CN110649617A - Single-phase or two-phase to three-phase power supply structure using balance wiring transformer - Google Patents

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

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Publication number
CN110649617A
CN110649617A CN201911085479.2A CN201911085479A CN110649617A CN 110649617 A CN110649617 A CN 110649617A CN 201911085479 A CN201911085479 A CN 201911085479A CN 110649617 A CN110649617 A CN 110649617A
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China
Prior art keywords
phase
terminal
impedance matching
power
transformer
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Pending
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CN201911085479.2A
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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 CN201911085479.2A priority Critical patent/CN110649617A/en
Publication of CN110649617A publication Critical patent/CN110649617A/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
    • Y02E40/30—Reactive power compensation

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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 a balanced wiring transformer, and belongs to the technical field of power supply and distribution of a power grid. The power supply structure includes: the power transmission line is connected with an A terminal of an input end of the impedance matching balance wiring transformer, a P terminal in an input port of the three-phase static var generator is connected with the power transmission line, a B terminal in the input end of the impedance matching balance wiring transformer is connected with an M terminal in an output port of the three-phase static var generator, a C terminal in the input end of the impedance matching balance wiring transformer is connected with an N terminal in the output port of the three-phase static var generator and is grounded GND; the output end a phase, b phase and c phase of the impedance matching balanced connection transformer are used as three-phase power supply provided for users.

Description

Single-phase or two-phase to three-phase power supply structure using balance wiring 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 object of the present invention is to provide a single-phase or two-phase to three-phase power supply structure using a balanced wiring transformer, which can effectively solve the technical problem of supplying three-phase power through a single-phase or two-phase power transmission line.
The purpose of the invention is realized by the following technical scheme: a single or two-to-three phase power supply configuration utilizing a balanced wiring transformer, the power supply configuration comprising: the power transmission line is connected with an A terminal of an input end of the impedance matching balance wiring transformer, a P terminal in an input port of the three-phase static var generator is connected with the power transmission line, a B terminal in the input end of the impedance matching balance wiring transformer is connected with an M terminal in an output port of the three-phase static var generator, a C terminal in the input end of the impedance matching balance wiring transformer is connected with an N terminal in the output port of the three-phase static var generator and is grounded GND; the output end a phase, b phase and c phase of the impedance matching balanced connection transformer are used as three-phase power supply provided 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 lineAP terminal and A terminal of impedance matching balance transformer respectively connected into input port of three-phase static var generator, B phase transmission line L of transmission lineBAnd the N terminal of the three-phase static var generator and the C terminal of the impedance matching balance transformer are 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 connected in parallel in the forward direction, the connection point of an emitter is a point e, the connection point of a collector is a point f, and a direct-current energy storage capacitor is connected between the point e and the point f; the control level of each high-power transistor BG is connected to the output end of a pulse width modulator CP;
input current I of the three-phase static var generator2For the current I of the transmission line 1One half; input voltage U between B terminal and C terminal in impedance matching balanced connection transformerBInput voltage U between A terminal and C terminal of impedance matching balanced connection transformerAEqual in magnitude and 90 degrees in phase to each other; input current I of B terminal in impedance matching balanced connection 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 transistor.
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 the three-phase static var generator according to the first embodiment of the present invention.
Fig. 4 is a connection diagram of a specific structure of the power supply structure according to 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 transmission line 1 be I, and the input current I of the A terminal in the impedance matching balanced connection transformer 21The input current of the three-phase static var generator is I2The input current of the B terminal in the impedance matching balanced connection transformer 2 is IBThe input voltage between the A terminal and the C terminal of the impedance matching balanced connection transformer 2 is UAThe input voltage between the B terminal and the C terminal of the impedance matching balanced connection transformer 2 is UB(ii) a Input current I of A terminal in impedance matching balanced connection transformer 21Is a transmission line LAIs one half of the current I of (a); input voltage U in impedance matching balanced wiring transformer 2BAnd an input voltage UAEqual in magnitude and phase with UAInput current I of terminal B in 90-degree impedance matching balanced connection transformer 2BEqual to input current I of three-phase static var generator2(ii) a The star winding side of the impedance matching balanced terminal 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 configuration using a balanced wiring transformer, which mainly includes a power transmission line 1, an impedance matching balanced wiring transformer 2, and a three-phase static var generator 3. The power transmission line 1 is used for carrying out current transmission on the impedance matching balanced connection transformer 2 and the three-phase static var generator 3; the impedance matching balance wiring 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 users; 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 impedance matching balanced wiring transformer 2; the power transmission line 1 is respectively connected with a three-phase static var generator 3 and an impedance matching balance wiring transformer 2, the three-phase static var generator 3 is connected with the impedance matching balance wiring transformer 2, and the impedance matching balance wiring transformer 2 provides a three-phase power supply for a user.
As shown in fig. 2 and fig. 3, a 220V transmission line 1 of a neutral point grounding grid is a single-phase transmission line and has a current I, and the transmission line 1 is respectively connected to an a terminal in an impedance matching balanced connection transformer 2 and a P terminal in a three-phase static var generator 3; the input impedance of the transmission line 1 is matched with the current of the A terminal in the balanced wiring transformer 2, and the current is I1The magnitude of the current input to the P terminal of the three-phase static var generator 3 is I2(ii) a The C terminal in the impedance matching balance wiring transformer 2 is connected with the N terminal of the three-phase static var generator 3, and the M terminal of the three-phase static var generator 3 is correspondingly connected with the B terminal in the impedance matching balance wiring transformer 2; 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 which are connected; 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 a pulse width modulator CP. The N terminal of the three-phase static var generator 3 is grounded; the star winding sides a, b, c of the impedance matching balanced terminal transformer 2 provide three-phase symmetric power to the user.
Wherein, the P terminal of the three-phase static var generator 3 is connectedInput current I2Is half the current I of the transmission line 1; input voltage U in impedance matching balanced wiring transformerBInput voltage U in impedance matching balanced connection transformerAEqual in magnitude and 90 degrees in phase with each other, impedance matching balances the input current I of the B terminal in the wiring transformer 2BEqual to input current I of three-phase static var generator2。
The high-power transistor BG disclosed by the embodiment of the invention is an integrated gate commutated thyristor IGCT; in practical implementation, an insulated gate bipolar transistor IGBT may also be used.
Example two
A single-phase or two-phase to three-phase power supply structure using a balanced connection transformer according to an 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, an impedance matching balanced connection transformer 2, and a three-phase static var generator 3. The power transmission line 1 is used for carrying out current transmission on an impedance matching balanced connection transformer 2 and a three-phase static var generator 3; the impedance matching balance wiring 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 impedance matching balanced wiring transformer 2; the power transmission line 1 is respectively connected with a three-phase static var generator 3 and an impedance matching balance wiring transformer 2, the three-phase static var generator 3 is connected with the impedance matching balance wiring transformer 2, and the impedance matching balance wiring transformer 2 provides a three-phase power supply for a user.
The structures and the connection modes of the six high-power transistors BG, the direct-current energy storage capacitors, and the pulse width modulators CP in the three-phase static var generator 3 in the embodiment of the present invention are completely the same as those 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, the pwm control flow is shown in fig. 5, and a single-phase or two-phase to three-phase power supply structure using a balanced connection transformer according to an embodiment of the present invention is different from the first embodiment of the present invention in that the power transmission line 1 according to the embodiment of the present invention is a two-phase power transmission 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 the A terminal of the impedance matching balanced connection transformer 2 and the P terminal of the three-phase static var generator 3, the A-phase transmission line LAThe current magnitude of the A terminal in the input impedance matching balanced connection transformer 2 is I1A phase transmission line LAThe current input to the P terminal of the three-phase static var generator 3 is I2(ii) a B-phase transmission line L in transmission line 1BThe N terminal of the three-phase static var generator 3 is accessed; the M terminal and the N terminal of the three-phase static var generator 3 are respectively and correspondingly connected with the B terminal and the C terminal in the impedance matching balanced connection transformer 2; the star winding sides a, b, c of the impedance matching balanced terminal transformer 2 provide three-phase symmetric power to the user.
Wherein, the P terminal of the three-phase static var generator 3 inputs current I2Is half the current I of the transmission line 1; input voltage U in impedance matching balanced wiring transformerBInput voltage U in impedance matching balanced connection transformerAEqual in magnitude and 90 degrees in phase with each other, impedance matching balances the input current I of the B terminal in the wiring transformer 2BEqual to input current I of three-phase static var generator2。

Claims (5)

1. A single or two-to-three phase power supply configuration utilizing a balanced wiring transformer, comprising: transmission line (1), impedance matching balance wiring transformer (2) and three-phase static var generator (3), its characterized in that: the power transmission line (1) is connected with an A terminal of an input end of an impedance matching balance wiring transformer (2), a P terminal of an input port of a three-phase static var generator (3) is connected with the power transmission line (1), a B terminal of the input end of the impedance matching balance wiring transformer (2) is connected with an M terminal of an output port of the three-phase static var generator (3), a C terminal of the input end of the impedance matching balance wiring transformer (2) is connected with an N terminal of the output port of the three-phase static var generator (3) and is grounded GND; the a phase, the b phase and the c phase of the output end of the impedance matching balanced connection transformer (2) are used as three-phase power supply provided for users.
2. A single or two-to-three phase power supply configuration using a balanced wiring transformer as claimed in claim 1 wherein: an A-phase power line L of the power line (1) when the power line (1) is a two-phase power lineARespectively connected to the P terminal of the input port of the three-phase static var generator (3), the A terminal of the impedance matching balance transformer (2), and the B-phase transmission line L of the transmission line (1)BAnd an N terminal of the three-phase static var generator (3) and a C terminal of the impedance matching balance transformer (2) are connected.
3. A single or two-to-three phase power supply configuration using a balanced wiring 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 connected in parallel in the forward direction, the connection point of an emitter is a point e, the connection point of a collector is a point f, and a direct-current energy storage capacitor is connected between the point e and the point f; the control level of each high-power transistor BG is connected to the output end of the pulse width modulator CP.
4. A single or two-to-three phase power supply configuration using a balanced wiring transformer as claimed in claim 1 wherein: input current I of the three-phase static var generator (3)2For electricity of the transmission line 1One half of stream I; input voltage U between terminal B and terminal C in impedance matching balanced connection transformer (2)BInput voltage U between A terminal and C terminal of impedance matching balanced connection transformer (2)AEqual in magnitude and 90 degrees in phase to each other; input current I of B terminal in impedance matching balanced connection transformer (2)BEqual to the input current I of the three-phase static var generator (3)2。
5. The structure of claim 3, wherein the high power transistor BG is an integrated gate commutated thyristor or an insulated gate bipolar transistor.
CN201911085479.2A 2019-11-08 2019-11-08 Single-phase or two-phase to three-phase power supply structure using balance wiring transformer Pending CN110649617A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201911085479.2A CN110649617A (en) 2019-11-08 2019-11-08 Single-phase or two-phase to three-phase power supply structure using balance wiring transformer

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201911085479.2A CN110649617A (en) 2019-11-08 2019-11-08 Single-phase or two-phase to three-phase power supply structure using balance wiring transformer

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CN110649617A true CN110649617A (en) 2020-01-03

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