CN-121983923-A - On-load voltage-regulating tap-changer protection circuit of arcless distribution transformer

CN121983923ACN 121983923 ACN121983923 ACN 121983923ACN-121983923-A

Abstract

The invention provides an on-load voltage-regulating tapping switch protection circuit of an arcless distribution transformer, which relates to the technical field of distribution transformers, and comprises the following steps: the intelligent power distribution transformer comprises a power distribution transformer body, a quick-acting protection action switch, an IGBT anti-parallel module, an arc extinguishing resistor, a signal acquisition and logic control system and a pulse triggering control module. The distribution transformer adopts Yyn0 wiring, and is provided with three gears, namely 1 gear for voltage up-regulation, 2 gear as a rated operation gear and 3 gear for voltage down-regulation. The IGBT anti-parallel module realizes tap arc-free switching, the arc extinguishing resistor suppresses transient over-current, the signal acquisition system monitors voltage, current and gear information, the logic control system generates gear switching logic and protection decision, and the pulse triggering module controls the on-off of the IGBT through PWM modulation. The invention can dynamically switch without arc, rapidly respond in ms level, effectively protect devices, and improve the reliability, economy and power supply quality of equipment.

Inventors

Zhao Zongluo
LI YABO
TANG AIHONG
TONG ZEJUN
GU LINGYUN
LUO BIN
YU CONG
HU QING
HUANG YADONG
LING XIAOWEI
CHEN YU
ZHANG JUN

Assignees

浙江容大电力工程有限公司
国网浙江省电力有限公司杭州市富阳区供电公司
武汉理工大学

Dates

Publication Date: 20260505
Application Date: 20251215

Claims (10)

1. The on-load voltage-regulating tapping switch protection circuit of the arcless distribution transformer is characterized by comprising a distribution transformer body, a quick-acting protection action switch, an IGBT anti-parallel module, an arc extinguishing resistor, a signal acquisition and logic control system and a pulse trigger control module; Three adjustable gears are arranged on the distribution transformer body by Yyn0 wiring, the primary side is connected with the signal acquisition and logic control system and the pulse trigger control module through a T1 winding to supply power, and the primary side is connected with a load through a T2 winding to supply power; The IGBT anti-parallel module is correspondingly connected with three gears of the distribution transformer body and is used for switching tap gears; The quick-action protection action switch is arranged between winding taps of 1 gear and 3 gears and the corresponding IGBT anti-parallel modules and is used for detecting overcurrent signals among windings and cutting off short-circuit current; The signal acquisition and logic control system is used for acquiring a primary side voltage signal, gear information, a primary side winding current signal and state information of the quick-acting protection action switch, generating a logic control decision and transmitting a control signal to the pulse trigger control module; And the pulse triggering control module generates a triggering signal through PWM modulation after receiving the control signal, and controls the on-off of the IGBT anti-parallel module.
2. The arc-less distribution transformer on-load tap changer protection circuit of claim 1, wherein the distribution transformer body is a dry distribution transformer adapted to a voltage class of 10kV/0.4kV, and of the three adjustable gears, 1 gear is used for voltage up-regulation, 2 gear is a rated running gear, and 3 gear is used for voltage down-regulation.
3. The protection circuit of the on-load tap changer of the arcless distribution transformer according to claim 1, wherein each IGBT anti-parallel module is composed of two IGBTs, two anti-parallel diodes and a resistance-capacitance absorption circuit, and the two IGBTs share one resistance-capacitance absorption circuit.
4. The protection circuit of the on-load voltage-regulating tap changer of the arcless distribution transformer according to claim 1, wherein the number of the snap-action protection action switches is two, and the two snap-action protection action switches are correspondingly arranged, and are used for tripping when overcurrent is generated by winding short circuit, so as to cut off the circulating short circuit current between the two windings and restore the transformer to the rated operation state of 2 gears.
5. The protection circuit of the on-load tap changer of the arcless distribution transformer according to claim 1, wherein the arc extinguishing resistor is determined by an adaptive parameter design and is matched with the IGBT anti-parallel module in the transient transition process of gear switching.
6. The protection circuit of the on-load tap changer of the arcless distribution transformer according to claim 1, wherein the logic control decisions of the signal acquisition and logic control system comprise gear switching logic and protection action decisions, and the signal connection is realized through a wireless data tag and the pulse trigger control module.
7. The protection circuit of the on-load tap changer of the arcless distribution transformer according to claim 1, further comprising an optocoupler trigger circuit of the anti-parallel IGBT module, wherein the optocoupler trigger circuit is used for triggering and conducting the anti-parallel IGBT modules of the 1 gear and the 3 gear, and a low-level triggering and conducting mode is adopted.
8. The protection circuit for the on-load voltage-regulating tap-changer of the arcless distribution transformer according to claim 1, wherein the optocoupler trigger circuit comprises an optocoupler module, a steady-state diode, a diode and a plurality of resistors, and the optocoupler trigger circuit is connected in series after a plurality of groups of optocouplers are connected in parallel with the resistors.
9. The protection circuit for the on-load tap changer of the arcless distribution transformer according to claim 1 is characterized in that the working flow of gear switching is that when the transformer is in a rated running state that a 2-gear IGBT anti-parallel module is conducted, a tap is adjusted from 2 gear to 3 gear when load voltage drops, and when load voltage rises, the tap is adjusted from 2 gear to 1 gear, and the switching process is consistent with the logic.
10. The on-load voltage-regulating tapping switch protection circuit of the arcless distribution transformer is characterized in that an IGBT anti-parallel module corresponding to a 2 gear is conducted after receiving a high-level signal generated by a pulse trigger control module, is turned off after receiving a low-level signal, and has passive automatic starting capability, the IGBT anti-parallel module corresponding to a 1 gear and a3 gear is turned off after receiving the high-level signal, is conducted after receiving the low-level signal, trigger control modes of the 2 gear, the 1 gear and the 3 gear are opposite, a quick-action protection action switch is only arranged at the 1 gear and the 3 gear, the impulse voltage amplitude of the IGBT anti-parallel module of the 2 gear is lower than that of the IGBT anti-parallel module of the 1 gear and the 3 gear, the voltage and the current redundancy margin of the IGBT anti-parallel module of the 2 gear are higher under the same IGBT device type selection condition, and the transformer is in a rated working state through the 2 gear conduction after the protection action.

Description

On-load voltage-regulating tap-changer protection circuit of arcless distribution transformer Technical Field The invention relates to the technical field of distribution transformers, in particular to an on-load voltage-regulating tap-changer protection circuit of an arcless distribution transformer. Background Due to the fluctuation and randomness of power generated by line terminal photovoltaic and electric loads for electric vehicles, the requirements and standards of urban and rural power distribution networks on flexible voltage regulation, node voltage stabilization and voltage and power quality of distribution transformers are gradually improved, and meanwhile, the requirements on overvoltage, overcurrent and lightning protection are also improved. The existing mechanical on-load voltage-regulating tap-changer transmission device can not realize the dynamic switching process of arc extinction, is easy to cause insulating oil pollution, has serious contact burning phenomenon and high equipment damage and power failure risk rate. The development of the arcless on-load voltage regulating tapping switch based on the semi-control type/full-control type power electronic device becomes an effective solution, the distribution transformer loaded with the arcless on-load voltage regulating tapping switch can realize the regulation targets of flexible voltage regulation at high frequency, 100% arcless switching, response action speed of ms level, high voltage stability control degree and the like, and has a great prospect in realizing load voltage regulation in distribution areas. The key component in the switching process of the arc-free on-load voltage regulation action is a switching tapping switch and a control module thereof. The switching tapping switch topology based on the semi-controlled thyristor/full-controlled IGBT and MOSFET power electronic device and the control module thereof are easy to generate accumulated heat, power electronic device aging and external fault overvoltage and overcurrent during long-term operation work, which can cause device damage, series short circuit of the voltage regulating winding of the distribution transformer body, and further cause integral fault damage of the transformer and increase of risk rate of cascading faults of the multi-area transformer. Therefore, the method has great necessity and research significance in researching a new on-load voltage-regulating tap-changer protection scheme, and further the patent of the invention can research a new on-load voltage-regulating tap-changer protection method of the arcless distribution transformer. The latest research aiming at the protection technology of the on-load voltage-regulating tapping switch is that the research literature issued by the Chinese know network website improves the reliability and stability of the slide protection of the ABB-BUL on-load voltage-regulating tapping switch, and the control method for improving the reliability and stability of the slide protection of the ABB-BUL on-load voltage-regulating tapping switch is provided, which enables a delay relay to work in a timing way, automatically cuts off a power supply when the power supply is overtime, and realizes the slide protection function. The research literature issued by the Chinese known network website shows the differential protection action characteristics of the on-load tap changer interstage short circuit faults of the converter transformer, and the research literature aims at the explosion fire problem caused by the on-load tap changer interstage short circuit faults, provides a direct field-path coupling-based transformer on-load tap changer interstage short circuit fault model and a solving method, and quantitatively analyzes the feasibility and the action characteristics of different protection schemes of taps in different positions of faults. Disclosure of Invention In view of the shortcomings of the prior art, the embodiment of the invention aims to provide a protection circuit for an on-load voltage-regulating tap changer of an arcless distribution transformer, which can solve the technical problems of winding short-circuit faults caused by heat accumulation, device aging and overvoltage and overcurrent of the on-load voltage-regulating tap changer in the prior art. The on-load voltage regulation tapping switch protection circuit of the arcless distribution transformer comprises a distribution transformer body, a quick-action protection action switch, an IGBT anti-parallel module, an arc extinguishing resistor, a signal acquisition, logic control system and a pulse trigger control module, wherein three adjustable gears are arranged on the distribution transformer body through Yyn0 wiring, a primary side is connected with the signal acquisition and logic control system and the pulse trigger control module through a T1 winding and is powered, the primary side is connected with a load through a T2 winding and is correspondingly