Pilot protection scheme for distribution network considering low voltage ride‐through of inverter‐interfaced distributed generators

Abstract

According to the latest grid-connected standard, the failure of IIDG (inverter-interfaced distributed generator), represented by wind power and photovoltaic power, is characterized by strong nonlinear output. Therefore, the protection scheme based on the traditional fault characteristics is difficult to be applied to the distribution network with high permeability IIDG access. Based on the low voltage traversing operation characteristics of PQ control strategy IIDG, the work analyzed the distribution characteristics of positive sequence fault components in distribution network, and proposed a pilot protection scheme for distribution networks based on the comparison of current amplitudes on both sides of line. This scheme not only reduced the strict requirement of pilot protection for synchronous sampling of communication facilities, but also eliminated the influence of load current. Moreover, it had good practicability and economy without the protection and cooperation with other components. At the same time, in order to avoid the misoperation of amplitude ratio protection criterion for non-fault line due to the existence of unmeasured load branches, the distribution characteristics of node branch current abrupt changes were used to establish the auxiliary criterion for node-branch current mutation. It solved the action dead zone of the ratio protection criterion. Finally, the feasibility of the proposed protection principle was verified by DIgSILENT simulation.

Injection Harmonic Current Differential Protection Based on Control-Protection Synergy for Distribution Networks with IBDGs

“…When the grid is disturbed, or a fault occurs, IBDGs need to inject reactive current as a priority to support the grid voltage during LVRT. Taking the standard of the latest Chinese grid connection as an example, the dynamic reactive current injected during LVRT operation can be expressed as [29,30]…”

Differential protection of distribution lines based on Hausdorff algorithm

“…In this method, the abrupt change of phase current is used as the starting criterion [9][10] . For the section with IOP Publishing doi:10.1088/1742-6596/2788/1/012032 2 power supply at both ends, after the FTU starting criterion is triggered, the phase current sampling sequence of one power frequency period from the associated FTU is sent and received to each associated FTU, and the Hausdorff distance between the current sampling sequence of the associated FTU is calculated to determine whether the fault occurs in the section [11] . The traditional three-stage current protection is used as the line protection method for the end line with only load [12] .…”

A Fault Section Location Method for Distribution Networks Based on Divide-and-Conquer

“…Modern power distribution systems mostly adopt multi-sectioned and multi-linked network structures so that faults can be limited to a smaller area to meet the increasingly demanding power supply service needs of electricity consumers [3]. However, the increase in the number of sections reduces the supply radius, resulting in insignificant differences in the magnitude of short-circuit currents in adjacent lines, which makes the fault location method based on the traditional three-stage current protection principle no longer applicable [4]. In the meantime, the problems of network scaling, distortion of fault information, and multiple faults in extreme cases also put higher requirements and challenges on the accuracy and speed of fault location [5].…”