Peak Current Limiting Apparatus with Trigger Element
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Solution Overview
Problem
Existing peak current limiting apparatuses are unable to effectively limit fault currents within a predetermined time frame, leading to potential damage to electric power appliances and circuit breakers due to delayed detection by over-current relays.
Innovation Solution
A peak current limiting apparatus comprising a trigger element, a main contact switch, a driving coil, and a peak limiting impedance element, which diverts fault currents to parallel paths and limits the first peak level of the fault current to a predetermined level, allowing for timely intervention and reducing thermal and mechanical stresses on electric power devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an over-current relay is used to detect fault current, then the circuit breaker can be controlled to prevent over-current, but the relay cannot detect the fault current if the current limiter operates earlier due to the 3-5 period detection delay
Solution Approach 1:
The patent applies preliminary action by implementing a trigger element that activates the current limiting function before the over-current relay can detect the fault. The trigger element monitors current in real-time and initiates the limiting process proactively, eliminating the 3-5 period detection delay of conventional relays and ensuring the circuit breaker is protected before fault current can cause damage.
Solution Approach 2:
The patent introduces a trigger element as an intermediary between the current monitoring system and the circuit breaker. This trigger element serves as a mediator that detects fault conditions and activates the current limiting mechanism, bridging the gap between current monitoring and circuit breaker operation to achieve faster response than direct relay control.
2Object-affected harmful factors
If a current limiter is used to limit fault current, then mechanical and thermal stresses on electric power appliances are reduced, but the fault current may still exceed the rated short circuit breaking current before being limited
Solution Approach 1:
The patent applies preliminary action by pre-positioning the current limiter in the circuit path and pre-configuring the trigger element to activate immediately upon detecting fault conditions. This ensures that when a fault occurs, the current is limited before it can generate excessive thermal or mechanical stress that would exceed the rated short circuit breaking current of connected appliances.
Solution Approach 2:
The patent implements beforehand cushioning by having the current limiter ready in advance to absorb and limit fault current peaks. The trigger element and current limiter work together to cushion the blow of fault current before it can reach levels that would damage electric power appliances, protecting them from thermal and mechanical overload.
3Reliability
If the trigger element diverts fault current to parallel paths, then the main contact switch is protected, but the driving coil may be damaged by excessive peak current
Solution Approach 1:
The patent applies local quality by providing different current paths with different characteristics for different components. The parallel path through the driving coil is designed with appropriate impedance to limit peak current to safe levels for the coil, while other parallel paths can handle higher currents for main contact switch protection. Each component receives the appropriate current quality it can withstand.
Solution Approach 2:
The patent introduces impedance elements as intermediaries in the parallel paths to regulate and limit current flow. These impedance elements act as mediators that control the distribution of fault current among parallel paths, ensuring that the driving coil receives limited current while the main contact switch receives adequate protection current.
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 apparatus effectively limits fault currents below the rated short circuit breaking current, preventing damage to electric power appliances and enabling the circuit breaker to operate safely, thereby prolonging the lifespan of connected devices.
Implementation Method 1
a driving coil connected in parallel with the trigger element, and generating a repulsive force in response to the fault current to detach a contact point of the main contact switch
Data Source
AI summary
The present disclosure is related to a peak current limiting apparatus of the present disclosure comprising a trigger element serially connected between a power supply source and the load, diverting a fault current to other paths connected in parallel when the fault current exceeding a threshold is generated, a main contact switch serially connected between the trigger element and a load, a driving coil connected in parallel with the trigger element, and generating a repulsive force in response to the fault current to detach a contact point of the main contact switch, and a peak limiting impedance element serially connected between a connection node between the trigger element and the main contact switch and the driving coil, and limiting a first peak level of the fault current flowing through the driving coil to a predetermined level.