Four-Position Load Break Switch With Arc-Free Vacuum Shunt
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electrical switchgear in power distribution networks faces challenges in breaking currents during load or fault conditions due to limitations in SF6 gas and vacuum switch technologies, which can lead to arc formation, insulation damage, and safety issues.
Innovation Solution
A load break or short-circuit currents switch with a main circuit and secondary circuit, where the moving contact of the switch-disconnector actuates a tilting mechanism to open the vacuum switch, preventing current spark-over and allowing the vacuum switch to close without electric current passage, thus enabling safe breaking and disconnecting operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a vacuum switch is placed in a secondary circuit to break current during switching operations, then the cost is reduced and the vacuum switch can be of lower performance, but the vacuum switch may be inadvertently actuated during closing sequences causing harmful arcs
Solution Approach 1:
An insulating shield is introduced as an intermediary element between the moving contact of the switch-disconnector and the tilting mechanism of the vacuum switch. This shield prevents direct contact during closing sequences, acting as a mediator that allows the moving contact to pass without triggering the vacuum switch, thereby preventing inadvertent actuation and harmful arcs while maintaining the cost-effective secondary circuit configuration
Solution Approach 2:
The switching mechanism is segmented into two independent parts: the switch-disconnector in the main circuit and the vacuum switch in the secondary circuit. The insulating shield further segments the interaction between these parts during closing operations, allowing each component to function independently without unwanted interference, thus ensuring reliable operation at reduced cost
2Productivity
If the moving contact of the switch-disconnector directly actuates the vacuum switch, then the breaking function is achieved, but current may flow through the secondary circuit during closing sequences causing arc formation and insulation damage
Solution Approach 1:
The insulating shield serves as a mediator that selectively blocks current flow during closing sequences while allowing mechanical actuation during opening sequences. It is positioned to be bypassed by the moving contact only when the contact is in the closing direction, preventing harmful arcs during closing while maintaining efficient switching operation
Solution Approach 2:
Instead of using a conductive connection that requires additional control mechanisms to prevent unwanted current flow, the invention inverts the approach by using an insulating barrier that naturally blocks current during closing sequences. The shield is strategically positioned to be automatically bypassed only during the intended actuation phase, simplifying the control logic and improving reliability
3Ease of operation
If a tilting mechanism is used to actuate the vacuum switch, then the breaking function is achieved, but the mechanism may be inadvertently triggered during closing sequences
Solution Approach 1:
The insulating shield acts as a passive intermediary that simplifies the control mechanism by providing inherent directional selectivity. It eliminates the need for complex control logic or additional sensors to prevent inadvertent triggering, as the shield's physical positioning automatically prevents contact during closing sequences while allowing actuation during opening sequences
Solution Approach 2:
The insulating shield provides self-service by automatically differentiating between closing and opening sequences through its strategic positioning. The shield's geometry and placement cause it to be naturally bypassed only during the intended actuation phase, allowing the tilting mechanism to function reliably without requiring external control signals or complex interlocking systems
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 effectively prevents arc formation and ensures safe operation by maintaining electrical insulation and avoiding current flow during closing sequences, allowing the vacuum switch to remain ready for subsequent breaking operations while ensuring the secondary circuit remains at the same electrical potential.
Implementation Method 1
a vacuum switch that is actuated by the moving contact of the switch - disconnector
Implementation Method 2
interrupting the electric current, extinguishing the electric arc
Implementation Method 3
an electrical equipment, such as a cell, which incorporates said load break or short-circuit currents switch in an insulated housing in a dielectric medium
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Load break or short-circuit currents switch (1) which can adopt at least three operating positions, making - breaking - disconnecting, as well as a fourth grounding position, in the latter case including a grounding contact, thus compactly arranging a load break or short-circuit currents switch capable of executing up to four operating positions (making, breaking, disconnecting and grounding) and that basically comprises a main circuit (2) for the circulation of electrical current and a secondary circuit (3) for circulation of electrical current in shunt, wherein the main circuit (2) comprises a switch - disconnector (4) equipped with a fixed contact (5) and a moving contact (6), and wherein the secondary circuit (3) comprises a vacuum switch (7) that in turn comprises a fixed contact (8) and a moving contact (9), the vacuum switch (7) being actuated by moving the moving contact (6) of the switch - disconnector (4) through a control mechanism (10).