CN111952059A - Transformer and transformer system - Google Patents

Transformer and transformer system Download PDF

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Publication number
CN111952059A
CN111952059A CN202010876436.2A CN202010876436A CN111952059A CN 111952059 A CN111952059 A CN 111952059A CN 202010876436 A CN202010876436 A CN 202010876436A CN 111952059 A CN111952059 A CN 111952059A
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China
Prior art keywords
transformer
iron core
window
winding
lead
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CN202010876436.2A
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Inventor
苏钟焕
阴祖强
孙树波
谭黎军
詹小彬
喻强
胡伟
王贵娟
徐紫风
欧强
李中祥
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TBEA Hengyang Transformer Co. Ltd
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TBEA Hengyang Transformer Co. Ltd
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Priority to CN202010876436.2A priority Critical patent/CN111952059A/en
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F27/00—Details of transformers or inductances, in general
    • H01F27/28—Coils; Windings; Conductive connections
    • H01F27/29—Terminals; Tapping arrangements for signal inductances
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F27/00—Details of transformers or inductances, in general
    • H01F27/28—Coils; Windings; Conductive connections
    • H01F27/30—Fastening or clamping coils, windings, or parts thereof together; Fastening or mounting coils or windings on core, casing, or other support
    • H01F27/306—Fastening or mounting coils or windings on core, casing or other support
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F27/00—Details of transformers or inductances, in general
    • H01F27/33—Arrangements for noise damping
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F27/00—Details of transformers or inductances, in general
    • H01F27/34—Special means for preventing or reducing unwanted electric or magnetic effects, e.g. no-load losses, reactive currents, harmonics, oscillations, leakage fields
    • H01F27/341—Preventing or reducing no-load losses or reactive currents
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F27/00—Details of transformers or inductances, in general
    • H01F27/34—Special means for preventing or reducing unwanted electric or magnetic effects, e.g. no-load losses, reactive currents, harmonics, oscillations, leakage fields
    • H01F27/38—Auxiliary core members; Auxiliary coils or windings

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Housings And Mounting Of Transformers (AREA)

Abstract

The present application relates to a transformer and a transformer system. The transformer comprises an iron core, a winding, a window lead and a compensation coil, wherein the compensation coil surrounds an iron core side yoke arranged on the iron core, the terminal polarities of the compensation coil and the window lead on the same side of the iron core are the same, and the second end of the window lead is connected with the terminal with the same polarity in the compensation coil. The first end of winding sets up in the first side of unshakable in one's determination, the second end of winding is drawn forth the second side of unshakable in one's determination through the window lead wire, the space of arranging of transformer has been practiced thrift, the window lead wire all induces the electromotive force with compensating coil, compensating coil and window lead wire are the same at the terminal polarity of unshakable in one's determination homonymy, the second end of window lead wire is connected with terminal that polarity is the same in the compensating coil, the electromotive force that makes window lead wire and compensating coil induced can offset, transformer zero sequence current has been eliminated, transformer empty load loss, noise and vibration level that have avoided causing by zero sequence current are higher, local overheat scheduling problem, the use reliability of transformer has been improved.

Description

Transformer and transformer system
Technical Field
The application relates to the technical field of electrical equipment, in particular to a transformer and a transformer system.
Background
The power transformer is the core equipment of energy transmission in the power grid, and the safe, reliable and economic operation of the power transformer has a crucial influence on the whole power grid. In the transformer manufacturing industry, a mode that the lead wires at the head end and the tail end of a winding are arranged on two sides of an iron core is adopted in part of transformers, and the transformer has the advantages that the lead wires at the head end and the tail end are arranged in different sides of a sleeve pipe conveniently, the overall arrangement space of the transformer is saved, and the window-through lead wires are formed accordingly.
The window lead-through turn-chain side yoke magnetic flux causes zero-sequence component of high-voltage side induced voltage, and when the transformer load operates, a zero-sequence loop is conducted to generate larger neutral point current. Neutral point current injects zero sequence current into the earth screen, which reduces the sensitivity of zero sequence protection, and also aggravates the unbalance of the magnetic flux distribution of the left and right side yokes of the transformer core, thereby causing the problems of empty load loss, higher noise and vibration level, local overheating and the like of the transformer. Therefore, the traditional transformer with the lead wires arranged at the different sides of the head end and the tail end has the risk of influencing the safe and reliable operation of a power grid.
Disclosure of Invention
In view of the above, it is desirable to provide a transformer and a transformer system, which address the above-mentioned drawbacks of the conventional transformer using the lead wires of the first and the second ends arranged on different sides.
A transformer comprises an iron core, a winding, a window lead and a compensation coil, wherein the winding is arranged around an iron core main column of the iron core, a first end and a second end of the winding are arranged on a first side of the iron core, a second end of the winding is connected with the first end of the window lead, the window lead penetrates through an iron core window of the iron core, the second end of the window lead is arranged on a second side of the iron core, which is opposite to the first side, the compensation coil is arranged around an iron core side yoke of the iron core, the compensation coil and the window lead are arranged on the same side of the iron core, the polarity of terminals of the compensation coil and the same side of the iron core are the same, and the second end of the window lead is connected with terminals of the same polarity in the compensation coil.
The transformer comprises an iron core, a winding, a window lead and a compensation coil, wherein the winding surrounds an iron core main column arranged on the iron core, a first end and a second end of the winding are arranged on a first side of the iron core, the second end of the winding is connected with the first end of the window lead, the window lead penetrates through an iron core window of the iron core, the second end of the window lead is arranged on a second side of the iron core, which is opposite to the first side, the compensation coil surrounds an iron core side yoke arranged on the iron core, the polarities of terminals of the compensation coil and the window lead on the same side of the iron core are the same, and the second end of the window lead is connected with the terminal of the compensation coil. The iron core and the winding can generate electromagnetic induction to realize voltage and current conversion, the first end of the winding is arranged on the first side of the iron core, the second end of the winding is led out to the second side of the iron core through the window lead, the first end and the tail end of the winding are arranged in different sides of the sleeve, the arrangement space of the transformer is saved, the window lead penetrates through the window of the iron core to induce electromotive force, the compensation coil is arranged on a side yoke of the iron core to induce electromotive force, the polarities of terminals of the compensation coil and the window lead on the same side of the iron core are the same, the second end of the window lead is connected with the terminal of the compensation coil, the electromotive force induced by the window lead and the compensation coil can be offset, the zero-sequence current of the transformer is eliminated, the problems of empty load loss, high noise and vibration level, local overheating and the like of the.
In one embodiment, the iron core is a three-phase five-column iron core, the number of the windings is three, the windings are connected in a star connection mode, and a common end of each winding is connected with the window lead.
In one embodiment, the transformer further includes three high-voltage bushings and a neutral point bushing, one end of each winding, which is far away from the common end, is disposed on a different high-voltage bushing, and the second end of the window lead and the compensation coil are disposed on the neutral point bushing.
In one embodiment, one end of the compensation coil, which is not connected with the window lead-through, is grounded.
In one embodiment, the transformer further comprises a grounding copper bar, and one end of the compensation coil, which is not connected with the window lead, is grounded through the grounding copper bar.
In one embodiment, the compensation coil and the through-window lead are both wrapped by an insulating layer.
In one embodiment, the cross-sectional dimension of the bucking coil is matched to the cross-sectional dimension of the through-window lead.
A transformer system comprises an oil tank and the transformer, wherein the transformer is arranged in the oil tank.
The transformer system comprises an iron core, a winding, a window lead and a compensation coil, wherein the winding surrounds an iron core main column arranged on the iron core, a first end and a second end of the winding are arranged on a first side of the iron core, a second end of the winding is connected with the first end of the window lead, the window lead penetrates through an iron core window of the iron core, the second end of the window lead is arranged on a second side of the iron core, which is opposite to the first side, the compensation coil surrounds an iron core side yoke arranged on the iron core, the terminal polarities of the compensation coil and the terminal of the window lead on the same side of the iron core are the same, and the second end of the window lead is connected with a terminal of the compensation. The iron core and the winding can generate electromagnetic induction to realize voltage and current conversion, the first end of the winding is arranged on the first side of the iron core, the second end of the winding is led out to the second side of the iron core through the window lead, the first end and the tail end of the winding are arranged in different sides of the sleeve, the arrangement space of the transformer is saved, the window lead penetrates through the window of the iron core to induce electromotive force, the compensation coil is arranged on a side yoke of the iron core to induce electromotive force, the polarities of terminals of the compensation coil and the window lead on the same side of the iron core are the same, the second end of the window lead is connected with the terminal of the compensation coil, the electromotive force induced by the window lead and the compensation coil can be offset, the zero-sequence current of the transformer is eliminated, the problems of empty load loss, high noise and vibration level, local overheating and the like of the.
In one embodiment, the oil tank is provided with an observation window at a position corresponding to the core side yoke, and the terminal of the compensation coil is led out of the oil tank through the observation window.
In one embodiment, a connecting terminal is arranged at the observation window, the connecting terminal is insulated from the observation window, and the compensating coil is connected with the connecting terminal.
Drawings
FIG. 1 is a block diagram of a transformer in one embodiment;
FIG. 2 is a block diagram of a transformer in another embodiment;
FIG. 3 is a block diagram of a transformer system in one embodiment;
FIG. 4 is a block diagram of a transformer system in another embodiment;
FIG. 5 is a partial block diagram of a transformer system in one embodiment;
FIG. 6 is a schematic diagram of the wiring of a transformer in one embodiment;
fig. 7 is a circuit diagram of the transformer in the embodiment.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described more fully below by way of examples in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
In one embodiment, referring to fig. 1 and 2, a transformer is provided, which includes an iron core 2, a winding 3, a window lead 5, and a compensation coil 7, wherein the winding 3 is disposed around an iron core main column 4 of the iron core 2, a first end and a second end of the winding 3 are both disposed on a first side of the iron core 2, the second end of the winding 3 is connected to the first end of the window lead 5, the window lead 5 passes through an iron core window of the iron core 2, the second end of the window lead 5 is disposed on a second side of the iron core 2 opposite to the first side, the compensation coil 7 is disposed around an iron core side yoke 6 of the iron core 2, the compensation coil 7 and the window lead 5 have the same polarity at a same side of the iron core 2, and the second end of the window lead 5 is connected to a terminal of the same polarity in the compensation. The iron core 2 and the winding 3 can generate electromagnetic induction to realize voltage and current conversion, the first end of the winding 3 is arranged at the first side of the iron core 2, the second end of the winding 3 is led out to the second side of the iron core 2 through the window lead 5, so that the first and the tail end sleeves are arranged in different sides, the arrangement space of the transformer is saved, the window lead 5 passes through the window of the iron core to induce electromotive force, the compensating coil 7 is arranged at the side yoke 6 of the iron core to induce electromotive force, the polarities of the terminals of the compensating coil 7 and the window lead 5 at the same side of the iron core 2 are the same, the second end of the window lead 5 is connected with the terminal with the same polarity in the compensating coil 7, the electromotive force induced by the window lead 5 and the compensating coil 7 can be counteracted, the zero sequence current of the transformer is eliminated, and the problems of empty load loss, high noise and vibration level, the use reliability of the transformer is improved.
Specifically, the transformer comprises an iron core 2 and a winding 3, wherein the iron core 2 comprises an iron core main column 4 and a side yoke 6, the winding 3 generally comprises a primary winding and a secondary winding, the part of the iron core 2, which is provided with the primary winding and the secondary winding, is the iron core main column 4, the other parts, which are not provided with the primary winding and the secondary winding, form a magnetic flux closed path are iron yokes, the iron yokes of the upper part and the lower part of the iron core 2 are called upper yokes, the iron yokes of the left part and the right part are called side yokes, and the side yoke is arranged in parallel. The space defined by the core main leg 4 and the yoke is a core window. The winding 3 is arranged around the iron core 2, specifically, the winding 3 is arranged on the iron core main column 4, a first end of the winding 3 can be understood as a head end of the winding 3, a second end of the winding 3 can be understood as a tail end of the winding 3, the head end of the winding 3 is located at the upper end of the winding 3, and the tail end of the winding 3 is located at the lower end of the winding 3.
In the present embodiment, in order to better explain the orientation of the core 2, the core 2 is taken as a three-phase five-limb core as an example, the three-phase five-limb core includes three core legs 4, two side yokes and upper and lower yokes, the side yokes are disposed in parallel with the core legs 4, the side yokes are disposed on the left and right sides of the core 2, the upper yoke is disposed on the upper side of the core 2, the lower yoke is disposed on the lower side of the core 2, the first side of the core 2 is the front side of the core 2, the second side of the core 2 is the rear side of the core, the front side and the rear side are disposed opposite to each other, in the drawing, the side of the core 2 close to the paper surface is the front side, and the side far from the paper surface is. The first end and the second end of the winding 3 are both arranged on the front side of the iron core 2, the second end of the winding 3 is connected with the first end of the window lead 5, the window lead 5 penetrates through an iron core window of the iron core 2, the second end of the window lead 5 is arranged on the second side of the iron core 2, which is opposite to the first side, the window lead 5 penetrates through the iron core window, and the two ends of the window lead 5 are respectively positioned on the front side and the rear side of the iron core 2. The window lead 5 leads the second end of the winding 3 to the rear side of the iron core 2, so that the first end and the second end of the winding 3 are respectively arranged at the front side and the rear side of the iron core 2, the different side arrangement of the two ends of the winding 3 is realized, and the arrangement space of the transformer can be saved.
The compensation coil 7 surrounds the core side yoke 6 disposed on the core 2, the number of turns of the compensation coil 7 is not unique, in this embodiment, the number of turns of the compensation coil 7 is one, the first end and the second end of the compensation coil 7 are not connected, the compensation coil 7 is an unclosed compensation coil 7, the first end and the second end of the compensation coil 7 are respectively located on the first side and the second side of the core 2, taking the first end of the compensation coil 7 located on the first side of the core 2 and the second end of the compensation coil 7 located on the second side of the core 2 as an example, and specifically, the second end of the compensation coil 7 is connected to the second end of the window lead 5. The polarities of terminals of the compensation coil 7 and the window lead 5 on the same side of the iron core 2 are the same, the second end of the window lead 5 is connected with a terminal with the same polarity in the compensation coil 7, namely the polarity of the first end of the compensation coil 7 is the same as that of the first end of the window lead 5, the polarity of the second end of the compensation coil 7 is the same as that of the second end of the window lead 5, so that the compensation coil 7 and the window lead 5 are connected in series in a reverse direction, the direction of electromotive force generated by the compensation coil 7 is opposite to the direction of zero sequence voltage induced by the window lead 5, and therefore the electromotive force and the zero sequence current of the transformer caused by the window lead 5 are cancelled out.
In one embodiment, referring to fig. 1 and 2, the core 2 is a three-phase five-limb core, the number of the windings 3 is three, the windings 3 are connected in a star connection manner, and the common end of each winding 3 is connected with the window lead 5.
Specifically, a three-phase five-limb core is a common core 2, and includes three main limbs and two side yokes, and further includes an upper yoke and a lower yoke. The quantity of winding 3 is three, three winding 3 is respectively around setting up on the different iron core principal post, every winding 3 all has head end and end, the head end is the first end of winding 3, the end is the second end of winding 3, three winding 3 adopts star connection's mode to connect, it is the head end to use the connecting terminal that winding 3 is close to 2 upsides on unshakable in one's determination of iron core, it is the end to be close to the connecting terminal of 2 downside on unshakable in one's determination of iron core, the respective head end of three winding 3 is drawn forth separately, the end of three winding 3 links to each other together, form the common link, the head end and the common link of three winding 3 all are located the first side of unshakable in one's determination 2, set up a wire in the first side of unshakable in one's determination 2, the end of. The common end of each winding 3 is connected with a window lead 5, specifically connected with one terminal of the window lead 5, and the window lead 5 is electrically connected with the common end of each winding 3, specifically electrically connected with any position of a wire, as long as the person skilled in the art thinks it can be realized.
In one embodiment, referring to fig. 3 and 4, the transformer further includes three high voltage bushings 10 and three neutral point bushings 11, wherein one end of each winding 3 away from the common end is disposed on a different high voltage bushing 10, and the second end of the window lead 5 and the compensation coil 7 are disposed on the neutral point bushings 11. The high-voltage bushing 10 and the neutral point bushing 11 are main insulation devices of the transformer, and the outgoing lines of the transformer winding 3 are led out through the high-voltage bushing 10 and the neutral point bushing 11, so that the outgoing lines and the transformer shell are insulated, the outgoing lines are fixed, and the safety performance of the transformer is improved.
Specifically, the number of the high-voltage bushings 10 corresponds to the number of the windings 3, taking the iron core 2 as a three-phase five-column iron core, the number of the windings 3 is three, the windings 3 are connected in a star connection manner, a common end of each winding 3 is connected with the window lead 5 as an example, the number of the high-voltage bushings 10 is three, one end of each winding 3, which is far away from the common end, is a first end of each winding 3, the first end of each winding 3 is respectively arranged on one high-voltage bushing 10, and terminals of the three windings 3 are led out. The common end of the three windings 3 is connected to a first end of a through-window lead 5, the first end of the through-window lead 5 being located at a first side of the core 2. The window lead 5 passes through the core window to connect the first side and the second side of the core 2, the second end of the window lead 5 is arranged at the second side of the core 2, and the first side and the second side of the core 2 are opposite and are equivalent to the front side and the rear side of the core 2. The common end of the three windings 3 is connected to a first end of a through-window lead 5, which through-window lead 5 can pass the current in the windings 3 from the first end to a second side of the core 2. The second end of the window lead 5 is equivalent to a neutral point of the transformer, the second end of the window lead 5 is connected with the compensating coil 7, the second end of the window lead 5 and the compensating coil 7 are both arranged on a neutral point sleeve 11, the connecting end of the window lead 5 and the compensating coil 7 is led out through the neutral point sleeve 11, a terminal at the high-voltage sleeve 10 is equivalent to a positive electrode, and a terminal at the neutral point sleeve 11 is equivalent to a negative electrode.
The types of the high-voltage bushing 10 and the neutral point bushing 11 are not unique, and different types of the high-voltage bushing 10 and the neutral point bushing 11 can be selected according to different voltage levels of the transformer, for example, an inflatable or oil-filled bushing can be adopted when the voltage range of a general transformer is 10-35 KV, a capacitive bushing is adopted when the voltage range of the transformer is above 110KV, a solid porcelain bushing is adopted when the voltage range of the transformer is low, and the like, and the type of the high-voltage bushing and the type of the neutral point bushing can be specifically adjusted according to.
In one embodiment, the end of the compensation coil 7 not connected to the through window lead 5 is grounded. The second end of the window lead 5 is equivalent to a neutral point of the transformer, the second end of the window lead 5 is connected with the compensating coil 7, the second end of the window lead 5 and the compensating coil 7 are both connected with the neutral point sleeve 11, one end of the window lead 5 connected with the compensating coil 7 is equivalent to the negative electrode of the compensating coil 7, one end of the compensating coil 7, which is not connected with the window lead 5, is equivalent to the positive electrode of the compensating coil 7, the positive electrode of the compensating coil 7 is grounded, so that the direction of electromotive force on the compensating coil 7 is opposite to the direction of electromotive force on the window lead 5, and the direction of electromotive force on the compensating coil 7 is equal to the magnitude of electromotive force on the window lead 5, so that the electromotive force on the compensating coil 7 can counteract the electromotive force on the window lead 5, and the zero sequence current of the transformer is eliminated.
In one embodiment, referring to fig. 3 and 4, the transformer further includes a ground copper bar 16, and one end of the compensation coil 7 not connected to the through-window lead 5 is grounded through the ground copper bar 16. The grounding copper bar 16 provides a grounding conductor and establishes an equipotential system with each metal part in the connection system, the voltage of the equipotential system is almost zero, the equipotential system can protect the safety of personnel and equipment when overcurrent or fault occurs, one end of the compensation coil 7, which is not connected with the through-window lead 5, is grounded through the grounding copper bar 16, the voltage on the grounding copper bar 16 is almost zero, and the ground potential counterattack accident can be prevented from being generated. The type of the ground copper bar 16 is not unique, and can be selected according to actual requirements, and the ground copper bar 16 can also be used for accessing other devices in an extensible manner, and is determined according to actual requirements, as long as the implementation can be realized by those skilled in the art.
In one implementation, the bucking coil 7 and the through window lead 5 are both encased by an insulating layer. The compensation coil 7 and the through-window lead 5 are both conductive wires which can transmit current to generate electromotive force. The compensating coil 7 comprises an inner lead and an outer insulating layer, the inner lead is used for transmitting current, the outer insulating layer wraps the inner lead, the inner lead can be insulated, and the electrical safety of the compensating coil 7 is guaranteed. The structure of the window lead 5 is similar to that of the compensation coil 7, the window lead 5 comprises an inner lead and an outer insulating layer, the inner lead is used for transmitting current, and the outer insulating layer wraps the inner lead, so that the electrical safety of the window lead 5 is ensured. It will be appreciated that in this embodiment the connection between the bucking coil 7 and the through-window lead 5 is an electrically conductive connection, i.e. the inner wire of the bucking coil 7 is connected to the inner wire of the through-window lead 5 to form a current path. The type of the insulating layer is not exclusive, and may be an insulating paper, that is, an insulating paper is wrapped outside the compensation coil 7 and the inner wire of the window lead-through 5, and the thickness of the insulating paper may be adjusted according to actual requirements. And in an expandable manner, the outside of the transformer coil is also wrapped with insulating paper with a certain thickness so as to ensure the electrical safety of the transformer.
In one embodiment, the cross-sectional dimensions of the compensation coil 7 and the cross-sectional dimensions of the through-window lead 5 are matched. When the cross-sectional dimension of the compensation coil 7 and the cross-sectional dimension of the through-window lead 5 are matched, the compensation coil 7 and the through-window lead 5 can be better connected, so that the working performance of the transformer is improved.
Specifically, the cross-sectional dimension of the compensation coil 7 is generally referred to as the gauge of the compensation coil 7, and the cross-sectional dimension of the window lead 5 is generally referred to as the gauge of the window lead 5. The wire gauge of the compensation coil 7 is matched with the wire gauge of the window lead-through 5, and generally means that the wire gauge of the compensation coil 7 is equal to the wire gauge of the window lead-through 5. When the compensation coil 7 and the window lead 5 both comprise an inner lead and an outer insulating layer, the cross section size of the inner lead of the compensation coil 7 is equal to that of the inner lead of the window lead 5, which is beneficial to lead welding of the window lead 5 and the compensation coil 7, the cross section size of the outer insulating layer of the compensation coil 7 is equal to that of the outer insulating layer of the window lead 5, and the insulation level of the compensation coil 7 is consistent with that of the window lead 5. It will be appreciated that in other embodiments the cross-sectional dimensions of the bucking coil 7 and the cross-sectional dimensions of the lead-through 5 may be approximately equal, as long as the skilled person realizes.
For a better understanding of the above embodiments, the following detailed description is given in conjunction with a specific embodiment. In one embodiment, referring to fig. 3 and 4, the transformer is a three-phase five-limb core, a compensation coil 7 connected in series with the window lead 5 in an anti-phase manner is added to a core side yoke 6 of the transformer, the compensation coil 7 is arranged on the core side yoke 6, and the wire gauge and the insulation binder of the compensation coil are consistent with those of the neutral point lead. The negative pole of the compensation coil 7 is connected to the neutral point bushing 11, and the positive pole of the compensation coil 7 is grounded. The positive pole and the negative pole of the compensating coil 7 are led out through the wiring terminals on the observation window 17 of the transformer oil tank 12, the wiring terminals are insulated from the observation window 17, and the zero sequence current of the transformer is eliminated by utilizing the principle that the zero sequence voltages induced by the compensating coil 7 and the window lead-through 5 are mutually offset.
When the compensation coil 7 is not arranged, zero-sequence voltage e0 is induced by the winding-link side yoke magnetic flux of the window lead 5, and zero-sequence current is injected into the earth screen by a neutral point, wherein the zero-sequence current has the following calculation formula:
Figure BDA0002652742410000101
in the formula (1), i0Is a zero sequence current, e0Is zero sequence voltage, ZS 0Is the zero sequence impedance of the system, ZT 0Is the zero sequence impedance of the transformer. After the compensation coil 7 is added, please refer to fig. 6 and 7, the zero sequence voltage induced by the compensation coil 7 and the window lead 5 is mutually offset, please refer to formula (2), the zero sequence current is zero, and the zero sequence current of the transformer is eliminated.
Figure BDA0002652742410000102
The transformer comprises an iron core 2, a winding 3, a window lead 5 and a compensation coil 7, wherein the winding 3 surrounds an iron core main column 4 arranged on the iron core 2, a first end and a second end of the winding 3 are both arranged on a first side of the iron core 2, a second end of the winding 3 is connected with the first end of the window lead 5, the window lead 5 penetrates through an iron core window of the iron core 2, the second end of the window lead 5 is arranged on a second side, opposite to the first side, of the iron core 2, the compensation coil 7 surrounds an iron core side yoke 6 arranged on the iron core 2, the polarities of terminals of the compensation coil 7 and the window lead 5 on the same side of the iron core 2 are the same, and the second end of the window lead 5 is connected with the terminal of the compensation coil 7. The iron core 2 and the winding 3 can generate electromagnetic induction to realize voltage and current conversion, the first end of the winding 3 is arranged at the first side of the iron core 2, the second end of the winding 3 is led out to the second side of the iron core 2 through the window lead 5, so that the first and the tail end sleeves are arranged in different sides, the arrangement space of the transformer is saved, the window lead 5 passes through the window of the iron core to induce electromotive force, the compensating coil 7 is arranged at the side yoke 6 of the iron core to induce electromotive force, the polarities of the terminals of the compensating coil 7 and the window lead 5 at the same side of the iron core 2 are the same, the second end of the window lead 5 is connected with the terminal with the same polarity in the compensating coil 7, the electromotive force induced by the window lead 5 and the compensating coil 7 can be counteracted, the zero sequence current of the transformer is eliminated, and the problems of empty load loss, high noise and vibration level, the use reliability of the transformer is improved.
In one embodiment, a transformer system is provided, referring to fig. 3 and 4, including a tank 12 and the transformer, wherein the transformer is disposed in the tank 12. The oil tank 12 is a transformer case in which the core 2 and the winding 3 are housed and filled with transformer oil, so that the core 2 and the winding 3 are immersed in the oil, and the transformer oil plays a role of insulation and heat dissipation. Further, according to the structure of the transformer, whether all the components of the transformer are disposed inside the oil tank 12 can be adjusted according to actual requirements. For example, when the transformer comprises the iron core 2, the winding 3, the window lead 5 and the compensation coil 7, the iron core 2 and the winding 3 are both arranged in the oil tank 12, most of the window lead 5 and the compensation coil 7 are also arranged in the oil tank 12, and the lead terminal can be led out of the oil tank 12 to be conveniently connected with other devices. When the transformer further comprises the high-voltage bushing 10, the neutral point bushing 11 and the ground copper bar 16, the high-voltage bushing 10, the neutral point bushing 11 and the ground copper bar 16 are all arranged outside the oil tank 12. It is understood that in other embodiments, if the transformer further includes other devices, the devices included in the transformer may be disposed inside the oil tank 12 or outside the oil tank 12, and may be selected according to actual needs, as long as the implementation is considered by those skilled in the art.
In one embodiment, referring to fig. 3 and 4, a viewing window 17 is opened at a position of the oil tank 12 corresponding to the core side yoke 6, and the terminal of the compensation coil 7 is led out of the oil tank 12 through the viewing window 17. The observation window 17 can facilitate the working state of the devices inside the oil tank 12 to be checked by the staff, and is convenient to overhaul and the like.
Specifically, the opening manner of the viewing window 17 is not exclusive, and in the present embodiment, the oil tank 12 is provided with a cover plate detachably connected to the wall of the oil tank 12 at a position corresponding to the core side yoke 6, and when the viewing window 17 is needed, the cover plate can be detached, and the window formed by detaching the cover plate is the viewing window 17. When the viewing window 17 is not needed, the cover plate can be arranged on the wall of the oil tank 12, so that the structure of the oil tank 12 is more complete. The terminal of the compensating coil 7 is led out to the outside of the oil tank 12 through the observation window 17, so that the terminal of the compensating coil 7 is convenient to be connected with other devices.
In one embodiment, referring to fig. 5, a connection terminal 15 is disposed at the viewing window 17, the connection terminal 15 is insulated from the viewing window 17, and a terminal of the compensation coil 7 is connected to the connection terminal. The terminal at the position of the observation window 17 can be led out to the outside of the oil tank 12, so that the terminal of the compensation coil 7 can be connected with other devices conveniently. The terminals are insulated from the viewing window 17, thus ensuring its electrical safety. Further, the transformer system may further include other devices, for example, referring to fig. 3 and 4, the transformer system includes a high voltage lead, an iron core 2, a high voltage winding 3, an iron core main column 4, a neutral point lead (window lead) 5, a side yoke 6, a compensation coil 7, a compensation coil cathode 8, a compensation coil anode 9, a high voltage bushing 10, a neutral point bushing 11, an oil tank 12, an external connection copper bar 13, a terminal insulation 14, a terminal 15, a ground copper bar 16, a viewing window 17, a base 18, and an insulator 19, wherein the base plays a role of fixing, and the insulator plays a role of insulation, thereby ensuring electrical safety thereof.
The transformer system comprises an iron core 2, a winding 3, a window lead 5 and a compensation coil 7, wherein the winding 3 surrounds an iron core main column 4 arranged on the iron core 2, a first end and a second end of the winding 3 are both arranged on a first side of the iron core 2, a second end of the winding 3 is connected with the first end of the window lead 5, the window lead 5 penetrates through an iron core window of the iron core 2, the second end of the window lead 5 is arranged on a second side of the iron core 2 opposite to the first side, the compensation coil 7 surrounds an iron core side yoke 6 arranged on the iron core 2, the polarities of terminals of the compensation coil 7 and the window lead 5 on the same side of the iron core 2 are the same, and the second end of the window lead 5 is connected with the terminal of the compensation coil 7 with the same. The iron core 2 and the winding 3 can generate electromagnetic induction to realize voltage and current conversion, the first end of the winding 3 is arranged at the first side of the iron core 2, the second end of the winding 3 is led out to the second side of the iron core 2 through the window lead 5, so that the first and the tail end sleeves are arranged in different sides, the arrangement space of the transformer is saved, the window lead 5 passes through the window of the iron core to induce electromotive force, the compensating coil 7 is arranged at the side yoke 6 of the iron core to induce electromotive force, the polarities of the terminals of the compensating coil 7 and the window lead 5 at the same side of the iron core 2 are the same, the second end of the window lead 5 is connected with the terminal with the same polarity in the compensating coil 7, the electromotive force induced by the window lead 5 and the compensating coil 7 can be counteracted, the zero sequence current of the transformer is eliminated, and the problems of empty load loss, high noise and vibration level, the use reliability of the transformer is improved.
The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims (10)

1. The transformer is characterized by comprising an iron core, a winding, a window lead and a compensation coil, wherein the winding is arranged around an iron core main column of the iron core, a first end and a second end of the winding are arranged on a first side of the iron core, a second end of the winding is connected with the first end of the window lead, the window lead penetrates through an iron core window of the iron core, the second end of the window lead is arranged on a second side of the iron core, which is opposite to the first side, the compensation coil is arranged around an iron core side yoke of the iron core, the compensation coil and the window lead are in the same terminal polarity on the same side of the iron core, and the second end of the window lead is connected with a terminal with the same polarity in the compensation coil.
2. The transformer according to claim 1, wherein the core is a three-phase five-limb core, the number of the windings is three, the windings are connected in a star connection manner, and a common end of each winding is connected with the through window lead.
3. The transformer according to claim 2, further comprising three high-voltage bushings and a neutral bushing, wherein one end of each winding, which is far away from the common end, is disposed on a different high-voltage bushing, and the second end of the window lead and the compensation coil are disposed on the neutral bushing.
4. The transformer of claim 3, wherein an end of the bucking coil not connected to the through-window lead is grounded.
5. The transformer of claim 4, further comprising a ground copper bar through which an end of the compensation coil not connected to the through-window lead is grounded.
6. The transformer of claim 1, wherein the bucking coil and the through window lead are each encased by an insulating layer.
7. The transformer of claim 1, wherein the compensation coil has a cross-sectional dimension that matches a cross-sectional dimension of the through-window lead.
8. A transformer system comprising a tank and a transformer according to any one of claims 1 to 7, said transformer being disposed within said tank.
9. The transformer system according to claim 8, wherein a viewing window is opened at a position of the oil tank corresponding to the core side yoke, and the terminal of the compensation coil is led out to the outside of the oil tank through the viewing window.
10. The transformer system of claim 9, wherein a terminal is disposed at the viewing window, the terminal is insulated from the viewing window, and the compensation coil is connected to the terminal.
CN202010876436.2A 2020-08-27 2020-08-27 Transformer and transformer system Pending CN111952059A (en)

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CN202010876436.2A CN111952059A (en) 2020-08-27 2020-08-27 Transformer and transformer system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202010876436.2A CN111952059A (en) 2020-08-27 2020-08-27 Transformer and transformer system

Publications (1)

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Country Link
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