation trends and predict potential failures, enabling preventive maintenance or automatic disconnection before actual failure occurs, thereby resolving the reliability issue without compromising switching speed.
2Ease of manufacture
If traditional mechanical breakers are used, then the structure is simple and ease of manufacture is improved, but the switching speed is slow and cannot meet micro power grid requirements
Solution Approach 1:
The patent replaces the traditional mechanical switching mechanism with a solid state switch device that uses semiconductor materials. This substitution eliminates mechanical moving parts, contacts, and arc suppression components, thereby achieving microsecond-level switching speeds while maintaining manufacturing feasibility through standardized semiconductor fabrication processes.
3Reliability
If fault detection capabilities are added to the circuit breaker, then reliability is improved through self-diagnosis, but device complexity increases
Solution Approach 1:
The fault detection circuit is designed to monitor multiple parameters (current, voltage, temperature, insulation resistance) using a unified measurement architecture. By employing multi-functional detection circuits that can sense various fault conditions through common hardware resources, the patent achieves comprehensive fault self-diagnosis capability while minimizing the increase in device complexity.
Solution Approach 2:
The patent combines the fault detection function with the existing control and protection circuits of the circuit breaker. By integrating temperature sensors, voltage dividers, and current sensing elements into the existing structural framework, and using a unified control logic for both normal operation and fault detection, the system achieves self-diagnosis capability with minimal additional complexity.
Data Source
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AI summary
A solid state circuit breaker (100) is disclosed, which includes a solid state switch (SW), an inductor (L) in series connected with the solid state switch (SW), and a fault detection circuit (1). The solid state switch (SW) has a gate electrode (g), a source electrode (s) and a drain electrode (d). The fault detection circuit (1) is configured for detecting health status of the solid state switch (SW) and identifying faulty type of the solid state switch (SW) in the condition that the solid state switch (SW) occurs fault based on one or more of a measured voltage (V1) of the solid state switch between the source electrode (s) and the drain electrode (d), a measured voltage (Vm) of the inductor, a reference voltage (Vr) and a switching control signal (Sg) provided to the gate electrode of the solid state switch. A motor driving system (200) is also disclosed.