Y-phase-shifting transformer with 16-fold winding output and power supply and distribution system

Abstract

According to the Y-phase-shifting transformer with 16 times of winding output, a high-voltage end winding adopts a Y-shaped connection method, a low-voltage end winding comprises at least one group winding, and each group winding comprises 16 three-phase low-voltage phase-shifting windings adopting an epitaxial connection method; each phase of coil of the low-voltage phase-shifting winding is composed of a basic coil D1 and an epitaxial coil Y1, the basic coil D1 is used for constructing a triangular edge of the phase-shifting winding, and the epitaxial coil Y1 is used for constructing a triangular extension edge of the phase-shifting winding; the method is characterized in that the theoretical phase angle distribution of each low-voltage phase-shifting winding of each small-group winding and the turn number combination configuration of a basic coil D1 and an epitaxial coil Y1 in each phase coil of different phase windings are arranged according to the data listed in the table.

Description

Technical Field

[0001] This invention relates to phase-shifting transformers and power supply and distribution systems, and particularly to a Y-Δ phase-shifting transformer with 16-fold winding output containing an extended coil and a power supply and distribution system for data centers. Background Technology

[0002] With the development of the communications and cloud computing industries, the volume of data is constantly increasing, and the construction of data centers has enormous potential. This places higher demands on the performance and cost-effectiveness of transformers used in data centers. The electrical load characteristics of data centers include a large number of DC power loads, such as server hosts with UPS modules.

[0003] In the DC power distribution cabinet of the data center, a large number of IGBT rectifier modules are configured to rectify the AC power input from the low-voltage phase-shifting winding of the transformer into DC power. The phase of the low-voltage phase-shifting winding is preferably matched with the trigger phase of the IGBT rectifier circuit. The phase-shifting output with multiple windings can greatly eliminate harmonics (commonly known as harmonic suppression). The prior art application number 201520526746.6, entitled "Oil-immersed 54-pulse frequency converter transformer for high-power high-voltage frequency converters," discloses a three-phase primary winding with a delta connection for high voltage and a multi-phase output winding with an extended delta connection for low voltage. Its characteristic is that the low-voltage winding is divided into three large groups. Each large group comprises nine low-voltage phase-shifting windings with phase shift angles of +26.67°, +20°, +13.33°, +6.67°, 0°, -6.67°, -13.33°, -20°, and -26.67°, respectively, with a 6.67° angle difference between each low-voltage phase-shifting winding. Each phase consists of several power units connected in series, with adjacent three-phase low-voltage outputs differing by 6.67°. These nine low-voltage phase-shifting windings are controlled by three-phase pulses with different timing sequences to trigger thyristor IGBTs, generating 27 positive and 27 negative pulses. The high-voltage windings are also divided into three large groups, with both high-voltage and low-voltage windings employing a pancake coil structure. Each phase on the secondary side outputs 27 windings, for a total of 81 windings across the three phases. The low-voltage bushings exit from the side wall of the oil tank, totaling 81 bushings. However, the existing technology, including the one described above, which uses a multi-winding extended coil Y1 for harmonic suppression, has the following problems in actual manufacturing: 1. Since the voltage levels of the high-voltage power systems in each data center may differ, redesigning transformers to accommodate these input voltage variations would obviously increase the workload significantly, delay delivery times, and increase manufacturing costs. 2. The transformer was redesigned to adapt to different voltage levels and user requirements, resulting in different phase shift angles on the secondary side, different filtering effects, and poor product consistency. 3. The transformer was redesigned to adapt to different voltage levels. The inconsistent number of turns slowed down the development cycle of new product projects and affected the actual commissioning of products.

[0004] To address the aforementioned issues, the applicant filed an invention patent on June 18, 2021, entitled "Δ-Δ Phase-Shifting Transformer and Power Distribution System with 16-fold Winding Output," with authorization announcement number CN113436870B. This patent resolves the issues of convenient design, manufacturing, harmonic suppression effect, and relatively balanced output waveform related to Δ-Δ phase-shifting transformers and power distribution systems with 16-fold winding output. However, this design cannot be directly applied to Y-Δ phase-shifting transformers with 16-fold winding output and requires further improvement. Summary of the Invention

[0005] For low-voltage multi-winding phase-shifting transformers, the purpose is not only to adapt to the large number of IGBT rectifier loads, but also to reduce harmonic interference to the power system. However, how to design a Y-Δ phase-shifting transformer with a 16-fold winding output that is versatile in design and manufacturing, or that has relatively optimized harmonic suppression performance when adapted to high-voltage systems of various voltage levels, is the problem that this invention attempts to solve. Based on this, the present invention proposes a Y-Δ phase-shifting transformer with 16-fold winding output. The high-voltage winding adopts a Y-connection, and the low-voltage winding includes at least one small group winding. Each small group winding includes 16 three-phase low-voltage phase-shifting windings with an extended Δ connection. Each phase coil of the low-voltage phase-shifting winding consists of a basic coil D1 and an extended coil Y1. The basic coil D1 is used to construct the triangular sides of the phase-shifting winding, and the extended coil Y1 is used to construct the extended triangular sides of the phase-shifting winding. The invention is characterized in that the theoretical phase angle distribution of each low-voltage phase-shifting winding of each small group winding, and the combination of the number of turns of the basic coil D1 and the extended coil Y1 in each phase coil of different phase windings are arranged according to the data listed in the table below.

[0006] Specifically, when the number of turns of the extended coil Y1 is zero, the low-voltage phase-shifting winding is entirely composed of the basic coil D1 in a delta connection; when the number of turns of the basic coil D1 is zero, the low-voltage phase-shifting winding is entirely composed of the extended coil Y1 in a Y connection. When the phase angle A1 is positive, it indicates that the low-voltage phase-shifting winding is arranged in a forward timing sequence; when the phase angle A1 is negative, it indicates that the low-voltage phase-shifting winding is arranged in a reverse timing sequence.

[0007] Each coil outputs a rectified pulse with two peaks, one high and one low. The output pulse count of the Y-Δ phase-shifting transformer with a 16-fold winding is 16 × 6 × n (n = 1, 2, 3, or 4). This means that based on the structure of this invention, n small winding groups can be designed. Theoretically, n can be further increased, but in actual production, a value of n less than 4 is generally sufficient for field applications.

[0008] In this configuration, the three coils of each low-voltage winding are connected in an extended triangle. Theoretically, each winding, or each coil, contains a basic coil D1 and an extended coil Y1. The number of turns of the basic coil D1 and the extended coil Y1 in each phase coil of different phase windings in the 16 low-voltage phase-shifting windings are configured according to the data in the table above. It should be noted that the basic coil D1 forms the basic triangle's sides, and the extended coil Y1 forms the extended sides of the triangle. When the number of turns of the basic coil D1 is zero, the three extended coils Y1 are connected in a Y-shape in a special case; when the number of turns of the extended coil Y1 is zero, the three basic coils D1 are connected in a standard Δ-shape in a special case.

[0009] The beneficial technical effect of the above technical solution is that, based on the optimized data in the table above, a Y-Δ phase-shifting transformer with a 16-fold winding output is constructed, which can obtain a relatively optimized harmonic suppression effect and a relatively balanced output waveform. When a Y-Δ phase-shifting transformer with a 16-fold winding output is required, it is only necessary to adjust the number of turns of the primary winding according to the different input voltage level or output voltage level, and then adjust other indicators such as the coil wire diameter or the number of the small windings according to the different output power. The harmonic suppression quality and standard not only have a relative advantage but also have predictability and stability.

[0010] Secondly, the present invention also provides a power supply and distribution system using the above-mentioned Y-Δ phase-shifting transformer with a 16-fold winding output, including the phase-shifting transformer, a high-voltage distribution cabinet disposed on the input side of the phase-shifting transformer, and a DC load distribution cabinet disposed on the output side of the phase-shifting transformer. The output terminal of the high-voltage distribution cabinet is electrically connected to the three-phase high-voltage winding of the phase-shifting transformer, and the low-voltage phase-shifting winding of the phase-shifting transformer is electrically connected to the input terminal of the DC load distribution cabinet.

[0011] Because of the above-mentioned advantages and features, this invention can be applied to Y-Δ phase-shifting transformer products with 16-fold winding output and power supply and distribution systems. Attached Figure Description

[0012] Appendix Figure 1 This is a wiring diagram of the phase-shifting transformer using the present invention. Figure 1 The secondary low-voltage winding contains four types of extended delta windings: (a), (b), (c), and (d). Appendix Figure 2 This is a schematic diagram of the electrical structure of a power supply and distribution system; Appendix Figure 3 This is a schematic diagram of the layout structure of the power supply and distribution system. Detailed Implementation

[0013] The following description, in conjunction with the accompanying drawings, illustrates the specific implementation structure of the Y-Δ phase-shifting transformer product 100 with 16-fold winding output and its power supply and distribution system, which implements the technical solution of this disclosure. The Y-Δ phase-shifting transformer 100 with 16-fold winding output comprises three core columns, on which three-phase high-voltage windings and three-phase low-voltage windings are arranged. The voltage rating of the high-voltage windings is 10kV. Each phase coil of the high-voltage windings is mounted on one of the three core columns, and the high-voltage windings are connected in a Y-shape to the 10kV input system. The low-voltage windings comprise 32 low-voltage phase-shifting windings, wherein every 16 low-voltage phase-shifting windings form a small group winding bundled together to form a winding unit. Two such small groups, or winding units, are arranged vertically on the core columns. To measure the operating temperature of the high-voltage and low-voltage windings, temperature probes are installed in each winding to detect and output the coil temperature signal to the central controller.

[0014] The 16 low-voltage phase-shifting windings of one of the group windings are constructed using a mixed configuration of basic coil D1 and extended coil Y1. The basic coil D1 is used to construct the triangular sides of the phase-shifting winding, and the extended coil Y1 is used to construct the triangular extended sides of the phase-shifting winding.

[0015] like Figure 1 As shown, the three coils of each low-voltage phase-shifting winding are connected in an extended triangle. Theoretically, each low-voltage phase-shifting winding, or each extended triangle coil, contains a basic coil D1 and an extended coil Y1. The number of turns of the basic coil D1 and the number of turns of the extended coil Y1 in the windings located at different phases of the 16 low-voltage phase-shifting windings are specifically configured according to the data in the table below. It should be noted that the basic coil D1 forms the basic triangle's sides, and the extended coil Y1 forms the extended sides of the triangle. When the number of turns of the extended coil Y1 is zero, for example, in the first coil listed in the table located at a phase angle of 30°, the three basic coils D1 are connected in a specific way, for example... Figure 1 As shown in Figure (a), the three extended coils Y1 are connected in a △ configuration when the number of turns of the basic coil D1 is zero, such as the 9th coil listed in the table at a phase angle of 0°. Figure 1 Figure (b) shows a Y-shaped connection. Figure 1 Figure (c) shows a schematic diagram of the arrangement of the low-voltage phase-shifting windings when they are arranged in positive phase. Figure 1Figure (d) shows a schematic diagram of the structure where the low-voltage phase-shifting windings are arranged in reverse phase.

[0016] This embodiment provides a phase distribution for each of the 16 low-voltage phase-shifting windings, a combination table of turns for the basic coil D1 and the extended coil Y1 in each phase coil corresponding to each phase angle, and five different combination tables of turns configuration data – combination 1 to combination 5. Based on the total number of turns of these basic coils D1 and extended coils Y1 and the input and output voltage levels, the number of turns of the input winding on the high-voltage side can be calculated based on common physics knowledge. Furthermore, based on the magnitude of the output power, the wire diameter of the input and output windings can be calculated.

[0017] For example, (1) the theoretical phase angle A1 of the low-voltage winding of serial number 1 is +30°. There are five possible combinations of turns. In combination 1, the basic coil D1 has 12 turns, while the extended coil Y1 has 0 turns, for a total of 12 turns. Thus, the low-voltage winding of serial number 1 is arranged as follows: Figure 1 The △ connection is shown in Figure (a); (2), the theoretical phase angle A1 of the low-voltage winding of serial number 3 is +22.5°, and there are also five possible combinations of turns. The basic coil D1 of combination 2 has 10 turns, while the extension coil Y1 has 2 turns, for a total of 12 turns. Thus, the low-voltage winding of serial number 3 is arranged as follows. Figure 1 The positive phase extension triangle connection is shown in Figure (c). (3) The theoretical phase angle A1 of the low-voltage winding of serial number 11 is -7.5°. There are also five possible combinations of turns. The basic coil D1 of combination 2 has 3 turns, while the extension coil Y1 has 6 turns, for a total of 9 turns. Thus, the low-voltage winding of serial number 11 is arranged as follows. Figure 1 The reverse phase extension triangle connection is shown in Figure (d).

[0018] It should be noted that the data from the five combinations cannot be mixed. For example, in the same transformer 100, coil number 1 cannot use combination 1, coil number 2 cannot use combination 2, and so on. That is, once a combination of data is decided, each coil can only use the data from that combination. For example, if combination 1 is chosen, coils 1 through 16 will all use combination 1.

[0019] like Figure 2As shown, a power supply and distribution system includes a three-phase phase-shifting transformer 100, a high-voltage distribution cabinet 101 disposed on the input side of the phase-shifting transformer 100, and a DC load distribution cabinet 102 disposed on the output side of the phase-shifting transformer 100. The phase-shifting transformer 100 is also integrated into a separate distribution cabinet. The high-voltage distribution cabinet 101, the phase-shifting transformer 100, and the DC load distribution cabinet 102 are arranged sequentially in a unit room. The voltage level of the phase-shifting transformer 100 and the high-voltage distribution cabinet 101 is 10KV. An outdoor 10KV three-phase high-voltage cable is connected to the input terminal of the high-voltage distribution cabinet 101. The high-voltage distribution cabinet 101 is equipped with at least a high-voltage disconnect switch and may also be equipped with an overload protection switch. The output terminal of the high-voltage distribution cabinet 101 is connected to the wiring terminals of the three-phase high-voltage winding of the phase-shifting transformer 100 via a high-voltage cable.

[0020] The low-voltage winding itself outputs AC power, but indirectly provides power to the DC load of the terminal, such as a server used in an information center, through an AC / DC rectifier (AC / DC) device, such as rectifier module 4 and DC bus 5. The output terminal of each low-voltage winding is connected to at least one AC / DC rectifier module 4. The output voltage of the low-voltage winding is adapted to the operating voltage level of the rectifier module 4, and the output voltage of the rectifier module 4 is adapted to the operating voltage level of the DC bus 5. In the specific wiring layout, the output terminal of the low-voltage winding is connected to the input terminal of the DC load distribution cabinet 102 through terminals and leads. The rectifier module 4 and DC bus 5 are arranged in the DC load distribution cabinet 102. Isolating switches can be installed between DC buses in different DC load distribution cabinets 102. The input terminal of the rectifier module 4 is connected to the input terminal of the DC load distribution cabinet 102 through a control switch, and an overload protection switch can also be installed. The output terminal of the rectifier module 4 is electrically connected to the DC bus 5 through a control switch.

[0021] In practical applications, different output power can be adjusted by changing the wire diameter of the coils on the high and low voltage sides, and the number of windings in the low-voltage output winding. Similarly, different input voltage levels can be achieved by changing the number of turns in the high-voltage winding, allowing the low-voltage winding to output different levels of low-voltage AC voltage. This enables the rectifier module 4 or DC bus 5 to output voltages of DC 336V, 240V, 110V, 64V, 48V, or even 12V, providing DC power to DC loads such as servers in information centers. The output terminals of the DC bus 5 can also be connected to different individual load devices, such as a server host, via separate switches.

[0022] The number of low-voltage windings arranged on each iron core column can be designed and determined to be 16×n (n=1, 2, 3 or 4) based on factors such as the size of the load itself and the capacity of the rectifier module 4. Furthermore, an energy storage device (not shown in the figure) is arranged on the side of the DC load distribution cabinet 102. The energy storage device is a battery pack, which is connected to the DC bus 5 through an energy storage controller. The energy storage controller is signal-connected to the central controller and is used for bidirectional operation, capable of both charging the battery pack and releasing energy to the DC bus 5.

[0023] Furthermore, temperature probes, such as PT100 (not shown in the figure), are respectively installed in the high-voltage winding and the low-voltage winding. A dedicated central control cabinet 103 is also installed on the side of the DC load distribution cabinet 102, containing a central controller. The temperature probe signals are connected to the central controller. Secondly, all control switches in the high-voltage distribution cabinet 101 and the DC load distribution cabinet 102 are also connected to the central controller. Thus, the central controller can not only link and control the control switches in the high-voltage distribution cabinet 101 and the DC load distribution cabinet 102, but also respond to the transformer temperature signal provided by the temperature probe, implementing alarms or controlling the primary side high-voltage switch or the low-voltage side low-voltage switch. Furthermore, a remote communication unit can be installed in the central control cabinet 103, allowing the central controller to interact with a remote control or monitoring center through this unit, transmitting various signals such as voltage, current, power consumption, and temperature.

[0024] The transformer 100 and the power supply and distribution system used in this embodiment can not only directly convert high voltage to low voltage, thus simplifying the structure of the high voltage power supply circuit, but also achieve a relatively good harmonic suppression effect due to the use of a relatively optimized low voltage winding electrical structure.

Claims

A Y-Δ phase-shifting transformer with a 1.16 multiple winding output, wherein the high-voltage winding adopts a Y-connection, and the low-voltage winding includes at least one small group winding, each of which comprises 16 three-phase low-voltage phase-shifting windings using an extended Δ connection; each phase coil of the low-voltage phase-shifting winding consists of a basic coil D1 and an extended coil Y1, wherein the basic coil D1 is used to construct the triangular sides of the phase-shifting winding, and the extended coil Y1 is used to construct the extended triangular sides of the phase-shifting winding; characterized in that, The theoretical phase angle distribution of each low-voltage phase-shifting winding of each group winding, and the combination of turns of the basic coil D1 and the extended coil Y1 in each phase coil of different phase windings, are arranged according to the data listed in the table below. Specifically, when the number of turns of the extended coil Y1 is zero, the low-voltage phase-shifting winding is entirely composed of the basic coil D1 in a delta connection; when the number of turns of the basic coil D1 is zero, the low-voltage phase-shifting winding is entirely composed of the extended coil Y1 in a Y connection. When the phase angle A1 is positive, it indicates that the low-voltage phase-shifting winding is arranged in a forward timing sequence; when the phase angle A1 is negative, it indicates that the low-voltage phase-shifting winding is arranged in a reverse timing sequence.

2. The phase-shifting transformer according to claim 1, characterized in that, Each phase coil of one of the group windings is tightly wound together, and the coils of different group windings are arranged side by side, one above the other.

3. The phase-shifting transformer according to claim 1, characterized in that, Temperature probes are installed in the high-voltage winding and the low-voltage winding respectively to detect and output the temperature signal of the coil.

4. A power supply and distribution system, comprising the phase-shifting transformer as described in claim 1, 2 or 3, a high-voltage distribution cabinet disposed on the input side of the phase-shifting transformer, and a DC load distribution cabinet disposed on the output side of the phase-shifting transformer, wherein the output terminal of the high-voltage distribution cabinet is electrically connected to the three-phase high-voltage winding of the phase-shifting transformer, and the low-voltage phase-shifting winding of the phase-shifting transformer is electrically connected to the input terminal of the DC load distribution cabinet.

5. The power supply and distribution system according to claim 4, characterized in that, The DC load distribution cabinet is equipped with an AC / DC rectifier module and a DC busbar. The rectifier module is used to convert the AC signal provided by the low-voltage phase-shifting winding into a DC signal and output it to the DC busbar. The DC busbar is used to provide DC power to the DC load.

6. The power supply and distribution system according to claim 5, characterized in that, Each output terminal of the low-voltage phase-shifting winding is connected to at least one AC / DC rectifier module.

7. The power supply and distribution system according to claim 5, characterized in that, It also includes an energy storage device, which is connected to the DC bus via an energy storage controller.

8. The power supply and distribution system according to claim 4, characterized in that, It also includes a central control cabinet configured on the side of the DC load distribution cabinet, wherein a central controller is provided in the central control cabinet, and the central controller is signal connected to the control switches configured in the high voltage distribution cabinet and the DC load distribution cabinet.

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