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CN-224205003-U - Automatic demagnetizing device and excitation system

CN224205003UCN 224205003 UCN224205003 UCN 224205003UCN-224205003-U

Abstract

The utility model relates to the technical field of excitation systems, in particular to an automatic de-excitation device and an excitation system, comprising a primary excitation power supply, a primary excitation power supply and a primary excitation power supply, wherein the primary excitation power supply is electrically connected with a generator rotor according to the current output direction; the de-excitation loop comprises a de-excitation switch and a de-excitation resistor which are sequentially connected between the positive pole and the negative pole of the primary excitation power supply, wherein the de-excitation resistor is connected with the generator rotor in parallel, and the overvoltage protection loop is connected with the de-excitation resistor in parallel and comprises an overvoltage jumper and an overvoltage resistor which are sequentially connected. The utility model can realize the overvoltage protection for the de-excitation circuit through the cooperation of the arranged primary excitation power supply, the de-excitation circuit and the overvoltage protection circuit, and realize the manual reset through the cooperation of the reset button and the remote/on-site control module, thereby solving the problem of remote and on-site control switching.

Inventors

  • SHI YIFENG
  • QIN HAO
  • LI YUQIU
  • LI XINGGUANG
  • ZANG GANG
  • LIN YASHAN
  • DING GUODONG
  • YI FENG

Assignees

  • 南京南瑞继保工程技术有限公司
  • 哈尔滨电机厂有限责任公司
  • 国投吉能(舟山)燃气发电有限公司

Dates

Publication Date
20260505
Application Date
20250403

Claims (10)

  1. 1. An automatic de-excitation device (M) is characterized by comprising a de-excitation cabinet, A primary excitation power supply (100) electrically connected to the generator rotor in the current output direction; The de-excitation loop (200) comprises a de-excitation switch (201) and a de-excitation resistor (202) which are sequentially connected between the positive pole and the negative pole of the primary excitation power supply (100), wherein the de-excitation resistor (202) is connected with the generator rotor in parallel, and The overvoltage protection loop (300) is connected in parallel with the de-excitation resistor (202) and comprises an overvoltage jumper (301) and an overvoltage resistor (302) which are connected in sequence.
  2. 2. The automatic demagnetizing device (M) according to claim 1, wherein at least two sets of the overvoltage protection circuits (300) are provided, and at least two sets of the overvoltage protection circuits (300) are respectively provided at both sides of the demagnetizing switch (201).
  3. 3. An automatic de-excitation device (M) as claimed in claim 1 or 2, characterized in that the overvoltage jumper (301) comprises an avalanche diode and a thyristor connected in series with an overvoltage resistor (302).
  4. 4. An automatic de-excitation device (M) as claimed in claim 3, characterized in that the overvoltage jumper (301) further comprises an overvoltage triggering circuit connected in parallel with an overvoltage resistor (302), The overvoltage triggering circuit comprises an overvoltage trigger (301 c-1) and an indicator lamp (301 c-2) which are sequentially connected in series and are arranged towards the outside of the demagnetizing cabinet.
  5. 5. The automatic demagnetizing device (M) according to claim 4, wherein the overvoltage jumper (301) further comprises a reset button (301 d) connected in parallel with the demagnetizing resistor (202) and disposed toward the outside of the demagnetizing cabinet, The reset button (301 d) has a normally open contact and a normally closed contact.
  6. 6. The automatic demagnetizing device (M) according to any of claims 1-2 and 4-5, wherein the primary excitation power source (100) comprises a primary excitation loop I (101) configured with alternating current or a primary excitation loop II (102) configured with direct current, The primary excitation loop one (101) is provided with a rectifier (101 a) for converting alternating current into direct current.
  7. 7. An automatic de-excitation device (M) as claimed in any one of claims 1-2, 4-5, further comprising a remote/on-site control module (400) located within the de-excitation cabinet, The remote/on-site control module (400) comprises a remote/on-site switching handle (401) connected with the demagnetization circuit (200) and a switching-off/switching-on handle (402) for controlling the demagnetization switch (201); The remote/on-site switch handle (401) has a normally open node and a normally closed node, The normally open node of the remote/on-site switching handle (401) is connected to the remote position of the de-excitation cabinet.
  8. 8. An excitation system, characterized by comprising an automatic de-excitation device (M) as claimed in claim 1, and An excitation adjusting unit (500) arranged in the adjusting cabinet and comprising an excitation regulator for controlling the primary excitation power supply (100); the power rectifying unit (600) arranged in the rectifying cabinet comprises a fan (601) arranged in the rectifying cabinet and a rectifying loop (602) used for maintaining voltage stability.
  9. 9. The excitation system of claim 8, wherein the rectifying circuit (602) comprises a rectifying bridge (602 a), a resistive-capacitive absorption circuit (602 b) and an overvoltage absorption circuit (602 c) which are sequentially connected, and a fast fuse (602 d) is arranged on the alternating current side of the resistive-capacitive absorption circuit (602 b) and the overvoltage absorption circuit (602 c).
  10. 10. The excitation system of claim 8 or 9, wherein the fans (601) are provided in two groups, and the power rectifying unit (600) further comprises a fan control loop (603) for automatically switching the two groups of fans (601).

Description

Automatic demagnetizing device and excitation system Technical Field The utility model relates to the technical field of excitation systems, in particular to an automatic de-excitation device and an excitation system. Background The excitation system is an important component of the generator and is used for providing adjustable excitation current for the generator so as to meet the requirements of normal power generation of the generator and safe operation of a power system. Therefore, the excitation of the generator is regulated and controlled, so that the running reliability, safety and stability of the generator and the power system can be ensured, and the technical and economic indexes of the generator and the power system can be improved. The field-weakening technology is applied to the situation that when a short-circuit accident occurs in the generator or between the main transformer of the generator and the generator end to the generator or the load switch, the relay protection trips, and meanwhile, the field-weakening system is started to cut off the excitation power supply of the generator and consume the energy stored by the excitation winding as soon as possible, so that the rotor current is attenuated as soon as possible, the electromotive force and the short-circuit current of the generator are reduced rapidly, and the possibility that the short-circuit current causes insulation burnout, conductor melting or iron core burnout and other generator, transformer damage or accident expansion is reduced. The prior art is inconvenient to protect a circuit after starting and de-excitation, particularly has a single de-excitation starting control mode, and most of the prior art can only be operated on site and lacks a remote automatic control means. Disclosure of utility model Some simplifications or omissions may be made in this section as well as in the description of the utility model and in the title of the utility model, which may not be used to limit the scope of the utility model. In order to solve the defects in the prior art, the utility model aims to provide an automatic demagnetizing device. In order to achieve the above object, the utility model adopts the following technical scheme that the automatic demagnetizing device comprises, The primary excitation power supply is electrically connected with the generator rotor according to the current output direction; the de-excitation loop comprises a de-excitation switch and a de-excitation resistor which are sequentially connected between the positive pole and the negative pole of the primary excitation power supply, wherein the de-excitation resistor is connected with the generator rotor in parallel, and The overvoltage protection loop is connected in parallel with the de-excitation resistor and comprises an overvoltage jumper and an overvoltage resistor which are sequentially connected. As an optimal scheme of the automatic demagnetizing device, at least two groups of overvoltage protection loops are arranged, and at least two groups of overvoltage protection loops are respectively arranged on two sides of a demagnetizing switch. As a preferable scheme of the automatic demagnetizing device, the overvoltage jumper comprises an avalanche diode and a thyristor which are connected in series with an overvoltage resistor. As a preferable scheme of the automatic demagnetizing device, the overvoltage jumper further comprises an overvoltage triggering circuit connected in parallel with the overvoltage resistor, The overvoltage triggering circuit comprises overvoltage triggers which are sequentially connected in series and an indicator lamp which is arranged outside the demagnetizing cabinet. As a preferable scheme of the automatic demagnetizing device, the overvoltage jumper further comprises a reset button which is connected with the demagnetizing resistor in parallel and is arranged towards the outside of the demagnetizing cabinet, The reset button has a normally open contact and a normally closed contact. As a preferable scheme of the automatic demagnetizing device, the primary excitation power supply comprises a primary excitation loop I configured with alternating current or a primary excitation loop II configured with direct current, The primary excitation loop I is provided with a rectifier for converting alternating current into direct current. As a preferable scheme of the automatic demagnetizing device, the utility model also comprises a remote/local control module arranged in the demagnetizing cabinet, The remote/on-site control module comprises a remote/on-site switching handle connected with the demagnetizing loop and a switching-off/switching-on handle for controlling the demagnetizing switch; The remote/on-site switch handle has a normally open node and a normally closed node, And the normally open node of the remote/on-site switching handle is connected with the remote position of the de-excitation cabinet. In order to solve the defect