Design points of customized switchgear

With the increasing demand for new energy and data centers, in addition to standardized products, there is a need for a large number of customized products based on demand. Some designs lack corresponding technical support and experimental verification, resulting in products being put into operation without any performance, quality assurance, or reliability verification, leaving hidden dangers for long-term reliable and safe operation.

Customized products, due to time constraints and low costs, lack sufficient funds and time for performance testing and reliability verification. Simple factory testing cannot guarantee safety and reliability.

Therefore, customized switchgear needs to pay attention to several points.

1. Customized based on mature and type tested products.

Customized products refer to standard products that cannot meet customer requirements, such as pre installed substation applications, which require a small depth and often unlimited width of the switchgear. Adopting circuit breaker compartment core modules and switch core units that have been verified through type testing to improve reliability. Do not change the core module, but modify the relatively unimportant cabinet and busbar parts.

Replace the circuit breaker with the same rocking in and out structure as much as possible, rather than redesigning it.

Gas insulated switchgear requires mature standardized products for its switch units, and the switch layout can be different, such as three positions and circuit breakers arranged from top to bottom to left and right, but dynamic and thermal stability analysis or testing is needed to verify.

Modular design, functional compartment units have been validated, and module units can be quickly assembled

2. Scientific theoretical foundation support

The selection of copper busbar current carrying capacity is based on certain conditions, such as ambient temperature, protection level of switch equipment, heat dissipation conditions, etc., as well as the heat generation of switch components. Therefore, customized products need to be determined through calculation, simulation analysis, etc. Through calculation and analysis, it can greatly reduce the cost cycle of prototype testing and improve reliability.

3. Persist in essential items

The safety of switchgear must be considered in some aspects, such as protection of breaking, insulation, temperature rise, and short-circuit withstand. However, some essential items may be overlooked, such as the pressure release of internal arc faults in medium voltage switchgear. The switchgear must have weak links for pressure release to ensure that serious explosion injuries are not caused.

The maintenance space after on-site installation must comply with corresponding regulatory requirements, such as the need for a handcart to pull out the cabinet for inspection and repair. Simply put, if it does not comply with safety regulations and cannot be put into operation, it will also leave security risks for later operation and maintenance.

4. Strictly control material requirements, ensuring the performance and safety of materials. Not all insulation boards can be taken over and used immediately. Performance parameters such as flame retardancy, arc resistance, and water absorption need to be determined based on the application scenario and safety requirements. Some 3240 epoxy boards are not flame retardant and cannot be used in switchgear. High quality insulation boards such as FR-4/GPO-3 should be used.

The material of outdoor switchgear needs to be corrosion-resistant, using galvanized or stainless steel plates. Standard parts need to be made of stainless steel material, and the sealing strip needs to have stable and reliable performance.

5. Leave enough margin.

Considering the different practical applications and the fact that the product has not been tested, the design of the switchgear needs to have sufficient margin and increase the cross-sectional area of the busbar slightly.