A Method for Identifying Transient Faults and Permanent Faults

Abstract

The invention provides a method for identifying temporary faults and permanent faults, for the purposes of realizing simple principle, simple structure and low cost. The method comprises the following steps: 1, recording initial disconnection current features after a common on-post vacuum breaker is powered up, and obtaining current features of initial disconnection after power-up; 2, connecting a high-voltage capacitor in parallel with a main contact of the common on-post vacuum breaker, wherein at the moment, the high-voltage capacitor, a power supply and a distribution transformer form a loop together; 3, at the moment when the main contact breaks short-circuit currents, detecting currents in a high-voltage capacitor loop; 4, comparing the current features of the initial disconnection after the power-up with current values in the high-voltage capacitor loop obtained in the third step; and 5, when the current values in the high-voltage capacitor loop are smaller than current values of the initial disconnection after the power-up, determining that faults are permanent, and otherwise, determining that the faults are temporary. The method provided by the invention can be applied to the field of fault detection.

Description

technical field [0001] The invention relates to the field of fault detection of power distribution lines, in particular to a method for identifying transient faults and permanent faults in power distribution lines. Background technique [0002] Since 70% to 80% of short-circuit faults in distribution lines are instantaneous faults, the use of automatic reclosing can effectively improve the reliability of power supply. However, some short-circuit faults are also permanent faults. When a permanent fault occurs, the circuit breaker will automatically reclose. On the one hand, the distribution network will be impacted by the short-circuit current again, which will cause a sag in the system voltage and may even cause other accidents; on the other hand, the relay protection will make the circuit breaker trip again If the circuit breaker cuts off the short-circuit current twice in a short period of time, the service life of the circuit breaker will be shortened, and it may even ca...

AI Technical Summary

Problems solved by technology

But it also has disadvantages, such as: high cost, which is not acceptable to ordinary users; it needs the cooperation of hardware (fast switch of three-phase independent mechanism) and software (40,000 test data), and the process is complicated, which also causes its high cost. one of the reasons

But its cost is still high, and it needs to invest in parallel vacuum trigger discharge gap, power electronic control circuit at the trigger end and corresponding judgment software to realize it, and the process is also relatively complicated

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