40.5KV 630A Potential Transformer High Voltage Switchgear Ring Main Unit RMU

Explore the pinnacle of power distribution technology with Kexunan's 40.5KV 630A Potential Transformer High Voltage Switchgear Ring Main Unit RMU. Crafted for durability and easy maintainability, our switchgear solutions, proudly presented by Kexunan, epitomize cutting-edge innovation. The robust design ensures lasting performance, while the easy-maintainable features simplify upkeep, ensuring operational reliability. For a detailed insight into our offerings and to experience the durability and user-friendly maintenance of our switchgear, contact us today. Choose Kexunan for a reliable, durable, and easy-maintainable solution, setting new benchmarks in high voltage technology.

Over the past few years, the growing advancements in society, economy, and switch technology have increased the complexity of engineering construction. There is a rising preference for switch equipment that is smaller in size, requires less maintenance, and is intelligent. As a result, local and international switch manufacturing companies are actively working on developing medium voltage gas-filled cabinets (C-GIS), also known as gas-insulated switchgear. A gas-insulated switchgear encloses high-voltage components like busbars, circuit breakers, isolating switches, and power cables within a lower gas-pressure shell.

1. By utilizing sulfur hexafluoride gas as both an insulating and arc extinguishing medium, the size of the switchgear can be significantly reduced, resulting in a more compact design and achieving miniaturization.

2. The main circuit's conductive component ensures high reliability and safety and is sealed within SF6 gas. This enclosure protects the high-voltage live conductor from external environmental conditions, ensuring long-term safe operation and high reliability.

3. Furthermore, there is no risk of electric shock or fire.

4. The switchgear features an independent modular design, with the air box constructed from precise aluminium plates that can be disassembled. The isolation switch adopts a three-position linear transmission. An additional control module, consisting of nearly 100 points of the programmable logic controller (PLC), is incorporated to enable grounding, isolation switch, and remote operations to minimize control relay and circuit complexity. The mechanism switch is designed modularly, with opening and closing points connected using plum blossom contacts. This eliminates any possibility of non-operation in the original rotary isolation switch and grounding switch. Additionally, it resolves the problem of unstable and excessive contact resistance found in the original rotary isolation switch by installing shielding and voltage equalization covers on each contact, effectively addressing the issue of partial discharge during switch breakpoint production.

5. The application and arrangement of gas-insulated switchgear are highly convenient. As an independent unit, it can fulfil the requirements of various main wiring configurations through combination. Delivering these units to the site significantly reduces the on-site installation duration and enhances overall reliability.

Execution standards

GB/T11022-1999 Common technical requirements for high-voltage switchgear and control equipment standards

GB3906-2006 3.6kV~40.5kV AC Metal Enclosed Switchgear and Control Equipment

GB311.1-1997 Insulation Coordination of High Voltage Transmission and Transformation Equipment

GB/T16927.1-1997 High voltage testing technology Part: General test requirements

GB/T16927.2-1997 High voltage testing techniques Part 2: Measurement systems

GB/T7354-2003 Partial discharge measurement

GB1984-1989 AC High Voltage Circuit Breakers

GB3309-1989 Mechanical tests of high-voltage switchgear at room temperature

GB4208-2008 Code for Degree of Protection Provided by Enclosures (IP)

GB12022-2006 Industrial sulfur hexafluoride

GB8905-1988 Guidelines for gas management and inspection in sulfur hexafluoride electrical equipment

GB11023-1989 Test method for sulfur hexafluoride gas sealing of high-voltage switchgear

GB/T13384-1992 General technical requirements for packaging of electromechanical products

GB4207-2003 Solid insulation materials - Determination of relative and resistance to electrical trace index under humid conditions

GB/T14598.3-2006 Electrical relays - Part 5: Insulation of electrical relays

GB/T17626.2-1998 Electromagnetic Compatibility Testing and Measurement Techniques - Electrostatic Discharge Reactance Interference Test

GB/T17626.4-2008 Electromagnetic Compatibility Testing and Measurement Techniques - Electrical Fast Transient Pulse Group Immunity Test

GB/T17626.5-2008 Electromagnetic Compatibility Testing and Measurement Techniques - Surge (Impulse) Immunity Test

GB/T17626.12-1998 Electromagnetic Compatibility Testing and Measurement Techniques - Oscillating Wave Immunity Test

Test Type

◆ Insulation test

◆ Temperature rise test

◆ Loop resistance measurement

◆ Short-time withstand current and peak withstand current tests.

◆ Verification of making and breaking capabilities

◆ Mechanical operation and mechanical characteristic testing tests

◆ Protection level detection

◆ Additional tests on auxiliary and control circuits

◆ Pressure tolerance test for inflatable compartments

◆ Sealing test

◆ Internal arc test

◆ Electromagnetic compatibility test

Basic Scheme

40.5KV 630A Potential Transformer High Voltage Switchgear Ring Main Unit RMU Operation Condition

40.5KV 630A Potential Transformer High Voltage Switchgear Ring Main Unit RMU Technical Parameter

Grounding and Separation

The C-GIS gas-insulated high-voltage switchgear is categorized into different current levels, including 630A, 1250A, 1600A, 2000A, 2500A, 3150A, etc. The size of the cabinet can be customized based on specific requirements. The external shell is created by cutting and bending an aluminium zinc-coated plate, while the gas box is constructed by welding 304 high-quality stainless steel plates. Each unit can be expanded and combined independently according to the design. The cabinet is divided into various sections:

• A secondary control room

• Busbar room

• Circuit breaker room

• Circuit breaker operating mechanism room

• Cable room

The cable connection height can reach up to 700mm, facilitating easy maintenance and installation.

Additionally, the cabinet is equipped with a comprehensive grounding protection system. The switchgear incorporates separate functional compartments, such as switch rooms, busbar rooms, cable rooms, and secondary circuit channels. These compartments are separated by grounding metal partitions, ensuring their independence.

Secondary control room

Located above the cabinet, the secondary control room is equipped with installation boards for components and brackets for securing terminal blocks. This room allows for the installation of various devices such as wiring terminals, small busbar terminals, comprehensive protection devices, as well as control and operation devices. These enable the remote control, telemetry, remote signaling, and local monitoring functions of the system. The left and right side panels of the room have circular holes that facilitate the connection of small busbars and terminals to the cabinet.

(Screenshot of the secondary box section)

Bus Compartment

The upper air box contains the busbar room and the isolation mechanism. Once the cabinet is positioned on the support on the ground, the left and right circuit cabinets and busbars are securely linked together by merging the cabinets.

Switch Room

The switch room is located at the centre of the cabinet and has a plate-type gas-insulated switch cabinet design with two chambers positioned above and below. The upper chamber contains a three-position isolation switch, while the lower chamber houses a vacuum circuit breaker. The arrangement of the busbar, isolation switch, and circuit breaker follows an "up, middle, and down" pattern. Using a single chamber structure is a simple, cost-effective option for manufacturing, but it can result in components easily affecting each other and lower reliability. On the other hand, a multi-chamber structure module offers the advantage of easy replacement and avoids mutual influence among multiple components, resulting in enhanced safety. However, the multi-chamber structure is more complex, challenging to manufacture, and expensive.

Institutional Room

The spring-operated mechanism is situated on a plane, with the isolation and circuit breaker mechanisms being separated independently. It is integrated with the vacuum arc extinguishing chamber's insulation rod at both ends, simplifying the transmission process. The mechanism's output characteristics align better with the circuit breaker's opening and closing characteristics, reducing power usage and enhancing mechanical reliability and flexibility.

Cable Room

The cable room is beneath the cabinet and includes a separate channel for releasing pressure. The distance from the ground to the cable connection terminals can be as high as 700mm. Grounding interlocks are incorporated in the cable room as per regulations, allowing for the installation of two cables and lightning arresters in each circuit. Additionally, the incoming and outgoing cables and the lightning arresters are connected using an internal cone insertion technique.