The neutral point grounding methods
commonly used in my country's power system are: the neutral point is directly grounded, the neutral point is not grounded, the neutral point is grounded through the arc suppression coil (resonance grounding), and the neutral point
is grounded through the resistance. The grounding operation mode of the power system involves many important issues such as the safe operation of the power grid, the reliability of power supply, and the safety of users' power consumption. In terms of professional technology, it involves many fields such as power system, overvoltage and insulation coordination, relay protection, communication and automatic control, electromagnetic compatibility, grounding design, etc. It is a system problem with a wide range of content. The neutral point grounding resistance cabinet is divided into protection objects: transformer neutral point grounding resistance cabinet and generator neutral point grounding resistance cabinet.
Among them, the neutral point is grounded by resistance is to connect a certain resistor in series between the neutral point of the power grid and the ground. Appropriate selection of the resistance value of the connected resistor can not only discharge the energy of the second half wave of the single-phase grounding arc, thereby reducing the possibility of arc reignition, suppressing the amplitude of the grid overvoltage, but also improving the sensitivity of the relay protection device In order to act on the trip, so as to effectively protect the normal operation of the system.
In AC power grids, the use of resistance grounding, especially in cable-powered networks, has become increasingly widespread.
The transformer neutral grounding resistance cabinet is a complete set of grounding equipment including grounding transformers, which can be installed in the plant power system of power plants, the power supply system of substations, and the power distribution system of industrial and mining enterprises to realize the use of neutral point resistance in these power grids. Grounded system operation mode.