Fault self-adaptive ground connecting processing system and method for distribution network power grid

Abstract

The invention discloses a fault self-adaptive ground connecting processing system and method for a distribution network power grid. The distribution network power grid comprises a bus. The grounding processing system comprises a grounding transformer, a small resistor putting system, arc extinction complete equipment and a main control system, wherein the arc extinction complete equipment is connected with the bus through the grounding transformer, the small resistor putting system comprises a small resistor and a high-voltage contactor, one end of the small resistor is grounded, the other end of the small resistor is connected with the high-voltage contactor, the high-voltage contactor is connected with the grounding transformer, and the main control system is used for controlling the arc extinction complete equipment and the high-voltage contactor. The embodiment of the invention further discloses a fault self-adaptive ground connecting processing method for the distribution network power grid. By means of the fault self-adaptive ground connecting processing system and method for the distribution network power grid, instant grounding and permanent grounding faults can be intelligently distinguished, frequent trips caused by instant grounding faults are prevented, a circuit with permanent grounding faults can be isolated rapidly and accurately, and stable power supply of the power grid is guaranteed.

Description

technical field [0001] The invention relates to a power grid grounding system and method, in particular to a distribution network fault self-adaptive grounding processing system and method. Background technique [0002] In the early stage of power system development, the capacity was small, and it was believed that the increase in power frequency voltage was the main cause of insulation faults. At the same time, the ability of power equipment to withstand frequent overcurrent shocks was overestimated. Therefore, the initial neutral point of power equipment All operate with direct grounding. [0003] With the development and expansion of the power system, the number of single-phase grounding faults increases, and the circuit breaker often trips, causing frequent power outages. Therefore, the direct grounding mode is changed to the non-grounding mode. [0004] Since then, due to the rapid development of industry, the power transmission capacity has increased, the distance has...

AI Technical Summary

Problems solved by technology

The traditional arc suppressing coil grounding method can automatically eliminate the instantaneous single-phase ground fault, which has the advantages of reducing the number of trips and the ground fault current. However, since the non-transient single-phase ground fault cannot be eliminated, the entire power distribution system must withstand a long 2 hours) power frequency overvoltage (line voltage), so the insulation level of the equipment is high, which is unfavorable for power distribution system equipment (especially for some imported equipment, such as cables); The existence of time is not conducive to equipment and personal safety

Moreover, the fault line selection in the traditional arc suppression coil grounding system has always been a technical problem, and the actual line selection accuracy is very low

The low-resistance grounding method can avoid the problem of long-term power frequency overvoltage in the power distribution system, and has relatively low requirements for equipment insulation. The disadvantage is that any single-phase grounding fault in the system will trip, resulting in a high tripping rate and reducing the power supply. reliability

[0006] Therefore, these two grounding methods have their own advantages and disadvantages, and can only be applied to certain conditions. It is urgent to seek a more complete new grounding method

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