CN110797869A - Single-phase or two-phase-to-three-phase power supply structure using YNVd transformer - Google Patents

Single-phase or two-phase-to-three-phase power supply structure using YNVd transformer Download PDF

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Publication number
CN110797869A
CN110797869A CN201911085321.5A CN201911085321A CN110797869A CN 110797869 A CN110797869 A CN 110797869A CN 201911085321 A CN201911085321 A CN 201911085321A CN 110797869 A CN110797869 A CN 110797869A
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China
Prior art keywords
phase
terminal
power
transmission line
transformer
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CN201911085321.5A
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Chinese (zh)
Inventor
易东
李群湛
黄小红
解绍锋
郭锴
张丽艳
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Southwest Jiaotong University
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Southwest Jiaotong University
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Priority to CN201911085321.5A priority Critical patent/CN110797869A/en
Publication of CN110797869A publication Critical patent/CN110797869A/en
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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/18—Arrangements for adjusting, eliminating or compensating reactive power in networks
    • H02J3/1821—Arrangements for adjusting, eliminating or compensating reactive power in networks using shunt compensators
    • H02J3/1835—Arrangements for adjusting, eliminating or compensating reactive power in networks using shunt compensators with stepless control
    • H02J3/1864—Arrangements for adjusting, eliminating or compensating reactive power in networks using shunt compensators with stepless control wherein the stepless control of reactive power is obtained by at least one reactive element connected in series with a semiconductor switch
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M5/00—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases
    • H02M5/02—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases without intermediate conversion into dc
    • H02M5/04—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases without intermediate conversion into dc by static converters
    • H02M5/10—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases without intermediate conversion into dc by static converters using transformers
    • H02M5/14—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases without intermediate conversion into dc by static converters using transformers for conversion between circuits of different phase number
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E40/00—Technologies for an efficient electrical power generation, transmission or distribution
    • Y02E40/10—Flexible AC transmission systems [FACTS]

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Ac-Ac Conversion (AREA)

Abstract

The invention discloses a single-phase or two-phase to three-phase power supply structure using an YNVd transformer, and relates to the technical field of power supply and distribution of a power grid. The power transmission line is connected with the YNV transformer, when the power transmission line is a single-phase power transmission line, the power transmission line is respectively connected with a P terminal in an input end of the three-phase static var generator and an A terminal in the YNV transformer, a K terminal in the YNV transformer is grounded, an N terminal of the three-phase static var generator is also grounded GND, B terminals and C terminals of the YNV transformer are respectively connected with an M terminal and an N terminal in an output end of the three-phase static var generator, and output ports a phase, B phase and C phase of the YNV transformer provide three-phase power for users.

Description

Single-phase or two-phase-to-three-phase power supply structure using YNVd transformer
Technical Field
The invention relates to the technical field of power supply and distribution of a power grid.
Background
In the ac power supply system of the power system, a three-phase ac power supply system is widely used. In the field of low-voltage power distribution in China, single-phase power transmission lines are generally erected to provide electric energy for users, users are geographically dispersed in partial regions, and a two-phase power transmission line mode is also adopted to provide electric energy for users. When a user who only accesses a single-phase or two-phase power transmission line needs to use a three-phase power supply, according to the prior art, only the three-phase power transmission line can be re-erected to provide the three-phase power supply for the user, and the method is long in time consumption, high in cost and low in economical efficiency.
Meanwhile, the transmission line is generally erected outdoors, so that the regional span is wide, the environmental conditions are variable, and various line breakage faults are generated due to the long-term mechanical force, the action of electromagnetic force, the thermal effect, serious oxidation, poor contact and the like, so that the equipment cannot normally operate. When the original three-phase transmission line has one or two-phase line break faults due to external reasons, the three-phase power supply mode is changed into a non-three-phase power supply mode, so that a three-phase power supply required by a user cannot be provided for the user. The existing solution can only provide a three-phase power supply in a short time through the economic rush repair of power maintenance personnel, and has great danger when the rescue is carried out in severe weather, so that the personal safety of the power maintenance personnel is difficult to ensure.
If the single-phase or two-phase power transmission line can be converted into a three-phase power supply mode through a simpler power equipment structure under the condition that the power quality of a power grid is allowed, a user can obtain a three-phase power supply at a lower cost in a shorter time, the cost input of a power transmission facility can be saved, the emergency supply of the three-phase power supply can be realized when the three-phase power transmission line is broken, the emergency maintenance of power maintenance personnel under the severe environment condition is avoided, and the personal safety of the power maintenance personnel is guaranteed.
Disclosure of Invention
The invention aims to provide a single-phase or two-phase to three-phase power supply structure utilizing an YNVd transformer, which can effectively solve the technical problem of providing three-phase power through a single-phase or two-phase power transmission line.
The purpose of the invention adopts the technical scheme as follows: a single or two-to-three phase power supply configuration utilizing an YNvd transformer, the power supply configuration comprising: the power transmission line is connected with the YNV transformer, when the power transmission line is a single-phase power transmission line, the power transmission line is respectively connected with a P terminal in an input end of the three-phase static var generator and an A terminal in the YNV transformer, a K terminal in the YNV transformer is grounded, an N terminal of the three-phase static var generator is also grounded GND, B terminals and C terminals of the YNV transformer are respectively connected with an M terminal and an N terminal in an output end of the three-phase static var generator, and output ports a phase, B phase and C phase of the YNV transformer provide three-phase power for users.
When the power transmission line is a two-phase power transmission line, the A-phase power transmission line L of the power transmission lineAThe three-phase static var generator is respectively connected with a P terminal in an input port of the three-phase static var generator and an A terminal of a V-shaped winding of an YNVd transformer; b-phase transmission line L of transmission lineBAnd the N terminal in the input port of the three-phase static var generator and the K terminal of the V-shaped winding of the YNVd transformer are respectively connected.
The three-phase static var generator comprises six high-power transistors BG, a direct-current energy storage capacitor and a pulse width modulator CP; every two high-power transistors BG are connected in series with the collector of another high-power transistor BG through the emitter of one high-power transistor BG to form a group of high-power transistor groups; the series points of the emitting electrodes and the collecting electrodes in the three groups of high-power transistor groups form the external P terminal, M terminal and N terminal of the three-phase static var generator; three groups of high-power transistor groups are arranged in parallel, the connection point of the emitting electrodes of the three groups of high-power transistor groups is point e, the connection point of the collecting electrodes of the three groups of high-power transistor groups is point f, and a direct-current energy storage capacitor is connected between the point e and the point f in parallel; the control electrode of each high-power transistor BG is connected with the output end of the pulse width modulator CP.
The input current of the P terminal of the three-phase static var generator is equal to one half of the input current in the power transmission line; input voltage U between terminal B and terminal C in YNVd transformerBInput voltage U between A terminal and K terminal in YNVd transformerAAre of equal magnitude and are in phase with each other90 degrees; input current I of terminal B in YNVd transformerBEqual to input current I of three-phase static var generator2。
The high-power transistor BG adopts an integrated gate commutated thyristor or an insulated gate bipolar thyristor.
Compared with the prior art, the technology of the invention has the beneficial effects that:
the method comprises the following steps that firstly, in a place where only a single-phase power transmission line with a neutral point grounded is erected in a power distribution network, as a three-phase power supply is needed in an emergency and the erection time of a new three-phase line is not allowed, under the condition that the power quality of the power distribution network is allowed, the three-phase power supply can be provided through the power supply structure;
secondly, in the place where only two-phase transmission lines are erected in the power distribution network, because three-phase power is needed in an emergency and the time for erecting a new three-phase line is not allowed, under the condition that the power quality of the power grid is allowed, the three-phase power can be provided through the power supply structure;
and thirdly, when one phase or two phases of the three-phase user are disconnected, and the maintenance environment is severe at that time, three-phase electric energy can be provided by the method, and the line is maintained after the weather environment is improved, so that potential safety hazards possibly existing in outdoor emergency repair of power maintenance personnel are reduced, and the possibility of larger accidents caused by emergency situations is also reduced.
Fourthly, the structure is simple, the universality is good, the economical efficiency is good, and the implementation is easy.
Drawings
Fig. 1 is a schematic diagram of the basic structure of the present invention.
Fig. 2 is a connection diagram of a specific structure of the present invention.
Fig. 3 is a schematic structural diagram of a three-phase static var generator according to the present invention.
Fig. 4 is a connection diagram of a specific structure of the second embodiment of the present invention.
Fig. 5 is a flow chart of the pulse width modulator control of the present invention.
Detailed Description
To make the objects, technical solutions and advantages of the present application more clear, embodiments of the present application will be described in further detail below with reference to the accompanying drawings.
The basic working principle of the power supply structure of the invention is as follows: the pulse width modulator CP (pulse width modulator) is adopted, the analog control mode is carried out on the analog circuit by utilizing the digital output of the microprocessor, the pulse width modulator can modulate the bias of a transistor base electrode or an MOS tube grid electrode according to the change of corresponding load, the change of the conduction time of the transistor or the MOS tube is realized, and the change of the output of the switching stabilized voltage power supply is realized.
Let the current of the power line 1 be I, the input current I of the A terminal in the YNVd transformer 21Input current I of terminal B in YNVd transformer 2BThe input current of the P terminal of the three-phase static var generator is I2The input voltage between the A terminal and the K terminal of the YNVd transformer 2 is UAThe input voltage between the terminal B and the terminal C of the YNVd transformer 2 is UB(ii) a P terminal input current I of three-phase static var generator 32Input current I of terminal B in YNVd transformer 2 is one-half of current I of power transmission line 1BInput current I to P terminal of three-phase static var generator 32Equal in size; input voltage U between terminal B and terminal C in YNVd transformer 2BAnd input voltage U between A terminal and K terminal in YNVd transformer 2AEqual in size and 90 degrees in phase with each other, the three-phase side of the YNV transformer 2 is operated by providing a symmetrical three-phase power supply for a load requiring three-phase power.
Example one
As shown in fig. 1, the embodiment of the present invention provides a single-phase or two-phase to three-phase power supply structure using an YNvd transformer, and the power supply structure mainly includes a power transmission line 1, an YNvd transformer 2, and a three-phase static var generator 3. The power transmission line 1 is used for carrying out current transmission on an YNVd transformer 2 and a three-phase static var generator 3; the YNVd transformer 2 is used for transforming and phase-modulating the current provided by the power transmission line 1 and the three-phase static var generator 3 and then providing a symmetrical three-phase power supply for a user; the three-phase static var generator 3 is used for converting the shunted current in the power transmission line 1 and supplying power to the YNVd transformer 2; the power transmission line 1 is respectively connected with a three-phase static var generator 3 and an YNVd transformer 2, the three-phase static var generator 3 is connected with the YNVd transformer 2, and the YNVd transformer 2 provides three-phase power for users backwards.
As shown in fig. 2 and 3, a 220V power transmission line 1 of the neutral point grounding power grid is a single-phase power transmission line and has current I, and the power transmission line 1 is respectively connected to an a terminal in an YNVd transformer 2 and a P terminal of a three-phase static var generator 3; the current magnitude of A terminal of power transmission line 1 input YNVd transformer 2 is I1The magnitude of the current input to the P terminal of the three-phase static var generator 3 is I2(ii) a The K terminal of the YNVd transformer 2 is connected with the N terminal of the three-phase static var generator 3 and then grounded; the three-phase static var generator 3 comprises six high-power transistors BG, a direct-current energy storage capacitor and a pulse width modulator CP; every two high-power transistors BG are connected in series with the collector of another high-power transistor BG through the emitter of one high-power transistor BG to form a group of high-power transistor groups; the three groups of high-power transistor groups are connected in parallel, the connection point of the emitter is a point e, the connection point of the collector is a point f, and a direct-current energy storage capacitor is connected between the point e and the point f; the control stage of each high-power transistor BG is connected to the output of the pulse width modulator CP. The M terminal of the three-phase static var generator 3 is correspondingly connected with the B terminal of the single three-phase combined transformer 2, and the N terminal of the three-phase static var generator 3 is correspondingly connected with the C terminal of the single three-phase combined transformer 2; the three-phase port sides a, b and c of the single three-phase combined transformer 2 provide three-phase symmetrical power supply for users.
Wherein, the input current I of the P terminal of the three-phase static var generator2Input current I of terminal B in YNVd transformer 2 is one-half of current I of power transmission line 1BInput current I to P terminal of three-phase static var generator2Equal in size; input voltage U between terminal B and terminal C in YNVd transformer 2BAnd input voltage U between A terminal and K terminal in YNVd transformer 2AThe YNVd transformer 2 has the same size and the phases are 90 degrees, and three-phase sides are provided with symmetrical three-phase power supplies for requiring three-phase electric energyThe load operation of (2).
The high-power transistor BG shown in FIG. 3 is an integrated gate commutated thyristor IGCT; in practical implementation, an insulated gate bipolar transistor IGBT may also be used.
Example two
The single-phase or two-phase to three-phase power supply structure using the YNVd transformer in the embodiment of the present invention is the same as the basic structure of the first embodiment of the present invention, that is, as shown in FIG. 1, the power supply structure mainly includes a power transmission line 1, a YNVd transformer 2 and a three-phase static var generator 3. The power transmission line 1 is used for carrying out current transmission on an YNVd transformer 2 and a three-phase static var generator 3; the YNVd transformer 2 is used for transforming and phase-modulating the current provided by the power transmission line 1 and the three-phase static var generator 3 and then providing a symmetrical three-phase power supply for a user; the three-phase static var generator 3 is used for converting the shunted current in the power transmission line 1 and supplying power to the YNVd transformer 2; the power transmission line 1 is respectively connected with a three-phase static var generator 3 and an YNVd transformer 2, the three-phase static var generator 3 is connected with the YNVd transformer 2, and the YNVd transformer 2 provides three-phase power for users backwards.
In the embodiment of the present invention, the structures of the six high-power transistors BG, the dc energy storage capacitor, and the pulse width modulator CP in the three-phase static var generator 3 and the connection manner among the three are completely the same as the structure shown in fig. 3 in the first embodiment of the present invention, and thus, the description thereof is omitted.
In the embodiment of the invention, the high-power transistor BG in the embodiment of the invention is an integrated gate commutated thyristor IGCT; in practical implementation, the high-power transistor BG may also adopt an insulated gate bipolar transistor IGBT.
Referring to fig. 2 and 4, a single-phase or two-phase to three-phase power supply structure using an YNvd transformer of the present embodiment is different from the first embodiment in that the power line 1 of the present embodiment is a two-phase power line; l in two-phase transmission linesA、LBThe voltage between the two lines is 220V, the input current in the power transmission line 1 is I, and the A-phase power transmission line L in the power transmission line 1ARespectively connected to A terminal and three-phase static var generator in YNVd transformer 2The current magnitude of the P terminal of the device 3 and the A terminal of the input YNVd transformer 2 is I1The magnitude of the current input to the P terminal of the three-phase static var generator 3 is I2(ii) a L in a transmission line 1BThe K terminal of the YNVd transformer 2 and the N terminal of the three-phase static var generator 3 are respectively connected; the M terminal and the N terminal of the three-phase static var generator 3 are respectively connected with the B terminal and the C terminal of the YNVd transformer 2; three-phase sides a, b and c of the YNVd transformer 2 provide three-phase symmetrical power for users.
The control flow of the pulse width modulator is shown in fig. 5, wherein the input current I of the P terminal of the three-phase static var generator2Input current I of terminal B in YNVd transformer 2 is one-half of current I of power transmission line 1BInput current I to P terminal of three-phase static var generator2Equal in size; input voltage U between terminal B and terminal C in YNVd transformer 2BAnd input voltage U between A terminal and K terminal in YNVd transformer 2AEqual in size and 90 degrees in phase with each other, the three-phase side of the YNV transformer 2 is operated by providing a symmetrical three-phase power supply for a load requiring three-phase power.

Claims (5)

1. A single or two-to-three phase power supply configuration utilizing an YNvd transformer, the power supply configuration comprising: power transmission line (1), YNVd transformer (2) and three-phase static var generator (3), power transmission line (1) are connected its characterized in that with YNVd transformer (2): when the power transmission line (1) is a single-phase power transmission line, the power transmission line (1) is respectively connected with a P terminal in an input end of a three-phase static var generator (3) and an A terminal in an YNVd transformer (2), a K terminal in the YNVd transformer (2) is grounded, an N terminal of the three-phase static var generator (3) is also grounded GND, a B terminal and a C terminal of the YNVd transformer (2) are respectively connected with an M terminal and an N terminal in an output end of the three-phase static var generator (3), and an output port a phase, a phase and a phase of the YNVd transformer (2) provide three-phase power for a user.
2. The single-phase or two-phase to three-phase power supply structure using the YNVd transformer as claimed in claim 1, wherein: when the transmission line (1) is a two-phase transmission lineA-phase transmission line L of the transmission line (1)AThe three-phase static var generator is respectively connected with a P terminal in an input port of the three-phase static var generator (3) and an A terminal of a V-shaped winding of the YNVd transformer (2); b-phase transmission line L of a transmission line (1)BAnd the N terminal in the input port of the three-phase static var generator (3) and the K terminal of the V-shaped winding of the YNVd transformer (2) are respectively connected.
3. The single-phase or two-phase to three-phase power supply structure using the YNVd transformer as claimed in claim 1, wherein: the three-phase static var generator (3) comprises six high-power transistors BG, a direct-current energy storage capacitor and a pulse width modulator CP; every two high-power transistors BG are connected in series with the collector of another high-power transistor BG through the emitter of one high-power transistor BG to form a group of high-power transistor groups; the series points of the emitting electrodes and the collecting electrodes in the three groups of high-power transistor groups form the external P terminal, M terminal and N terminal of the three-phase static var generator; three groups of high-power transistor groups are arranged in parallel, the connection point of the emitting electrodes of the three groups of high-power transistor groups is point e, the connection point of the collecting electrodes of the three groups of high-power transistor groups is point f, and a direct-current energy storage capacitor is connected between the point e and the point f in parallel; the control electrode of each high-power transistor BG is connected with the output end of the pulse width modulator CP.
4. The single-phase or two-phase to three-phase power supply structure using the YNVd transformer as claimed in claim 1, wherein: the input current of the P terminal of the three-phase static var generator (3) is equal to one half of the input current of the power transmission line (1); input voltage U between terminal B and terminal C in YNVd transformer (2)BAnd input voltage U between A terminal and K terminal in YNVd transformer (2)AEqual in magnitude and 90 degrees in phase to each other; input current I of terminal B in YNVd transformer (2)BEqual to the input current I of the three-phase static var generator (3)2。
5. A single phase or two-to-three phase power supply configuration using YNvd transformer as claimed in claim 3, wherein: the high-power transistor BG adopts an integrated gate commutated thyristor or an insulated gate bipolar thyristor.
CN201911085321.5A 2019-11-08 2019-11-08 Single-phase or two-phase-to-three-phase power supply structure using YNVd transformer Pending CN110797869A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201911085321.5A CN110797869A (en) 2019-11-08 2019-11-08 Single-phase or two-phase-to-three-phase power supply structure using YNVd transformer

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201911085321.5A CN110797869A (en) 2019-11-08 2019-11-08 Single-phase or two-phase-to-three-phase power supply structure using YNVd transformer

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CN110797869A true CN110797869A (en) 2020-02-14

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