Trip Actuator with Thomson Drive for Fast Circuit Opening

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Solution Overview

Problem

Existing small-sized actuators for electric power circuit switches, such as solenoid and permanent magnetic actuators, experience significant delays in applying driving force, which can lead to a 5 to 6 millisecond delay in switching mechanisms, potentially causing further delays up to 10 to 13 milliseconds when protection circuits are involved, hindering fast circuit opening during fault conditions.

Innovation Solution

A trip actuator design incorporating a solenoid actuator with a spring mechanism between movable and stationary ferromagnetic cores, where the spring applies elastic force to move the movable core away from the stationary core when the driving coil is demagnetized, combined with a Thomson drive unit that uses a repulsive plate and coil to rapidly release the latch, minimizing delay by utilizing both magnetic and elastic forces for swift operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If a solenoid actuator or permanent magnetic actuator is used to manipulate the latch, then the actuator can be made small-sized, but a delay of about 5 to 6 msec occurs until driving force is applied

Engineering Contradiction:
Improveactuator sizeVSAvoiddelay time
Core Design Contradiction:
Volume of moving objectVSLoss of time

Solution Approach 1:

The trip spring is pre-charged to a compressed state before operation, storing elastic energy in advance. The latch holds this pre-loaded spring in a restricted position. When triggered, the stored energy is immediately released, eliminating delay. This is implemented through the trip actuator that releases the latch, allowing the pre-compressed spring to rapidly drive the operating mechanism.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system uses periodic charging and discharging of the trip spring. The spring is continuously charged during normal operation and rapidly discharged when fault detection occurs. This periodic energy storage and release mechanism ensures that driving force is always available and can be applied instantly when needed, reducing response delay.

Inventive Principle:
Principle #19Periodic action

2Reliability

If a protection circuit is employed to prevent damage of the coil, then coil protection is improved, but the time delay increases by about 10 to 13 msec

Engineering Contradiction:
Improvecoil protectionVSAvoidtime delay
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The invention replaces the electromagnetic solenoid actuator with a mechanically-driven trip actuator system. Instead of using a coil that requires electrical protection circuits, the system uses a mechanically-charged spring that is released by a trip actuator. This mechanical substitution eliminates the need for protection circuits while achieving faster response time, as mechanical energy release is instantaneous once triggered.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The trip spring serves its own protection function through the mechanical trip actuator design. The latch mechanism inherently protects the spring by containing it in a restricted position during charging, and the trip actuator provides controlled release. This self-contained mechanical system eliminates the need for separate electrical protection circuits, thereby avoiding the associated time delays.

Inventive Principle:
Principle #25Self-service

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

This configuration enables fast and efficient opening of the electric power circuit by minimizing time delays, with the Thomson drive unit operating in under 1 millisecond and the solenoid actuator in 5 milliseconds, ensuring rapid protection from fault currents.

Implementation Method 1

a spring installed between the movable core and the stationary core and configured to apply an elastic force to the movable core such that the movable core is moved away from the stationary core when the driving coil is demagnetized

Methodology Applied
Scientific EffectElastic force: Elasticity

Implementation Method 2

the solenoid actuator and the permanent magnetic actuator use a magnetic attractive force of a ferromagnetic substance responsive to a magnetization of a coil

Methodology Applied
Scientific EffectMagnetic attractive force: Magnetism

Implementation Method 3

a Thomson drive unit that uses a repulsive plate and coil to rapidly release the latch, minimizing delay

Methodology Applied
Scientific EffectThomson drive: Electromagnetic Induction

Data Source

PatentEP2779191B1Trip actuator for switch of electric power circuit
Publication Date: 2018.01.10 LSIS CO LTD
  • EP2779191B1 patent drawingFigure 1
  • EP2779191B1 patent drawingFigure 2

AI summary

The present disclosure relates to a small-sized trip actuator for a switch of an electric power circuit, capable of triggering a switching mechanism to a circuit opening position at fast speed by minimizing a delay of time, the trip actuator including a main driving unit configured by a solenoid actuator comprises an output pin which is linearly movable, and a sub driving unit configured by a Thomson drive unit comprises a repulsive plate connected to the output pin, and a Thomson coil causing the repulsive plate to be repulsively moved when a current flows therethrough, such that the output pin is linearly moved, the sub driving unit operating to linearly move the output pin, before the main driving unit operates, upon opening the electric power circuit.