Self-adaptive current fast tripping protection method for distribution network comprising inverse distributed power

Abstract

The invention belongs to the technical field of relay protection of distribution networks, relates to a protection method for a distribution network comprising inverse distributed power, and provides an improved self-adaptive current fast tripping protection proposal comprising an IIDG power distribution system on the basis of the prior self-adaptive current fast tripping protection. The protection method still performs online setting on protection according to the prior mode of a self-adaptive setting value expression under the condition of no consideration of the connection of an IIDG when the IIDG is connected to the rear side of the protection, utilizes a negative sequence component to solve for the actual equivalent impedance of the rear side of the protection and uses an equivalent electric potential under the current failure state to set the protection under the condition of two-phase short circuit, still adopts a calculation method under the condition of no connection of the IIDG to solve for the equivalent impedance under the current failure state, obtains a corresponding equivalent electric potential according to the equivalent impedance, and uses the equivalent electricpotential to set the protection under the condition of three-phase short circuit. The method improves the prior current protection configuration and guarantees the reliable failure removal of a distribution system comprising an inverse DG.

Description

technical field [0001] The invention relates to the field of relay protection for power system distribution networks, and proposes an adaptive current quick-break protection scheme suitable for distribution networks with inverter-type distributed power sources (IIDG). Background technique [0002] There are many types of distributed power generation (DG), which can generally be divided into traditional rotary type DG and inverter type DG (IIDG) according to different operation modes. The traditional rotary type DG has the same characteristics as the traditional generator, which can be equivalent to the series connection of the potential source and the impedance; while the IIDG is quite different from them. After a large number of distributed power sources, especially inverter-type distributed power sources, are connected to the distribution network, traditional distribution network protection will inevitably be affected. For wind power generation, solar power generation, et...

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Problems solved by technology

[0003] The purpose of the present invention is to solve the problem of difficult setting of protection setting after IIDG is connected to the distribution network, combined with the characteristics of faults in the distribution system containing IIDG, the existing self-adaptive current quick-break protection basis without considering IIDG connection Above, an adaptive current quick-break protection scheme for power distribution system with IIDG is given

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