Distributed power supply-containing petal-type urban power grid regional backup protection method

Abstract

The invention provides a distributed power supply-containing petal-type urban power grid regional backup protection method, and the method comprises the steps: enabling two ends of each line on a petal-type urban power grid trunk line to be provided with a protection device and a circuit breaker, and enabling each petal-type looped network trunk line to be provided with an even number of protection devices; setting each petal of the petal type urban power grid as an area, and setting an information processing center at each transformer substation; when a three-phase earth fault occurs on a trunk line of a petal type urban power grid containing a plurality of distributed power supplies, determining a fault section or a fault line step by step according to a comparison result of amplitudes of currents flowing through protections on two sides of a grid-connected point of the distributed power supplies; in the prior art, secondary equipment current transformers in a petal type urban powergrid are broken, so that the current at the current transformers cannot be obtained, maloperation or refusal of a protection device is possibly caused, heavy losses are further caused, and different countermeasures should be taken for the broken current transformers at different positions according to the situation.

Description

technical field [0001] The invention belongs to the field of protection and control of power system distribution network. Based on the analysis results of the fault characteristics of the petal-type urban power grid, a method for regional backup protection of the petal-type urban power grid with distributed power sources based on multi-source information is proposed. Background technique [0002] With the rapid increase of load density, the traditional radial power grid has a large range of faults, and it is difficult to meet the development needs of high power supply reliability in urban power grids. Urban power grids gradually adopt single-loop and double-loop networks with "closed-loop design and open-loop operation" Wait for the wiring method. In addition, the petal-type wiring and operation mode have attracted widespread attention because of its high reliability, and more and more areas with high load density and high power supply reliability have begun to adopt this ne...

AI Technical Summary

Problems solved by technology

On the other hand, with the high proportion of distributed power access, the complexity of the urban power grid topology increases, the system operation mode is changeable, and the direction of the power flow is uncertain, which makes the urban power grid present new fault characteristics, resulting in the traditional local-based A large amount of relay protection sensitivity is reduced or even lost selectivity, it is difficult to remove the fault with correct action

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