A Microgrid Fault Location Method Based on Active Construction of Fault Features

Abstract

The invention discloses a micro-grid fault location method based on active construction of fault characteristics. The steps include: micro-power sources calculate fault current instructions according to positive-sequence fault voltage components of grid-connected points; micro-grid protection devices judge faults according to phase relationships of positive-sequence fault components direction; the microgrid protection system collects the fault direction information of the protection device, and locates the line where the fault point is located. The invention constructs a fault feature that can be used for fault direction discrimination in the micro-grid through micro-power fault control, and the protection system can accurately locate the fault line of the micro-grid by using the feature, and the detection result is accurate and reliable, and has high operability.

Description

technical field [0001] The invention relates to micro-grid fault location technology, in particular to a micro-grid fault location method based on active construction of fault features. Background technique [0002] Microgrid is an important part of smart grid and has broad application prospects. However, in the actual operation process, due to the constraints of insulation level, operating environment, equipment aging and other factors, various faults will inevitably occur in the microgrid. In order to ensure the reliability of power supply for users, the microgrid must remove faulty equipment quickly and accurately. Although the microgrid and the distribution network have similar radial feeder structure and voltage level, it is generally believed that the three-stage current protection scheme used in the distribution network is no longer suitable for the microgrid. The main reasons are as follows: 1 ) Most of the micro-power sources in the micro-grid are inverter-type mi...

AI Technical Summary

Problems solved by technology

Although the microgrid and the distribution network have similar radial feeder structure and voltage level, it is generally believed that the three-stage current protection scheme used in the distribution network is no longer suitable for the microgrid. The main reasons are as follows: 1 ) Most of the micro-power sources in the micro-grid are inverter-type micro-power sources (the micro-power sources mentioned later refer to inverter-type micro-power sources), and their maximum fault output current is generally limited to within 2 times the rated current; 2) The micro-grid has There are two operating modes: island and grid-connected, and the output power of some micro-power sources is not constant, resulting in a large uncertainty in the fault current level of the micro-grid

In addition, the micro-power fault control method also has a significant impact on the fault response characteristics of the micro-grid, which directly affects the fault status of the micro-grid and the reliability of protection actions.

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