Partial excitation loss fault identification method for pulse loss

Abstract

The invention discloses a partial excitation loss fault identification method for pulse loss. According to the partial excitation loss fault identification method, a partial excitation loss fault of pulse loss is identified by analyzing and comparing differences among six pulse waves in one cycle of an excitation voltage, and during comparison, 10% of maximum data is removed from data of each pulse wave, so that the influence of excitation voltage peaks on calculation during rectification and commutation can be reduced; and 50% of minimum data is removed, therefore, sampling data of a normal pulse wave without lost pulse is basically a relatively large positive value, an average value cannot be reduced or even close to 0 due to the excitation voltage negative value part, the average valueof the pulse waves of the lost pulse is generally close to 0 or smaller than 0, a large difference exists between the average value and the pulse waves without the lost pulse, and the difference is used for identifying the excitation loss fault of the partial excitation loss fault.

Description

technical field [0001] The invention relates to a partial demagnetization fault identification method for pulse loss, which belongs to the technical field of electric power system relay protection. Background technique [0002] As the protection of total loss of excitation fault caused by loss of excitation or partial loss of excitation fault caused by reduced excitation, loss of excitation protection is already one of the protections that must be configured for synchronous motors with excitation systems such as generators and condensers. [0003] Pulse loss is one of the types of faults that lead to partial loss of excitation. After the pulse is lost, the average value of the excitation voltage will decrease to a certain extent due to the decrease in the output pulse number of the rectifier circuit of the excitation system. Since the average value of the excitation current is proportional to the average value of the excitation voltage, the average value of the excitation cu...

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Problems solved by technology

[0003] Pulse loss is one of the types of faults that lead to partial loss of excitation. After the pulse is lost, the average value of the excitation voltage will decrease to a certain extent due to the decrease in the number of output pulses from the rectifier circuit of the excitation system.

Since the average value of the field current is proportional to the average value of the field voltage, the average value of the field current will also decrease, resulting in a partial loss of field fault

[0004] At present, the criterion of the rotor side of the loss-of-excitation protection configured for generator protection or condenser protection is the criterion of excitation low voltage. The voltage criterion can only simply judge the magnitude of the excitation voltage, but cannot judge whether the excitation voltage has a fault of pulse loss

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