CN210780099U - Combined transformer power supply structure - Google Patents
Combined transformer power supply structure Download PDFInfo
- Publication number
- CN210780099U CN210780099U CN201921917737.4U CN201921917737U CN210780099U CN 210780099 U CN210780099 U CN 210780099U CN 201921917737 U CN201921917737 U CN 201921917737U CN 210780099 U CN210780099 U CN 210780099U
- Authority
- CN
- China
- Prior art keywords
- power
- phase
- terminal
- transformer
- transmission line
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Landscapes
- Ac-Ac Conversion (AREA)
Abstract
The utility model discloses a modular transformer power supply structure relates to electric power electric wire netting and supplies distribution technical field. A single-phase transformer T1 and a three-phase transformer T2 are connected to form a single three-phase combined transformer, the input side of a single-phase transformer T1 is connected with the power transmission line, a u terminal in the output port of the single-phase transformer T1 is connected with a b-phase line on the three-phase output side of the three-phase transformer T2, and a v terminal in the output port of a single-phase transformer T1 is connected with a c-phase line on the three-phase output side of the three-phase transformer T2; the input end of a three-phase transformer T2 in the single three-phase combined transformer is connected with the output end of the power converter; the B terminal and the C terminal in the single three-phase combined transformer are respectively connected with the M terminal and the N terminal in the output port of the power converter, and the A terminal in the single three-phase combined transformer is connected with a power transmission line; and the three-phase port of the single three-phase combined transformer is used as an output port to provide a three-phase power supply for a user.
Description
Technical Field
The utility model relates to an electric power electric wire netting power supply and distribution technical field.
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.
SUMMERY OF THE UTILITY MODEL
The utility model aims at providing a modular transformer power supply structure, it can solve effectively and provide three phase power's technical problem through single-phase or double-phase power transmission line.
The purpose of the utility model is realized through the following technical scheme: a combined transformer power supply structure comprises a power transmission line connected with a power grid, a power converter connected with a single-phase transformer, wherein the input end of the power converter is connected with the power transmission line, the single-phase transformer T1 and a three-phase transformer T2 are connected to form a single three-phase combined transformer, the input side of a single-phase transformer T1 in the single three-phase combined transformer is connected with the power transmission line, a u terminal in the output port of a single-phase transformer T1 is connected with a b-phase line on the three-phase output side of a three-phase transformer T2, and a v terminal in the output port of a single-phase transformer T1 is connected with a c-phase line on the three; the input end of a three-phase transformer T2 in the single three-phase combined transformer is connected with the output end of the power converter; the B terminal and the C terminal in the single three-phase combined transformer are respectively connected with the M terminal and the N terminal in the output port of the power converter, and the A terminal in the single three-phase combined transformer is connected with the power transmission line; and the three-phase port of the single three-phase combined transformer is used as an output port to provide a three-phase power supply for a user.
When the power transmission line is a single-phase power transmission line, a P terminal in the input end of the power converter is connected with the power transmission line, and a Q terminal in the input end of the power converter is grounded GND; the K terminal in the single three-phase combined transformer is grounded GND.
When the power transmission line is a two-phase power transmission line, the P terminal and the Q terminal in the input end of the power converter are respectively connected with the A-phase power transmission line L in the power transmission lineAB phase transmission line LBConnecting; a terminal and K terminal in single three-phase combined transformer are respectively connected with A phase transmission line L in transmission lineAB phase power transmission line LBAre connected.
The power converter comprises a first high-power switching device SVG1 on a rectifying side, a second high-power switching device SVG2 on an inverting side, a direct-current energy storage capacitor Ca and a pulse width modulator, wherein the first high-power switching device SVG1 and the second high-power switching device SVG2 are connected in series, and the direct-current energy storage capacitor Ca is connected between connection points of the first high-power switching device SVG1 and the second high-power switching device SVG2 and used for providing voltage support between an emitter and a collector of the first high-power switching device and the second high-power switching device; the output end of the pulse width modulator is respectively connected with the control electrodes of the first high-power switching device SVG1 and the second high-power switching device SVG 2. The pulse width modulator controls the first high-power switching device SVG1 and the second high-power switching device SVG2 through control poles thereof.
The input current of a first high-power switching device SVG1 of the power converter is equal to one half of the input current in the power transmission line; input voltage U between B terminal and C terminal in three-phase transformer T2BAnd the input voltage U between the A terminal and the K terminal of the single-phase transformer T1AEqual in magnitude and 90 degrees in phase to each other.
The first high-power switching device SVG1 comprises four high-power transistors BG, and the control electrode of each high-power transistor BG is connected with a pulse width modulator; 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 emitters of the two groups of high-power transistor groups are connected in pairs, and the collectors of the two groups of high-power transistor groups are also connected in pairs; the series points of the emitters and the collectors in the two groups of high-power transistor groups form a P terminal and a Q terminal of a current input end of a first high-power switching device SVG 1.
The second high-power switching device SVG2 comprises four high-power transistors BG, and the pulse width modulator controls each high-power transistor BG through a control electrode of the transistor; 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 emitters of the two groups of high-power transistor groups are connected in pairs, and the collectors of the two groups of high-power transistor groups are also connected in pairs; the series points of the emitter and the collector in the two groups of high-power transistor groups form an M terminal and an N terminal of a current output end of a second high-power switching device SVG 2.
The high-power transistor BG adopts an integrated gate commutated thyristor or an insulated gate bipolar transistor.
Compared with the prior art, the utility model discloses the beneficial effect of technique is:
firstly, in the place where only a single-phase transmission line with a grounded neutral point is erected in a power distribution network, because a three-phase power supply is needed in an emergency and the time for erecting a new three-phase line is not allowed, under the condition that the electric energy quality of the power distribution network is allowed, the three-phase power supply can be provided through the power supply structure of the utility model;
secondly, in the place where only two-phase power transmission lines are erected in the power distribution network, because three-phase power is needed in an emergency and short time, the time for erecting a new three-phase line is not allowed, and under the condition that the power quality of the power distribution network is allowed, the three-phase power can be provided through the power supply structure of the utility model;
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 a basic structure of the power supply structure according to the first embodiment of the present invention.
Fig. 2 is a connection diagram of a specific structure of the power supply structure according to the first embodiment of the present invention.
Fig. 3 is a schematic structural diagram of a power converter according to a 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.
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 is as follows: the pulse width modulator (pulse width modulator) is adopted, the digital output of the microprocessor is utilized to carry out an analog control mode on the analog circuit, and 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 to realize the change of the conduction time of the transistor or the MOS tube, thereby realizing the change of the output of the switching stabilized voltage power supply.
Let the current of the transmission line 1 be I, the input current I of the A terminal in the single three-phase combined transformer 21The input current of the first high-power switching device SVG1 is I2The input voltage between the A terminal and the K terminal in the single three-phase combined transformer 2 is UAThe input voltage between the terminal B and the terminal C of the single-three phase combined transformer 2 is UB. Control of input current I of first high-power switching device SVG1 in power converter 3 by pulse width modulator2Is a transmission line LAIs one half of the current I of (a); input voltage U between B terminal and C terminal of three-phase transformer T2BAnd an input voltage U between the A terminal and the K terminal of the single-phase transformer T1AEqual in size and 90 ° in phase with each other, the three-phase side of the single three-phase combined transformer 2 is operated by providing a symmetrical three-phase power supply for a load requiring three-phase electric power.
Example one
As shown in fig. 1, an embodiment of the present invention provides a combined transformer power supply structure, which mainly includes a power transmission line 1, a single three-phase combined transformer 2 and a power converter 3. The power transmission line 1 is used for carrying out current transmission on a single three-phase combined transformer 2 and a power converter 3; the single-three phase combined transformer 2 is composed of a single-phase transformer T1 and a three-phase transformer T2 according to the connection mode of figure 2, and is used for transforming and phase modulating the current provided by the power transmission line 1 and the power converter 3 and then providing a symmetrical three-phase power supply for users; the power converter 3 is used for converting the shunted current in the power transmission line 1 and supplying power to the single three-phase combined transformer 2; the power transmission line 1 is respectively connected with a power converter 3 and a single three-phase combined transformer 2, the power converter 3 is connected with the single three-phase combined transformer 2, and the three-phase side of the single three-phase combined transformer 2 provides three-phase power for users.
As shown in fig. 2 and 3, a 220V transmission line 1 of the neutral point grounding grid is a single-phase transmission line and has current I, and the transmission line 1 is respectively connected to an a terminal in a single three-phase combined transformer 2 and a P terminal in a power converter 3; the current magnitude of the A terminal of the power transmission line 1 input into the single three-phase combined transformer 2 is I1The magnitude of the current input to the P terminal of the power converter 3 is I2(ii) a The K terminal in the single three-phase combined transformer 2 is grounded GND; the power converter 3 comprises a first high-power switching device SVG1 serving as a rectifying side and a second high-power switching device SVG2 serving as an inverting side, the first high-power switching device SVG1 and the second high-power switching device SVG2 are connected in series, and a direct-current energy storage capacitor Ca is arranged between the connection points of the first high-power switching device SVG1 and the second high-power switching device SVG2 in parallel; the direct current energy storage capacitor Ca is used for providing voltage support for the emitter and the collector of the first high-power switching device and the second high-power switching device; the control electrodes of the first high-power switching device SVG1 and the second high-power switching device SVG2 are both connected with the pulse modem 4; a Q terminal of the power converter 3 is grounded GND, and an M terminal and an N terminal of the power converter 3 are correspondingly connected with a B terminal and a C terminal of the three-phase transformer 2 respectively; the three-phase 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 first high-power switch device SVG1 in the power converter 32Is a transmission line LAIs one half of the current I of (a); input voltage U between B terminal and C terminal in three-phase transformer T2BAnd the input voltage U between the A terminal and the K terminal of the single-phase transformer T1AEqual in magnitude and 90 degrees in phase to each other.
In the embodiment of the present invention, the first high-power switching device SVG1 includes four high-power transistors BG, and a control electrode of each high-power transistor BG is connected to an output terminal of the pulse width modulator 4; 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; emitters which are not connected in series in the two groups of high-power transistors in the first high-power switching device SVG1 are connected, and collectors which are not connected in series in the two groups of high-power transistors in the first high-power switching device SVG1 are connected.
In the embodiment of the present invention, the second high-power switching device SVG2 has the same structure as the first high-power switching device SVG1, the second high-power switching device SVG2 includes four high-power transistors BG, and the control electrode of each high-power transistor BG is connected to the output end of the pulse width modulator 4; 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 emitters and the collectors in the two groups of high-power transistor groups form a current output end M and an output end N of a second high-power switching device SVG 2; emitters which are not connected in series in two groups of high-power transistors in the second high-power switching device SVG2 are connected, and collectors which are not connected in series in two groups of high-power transistors in the second high-power switching device SVG2 are connected.
The high-power transistor BG shown in fig. 4 is an integrated gate commutated thyristor IGCT; in practical implementation, an insulated gate bipolar transistor IGBT may also be used.
Example two
The embodiment of the utility model provides a modular transformer power supply structure with above-mentioned the utility model provides a basic structure is the same, as shown in figure 1 promptly, this power supply structure mainly includes power transmission line 1, single three-phase combined transformer 2 and power converter 3. The power transmission line 1 is used for carrying out current transmission on a single three-phase combined transformer 2 and a power converter 3; the single three-phase combined transformer 2 is used for transforming and phase-modulating the current provided by the power transmission line 1 and the power converter 3 and then providing a symmetrical three-phase power supply for users; the power converter 3 is used for converting the shunted current in the power transmission line 1 and supplying power to the single three-phase combined transformer 2; the power transmission line 1 is respectively connected with a power converter 3 and a single three-phase combined transformer 2, the power converter 3 is connected with the single three-phase combined transformer 2, and the single three-phase combined transformer 2 provides three-phase power for users.
The embodiment of the utility model provides an in power converter 3 in first high power switch device SVG1 the structure of second high power switch device SVG2 and direct current energy storage electric capacity Ca and the connected mode between the three with above-mentioned utility model embodiment one in as shown in figure 3 the structure identical, so this no longer give unnecessary details.
In the embodiment of the utility model, the high-power transistor BG in the embodiment of the utility model 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 power supply structure of a combined 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 an 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 single-three phase combined transformer 2 and the P terminal of the power converter 3, and the current input to the A terminal of the single-three phase combined transformer 2 is I1The magnitude of the current input to the P terminal of the power converter 3 is I2(ii) a B-phase transmission line L in transmission line 1BA K terminal in the single three-phase combined transformer 2 and a Q terminal of the power converter 3 are respectively connected; the power converter 3 comprises a first high-power switch device SVG1 serving as a rectifying side and a second high-power switch device SVG2 serving as an inverting side, a direct-current energy storage capacitor Ca is arranged between connection points of the first high-power switch device SVG1 and the second high-power switch device SVG2 in parallel and used for providing voltage support for an emitter and a collector of the first high-power switch device and the second high-power switch device, and control electrodes of the first high-power switch device SVG1 and the second high-power switch device SVG2 are connected with an output end of the pulse width modulator 4; the M terminal and the N terminal of the power converter 3 are respectively and correspondingly connected with the B terminal and the C terminal of the single three-phase combined transformer 2; three-phase side a of single three-phase combined transformer 2B, c provide three-phase symmetrical power supply to users.
Wherein, the input current I of the first high-power switch device SVG1 in the power converter 32Is a transmission line LAIs one half of the current I of (a); input voltage U between the B terminal and the C terminal in the second single-phase transformer T2BAnd an input voltage U between the A terminal and the K terminal of the first single-phase transformer T1AEqual in magnitude and 90 degrees in phase to each other.
Claims (8)
1. A modular transformer power supply configuration comprising a transmission line (1) connected to a power network, a power converter (3) connected to a single-phase transformer, the input of said power converter (3) being connected to the transmission line (1), characterized in that: a single three-phase combined transformer (2) is formed by connecting a single-phase transformer T1 and a three-phase transformer T2, the input side of a single-phase transformer T1 in the single three-phase combined transformer (2) is connected with the power transmission line (1), a u terminal in the output port of the single-phase transformer T1 is connected with a b-phase line on the three-phase output side of the three-phase transformer T2, and a v terminal in the output port of the single-phase transformer T1 is connected with a c-phase line on the three-phase output side of the three-phase transformer T2; the input end of a three-phase transformer T2 in the single three-phase combined transformer (2) is connected with the output end of the power converter (3); the B terminal and the C terminal in the single three-phase combined transformer (2) are respectively connected with the M terminal and the N terminal in the output port of the power converter (3), and the A terminal in the single three-phase combined transformer (2) is connected with the power transmission line (1); and the three-phase port of the single three-phase combined transformer (2) is used as an output port to provide three-phase power for users.
2. The modular transformer power supply architecture of claim 1, wherein: when the power transmission line (1) is a single-phase power transmission line, a P terminal in the input end of the power converter (3) is connected with the power transmission line (1), and a Q terminal in the input end of the power converter is grounded GND; the K terminal in the single three-phase combined transformer (2) is grounded GND.
3. The modular transformer power supply configuration of claim 1, wherein: when the power transmission line (1) is a two-phase power transmission line, the P terminal and the Q terminal in the input end of the power converter (3) are respectively connected with the A-phase power transmission line L in the power transmission line (1)AB phase transmission line LBConnecting; a terminal and K terminal in the single three-phase combined transformer (2) are respectively connected with an A-phase transmission line L in the transmission line (1)AB phase power transmission line LBAre connected.
4. The modular transformer power supply architecture of claim 1, wherein: the power converter (3) comprises a first high-power switching device SVG1 on a rectifying side, a second high-power switching device SVG2 on an inverting side, a direct-current energy storage capacitor Ca and a pulse width modulator (4), wherein the first high-power switching device SVG1 and the second high-power switching device SVG2 are connected in a back-to-back mode, and the direct-current energy storage capacitor Ca is connected between connection points of the first high-power switching device SVG1 and the second high-power switching device SVG2 and used for providing voltage support between an emitter and a collector of the first high-power switching device and the second high-power switching device; the output end of the pulse width modulator (4) is respectively connected with the control electrodes of the first high-power switching device SVG1 and the second high-power switching device SVG 2.
5. A modular transformer power supply configuration according to claim 2, wherein: the input current of a first high-power switching device SVG1 of the power converter (3) is equal to one half of the input current of the power transmission line (1); input voltage U between B terminal and C terminal in three-phase transformer T2BAnd the input voltage U between the A terminal and the K terminal of the single-phase transformer T1AEqual in magnitude and 90 degrees in phase to each other.
6. The modular transformer power supply architecture of claim 5, wherein: the first high-power switching device SVG1 comprises four high-power transistors BG, and the pulse width modulator (4) is controlled by a control electrode of each high-power transistor BG; 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 emitters of the two groups of high-power transistor groups are connected in pairs, and the collectors of the two groups of high-power transistor groups are also connected in pairs; the series points of the emitters and the collectors in the two groups of high-power transistor groups form a P terminal and a Q terminal of a current input end of a first high-power switching device SVG 1.
7. A combined transformer supply configuration according to claim 4, characterised in that said second high power switching device SVG2 comprises four high power transistors BG, the control electrode of each high power transistor BG being connected to a pulse width modulator (4); 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 emitters of the two groups of high-power transistor groups are connected in pairs, and the collectors of the two groups of high-power transistor groups are also connected in pairs; the series points of the emitter and the collector in the two groups of high-power transistor groups form an M terminal and an N terminal of a current output end of a second high-power switching device SVG 2.
8. The combined transformer power supply structure as claimed in claim 6, wherein the high power transistor BG employs an integrated gate commutated thyristor or an insulated gate bipolar transistor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921917737.4U CN210780099U (en) | 2019-11-08 | 2019-11-08 | Combined transformer power supply structure |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921917737.4U CN210780099U (en) | 2019-11-08 | 2019-11-08 | Combined transformer power supply structure |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN210780099U true CN210780099U (en) | 2020-06-16 |
Family
ID=71046029
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201921917737.4U Active CN210780099U (en) | 2019-11-08 | 2019-11-08 | Combined transformer power supply structure |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN210780099U (en) |
-
2019
- 2019-11-08 CN CN201921917737.4U patent/CN210780099U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP3082212B1 (en) | Tripolar flexible direct-current power transmission system and method | |
| WO2015074624A1 (en) | Power transmission system for improving transmission capacity of urban power grid through non-sine alternating current power transmission | |
| EP4075625A1 (en) | Sea island power transmission system and control method therefor | |
| CN110649609A (en) | Single-phase or two-phase-to-three-phase power supply structure using YNVd transformer | |
| CN210444020U (en) | Single-phase or two-phase-to-three-phase power supply structure using YNVd transformer | |
| CN110797867B (en) | Single-phase or two-phase conversion three-phase power supply structure | |
| CN210780099U (en) | Combined transformer power supply structure | |
| CN210608539U (en) | Single-phase or two-phase to three-phase power supply structure | |
| CN210608538U (en) | Single-phase or two-phase-to-three-phase power supply structure using YNVd transformer | |
| CN210744743U (en) | Three-phase power supply structure of single three-phase combined transformer | |
| CN210629103U (en) | Single-phase or two-phase to three-phase power supply structure using balance wiring transformer | |
| CN208112250U (en) | (PCC) power, wind power generating set and wind power plant | |
| CN110649607A (en) | Non-three-phase-to-three-phase power supply structure based on three-phase transformer | |
| CN108242896B (en) | Current converter, DC-side grounded three-level structure flexible DC system and control method | |
| CN210669531U (en) | Non-three-phase-to-three-phase power supply structure based on Scott wiring transformer | |
| CN210927100U (en) | Non-three-phase to three-phase power supply structure based on wood bridge connection line transformer | |
| CN110635482B (en) | Single-phase combined transformer power supply structure | |
| CN110768252A (en) | Non-three-phase to three-phase power supply system based on Lebrank wiring transformer | |
| CN110635481A (en) | Combined transformer power supply structure | |
| CN210927099U (en) | Non-three-phase-to-three-phase power supply structure based on three-phase transformer | |
| CN110797868A (en) | Single-phase or two-phase to three-phase power supply structure | |
| CN110676848A (en) | Non-three-phase-to-three-phase power supply structure based on Scott wiring transformer | |
| CN110661262A (en) | Three-phase power supply structure of single three-phase combined transformer | |
| CN110797869A (en) | Single-phase or two-phase-to-three-phase power supply structure using YNVd transformer | |
| CN211183415U (en) | DC line reformed by same-tower double-circuit AC line |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |