szy-rd5-375-20211


Release time:

2024-04-22

The narrow cabinet high-voltage grounding switch product is the core safety structural product of the high-voltage complete switchgear. It ensures that the residual electrical energy that may be generated by the load can cause personal injury when it is in working condition; it has to withstand the influence of electrical and thermal stresses of the main circuit when it is not in working condition, as well as to ensure that the equipment and the load are not subjected to secondary damage when it is in fault condition. In the process of operation, it should not only ensure accurate positioning, but also ensure the smooth operation of the mechanical mechanism; it should be able to safely withstand the impact of the electrical energy that may be generated at the load side, but also ensure the safe isolation of the main circuit electrical energy from the load circuit. Finally, in the manual operation state, it should be light and labor-saving.

szy-rd5-375-20211

Development of Narrow Cabinet Grounding Switch Model 450-375

I. Product Introduction:

Narrow-cabinet high-voltage grounding switch product is the core safety structural product of high-voltage complete switchgear. It ensures that the residual electric energy that may be generated by the load may cause personal injury when it is in working condition; it has to withstand the influence of electric and thermal stresses of the main circuit when it is not in working condition, as well as to ensure that the equipment and the load are not subjected to secondary damage when it is in fault condition. In the process of operation, it should not only ensure accurate positioning, but also ensure the smooth operation of the mechanical mechanism; it should be able to safely withstand the impact of the electrical energy that may be generated at the load side, but also ensure the safe isolation of the main circuit electrical energy from the load circuit. Finally, in the manual operation state, to do light and labor-saving.

 

Second, industry trends:

With the gradual implementation of national energy conservation and emission reduction, carbon reduction policy, the construction of new energy power plants, power equipment expansion and upgrading needs, high-voltage switchgear miniaturization of the market potential is growing, and its key safety components, "narrow cabinet high-voltage grounding switches," the level of technology and manufacturing level will have a serious impact on the process of miniaturization of high-voltage switchgear and the development of the switchgear.

This type of product was introduced into China in 2002, using the gas insulation method, due to a small footprint, high degree of intelligence, maintenance-free, full working conditions, etc., so that it gradually became a new choice, and is widely used in metallurgy, petrochemicals, mines, development zones, urban rail transit and high-rise buildings and other scenarios. However, SF6 insulating gas was recognized as a major greenhouse gas in the 1997 Kyoto Protocol, and relevant regulations clearly phased out the use of SF6 in 2030. As a result, market demand has been clearly characterized by a reduction in the use of greenhouse gases and the adoption of composite insulation technology with air and solid insulation. The key to reducing product space size and the use of air-solid composite insulation is the development of suitable "narrow-cabinet high-voltage grounding switch technology and products".

 

Third, the development of 450-375 narrow cabinet grounding switch:

In order to replace SF6 gas-filled cabinets and to make vacuum breaking high-voltage switchgear more practical, the R&D department made a technological revolution in the traditional "28 cabinets". The core primary electrical components and secondary power distribution equipment have been technically broken through, and various corresponding power distribution programs (e.g. load switch, isolation trolley, PT trolley, metering cabinet, etc.) can be adapted to the extreme 375 mm cabinet width of the high-voltage switchgear.

Narrow cabinet high-voltage grounding switch is suitable for high-voltage (12kV) AC metal-enclosed armored transfer-open complete set of switchgear high-voltage switchgear cabinet width of 370-500mm, height of about 1800mm, depth of about 1300mm. In the case of the same rated current of the main circuit, controlling the phase spacing of the busbar coupling system within it requires a technological breakthrough.

In addition to the phase spacing problem, the narrow cabinet high-voltage grounding switch needs to solve the technical critical problems are:

--Five-prevention interlocking device with it;

--Internal coupling busbar system using right-in-left-out copper rod connection in the circuit breaker section.

--Integrated whole contact box structure, connecting copper rod using epoxy resin whole package casting and air insulation to form a composite insulation;

--Earth switch is connected to the main circuit busbar by insulating cover combined with silicone sleeve to form a multi-insulation structure;

--Reasonable cable overlap position is convenient for on-site construction;

--Reasonable cable connection location is convenient for on-site construction; --To realize the parallel cabinet with KYN28A-12 series wide cabinets; --Current transformer and contactor.

--Current transformer and contact box adopt one-piece structure to reduce the connection copper rows and connection points;

--Compact structure maximizes internal space to reduce the probability of discharge.

Innovative points include:

1, the use of a U-shaped structure column busbar and rectangular busbar lap terminals to maximize the contact area and reduce the contact resistance.

2, three-phase conductive body surface sandblasting, epoxy resin casting of the whole insulation, insulation surface crawling groove design in order to increase the creepage distance, so that the product in a narrow space, the impact resistance voltage of 4.8kV.

3. Under manual operation, the application of force-reducing mechanical operating arm and transmission gear mechanism reduces the operating torque from 100 Nm to less than 80 Nm.

Design Points of Grounding Switch

The grounding switch is a mechanical switching device used to ground the load when the main circuit is disconnected, and should be able to carry a certain current impact. And under normal circuit conditions, it still has to withstand the electromagnetic and thermal environments inside the cabinet, as well as the mechanical and thermal shocks generated under fault conditions.

In actual operation, the following procedures must be strictly followed: when the disconnecting switch is closed, the grounding switch must be tripped; after the main circuit switch is tripped, the grounding switch can only be closed.

Because of the reconfiguration of the circuit breakers under narrow cabinet conditions and the space limitations inside the cabinet, the narrow cabinet high-voltage grounding switch has relatively great difficulties in size construction. Narrow-cabinet high-voltage grounding switch adopts three-phase synchronous fast breaking and closing grounding.