Transformer excitation inrush current suppression system based on closing voltage frequency control and transformer excitation inrush current suppression method thereof

Abstract

The invention discloses a transformer excitation inrush current suppression system based on closing voltage frequency control and a transformer excitation inrush current suppression method thereof. The transformer excitation inrush current suppression method comprises the steps that residual magnetism detection and parameter setting are performed; a control function is generated, and the parameters of the control function are calculated; and a system power supply and the primary side of a transformer are connected through a closing voltage frequency control system, voltage frequency inputted to the transformer is changed according to the control function, and control is ended and the closing voltage frequency control system is disconnected and the power supply and the primary side of the transformer are directly switched on. The beneficial effects of the system and the method are that the size of magnetic flux in the no-load closing process of the transformer can be accurately controlled so that the magnetic flux is enabled not to exceed saturation magnetic flux which can be borne by a transformer iron core, and the objective of excitation inrush current can be achieved; excitation inrush current can be fundamentally suppressed, and the influence of excitation inrush current on the transformer and transformer protection equipment can be more effectively avoided; and selection and setting of the control function are allowed so that flexibility of the control scheme and adaptability to different types of transformers can be ensured.

Description

technical field [0001] The invention belongs to power system transformer protection technology, in particular to a transformer excitation inrush suppression system and method based on closing voltage frequency control. Background technique [0002] The power transformer is an important equipment in the power system. When the transformer is closed with no load, the external fault is removed, or the power supply side is overvoltage, due to the inductive characteristics of the transformer, a large excitation inrush current will be generated. In severe cases, it can reach 60% of the rated current of the transformer. to eight times. A large inrush current will increase the heat generation of the transformer core and affect the service life of the transformer; it will generate a large number of harmonics and affect the power quality; it will also cause the relay protection device to malfunction, affecting the safe and reliable operation of the power grid. Among them, the excitati...

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Problems solved by technology

This type of method needs to change the system structure, and can only suppress the inrush current to a certain extent

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