Three-phase unbalance controller with fault current limiting function

Abstract

The invention provides a three-phase unbalance governor with a fault current limiting function, which comprises an annular transformer iron core, three groups of AC coupled coils and one group of auxiliary coil, wherein the three groups of AC coupled coils and the auxiliary coil are wound on the transformer iron core in the same winding direction; in the three groups of AC coupled coils, any one group of AC coupled coil is serially connected to one phase of line in a three-phase power grid, and any two groups of AC coupled coil are connected to different phases of lines in the three-phase power grid; and an IGBT-based voltage source converter or an anti-parallel thyristor is parallelly connected onto two ends of the auxiliary coil, and through the IGBT-based voltage source converter or the anti-parallel thyristor, current in the auxiliary coil is adjusted to suppress balance grounding fault in the circuit or compensate low / over voltage. Government is carried out effectively in view of fault and normal unbalance, the fault current limiting function is also realized, and the operation condition and the safety and the stability of the power grid are not influenced when no unbalance and short circuit fault exists in the power grid.

Description

technical field [0001] The invention relates to the field of electrotechnical technology, in particular to a three-phase unbalance controller with fault current limiting function, which can control fault / stable unbalance and short-circuit faults. Background technique [0002] The three-phase unbalance of the power system can be divided into two types: fault unbalance and normal unbalance. Phase-to-phase faults, etc.; normal unbalance refers to the unbalanced conditions that occur when the power grid operates in a steady state. [0003] Fault unbalance usually requires fault protection. Under the background of grid scale development, the short-circuit current level of power grid continues to increase, and the difficulty of fault protection continues to increase. There is an urgent need for a governance method that can effectively limit fault transient unbalance. The normal imbalance is caused by the unbalanced operation of the five links of generation, transmission, transfor...

AI Technical Summary

Problems solved by technology

[0005] Purpose of the invention: In order to solve the technical problem that the existing unbalance controller cannot quickly respond to the normal unbalance, let alone effectively deal with the fault unbalance and grounding fault, the present invention proposes a fault current limiting function Three-phase unbalance controller, the three-phase unbalance controller with fault current limiting function can effectively control the fault and normal imbalance when there is no unbalance and short-circuit fault in the power grid, and at the same time it will not affect the operating conditions of the power grid and safety and stability

Images