CN110768212B - Transformer internal short-circuit fault protection device and control method thereof - Google Patents

Transformer internal short-circuit fault protection device and control method thereof Download PDF

Info

Publication number
CN110768212B
CN110768212B CN201911020518.0A CN201911020518A CN110768212B CN 110768212 B CN110768212 B CN 110768212B CN 201911020518 A CN201911020518 A CN 201911020518A CN 110768212 B CN110768212 B CN 110768212B
Authority
CN
China
Prior art keywords
current
transformer
switch
contact
value
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN201911020518.0A
Other languages
Chinese (zh)
Other versions
CN110768212A (en
Inventor
袁耀
刁均伟
杨家辉
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Guangzhou Power Supply Bureau Co Ltd
Research Institute of Southern Power Grid Co Ltd
Original Assignee
Guangzhou Power Supply Bureau Co Ltd
Research Institute of Southern Power Grid Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Guangzhou Power Supply Bureau Co Ltd, Research Institute of Southern Power Grid Co Ltd filed Critical Guangzhou Power Supply Bureau Co Ltd
Priority to CN201911020518.0A priority Critical patent/CN110768212B/en
Publication of CN110768212A publication Critical patent/CN110768212A/en
Application granted granted Critical
Publication of CN110768212B publication Critical patent/CN110768212B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
    • H02H7/04—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for transformers
    • H02H7/055—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for transformers for tapped transformers or tap-changing means thereof
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
    • H02H7/04—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for transformers
    • H02H7/045—Differential protection of transformers

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Protection Of Transformers (AREA)

Abstract

The invention discloses a short-circuit fault protection device in a transformer and a control method thereof, wherein the device comprises a first current transformer, a second current transformer, a third current transformer, a controller and a quick switch; the first end of the first current transformer is connected with a main current-carrying contact of a first switch in the change-over switch, the second end of the first current transformer is connected with the first end of the quick switch, and the second end of the quick switch is connected with a first contact of the tapping selector; the first end of the second current transformer is connected with a main current-carrying contact of a second switch in the change-over switch, and the second end of the second current transformer is connected with a second contact of the tapping selector; the third current transformer is arranged on an outgoing line of the on-load voltage regulation tap switch; the output ends of the first current transformer, the second current transformer and the third current transformer are connected with the input end of the controller, the output end of the controller is connected with the control end of the quick switch, and the problem that the position of an internal fault point of the transformer cannot be judged in the prior art can be effectively solved, so that accurate protection is realized.

Description

Transformer internal short-circuit fault protection device and control method thereof
Technical Field
The invention relates to the technical field of power systems, in particular to a transformer internal short-circuit fault protection device and a control method thereof.
Background
In an electric power system, a transformer is an important core device for power transmission. Generally, a power transformer is provided with an on-load tap changer, and the number of turns of a transformer winding can be adjusted through the on-load tap changer, so that the effect of adjusting the output voltage of the transformer is achieved. The on-load tap changer mainly comprises two parts: tap selection and a diverter switch. When the transformer is shifted, the tapping selector is adjusted to a pre-selection tapping position in advance, and then the mechanism controls the action of the selector switch to switch the load current from the last tapping position to the pre-selection tapping position, so that the shifting is completed. During the gear shifting, the load current is not allowed to be switched off. Generally, for a combined voltage regulating tap switch, the tap selector and the winding are both in the transformer tank, and the diverter switch is separately placed in an independent oil chamber and is not communicated with the transformer tank.
The reliability of the on-load tap changer is crucial to the normal operation of the transformer, once the on-load tap changer breaks down, the transformer can be directly shut down, and explosion and fire of the transformer are caused in serious cases. In recent years, transformer explosion and fire faults caused by abnormity in the gear shifting process of the on-load tap changer appear in a power grid for many times, great influence is brought to safe and stable operation of a power system, and great loss is caused to power departments and the society. When faults such as incomplete switching or incapability of arc extinction and the like occur in the gear shifting process of the on-load voltage-regulating tap switch, an interstage short circuit can be caused, namely, a winding between two taps of a voltage-regulating winding of a transformer is directly short-circuited, and the short-circuit current usually reaches dozens of kiloamperes, so that serious consequences are caused.
When an inter-stage short circuit occurs, most of inter-stage short circuit current only forms a loop between the short-circuited tapping windings, and only a small part of the inter-stage short circuit current flows into the rest windings of the transformer. Therefore, the interstage short-circuit current cannot be effectively detected on the current transformers of the outgoing bushings at the two ends of the transformer winding. At present, internal short-circuit faults (turn-to-turn short circuits, winding-to-ground short circuits and inter-stage short circuits caused by on-load tap-changers) of transformers are generally removed through differential protection, although the internal short-circuit faults of the transformers can be removed in time through the differential protection, the situation that the initial point of the internal faults is in a main transformer oil tank or a change-over switch oil chamber of the on-load tap-changer cannot be judged, analysis and maintenance of the fault reasons of the transformers are not facilitated, fault responsibility reasons and responsibility parties cannot be clarified, and unnecessary troubles are brought to power departments.
Disclosure of Invention
The embodiment of the invention provides a transformer internal short-circuit fault protection device and a control method thereof, which can effectively solve the problem that the position of a fault point in a transformer cannot be judged due to the deficiency of transformer differential protection in the prior art.
The invention provides a short-circuit fault protection device in a transformer, which comprises a first current transformer, a second current transformer, a third current transformer, a controller and a quick switch, wherein the first current transformer, the second current transformer, the third current transformer, the controller and the quick switch are connected with the controller; the on-load voltage regulation tap switch of the transformer comprises a tap selector and a change-over switch; the first end of the first current transformer is connected with a main current-carrying contact of a first switch in the change-over switch, the second end of the first current transformer is connected with the first end of the fast switch, and the second end of the fast switch is connected with a first contact of the tapping selector; a first end of the second current transformer is connected with a main current-carrying contact of a second switch in the selector switch, and a second end of the second current transformer is connected with a second contact of the tapping selector; the third current transformer is arranged on an outlet wire of the on-load voltage regulation tap switch; the output ends of the first current transformer, the second current transformer and the third current transformer are connected with the input end of the controller, and the output end of the controller is connected with the control end of the quick switch.
As an improvement of the above scheme, the transformer further comprises a transformer winding, a transformer regulating winding, a first sleeve and a second sleeve;
the transformer winding is connected with the first sleeve, the transformer voltage regulating winding is connected with the tapping selector, and the wire outlet end of the change-over switch is connected with the second sleeve.
As a modification of the above, the changeover switch includes a first resistor and a second resistor;
one end of the first resistor is connected with the first end of the first current transformer, and the other end of the first resistor is connected with the auxiliary contact of the first switch;
one end of the second resistor is connected with the first end of the second current transformer, and the other end of the second resistor is connected with the auxiliary contact of the second switch.
As an improvement of the above scheme, when the first contact is an odd-numbered gear contact, the second contact is an even-numbered gear contact;
or when the first contact is an even gear contact, the second contact is an odd gear contact.
Another embodiment of the present invention correspondingly provides a method for controlling the internal short-circuit fault protection device of the transformer, including the following steps:
receiving a first current value from the first current transformer, a second current value from the second current transformer, and a third current value from the third current transformer;
respectively calculating current difference values of the first current value, the second current value and the third current value, and judging whether a fault occurs in the on-load tap-changer according to the current difference values;
and when the inside of the on-load voltage regulation tapping switch breaks down, the quick switch is controlled to be switched off.
As an improvement of the foregoing solution, the calculating the current difference values of the first current value, the second current value, and the third current value respectively specifically includes:
calculating a first current difference value between the first current value and the third current value;
calculating a second current difference value between the second current value and the third current value;
calculating a third current difference value between the first current value and the second current value;
a fourth current difference value of the second current value and the first current value is calculated.
As an improvement of the above scheme, the determining whether a fault occurs inside the on-load tap-changer according to each of the current difference values specifically includes:
and when the sum of the first current difference value and the second current difference value is the opposite number of the load current in normal operation, and the third current difference value and the fourth current difference value are not zero, judging that no fault occurs in the on-load tap-changer.
As an improvement of the above scheme, the determining whether a fault occurs in the on-load tap-changer according to each of the current difference values further includes:
when the sum of the first current difference value and the second current difference value is k times of the load current in normal operation, and the third current difference value and the fourth current difference value are both zero, judging that a fault occurs inside the on-load tap-changer; wherein k > 1.
Compared with the prior art, the short-circuit fault protection device in the transformer disclosed by the embodiment of the invention comprises a first current transformer, a second current transformer, a third current transformer, a controller and a quick switch; the on-load voltage regulation tap switch of the transformer comprises a tap selector and a change-over switch; the first end of the first current transformer is connected with a main current-carrying contact of a first switch in the change-over switch, the second end of the first current transformer is connected with the first end of the fast switch, and the second end of the fast switch is connected with a first contact of the tapping selector; a first end of the second current transformer is connected with a main current-carrying contact of a second switch in the selector switch, and a second end of the second current transformer is connected with a second contact of the tapping selector; the third current transformer is arranged on an outlet wire of the on-load voltage regulation tap switch; the output ends of the first current transformer, the second current transformer and the third current transformer are connected with the input end of the controller, and the output end of the controller is connected with the control end of the quick switch. By adopting the structure, the controller receives the first current value from the first current transformer, the second current value from the second current transformer and the third current value from the third current transformer, further calculates the current difference value of the first current value, the second current value and the third current value respectively, and judges whether the on-load tap-changer is internally faulted or not according to the current difference values, thereby controlling the quick switch to be switched off when the on-load tap-changer is internally faulted, effectively solving the problem that the position of a fault point in the transformer cannot be judged due to the deficiency of the differential protection of the transformer in the prior art, realizing accurate positioning of the fault position in the on-load tap-changer and realizing the fault positioning in the transformer compared with the traditional differential protection of the transformer, further realizing accurate protection, thereby effectively improving the reliability of the on-load tap-changer, the stability of transformer operation can be effectively improved.
Drawings
Fig. 1 is a schematic structural diagram of an internal short-circuit fault protection device for a transformer according to an embodiment of the present invention;
fig. 2 is a schematic flowchart of a control method of a transformer internal short-circuit fault protection device according to a second embodiment of the present invention;
fig. 3 is a schematic connection diagram of an on-load tap changer during normal operation of odd gears of a tap selector according to a second embodiment of the present invention;
fig. 4 is a schematic connection diagram of the on-load tap changer in normal operation in even-numbered gears of the tap selector according to the second embodiment of the present invention;
FIG. 5 is a schematic diagram of three stages in the shift from odd gears to even gears of the tap selector in accordance with a second embodiment of the present invention;
fig. 6 is a schematic diagram of a short-circuit current loop under an inter-stage short-circuit fault of an on-load tap changer in the second embodiment of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Example one
Referring to fig. 1, a schematic structural diagram of a transformer internal short-circuit fault protection device according to an embodiment of the present invention includes: the current transformer comprises a first current transformer 1, a second current transformer 2, a third current transformer 3, a controller 4 and a fast switch 5; the on-load tap changer 6 of the transformer comprises a tap selector 61 and a change-over switch 62; the first end of the first current transformer 1 is connected with a main current-carrying contact a1 of a first switch K1 in the change-over switch 62, the second end is connected with the first end of the fast switch 5, and the second end of the fast switch 5 is connected with a first contact b1 of the tap selector 61; the first end of the second current transformer 2 is connected with the main current-carrying contact a3 of a second switch K2 in the change-over switch 62, and the second end is connected with the second contact b2 of the tap selector 61; the third current transformer 3 is arranged on an outlet wire of the on-load tap-changer 6; the output ends of the first current transformer 1, the second current transformer 2 and the third current transformer 3 are connected with the input end of the controller 4, and the output end of the controller 4 is connected with the control end of the fast switch 5.
Referring to fig. 1, the transformer further includes a transformer winding 7, a transformer regulating winding 8, a first bushing 9 and a second bushing 10;
the transformer winding 7 is connected with the first sleeve 9, the transformer voltage regulating winding 8 is connected with the tapping selector 61, and the outlet end of the selector switch 62 is connected with the second sleeve 10.
In an alternative embodiment, referring to fig. 1, when the first contact b1 is an odd-numbered gear contact, the second contact b2 is an even-numbered gear contact; or when the first contact b1 is an even gear contact, the second contact b2 is an odd gear contact.
In this embodiment, the change-over switch 62 includes a first switch K1, a second switch K2 and a fixed contact a5, the fixed contact a5 is connected to the third current transformer 3, and each of the first switch K1 and the second switch K2 includes a main current-carrying contact and an auxiliary contact thereof. The first current transformer 1 and the second current transformer 2 are respectively connected to two moving contacts on the tapping selector 61, and in this embodiment, the moving contacts are odd-numbered gear contacts and even-numbered gear contacts.
In an alternative embodiment, referring to fig. 1, the switch 62 includes a first resistor R1 and a second resistor R2;
one end of the first resistor R1 is connected to the first end of the first current transformer 1, and the other end is connected to the auxiliary contact a2 of the first switch K1;
one end of the second resistor R2 is connected to the first end of the second current transformer 2, and the other end is connected to the auxiliary contact a4 of the second switch K2.
The short-circuit fault protection device in the transformer comprises a first current transformer, a second current transformer, a third current transformer, a controller and a quick switch, wherein the first current transformer, the second current transformer, the third current transformer, the controller and the quick switch are connected with the controller; the on-load voltage regulation tap switch of the transformer comprises a tap selector and a change-over switch; the first end of the first current transformer is connected with a main current-carrying contact of a first switch in the change-over switch, the second end of the first current transformer is connected with the first end of the fast switch, and the second end of the fast switch is connected with a first contact of the tapping selector; a first end of the second current transformer is connected with a main current-carrying contact of a second switch in the selector switch, and a second end of the second current transformer is connected with a second contact of the tapping selector; the third current transformer is arranged on an outlet wire of the on-load voltage regulation tap switch; the output end of the first current transformer, the output end of the second current transformer and the output end of the third current transformer are connected with the input end of the controller, the output end of the controller is connected with the control end of the quick switch, the accurate positioning of the fault position inside the on-load voltage regulation tap switch can be achieved, the fault positioning inside the transformer can be achieved, and then accurate protection can be achieved, so that the reliability of the on-load voltage regulation tap switch can be effectively improved, and the stability of the operation of the transformer can be effectively improved.
Example two
Referring to fig. 2, a flowchart of a control method of a transformer internal short-circuit fault protection device according to a second embodiment of the present invention is shown, where the method includes steps S201 to S203.
S201, receiving a first current value from the first current transformer, a second current value from the second current transformer and a third current value from the third current transformer.
In an alternative embodiment, referring to fig. 3, a schematic connection diagram of an on-load tap changer in normal operation of odd-numbered gears of a tap selector according to a second embodiment of the present invention is shown. Illustratively, when the first contact b1 is an odd-numbered gear contact,the second contact b2 is an even-numbered gear contact. As shown in fig. 3, d5 and d7 are odd gears, and d4, d6 and d8 are even gears. When the fixed contact a5 of the change-over switch 62 is connected with the main current-carrying contact a1 and the auxiliary contact a2 of the first switch K1, that is, when the on-load tap-changer 6 normally operates in an odd-numbered gear, according to the principle of the on-load tap-changer, the first current transformer 1 detects a first current value I1, which is equal to a third current value I3 detected by the third current transformer 3, and at this time, the third current value I3 is a load current ILAnd the second current transformer 2 does not detect current, and the relationship of each current transformer is obtained by formula (1):
Figure BDA0002247063120000081
in an alternative embodiment, referring to fig. 4, a schematic connection diagram of an on-load tap changer in normal operation of even-numbered gears of a tap selector according to a second embodiment of the present invention is shown. When the fixed contact a5 of the change-over switch 62 is connected with the main current-carrying contact a3 and the auxiliary contact a4 of the second switch K2, that is, when the on-load tap-changer 6 normally operates in even-numbered gears, according to the principle of the on-load tap-changer, the second current value I2 is detected on the second current transformer 2 and is equal to the third current value I3 detected on the third current transformer 3, and at this time, the third current value I3 is still the load current ILAnd the first current transformer 1 does not detect current, and the relationship of each current transformer is obtained by formula (2):
Figure BDA0002247063120000082
in an alternative embodiment, referring to fig. 5, a schematic diagram of three stages of shifting from odd gears to even gears of the tap selector in accordance with a second embodiment of the present invention is shown. Fig. 5(a) is a schematic connection diagram of the on-load tap changer in the first stage when odd-numbered gears are shifted to even-numbered gears, fig. 5(b) is a schematic connection diagram of the on-load tap changer in the second stage when odd-numbered gears are shifted to even-numbered gears, and fig. 5(c) is a schematic connection diagram of the on-load tap changer in the third stage when odd-numbered gears are shifted to even-numbered gears.
Referring to fig. 5(a), the change-over switch 62 is switched from the main current-carrying contact a1 of the first switch K1 to the auxiliary contact a2 of the first switch K1, and at this time, the first resistor R1 is connected to the loop, although the current magnitude is reduced, the currents detected by the first current transformer 1 and the third current transformer 3 are still equal, and the current is not detected by the second current transformer 2, that is, the formula (1) is still satisfied.
Further, referring to fig. 5(b), the switch 62 bridges the auxiliary contact a2 of the first switch K1 and the auxiliary contact a4 of the second switch K2, at this time, a voltage difference Us is formed between the odd-numbered gears and the even-numbered gears, the voltage difference is the step voltage of the tap changer, the voltage forms a circulating current Ic between the two gears, and the circuit relationship in the loop is shown in formula (3):
Figure BDA0002247063120000091
further, equation (3) may be transformed into equation (4):
Figure BDA0002247063120000092
as can be seen from the formula (4), in the second stage, the current difference between the first current transformer 1 and the second current transformer 2 is 2 times of circulating current, the current difference between the first current transformer 1 and the third current transformer 3 is 1 time of circulating current and half of load current, and the current difference between the second current transformer 2 and the third current transformer 3 is 1 time of circulating current opposite number and half of load current difference.
Further, referring to fig. 5(c), the switch 62 is connected to the auxiliary contact a4 of the second switch K2, at this time, the currents detected by the second current transformer 2 and the third current transformer 3 are still equal, and no current is detected by the first current transformer 1, that is, the formula (2) is still true.
In an alternative embodiment, equation (4) still holds when the on-load tap-changer 6 is shifted from the second contact b2 to the first contact b 1.
In an alternative embodiment, fig. 6 is a schematic diagram of a short-circuit current loop under an inter-stage short-circuit fault of an on-load tap changer in the second embodiment of the present invention. When an inter-stage short circuit occurs due to a fault in the on-load tap changer 6, an arc is generated between the main current-carrying contact a1 of the first switch and the main current-carrying contact a3 of the second switch K2, and a short-circuit current flows as shown in fig. 6. When the interstage is short-circuited, the short-circuit current flows through the first current transformer 1 and the second current transformer 2, and the interstage short-circuit current I is at the momentdMuch larger than the load current ILThe relationship between the two is shown in formula (5):
I1＝I2＝Id＞＞I3＝IL (5)
in an alternative embodiment, when the main transformer winding is in turn-to-turn short circuit or inter-cake short circuit due to the non-on-load tap changer, the short-circuit current only flows between the windings in which the turn-to-turn short circuit or inter-cake short circuit occurs, and therefore, the current detected by the first current transformer 1 and the second current transformer 2 is still the load current ILThat is, the formula (1) or the formula (2) holds.
S202, calculating current difference values of the first current value, the second current value and the third current value respectively, and judging whether a fault occurs in the on-load tap-changer according to the current difference values.
Specifically, step S202 includes:
calculating a first current difference Δ I1 between the first current value and the third current value;
calculating a second current difference Δ I2 between the second current value and the third current value;
calculating a third current difference Δ 13 between the first current value and the second current value;
a fourth current difference Δ I4 is calculated between the second current value and the first current value.
And S203, controlling the quick switch to be switched off when the on-load tap-changer has a fault inside.
Based on the above parameters defining the current difference, the following characteristics can be obtained:
1. when the on-load tap changer 6 normally operates in the gear corresponding to the first contact b1 of the tap selector, Δ I1 is 0, and Δ I2 is-IL，ΔI3＝IL，ΔI4＝-IL；
2. When the on-load tap changer 6 normally operates in the gear corresponding to the second contact b2 of the tap selector, the delta I1 is equal to-IL，ΔI2＝0，ΔI3＝IL，ΔI4＝IL；
3. In the process of shifting the loaded tap-changer 6, a loop current appears between the shift windings corresponding to the first contact b1 and the second contact b2, and the delta I1 is-0.5IL+IC，ΔI2＝-0.5IL-IC，|ΔI3|＝|ΔI4|＝2ICOr Δ I1 ═ 0.5IL-IC，ΔI2＝-0.5IL+IC，|ΔI3|＝|ΔI4|＝2IC；
4. When the on-load tap changer 6 has an inter-stage short circuit fault, the delta I1 is equal to delta I2 is equal to Id-IL，ΔI3＝ΔI4＝0：
5. When the transformer generates turn-to-turn short circuit or inter-cake short circuit due to the non-loaded voltage regulating tap switch, the characteristics of the transformer are consistent with the characteristics 1 and 2.
Therefore, in an optional embodiment, when the sum of the first current difference and the second current difference is the opposite number of the load current during normal operation, and the third current difference and the fourth current difference are not zero, it is determined that no fault occurs inside the on-load tap-changer.
In another optional embodiment, when the sum of the first current difference and the second current difference is k times of the load current during normal operation, and the third current difference and the fourth current difference are both zero, it is determined that a fault occurs inside the on-load tap-changer; wherein k > 1.
It will be appreciated that the protection device operating conditions are as follows: the current values of the first current transformer 1, the second current transformer 2 and the third current transformer 3 are detected in real time, the detected current values are transmitted to the control system 4, and current difference values delta I1, delta I2, delta I3 and delta I4 are calculated in real time in the control system 4. When the on-load tap-changer 6 is judged not to have a fault, the fast switch 5 is in a closed state; and when the internal fault of the on-load tap changer 6 is judged, the control system 4 controls the quick switch 5 to be switched on and cuts off the inter-stage short-circuit current of the tap changer.
The control method of the transformer internal short-circuit fault protection device provided by the embodiment of the invention comprises the steps of receiving a first current value from a first current transformer, a second current value from a second current transformer and a third current value from a third current transformer; respectively calculating current difference values of the first current value, the second current value and the third current value, and judging whether a fault occurs in the on-load tap-changer according to the current difference values; when the on-load tap-changer has a fault inside, the quick switch is controlled to be switched off, and a first current transformer, a second current transformer and a third current transformer are additionally arranged on the inlet and outlet wires of the change-over switch of the on-load tap-changer, and by setting the fast switch and the control system and combining the fault criterion, whether the internal fault of the transformer is caused by the tap switch can be judged, and then protection removal is carried out according to the positioned fault point, the problem that the position of the fault point in the transformer can not be judged due to the deficiency of the differential protection of the transformer in the prior art can be effectively solved, compared with the traditional differential protection of the transformer, the accurate positioning of the fault position in the on-load tap-changer can be realized, the fault positioning in the transformer can be realized, and then realize accurate protection to can effectively improve on-load tap-changer's reliability, can effectively improve the stability of transformer operation.
It should be noted that the above-described device embodiments are merely illustrative, where the units described as separate parts may or may not be physically separate, and the parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment. In addition, in the drawings of the embodiment of the apparatus provided by the present invention, the connection relationship between the modules indicates that there is a communication connection between them, and may be specifically implemented as one or more communication buses or signal lines. One of ordinary skill in the art can understand and implement it without inventive effort.
While the foregoing is directed to the preferred embodiment of the present invention, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention.

Claims (7)

1. A control method of a short-circuit fault protection device in a transformer is characterized in that the short-circuit fault protection device in the transformer comprises a first current transformer, a second current transformer, a third current transformer, a controller and a quick switch; the on-load voltage regulation tap switch of the transformer comprises a tap selector and a change-over switch; the first end of the first current transformer is connected with a main current-carrying contact of a first switch in the change-over switch, the second end of the first current transformer is connected with the first end of the fast switch, and the second end of the fast switch is connected with a first contact of the tapping selector; a first end of the second current transformer is connected with a main current-carrying contact of a second switch in the selector switch, and a second end of the second current transformer is connected with a second contact of the tapping selector; the third current transformer is arranged on an outlet wire of the on-load voltage regulation tap switch; the output ends of the first current transformer, the second current transformer and the third current transformer are all connected with the input end of the controller, and the output end of the controller is connected with the control end of the fast switch;
the control method comprises the following steps:
receiving a first current value from the first current transformer, a second current value from the second current transformer, and a third current value from the third current transformer;
respectively calculating current difference values of the first current value, the second current value and the third current value, and judging whether a fault occurs in the on-load tap-changer according to the current difference values;
and when the inside of the on-load voltage regulation tapping switch breaks down, the quick switch is controlled to be switched off.
2. The method of claim 1, wherein the transformer further comprises a transformer winding, a transformer regulating winding, a first bushing, and a second bushing;
the transformer winding is connected with the first sleeve, the transformer voltage regulating winding is connected with the tapping selector, and the wire outlet end of the change-over switch is connected with the second sleeve.
3. The control method of a transformer internal short-circuit fault protection device according to claim 1, wherein the changeover switch includes a first resistor and a second resistor;
one end of the first resistor is connected with the first end of the first current transformer, and the other end of the first resistor is connected with the auxiliary contact of the first switch;
one end of the second resistor is connected with the first end of the second current transformer, and the other end of the second resistor is connected with the auxiliary contact of the second switch.
4. The method for controlling the internal short-circuit fault protection device of the transformer according to claim 1, wherein when the first contact is an odd-numbered gear contact, the second contact is an even-numbered gear contact;
or when the first contact is an even gear contact, the second contact is an odd gear contact.
5. The method according to claim 1, wherein the calculating the current difference between the first current value, the second current value, and the third current value includes:
calculating a first current difference value between the first current value and the third current value;
calculating a second current difference value between the second current value and the third current value;
calculating a third current difference value between the first current value and the second current value;
a fourth current difference value of the second current value and the first current value is calculated.
6. The method according to claim 5, wherein the determining whether the on-load tap-changer has a fault according to the current difference specifically includes:
and when the sum of the first current difference value and the second current difference value is the opposite number of the load current in normal operation, and the third current difference value and the fourth current difference value are not zero, judging that no fault occurs in the on-load tap-changer.
7. The method according to claim 5, wherein the determining whether the on-load tap-changer has a fault according to each of the current difference values further comprises:
when the sum of the first current difference value and the second current difference value is k times of the load current in normal operation, and the third current difference value and the fourth current difference value are both zero, judging that a fault occurs inside the on-load tap-changer; wherein k > 1.
CN201911020518.0A 2019-10-25 2019-10-25 Transformer internal short-circuit fault protection device and control method thereof Active CN110768212B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201911020518.0A CN110768212B (en) 2019-10-25 2019-10-25 Transformer internal short-circuit fault protection device and control method thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201911020518.0A CN110768212B (en) 2019-10-25 2019-10-25 Transformer internal short-circuit fault protection device and control method thereof

Publications (2)

Publication Number Publication Date
CN110768212A CN110768212A (en) 2020-02-07
CN110768212B true CN110768212B (en) 2021-09-03

Family

ID=69333877

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201911020518.0A Active CN110768212B (en) 2019-10-25 2019-10-25 Transformer internal short-circuit fault protection device and control method thereof

Country Status (1)

Country Link
CN (1) CN110768212B (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112670067B (en) * 2020-11-18 2022-07-01 中国电力科学研究院有限公司 Symmetrical vacuum bubble load balancing transition circuit device and control method
CN114512956A (en) * 2022-03-15 2022-05-17 南京南瑞继保电气有限公司 Transformer tap switch protection method based on built-in current and temperature sensor

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102725809A (en) * 2009-09-15 2012-10-10 皇家创新公司 Method and apparatus for performing on-load mechanical switching operations
CN103019284A (en) * 2012-12-27 2013-04-03 山东大学 Load tap-changer with thyristor auxiliary
CN104157433A (en) * 2014-07-11 2014-11-19 中国农业大学 Split blowout on-load tap changer for transformer
CN205844392U (en) * 2016-07-14 2016-12-28 蒋同有 A kind of load ratio bridging switch electric current on-line measurement unit
CN106298295A (en) * 2015-05-25 2017-01-04 北京华天机电研究所有限公司 On-load shunting switch with bridge connection
CN106324444A (en) * 2015-06-23 2017-01-11 中国电力科学研究院 Transformer test platform

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN202916409U (en) * 2012-10-17 2013-05-01 山西省电力公司阳泉供电分公司 Comprehensive mechanical fault diagnosing and analyzing system for transformer on-load voltage regulating tap switch
CN104242242A (en) * 2014-09-25 2014-12-24 国家电网公司 Method for calculating three-side longitudinal difference protection braking current of tail-end transformer of power system

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102725809A (en) * 2009-09-15 2012-10-10 皇家创新公司 Method and apparatus for performing on-load mechanical switching operations
CN103019284A (en) * 2012-12-27 2013-04-03 山东大学 Load tap-changer with thyristor auxiliary
CN104157433A (en) * 2014-07-11 2014-11-19 中国农业大学 Split blowout on-load tap changer for transformer
CN106298295A (en) * 2015-05-25 2017-01-04 北京华天机电研究所有限公司 On-load shunting switch with bridge connection
CN106324444A (en) * 2015-06-23 2017-01-11 中国电力科学研究院 Transformer test platform
CN205844392U (en) * 2016-07-14 2016-12-28 蒋同有 A kind of load ratio bridging switch electric current on-line measurement unit

Also Published As

Publication number Publication date
CN110768212A (en) 2020-02-07

Similar Documents

Publication Publication Date Title
CN110768212B (en) Transformer internal short-circuit fault protection device and control method thereof
US9618950B2 (en) Voltage control system
JP2007227908A (en) On-load tap changer
US20120327538A1 (en) Superconducting fault current limiter for suppressing bus voltage drop in electric power system
US10663516B2 (en) Method and device for testing a tap changer of a transformer
US10768233B2 (en) Method and device for testing a tap changer of a transformer
CN112670068B (en) Transition circuit device with vacuum on-load tap-changer and control method
JP2012080654A (en) Voltage regulator for distribution line
CN112216494A (en) On-load tap-changer and operation control method thereof
CN110634660A (en) Voltage regulating coil and transformer for increasing one time voltage regulating gear
CN207381234U (en) A kind of distribution transformer on-load voltage regulation system
RU143195U1 (en) TYRISTOR CONTROLLED PHASE TURNING DEVICE
WO2021258621A1 (en) Vacuum on-load tap-changer transition circuit with isolation contacts and voltage regulation method
US2449367A (en) Tapped transformer system
CN111477441A (en) Automatic on-load voltage regulation distribution transformer and voltage regulation method
EP2294495B1 (en) Voltage regulation system
CN114038667B (en) Seamless switching on-load voltage regulating transformer
US11875963B2 (en) Device for connecting to a high-voltage grid
US3015057A (en) Transformer tap changing system
CN213211935U (en) Double-resistor transition circuit of vacuum on-load tap-changer
CN215817529U (en) Suppression device for resonant overvoltage of disconnection fault of distribution network
CN113889329B (en) On-load tap-changer switching method, circuit and device
JP2002218652A (en) Automatic voltage regulator
US2853628A (en) Parallel operation of transformers
US3805087A (en) Tap-changing transfer switch having series breaks and means for controlling the recovery voltage between breaks

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant