A single-phase or two-phase to three-phase power supply structure device using a YNvd transformer
By using YNvd transformers and power converters in low-voltage distribution networks to convert single-phase or two-phase transmission lines into three-phase power supply, the problem of users needing to re-erect three-phase transmission lines when they need three-phase power is solved, achieving It provides fast and economical three-phase power supply and reduces the risk of emergency repairs for power maintenance personnel.
Patent Information
- Application Number
- CN201911085140.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2019-11-08
- Publication Date
- 2025-01-24
- Estimated Expiration
- 2039-11-08
AI Technical Summary
In the field of low-voltage power distribution, single-phase or two-phase transmission lines cannot directly provide three-phase power, resulting in users needing a three-phase transmission line to reinstall when they need a three-phase power supply, which is time-consuming and costly. At the same time, emergency repairs occur in bad weather. Safety hazards.
Using the YNVD transformer and power converter, connect with the YNVD transformer and the power converter through a single or two -phase transmission line, and use the triangular winding and star winding of the YNVD transformer to combine the rectification and inverter function of the power converter to realize the single single single The transformer and adjustment of the two -phase current, and the symmetrical three -phase power supply.
In the case of re -setting up three -phase transmission lines, three -phase power supply is quickly provided, reducing costs and time inputs, and three -phase power supply can be urgently provided when a three -phase transmission line is disconnected. Risk of repair in harsh environments.
Smart Images
Figure CN110649609B_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of power supply and distribution of electric power grids. Background Art
[0002] Among the AC power supply methods of the power system, the three-phase AC power supply system is widely used. In my country's low-voltage power distribution field, single-phase transmission lines are generally used to provide electricity to users. In some areas where users are geographically dispersed, two-phase transmission lines are also used to provide electricity to users. When users who are only connected to single-phase or two-phase transmission lines need to use three-phase power, according to existing technology, they can only re-erect three-phase transmission lines to provide three-phase power to users, which is time-consuming, costly, and uneconomical.
[0003] At the same time, since the transmission lines are generally erected outdoors, the geographical span is wide, and the environmental conditions are changeable, various disconnection faults occur due to long-term mechanical force, electromagnetic force and thermal effect, as well as severe oxidation, poor contact and other reasons, making the equipment unable to operate normally. When the original three-phase transmission line has one or two phase disconnection faults due to external reasons, the three-phase power supply mode becomes a non-three-phase power supply mode, and it is impossible to provide users with the three-phase power supply they need. The existing solution can only provide three-phase power supply in a short time through economical emergency repairs by power maintenance personnel, but emergency repairs in bad weather are very dangerous, and the personal safety of power maintenance personnel is difficult to guarantee.
[0004] If the power quality of the power grid permits, a single-phase or two-phase transmission line can be converted into a three-phase power supply through a relatively simple power equipment structure, so that users can obtain three-phase power in a shorter time and at a lower cost. This can not only save the cost of transmission facilities, but also provide emergency three-phase power when a three-phase transmission line breaks, avoiding power maintenance personnel from having to perform emergency repairs under harsh environmental conditions and ensuring their personal safety. Summary of the invention
[0005] The object of the present invention is to provide a single-phase or two-phase to three-phase power supply construction device using a YNvd transformer, which can effectively solve the technical problem of providing three-phase power through a single-phase or two-phase transmission line.
[0006] The objective of the present invention is achieved through the following technical solutions: a single-phase or two-phase to three-phase power supply construction device using a YNvd transformer, the power supply construction device comprising: a transmission line, a YNvd transformer and a power converter, the transmission line is respectively connected to the input end of the YNvd transformer and the input end of the power converter, the B terminal and the C terminal of the delta winding in the YNvd transformer are respectively connected to the M terminal and the N terminal in the output end of the power converter, when the transmission line is a single-phase transmission line, the P terminal in the input end of the power converter is connected to the transmission line, and the Q terminal in its input end is grounded; the A terminal of the V-shaped winding in the YNvd transformer is connected to the transmission line, and the K terminal is grounded; when the transmission line is a two-phase transmission line, the P terminal and the Q terminal in the input port of the power converter are respectively connected to the A-phase transmission line of the transmission line. L A , B-phase transmission line L B The A terminal and K terminal of the YNvd transformer are connected to the A phase transmission line of the transmission line respectively. L A , B-phase transmission line L B The a, b, and c three-phase ports of the star winding of the YNvd transformer serve as output ports to provide three-phase power to users.
[0007] The power converter 3 includes a first high-power switch device SVG1 on the rectifier side, a second high-power switch device SVG2 on the inverter side, a DC energy storage capacitor Ca and a pulse width modulator. The first high-power switch device SVG1 and the second high-power switch device SVG2 are connected in series. The DC energy storage capacitor Ca is connected between the connection point of the first high-power switch device SVG1 and the second high-power switch device SVG2 to provide voltage support between the emitter E and the collector j of the first high-power switch device and the second high-power switch device; the output end of the pulse width modulator is respectively connected to the control electrode G of the first high-power switch device SVG1 and the second high-power switch device SVG2.
[0008] The first high-power switching device SVG1 includes four high-power transistors BG, and the control electrode G of each high-power transistor BG is connected to the output end of the pulse width modulator; every two high-power transistors BG are connected in series through the emitter E of one of the high-power transistors BG and the collector j of the other high-power transistor BG to form a group of high-power transistors, and the emitters E of the two groups of high-power transistors are connected in pairs, and the collectors j are also connected in pairs; the series connection point of the emitters E and the collectors j in the two groups of high-power transistors constitutes the current input terminal P and input terminal Q of the first high-power switching device SVG1.
[0009] The second high-power switch device SVG2 comprises four high-power transistors BG, the control electrode of each high-power transistor BG is connected to the output end of the pulse width modulator; every two high-power transistors BG are connected in series via the emitter E and the collector j to form a group of high-power transistors, the emitters E of the two groups of high-power transistors are connected in pairs, and the collectors j are also connected in pairs; the series connection point of the emitters E and the collectors j in the two groups of high-power transistors constitutes the current output end of the second high-power switch device SVG2, that is, the M terminal and the N terminal of the output end of the power converter (3).
[0010] The input current of the first high-power switch device SVG1 of the power converter is equal to half of the input current in the transmission line; the input voltage between the B terminal and the C terminal of the delta winding in the YNvd transformer is UB The input voltage between the A terminal and the K terminal of the V-shaped winding in the YNvd transformer UA Equal in magnitude and 90 degrees in phase with each other.
[0011] The high-power transistor BG is an integrated gate-commutated thyristor or an insulated gate bipolar thyristor.
[0012] Compared with the prior art, the beneficial effects of the technology of the present invention are:
[0013] 1. In a place where only a single-phase transmission line with a grounded neutral point is erected in the distribution network, due to the emergency short-term need for three-phase power supply, and the time for erecting a new three-phase line is not allowed, the power supply structure of the present invention can be used to provide three-phase power supply if the power quality of the power grid allows;
[0014] Second, in places where only two-phase transmission lines are set up in the distribution network, due to the emergency and short-term need for three-phase power supply, and the time for setting up new three-phase lines does not allow, if the power quality of the power grid allows, the power supply structure of the present invention can provide three-phase power supply;
[0015] 3. When one or two phases of a three-phase user are disconnected and the maintenance environment is relatively bad at the time, this method can be used to provide three-phase power and the line can be repaired after the climate environment improves. This reduces the potential safety hazards of outdoor emergency repairs by power maintenance personnel and also reduces the possibility of larger accidents due to emergency situations.
[0016] 4. Simple structure, good versatility, good economy and easy implementation. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 It is a basic structural schematic diagram of the present invention.
[0018] Figure 2 It is a schematic diagram of the specific structural connection of the present invention.
[0019] Figure 3 It is a structural schematic diagram of the power converter of the present invention.
[0020] Figure 4 It is a specific structural connection diagram of the power supply structure of the present invention.
[0021] Figure 5 It is a control flow chart of the pulse width modulator of the present invention. DETAILED DESCRIPTION
[0022] In order to make the objectives, technical solutions and advantages of the present application clearer, the implementation methods of the present application will be further described in detail below in conjunction with the accompanying drawings.
[0023] The basic working principle of the power supply structure of the present invention is as follows: a pulse width modulator (PWM) is used to perform analog control on an analog circuit using the digital output of a microprocessor. The PWM can modulate the bias of a transistor base or a MOS tube gate according to changes in the corresponding load to achieve a change in the conduction time of the transistor or MOS tube, thereby achieving a change in the output of the switching regulated power supply.
[0024] Assume that the current in transmission line 1 is I 、The input current of terminal A in YNvd transformer 2 I 1. The input current of the first high-power switch device SVG1 is I 2. The input voltage between the A terminal and the K terminal of the YNvd transformer 2 is U A , the input voltage between the B terminal and the C terminal in the delta winding of the YNvd transformer 2 is U B ; Use the pulse width modulator to control the input current of the first high power switch device SVG1 I 2 for transmission lines L A Current I One-half of the input voltage between the B terminal and the C terminal of the YNvd transformer 2 U B The input voltage between the A terminal and the K terminal of the YNvd transformer 2 U A The output end of the YNvd transformer 2 provides a symmetrical three-phase power supply through ports a, b, and c to supply the load that requires three-phase power.
[0025] Embodiment 1
[0026] like Figure 1As shown, the embodiment of the present invention provides a single-phase or two-phase to three-phase power supply structure device using a YNvd transformer, and the power supply structure includes a transmission line 1, a YNvd transformer 2 and a power converter 3. The transmission line 1 is used to transmit current to the YNvd transformer 2 and the power converter 3; the YNvd transformer 2 is used to transform and phase-modulate the current provided by the transmission line 1 and the power converter 3 and then provide a symmetrical three-phase power supply to the user; the power converter 3 is used to transform the shunted current in the transmission line 1 and then supply power to the YNvd transformer 2; wherein the transmission line 1 is connected to the power converter 3 and the YNvd transformer 2 respectively, the power converter 3 is connected to the YNvd transformer 2, and the output end of the YNvd transformer 2 provides a three-phase power supply to the user.
[0027] like Figure 2 and Figure 3 As shown, the 220V transmission line 1 of the neutral point grounded power grid is a single-phase transmission line and the current is I. The transmission line 1 is connected to the A terminal of the YNvd transformer 2 and the P terminal of the power converter 3 respectively; the current magnitude of the A terminal of the YNvd transformer 2 input by the transmission line 1 is I 1. The current at the P terminal of the input power converter 3 is I 2; the K terminal in the YNvd transformer 2 is grounded; the power converter 3 includes a first high-power switching device SVG1 as a rectifier side and a second high-power switching device SVG2 as an inverter side, the first high-power switching device SVG1 and the second high-power switching device SVG2 are connected in series and a DC energy storage capacitor Ca is arranged in parallel between the connection points of the two; the DC energy storage capacitor is used to provide voltage support for the emitter E and collector j of the first high-power switching device and the second high-power switching device; the control electrodes G of the first high-power switching device SVG1 and the second high-power switching device SVG2 are both connected to the output end of the pulse width modulator 4; the Q terminal of the power converter 3 is grounded, and the M terminal and the N terminal of the power converter 3 are respectively connected to the B terminal and the C terminal in the YNvd transformer 2; the three-phase sides a, b, and c of the YNvd transformer 2 provide three-phase symmetrical power to the user.
[0028] Among them, the input current of the first high-power switch device SVG1 in the power converter 3 is I 2 for transmission lines L A Current I One-half of the input voltage between the B and C terminals of the YNvd transformer U B The input voltage between the A terminal and the K terminal of the YNvd transformer U A Equal in magnitude and 90 degrees in phase with each other.
[0029] In the embodiment of the present invention, the first high-power switch device SVG1 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 through the emitter E of one of the high-power transistors BG and the collector j of the other high-power transistor BG to form a group of high-power transistors, and the emitters E of the two groups of high-power transistors are connected in pairs, and the collectors j are also connected in pairs; the series connection point of the emitters E and the collectors j in the two groups of high-power transistors constitutes the current input terminal P and the input terminal Q of the first high-power switch device SVG1. The emitters E in the two groups of high-power transistors in the first high-power switch device SVG1 that are not connected in series are connected to the collectors j in the two groups of high-power transistors in the first high-power switch device SVG1 that are not connected in series.
[0030] In the embodiment of the present invention, the second high-power switch device SVG2 has the same structure as the first high-power switch device SVG1. The second high-power switch device SVG2 includes four high-power transistors BG, and the control electrode G 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 through the emitter E of one of the high-power transistors BG and the collector j of the other high-power transistor BG to form a group of high-power transistor groups, and the emitters E of the two groups of high-power transistor groups are connected in pairs, and the collectors j are also connected in pairs; the series connection point of the emitters E and the collectors j in the two groups of high-power transistor groups constitutes the current output end of the second high-power switch device SVG2, that is, the output terminal M and N terminal of the power converter 3. The emitters E in the two groups of high-power transistor groups in the second high-power switch device SVG2 that are not connected in series are connected, and the collectors j in the two groups of high-power transistor groups in the second high-power switch device SVG2 that are not connected in series are connected.
[0031] In the embodiment of the present invention, the second high-power switch device SVG2 is connected back-to-back with the first high-power switch device SVG1, and a DC energy storage capacitor Ca is connected therebetween.
[0032] Figure 4 The high-power transistor BG shown is an integrated gate-commutated thyristor IGCT; in actual implementation, an insulated gate bipolar transistor IGBT may also be used.
[0033] Embodiment 2
[0034] The single-phase or two-phase to three-phase power supply structure device using a YNvd transformer described in the embodiment of the present invention has the same basic structure as the above-mentioned embodiment of the present invention, that is, Figure 1As shown, the power supply structure mainly includes a transmission line 1, a YNvd transformer 2 and a power converter 3. The transmission line 1 is used to transmit current to the YNvd transformer 2 and the power converter 3; the YNvd transformer 2 is used to transform and phase-modulate the current provided by the transmission line 1 and the power converter 3 and then provide a symmetrical three-phase power supply to the user; the power converter 3 is used to transform the shunted current in the transmission line 1 and then supply power to the YNvd transformer 2; wherein the transmission line 1 is connected to the power converter 3 and the YNvd transformer 2 respectively, the power converter 3 is connected to the YNvd transformer 2, and the YNvd transformer 2 provides a three-phase power supply to the user in the back.
[0035] The structures of the first high-power switch device SVG1, the second high-power switch device SVG2 and the DC energy storage capacitor Ca in the power converter 3 of the embodiment of the present invention and the connection method therebetween are similar to those in the first embodiment of the present invention. Figure 3 The structures shown are exactly the same, so they will not be described again here.
[0036] In the embodiment of the present invention, the high-power transistor BG is an integrated gate-commutated thyristor IGCT; in actual implementation, the high-power transistor BG may also be an insulated gate bipolar transistor IGBT.
[0037] Combination Figure 2 and Figure 4 As shown, the single-phase or two-phase to three-phase power supply structure using a YNvd transformer described in the embodiment of the present invention is different from the above-mentioned embodiment 1 of the invention in that the transmission line 1 described in the embodiment of the present invention is a two-phase transmission line; L A , L B The voltage between them is 220V, and the input current in transmission line 1 is I , in transmission line 1 L A Connect the A terminal of the YNvd transformer 2 and the P terminal of the power converter 3 respectively. The current input to the A terminal of the YNvd transformer 2 is I 1. The current at the P terminal of the input power converter 3 is I 2; Transmission line 1 L BThey are respectively connected to the K terminal in the YNvd transformer 2 and the Q terminal of the power converter 3; the power converter 3 includes a first high-power switching device SVG1 as a rectifier side and a second high-power switching device SVG2 as an inverter side. The first high-power switching device SVG1 and the second high-power switching device SVG2 are connected in series, and a DC energy storage capacitor Ca is arranged in parallel between them to provide voltage support for the emitter E and collector j of the first high-power switching device and the second high-power switching device. The control electrodes G of the first high-power switching device SVG1 and the second high-power switching device SVG2 are both connected to the pulse width modulator 4; the M terminal and the N terminal at the output end of the power converter 3 are respectively connected to the B terminal and the C terminal in the YNvd transformer 2; the three-phase sides a, b, and c of the YNvd transformer 2 provide three-phase symmetrical power to the user.
[0038] Figure 5 is a pulse width modulator control flow chart, wherein the input current of the first high power switch device SVG1 in the power converter 3 is I 2 for transmission lines L A Current I One-half of the input voltage between the B and C terminals of the YNvd transformer U B The input voltage between the A terminal and the K terminal of the YNvd transformer U A Equal in magnitude and 90 degrees in phase with each other.
Claims
1. A single-phase or two-phase to three-phase power supply structure device using a YNvd transformer, the power supply structure device comprising: A transmission line (1), a YNvd transformer (2) and a power converter (3), wherein the transmission line (1) is respectively connected to the input end of the YNvd transformer (2) and the input end of the power converter (3), characterized in that: the B terminal and the C terminal of the delta winding in the YNvd transformer (2) are respectively connected to the M terminal and the N terminal at the output end of the power converter (3); when the transmission line (1) is a single-phase transmission line, the P terminal at the input end of the power converter (3) is connected to the transmission line (1), and the Q terminal at its input end is grounded; the A terminal of the V-shaped winding in the YNvd transformer (2) is connected to the transmission line (1), and the K terminal is grounded; when the transmission line (1) is a two-phase transmission line, the P terminal and the Q terminal at the input port of the power converter (3) are respectively connected to the A-phase transmission line of the transmission line (1). L A , B-phase transmission line L B The A terminal and the K terminal of the YNvd transformer (2) are connected to the A phase transmission line of the transmission line (1) respectively. L A , B-phase transmission line L B The three-phase ports a, b, and c of the star winding of the YNvd transformer (2) are used as output ports to provide three-phase power to the user; The power converter (3) comprises a first high-power switch device SVG1 on the rectifier side, a second high-power switch device SVG2 on the inverter side, a DC energy storage capacitor Ca and a pulse width modulator (4); the first high-power switch device SVG1 and the second high-power switch device SVG2 are connected in series; a DC energy storage capacitor Ca is connected between the connection point of the first high-power switch device SVG1 and the second high-power switch device SVG2 to provide voltage support between the emitter E and the collector j of the first high-power switch device and the second high-power switch device; the output end of the pulse width modulator (4) is respectively connected to the control electrode C of the first high-power switch device SVG1 and the second high-power switch device SVG2; the input current of the first high-power switch device SVG1 of the power converter (3) is equal to half of the input current of the transmission line (1); the input voltage between the B terminal and the C terminal of the delta winding in the YNvd transformer (2) is U B The input voltage between the A and K terminals of the V-shaped winding in the YNvd transformer (2) U A Equal in magnitude and 90 degrees in phase with each other.
2. According to claim 1, a single-phase or two-phase to three-phase power supply structure device using a YNvd transformer is characterized in that: The first high-power switch device SVG1 comprises four high-power transistors BG, wherein the control electrode G of each high-power transistor BG is connected to the output end of the pulse width modulator (4); each two high-power transistors BG are connected in series via the emitter E of one of the high-power transistors BG and the collector j of the other high-power transistor BG to form a group of high-power transistors, wherein the emitters E of the two groups of high-power transistors are connected in pairs and the collectors j are also connected in pairs; and the series connection point between the emitters E and the collectors j in the two groups of high-power transistors forms the current input terminal P and the input terminal Q of the first high-power switch device SVG1.
3. The single-phase or two-phase to three-phase power supply structure device using a YNvd transformer according to claim 1, characterized in that: The second high-power switch device SVG2 comprises four high-power transistors BG, the control electrode G 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 via the emitter E and the collector j to form a group of high-power transistors, the emitters E of the two groups of high-power transistors are connected in pairs, and the collectors j are also connected in pairs; the series connection point of the emitters E and the collectors j in the two groups of high-power transistors constitutes the current output end of the second high-power switch device SVG2, and the M terminal and the N terminal of the output end of the power converter (3).
4. The single-phase or two-phase to three-phase power supply structure device using a YNvd transformer according to claim 2, characterized in that: The high-power transistor BG is an integrated gate-commutated thyristor or an insulated gate bipolar thyristor.
Citation Information
Patent Citations
Single-phase or two-phase to three-phase power supply structure utilizing YNvd transformer
CN210608538U