Transformer Neutral Point Grounding Resistor Cabinet

With the development of urban power grids, the proportion of cable lines is increasing year by year, leading to a surge in ground capacitance current. For distribution networks primarily composed of cable lines, if the neutral point is not grounded or grounded via an arc suppression coil, a single-phase ground fault can generate overvoltages several times higher than the normal value, easily developing into phase-to-phase short circuits, exacerbating the fault, damaging electrical equipment, and jeopardizing the safe operation of the system. Using a neutral point grounded with a small resistance can reduce the overvoltage multiple to below 2.5 times, preventing damage to electrical equipment, extending the service life of electrical equipment, and ensuring reliable operation of relay protection devices, selectively and quickly disconnecting faulty lines.

The SMR-NGR series transformer neutral point grounding resistor cabinet standard equipment consists of grounding resistor elements, supporting insulators, insulating bushings, internal wiring, and a cabinet. It is suitable for 50/60Hz voltage levels of 6–66kV transmission and distribution systems and is a current-limiting protective device used to connect the transformer neutral point to the ground. After installing a neutral point grounding resistor cabinet, when a non-metallic grounding occurs, the current flowing through the grounding point and neutral point is significantly reduced compared to a metallic grounding. The voltage rise of the non-faulty phases is also significantly reduced, providing a current-limiting and voltage-reducing effect and preventing potential damage to lines and equipment. It is typically used for short-time operation and does not consider the ability to carry large currents for extended periods. Its power and voltage rating depend on the specific conditions of the power transmission and distribution system.

1.Power Plants: Neutral point grounding for 6kV or 10kV power supply systems.

2.Substations: Neutral point grounding for 10kV and 35kV distribution systems.

3.Industry and Manufacturing: Power distribution networks for steel, chemical, mining, petroleum, data centers, and large manufacturing plants.

4.Urban Power Grids and Infrastructure: Power supply systems for subways, airports, ports, hospitals, and commercial complexes.

5.Renewable Energy: Medium-voltage side of step-up substations for wind farms and photovoltaic power plants.

Baoding Simaier Electric Co., Ltd. has a 3,600-square-meter production base with advanced production equipment, a technical team, and an R&D team. We can customize products according to customer needs and strictly implement quality management systems to ensure product quality and production efficiency.