In my country’s power system, the 6-35KV AC power grid plays a crucial role in ensuring a steady and reliable power supply to urban areas. Within this system, the neutral points are managed through various grounding methods such as arc suppression coils, high resistance grounding, and small resistance grounding. However, one method that stands out for its effectiveness is the neutral point resistance grounding, which involves the use of a transformer neutral point grounding resistance cabinet.
In power systems, especially those with cables as the main transmission lines, the ground capacitor current can be significant, leading to the occurrence of “intermittent” arc ground overvoltage under specific “critical” conditions. This is where the neutral point resistance grounding method comes into play. By generating ground overvoltage and forming a discharge channel for the energy in the grid-to-ground capacitance, this method injects resistance current into the fault point, causing a ground fault current to occur.
The resistance-capacitance property of the neutral point resistance grounding method reduces the phase angle difference with the voltage, thereby lowering the re-ignition rate after the fault point current crosses zero. This effectively breaks the “critical” condition of arc overvoltage and limits the overvoltage to several times the phase voltage within 2.6. Additionally, this method ensures highly sensitive ground fault protection while accurately determining and removing the primary and secondary faults of the feeder, thereby safeguarding the normal operation of the system.
The transformer neutral point grounding resistance cabinet plays a pivotal role in implementing the neutral point resistance grounding method. It provides the necessary infrastructure to manage and control the grounding resistance, ensuring that the power system operates efficiently and safely. By understanding the importance of this equipment and the method it facilitates, power system operators can effectively protect against ground faults and ensure the uninterrupted supply of electricity to urban areas.
In conclusion, the transformer neutral point grounding resistance cabinet, in conjunction with the neutral point resistance grounding method, is a critical component in maintaining the stability and reliability of power systems. Its role in mitigating ground faults and overvoltages is essential for ensuring the continuous and safe operation of urban power supply systems.
Post time: May-27-2024