A device and control method for evaluating and degaussing the residual magnetism of a power transformer

A power transformer and remanence technology, applied in transformer/inductor components, measuring devices, transformer/inductor circuits, etc., can solve the malfunction of transformer differential protection, reduce power supply quality of power supply system, transformer input and output current Large difference, etc., to achieve the effect of accurate and rapid degaussing, boosting time and degaussing effect

CN109254253BActive Publication Date: 2020-11-10STATE GRID JIANGSU ELECTRIC POWER CO ELECTRIC POWER RES INST +5
8 Cites 0 Cited by

Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Publication Date
2020-11-10

Smart Images

  • Figure 1
    Figure 1
  • Figure 2
    Figure 2
  • Figure 3
    Figure 3
Patent Text Reader

Abstract

The invention discloses a device for evaluating and degaussing the residual magnetism of a power transformer. The main circuit includes: a filter capacitor and a resistor R0 are connected in parallel at both ends of a switching power supply, a main switch T5 is connected in series at the forward end of the switching power supply, and a rear end of the main switch T5 is connected in series. In parallel, there are switch T6 and resistor R1 series branch, switch 1 and switch 2 series branch, switch 3 and switch 4 series branch; the drive circuit is connected with main switch T5, switch T6, switch 1, switch 2 and switch 3 1. The driving end of the switch 4 is connected, and the control circuit is connected with the driving circuit, and is used to issue instructions to the driving circuit. In order to realize accurate and fast degaussing, the present invention provides a reference basis, is more intelligent, can realize fast and complete degaussing, and greatly improves the degaussing time and degaussing effect on site.
Need to check novelty before this filing date? Find Prior Art

Description

technical field

[0001] The invention relates to a device and a control method for evaluating and demagnetizing residual magnetism of a power transformer, and belongs to the technical field of power system safety control. Background technique

[0002] After the power transformer is out of operation and after the DC resistance test, there will be residual magnetism. The amount of residual magnetism depends on the winding current before the switching action, the strength and time of the DC current passing through the winding. The influence of transformer core remanence mainly includes the following aspects:

[0003] (1) When the residual magnetism of the transformer is large, the excitation inrush current generated by no-load charging may lead to a large difference between the input and output currents of the transformer, causing the transformer differential protection to malfunction.

[0004] (2) The impact excitation inrush current formed when the transformer is charged with...

Examples

Embodiment 1

[0052] The switching power supply of the main circuit is 96V. T5 is the main switch, T5 is turned on when charging, T5 is turned off when discharging; T6 and T7 are discharge switches, T6 and T7 are turned off when charging, and turned on when discharging, corresponding to different current values, select the discharge resistor to improve the discharge speed of the winding L to be tested (When the current is above 1A, T6 is turned on and discharged through R1; when the current is less than 1A, T7 is turned on and discharged through R1 and R2 at the same time to speed up the discharge speed); T1 and T4 are forward charging switches, which are turned on when charging forward and turned off when discharging; T2 and T3 are negative charging switches, which are turned on during negative charging and turned off when discharging; resistor R0 is the discharge resistor of the filter capacitor; resistors R1 and R2 are the discharge resistors of the transformer winding, where R2<R1; L is ...