A flexible grounding protection control system for distribution network

Abstract

The invention provides a flexible grounding protection control system for distribution network. The AC quantity acquisition unit performs three-phase voltage, neutral point voltage, neutral point arc suppression coil branch current, small resistance current and zero sequence current signals of each branch of the power grid. Data acquisition; the digital quantity acquisition unit collects data on the arc suppression coil gear position, the switching state of the small resistance and the switching state of each branch circuit breaker; the monitoring algorithm unit collects and controls the AC quantity acquisition unit and the digital quantity acquisition unit, And according to the data collected by the AC quantity collection unit and the digital quantity collection unit, the arc suppression coil gear adjustment, small resistance switching and each branch trip control signal are generated; the control signal output unit realizes arc suppression according to the control signal generated by the monitoring algorithm unit. Coil shift control, small resistance switching control and each branch trip control. The invention realizes the measurement and control of the arc suppression coil system, the control functions of the small resistance system, and the functions of grounding line selection and line selection tripping.

Description

technical field [0001] The invention relates to a flexible grounding protection technology for a distribution network in the technical field of power supply and distribution networks, in particular to a flexible grounding protection control system for a distribution network. Background technique [0002] In the 6-35kV power supply and distribution network, two neutral point grounding methods are mainly used: the neutral point is grounded through the arc suppression coil, and the neutral point is grounded through a small resistance. [0003] For the distribution network dominated by overhead lines, due to the limited capacitance current after single-phase grounding, the neutral point is generally grounded through the arc suppression coil, and the arc suppression coil can compensate the capacitor current after the grounding. After the grounding current is compensated by the arc suppression coil, the grounding current is obviously reduced, so that the line selection device cann...

AI Technical Summary

Problems solved by technology

[0010] 1. Frequent switching of small resistors caused by unsatisfactory cooperation with DTU / FTU and other equipment in the distribution network, and faults cannot be isolated;

[0011] 2. Insufficient selectivity of zero-sequence overcurrent protection when high-impedance grounding;

[0012] 3. Misoperation of small resistors caused by too simple identification of ground faults;

At present, there is no description or report of the similar technology of the present invention, and no similar data at home and abroad have been collected yet.

Images