Switchgear Disconnector Linkage to Block ON-State Switching

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Solution Overview

Problem

Conventional disconnector assemblies in switchgears cannot operate safely when the circuit breaker is in the ON position, as they may cause interruptions in load current, dielectric flashes, and internal arching faults, potentially damaging the switchgear and connected equipment.

Innovation Solution

A disconnector assembly with a first link pivotally coupled to the circuit breaker, a cam, an actuator pin, and a second link that pivots between two operating positions, allowing selective operation based on the circuit breaker's position, ensuring safe operation by restricting or allowing disconnection only when the circuit breaker is in the OFF position.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the disconnector assembly is operated when the circuit breaker is in ON position, then the disconnector assembly can be switched OFF, but it may lead to interruption in load current, dielectric flashes, and internal arching faults which may destroy the complete switchgear

Engineering Contradiction:
Improvedisconnector assembly operationVSAvoidswitchgear safety
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent introduces an intermediary mechanism consisting of a first link, cam, actuator pin, and second link that mediates between the circuit breaker position and disconnector assembly operation. This intermediary mechanism detects the circuit breaker position through the first link's movement and translates it into appropriate enabling or disabling of disconnector operation via the cam and actuator pin, preventing unsafe operations while allowing necessary ones

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The disconnector assembly automatically detects and responds to the circuit breaker position through the mechanical linkage system. The first link pivotally coupled to the circuit breaker shaft self-actuates the cam mechanism, which in turn positions the actuator pin to either enable or restrict disconnector operation based on whether the circuit breaker is ON or OFF, eliminating the need for external control systems

Inventive Principle:
Principle #25Self-service

2Reliability

If a mechanical linkage system is added to detect circuit breaker position and control disconnector operation, then operational safety is improved, but device complexity increases

Engineering Contradiction:
Improveoperational safetyVSAvoiddisconnector assembly structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces complex electrical control systems, sensors, and electronic control logic with a purely mechanical linkage system. The mechanical components (first link, cam, actuator pin, second link) directly translate the circuit breaker's mechanical position into corresponding operational states for the disconnector assembly, simplifying the overall system by eliminating electronics while maintaining safety

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

Solution Approach 2:

The mechanism employs dynamic components including a pivotally coupled first link that rotates with the circuit breaker shaft, a cam that converts rotational movement into linear displacement of the actuator pin, and a second link that pivots to enable or disable disconnector operation. This dynamic mechanical system adaptively responds to circuit breaker position changes without requiring complex control logic

Inventive Principle:
Principle #15Dynamics

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 solution ensures safe and reliable operation of the disconnector assembly, preventing damage to the switchgear and connected equipment by restricting operation when the circuit breaker is ON and allowing it when OFF, thereby preventing interruptions and faults.

Implementation Method 1

a cam (110) movably connected to the second end (108) of the first link (106) and configured to displace relative to displacement of the second end (108)

Methodology Applied
Scientific EffectCam mechanism: Cam

Implementation Method 2

a first link (106) pivotally coupled to a body (120) of a circuit breaker (102) of the switchgear (100). The first link (106) includes a first end (107) rotatably coupled to a shaft (105) of the circuit breaker (102), and a second end (108) movably disposed in a slot (116) defined in the body (120) and configured to displace relative to a rotation of the first end (107)

Methodology Applied
Scientific EffectMechanical linkage: Lever

Implementation Method 3

an actuator pin (111) disposed on a platform (112) connected to the body (120) and configured to displace linearly relative to displacement of the cam (110). Additionally, the disconnector assembly (103) includes a second link (115) pivotally coupled to the actuator pin (111) and configured to pivot between a first operating position and a second operating position relative to the linear displacement of the actuator pin (111)

Methodology Applied
Scientific EffectMechanical advantage: Mechanical Advantage

Data Source

PatentEP4283651A1A disconnector assembly of a switchgear
Publication Date: 2023.11.29 ABB (SCHWEIZ) AG
  • EP4283651A1 patent drawingFigure 1
  • EP4283651A1 patent drawingFigure 2
  • EP4283651A1 patent drawingFigure 3

AI summary

Present disclosure discloses a disconnector assembly of a switchgear. The disconnectorincludes a first link pivotally coupled to a body of a circuit breaker of the switchgear. The firstlink includes a first end rotatably coupled to a shaft of the circuit breaker, and a second end movably disposed in a slot defined in the body. Further, the disconnector assembly includes a cam movably connected to the second end of the first link and configured to displace relative to displacement of the second end, and an actuator pin disposed on a platform and configured to displace linearly relative to displacement of the cam. Additionally, the disconnector assembly includes a second link pivotally coupled to the actuator pin and configured to pivot between a first operating position and a second operating position relative to the linear displacement of the actuator pin for selective operation of the disconnector assembly.