Distribution network disconnection fault location and identification method and system based on phase current amplitude

A technology of disconnection fault and current amplitude, which is applied in the direction of fault location, fault detection according to conductor type, and electrical measurement. The effect of perfect fault monitoring function and simple data processing

CN112255499BActive Publication Date: 2021-09-07CHONGQING UNIV
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Publication Date
2021-09-07

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Abstract

The invention discloses a distribution network disconnection fault location and identification method and system based on phase current amplitude, which is judged based on the difference between the amplitude of the three-phase current at the current sampling time and the amplitude of the three-phase current at the previous sampling time Whether a disconnection fault occurs, and if so, record the phase with the smallest amplitude of the three-phase current at the current sampling time as the phase where a short-circuit fault occurs; The fault phase current amplitude difference between adjacent points on the line at the current sampling time, and then determine the upstream point and downstream point of the fault area, based on the fault phase current amplitude judgment of the upstream point and downstream point of the fault area Type of disconnection fault. The present invention can realize the fault location of distribution network disconnection and the discrimination of disconnected non-ground fault, disconnected power supply side grounding or disconnected load side grounding fault in distribution network only by using the phase current amplitude, without needing signal synchronization and not relying on fast sampling. Higher reliability and better practicality.
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Description

technical field

[0001] The invention relates to the field of relay protection of power systems, in particular to a method and system for locating and identifying disconnection faults of distribution networks based on phase current amplitudes. Background technique

[0002] The distribution network is a power supply network that directly faces users and is an important part of the power system. Its power supply reliability and quality directly affect industrial production and social and economic development, and are also closely related to people's quality of life. With the development of cities, the scale of power distribution network becomes increasingly large and complex. Due to the large number of lines in the network and the large number of equipment with different levels, it is easy to fail due to self and external reasons during daily operation.

[0003] With the increasing application proportion of overhead insulated conductors in distribution network year by year, th...

Examples

Embodiment Construction

[0065] The present invention will be further described in detail below in conjunction with the accompanying drawings.

[0066] by figure 1 The 10kV distribution network structure shown is taken as an example. Among them, Z1 is the main transformer, Z2 is the grounding transformer, and the neutral point grounding resistance R 0 is 10Ω. There are 6 feeder lines in total, and the line lengths are 10km, 8km, 9km, 7km, 6km, and 5km. The feeder positive sequence parameter is: R 1 = 0.031Ω / km, L 1 =0.096mH / km, C 1 =0.338μF / km, the zero sequence parameter of the feeder is: R 0 = 0.234Ω / km, L 0 = 0.355mH / km, C 0 = 0.3 μF / km. On-line monitoring devices T1, T2, T3 and T4 are installed at 1km, 2km, 5km and 8km of feeder 1, respectively. There are loads connected between adjacent devices, which are 0.5MW, 3MW, 1MW and 2MW respectively.

[0067] Such as figure 2 As shown, the present invention discloses a distribution network disconnection fault location and identification meth...