Medium Voltage Switching Device Segmentation for Sealed Maintenance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing medium voltage electrical cut-off devices are complex, bulky, expensive, and pose maintenance challenges, particularly with SF6 systems, which require restrictive recharging after operation and lack effective sealing for immersion conditions.
Innovation Solution
The electrical cut-off device is designed with two compartments: one sealed under controlled atmosphere housing disconnectors and the other containing control and protection means, with a hatch allowing access for maintenance while ensuring perfect sealing, using inflatable seals and mechanical venting to maintain pressure and prevent overpressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a sealed cabinet under controlled atmosphere (SF6) is used to house electrical equipment, then the breaking capacity is improved and device size is reduced, but maintenance becomes problematic and requires restrictive recharging procedures
Solution Approach 1:
The cabinet is divided into two separate compartments: a first compartment under controlled atmosphere (SF6) housing the disconnector, and a second compartment accessible from outside housing control and protection means. This segmentation allows maintenance personnel to access the second compartment without breaching the sealed atmosphere of the first compartment, resolving the contradiction between maintaining reliable breaking capacity and enabling easy maintenance.
2Reliability
If a sealed cabinet is used to protect equipment, then waterproofing and sealing are improved, but access for maintenance requires opening the seal which compromises the sealed environment
Solution Approach 1:
The cabinet structure is segmented into a sealed first compartment and an accessible second compartment. The hatch providing access to the second compartment does not compromise the seal of the first compartment, allowing maintenance personnel to access control and protection means while the disconnector remains protected in the sealed SF6 atmosphere.
Solution Approach 2:
A hatch with sealing means acts as an intermediary element between the sealed first compartment and the accessible second compartment. This intermediary allows selective access to the second compartment while maintaining the integrity of the sealed environment in the first compartment, resolving the contradiction between sealing and maintenance access.
3Volume of moving object
If control and protection means are housed in the same sealed compartment as disconnectors, then device compactness is improved, but maintenance requires breaching the sealed atmosphere requiring SF6 recharging
Solution Approach 1:
The device is segmented into two functional compartments: the first compartment under controlled atmosphere housing the disconnector, and the second compartment housing control and protection means accessible from outside. This segmentation maintains compactness while eliminating the need for SF6 recharging during maintenance of control and protection equipment.
4Ease of repair
If a hatch is added to allow access for maintenance, then maintenance ease is improved, but the sealing integrity may be compromised
Solution Approach 1:
A specially designed hatch with integrated sealing means serves as an intermediary between the external environment and the second compartment. The sealing means include a seal element and compression mechanism that maintain sealing integrity when the hatch is closed, while allowing access when open. This resolves the contradiction by providing maintenance access without compromising the sealed environment of the first compartment.
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 provides a reliable, waterproof, compact, and cost-effective medium voltage electrical cut-off device that maintains sealing during immersion and allows for easy maintenance without recharging, enhancing operational continuity.
Implementation Method 1
The door has on its inner peripheral edge a seal. And on its external face, the door comprises a central handle cooperating with a set of connecting rods secured to the internal face of the door and making it possible to actuate in pivoting a multiplicity of fingers each around an axis perpendicular to the plane of said door and each intended to exert a pressure during their pivoting on the internal edge of the trunk by means of a stop having a face inclined with respect to said edges so as to bring the edge of the door and the edge of the trunk closer together while compressing the seal.
Implementation Method 2
The hatch 32 is adapted to guarantee the tightness of the compartment 30 and, in doing so, of the whole of the housing 10 in the closed state of the hatch 32.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The device has a case (10) divided into two main compartments, where one of the compartments is sealed and placed under controlled temperature and includes disconnecting switches (110, 116). The other compartment includes a circuit breaker (112) and a transformer (114) and a trap door (32) for permitting an operator to access the units. The latter compartment has a sealing unit adapted to guarantee sealing of the latter compartment in closed state of the door.