Medium voltage power device and power supply system

Abstract

The embodiment of the application discloses a kind of medium voltage power device and power supply system, it is related to power electronics field, it is solved how to provide power supply to data center, to reduce security risk, do not occupy indoor space, subsequent load expansion and flexible evolution are convenient, and the problem of convenient power distribution is solved. Specifically, in the medium voltage power device: the first end of the first electronic switch is used to be connected with the first power grid, the electrode of the first battery is connected with the DC side of the first current transformer, the AC side of the first current transformer is connected with the low voltage side of the first transformer, the high voltage side of the first transformer is connected with one end of the first automatic switch, the other end of the first automatic switch and the second end of the first electronic switch are used to be connected with the high voltage side of the second transformer, and the low voltage side of the second transformer is used to be connected with the first load.The first battery is used to provide power supply to the first load in the case of power failure of the first power grid, and is also used to charge in the electricity price valley period and discharge in the electricity price peak period.

Description

Technical Field

[0001] This application relates to the field of power electronics technology, and in particular to a medium-voltage power device and power supply system. Background Technology

[0002] The power supply system of a data center includes energy storage batteries, a power conversion system (PCS), a first transformer, a second transformer, an uninterruptible power supply (UPS), and backup batteries. The power conversion system, also known as a converter, is used to convert electrical energy between AC and DC. The UPS supplies power to the load when the power grid fails. Specifically, the electrodes of the energy storage batteries are connected to the DC side of the converter, the AC side of the converter is connected to the low-voltage side of the first transformer, the high-voltage sides of the first and second transformers are connected to the power grid, the low-voltage side of the second transformer is connected to the AC input of the UPS, the DC terminal of the UPS is connected to the electrodes of the backup batteries, and the AC output of the UPS is connected to the load.

[0003] Energy storage batteries are typically placed outdoors. They are used to charge during off-peak hours and discharge during peak hours to achieve peak-valley arbitrage. Backup batteries are typically placed indoors and are used to provide power to the load in the event of a grid outage.

[0004] However, placing backup batteries indoors poses safety hazards, occupies indoor space, hinders subsequent load expansion and flexible evolution, and makes power distribution extremely complex as load capacity increases. Therefore, how to provide power to data centers in a way that reduces safety hazards, does not occupy indoor space, facilitates subsequent load expansion and flexible evolution, and provides convenient power distribution has become an urgent problem to be solved. Summary of the Invention

[0005] This application provides a medium-voltage power device and power supply system, which solves the problem of how to provide power to data centers to reduce safety hazards, not occupy indoor space, facilitate subsequent load expansion and flexible evolution, and facilitate power distribution.

[0006] To achieve the above objectives, the embodiments of this application adopt the following technical solutions:

[0007] A first aspect of this application provides a medium-voltage power device, comprising a first electronic switch, a first battery, a first converter, a first transformer, and a first automatic switch. A first terminal of the first electronic switch is connected to a first power grid. An electrode of the first battery is connected to the DC side of the first converter. The AC side of the first converter is connected to the low-voltage side of the first transformer. The high-voltage side of the first transformer is connected to one terminal of the first automatic switch. The other terminal of the first automatic switch and a second terminal of the first electronic switch are connected to the high-voltage side of a second transformer. The low-voltage side of the second transformer is connected to a first load. The first battery is used to provide power to the first load in the event of a power grid outage.

[0008] Based on this solution, the medium-voltage power device can be applied to a power supply system that can provide power to a data center. In this medium-voltage power device, a backup battery and an energy storage battery are integrated into a first battery. This first battery is used to realize the functions of both an energy storage battery and a backup battery. The DC power output from the first battery is converted into AC power by a first converter, and then stepped up by a first transformer. High-voltage energy transmission is used. Therefore, the first battery can be placed outdoors at a certain distance from the load (first load) to achieve long-distance power supply, thereby reducing safety hazards, not occupying indoor space, facilitating subsequent load expansion and flexible evolution, and making power distribution convenient as the load capacity increases.

[0009] In conjunction with the first aspect, in one embodiment, the medium-voltage power device further includes a second automatic switch, which is connected in parallel with the first electronic switch.

[0010] Based on this solution, firstly, in the event of a failure of the first electronic switch, the second automatic switch can remain closed, allowing the first power grid to continue supplying power to the first load, thus improving the reliability of the medium-voltage power equipment. Secondly, during the startup process of the first or second transformer, the first automatic switch and the first electronic switch can simultaneously bear the current, thereby reducing the burden on individual switches, decreasing transformer inrush current, and further improving the reliability of the medium-voltage power equipment.

[0011] In conjunction with the first aspect, in one embodiment, the medium-voltage power unit further includes a second electronic switch, a second battery, a second converter, a third transformer, and a third automatic switch. A first terminal of the first electronic switch is connected to the output terminal of a first medium-voltage distribution cabinet, and a first input terminal of the first medium-voltage distribution cabinet is connected to a first power grid. A first terminal of the second electronic switch is connected to the output terminal of a second medium-voltage distribution cabinet, and a first input terminal of the second medium-voltage distribution cabinet is connected to a second power grid. The input / output terminals of the second medium-voltage distribution cabinet are connected to one terminal of a fourth automatic switch, and the input / output terminals of the first medium-voltage distribution cabinet are connected to the other terminal of the fourth automatic switch. The electrodes of the second battery are connected to the DC side of the second converter, the AC side of the second converter is connected to the low-voltage side of the third transformer, the high-voltage side of the third transformer is connected to one terminal of the third automatic switch, and the other terminal of the third automatic switch and the second terminal of the second electronic switch are connected to the high-voltage side of the fourth transformer. The low-voltage side of the second transformer is connected to the input terminal of the first low-voltage distribution cabinet, and the output terminal of the first low-voltage distribution cabinet is connected to the first load. The low-voltage side of the fourth transformer is connected to the input terminal of the second low-voltage distribution cabinet, and the output terminal of the second low-voltage distribution cabinet is connected to the second load. The input and output terminals of the first low-voltage distribution cabinet are connected to one end of the fifth automatic switch, and the input and output terminals of the second low-voltage distribution cabinet are connected to the other end of the fifth automatic switch. The first battery is also used to provide power to the second load in the event of a power outage in the second power grid. The second battery is used to provide power to the first or second load in the event of a power outage in either the first or second power grid, and is also used to charge during off-peak hours and discharge during peak hours.

[0012] Based on this solution, the medium-voltage power supply can provide power to the first load through the second power grid or the second battery, and can provide power to the second load through the first power grid or the first battery, thereby improving the reliability of the medium-voltage power supply.

[0013] In conjunction with the first aspect, in one embodiment, the medium-voltage power supply further includes a sixth automatic switch, which is connected in parallel with the second electronic switch.

[0014] Based on this scheme, firstly, in the event of a failure of the second electronic switch, the sixth automatic switch can remain closed, allowing the second power grid to continue supplying power to the second load, thus improving the reliability of the medium-voltage power equipment. Secondly, during the startup of the third or fourth transformer, the sixth automatic switch can simultaneously bear the current with the second electronic switch, thereby reducing the load on individual switches, decreasing transformer inrush current, and further improving the reliability of the medium-voltage power equipment.

[0015] In conjunction with the first aspect, in one embodiment, the medium-voltage power device further includes a controller. A first automatic switch is always closed when the first battery, first converter, and first transformer are operating normally. The controller is configured to, in the event of a power outage in the first grid, control the first electronic switch and the second automatic switch to open, simultaneously control the first converter to operate so that the first battery provides power to the first load, and control the fourth automatic switch to close. The controller is also configured to, after controlling the first converter to operate and the first battery to provide power to the first load, control the phase of the first converter's output voltage to be the same as the phase of the second grid voltage. The controller is further configured to, when the phase of the first converter's output voltage is the same as the phase of the second grid voltage, control the first electronic switch to close so that the first battery and the second grid simultaneously provide power to the first load. The controller is also configured to, after controlling the first electronic switch to close, control the first converter to slowly stop operating so that the second grid provides power to the first load.

[0016] Based on this solution, in the event of a power outage in the first power grid, power can be supplied to the first load without interruption, thereby improving the power supply reliability of medium-voltage power equipment.

[0017] In conjunction with the first aspect, in one embodiment, the second input terminals of the first and second medium-voltage distribution cabinets are used to connect to the output terminal of the diesel generator. The medium-voltage power unit also includes a controller. The first automatic switch is always closed when the first battery, the first converter, and the first transformer are operating normally. The controller is used to control the first electronic switch and the second automatic switch to open when both the first and second power grids are de-energized, and simultaneously control the first converter to operate, so that the first battery provides power to the first load, and control the diesel generator to start operating. The controller is also used to control the phase of the first converter's output voltage to be the same as the phase of the diesel generator's output voltage after controlling the first converter to operate and the first battery to provide power to the first load. The controller is also used to control the first electronic switch to close when the phase of the first converter's output voltage is the same as the phase of the diesel generator's output voltage, so that the first battery and the diesel generator simultaneously provide power to the first load. The controller is also used to control the first converter to slowly stop operating after controlling the first electronic switch to close, so that the diesel generator provides power to the first load.

[0018] Based on this scheme, even if both the first and second power grids are de-energized, power can be supplied to the first load uninterruptedly, thereby improving the power supply reliability of medium-voltage power equipment.

[0019] In conjunction with the first aspect, in one embodiment, the medium-voltage power unit further includes a controller for controlling the closing of a fifth automatic switch in the event of a circuit breaker fault in the second transformer, so that the second power grid or the second battery provides power to the first load.

[0020] Based on this scheme, in the event of a circuit breaker failure in the second transformer, power can be supplied to the first load without interruption, thereby improving the power supply reliability of medium-voltage power equipment.

[0021] In conjunction with the first aspect, in one embodiment, the medium-voltage power unit further includes a plurality of sixth automatic switches. The second terminal of the first electronic switch is connected to one terminal of each of the plurality of sixth automatic switches. The other terminals of the plurality of sixth automatic switches are respectively used to connect to the high-voltage side of a plurality of second transformers, and the low-voltage side of the plurality of second transformers is used to connect to a plurality of first loads. The controller is further configured to, in the event of a short-circuit fault in any of the second transformers, control the second automatic switch to close and control the sixth automatic switch corresponding to the short-circuit faulted second transformer to open. The controller is also configured to, after controlling the sixth automatic switch corresponding to the short-circuit faulted second transformer to open, control the second automatic switch to open.

[0022] Based on this scheme, compared with the first electronic switch, the second automatic switch has a higher withstand voltage and current withstand value. Therefore, in the event of a short circuit fault in any of the multiple second transformers, the first electronic switch can be prevented from being damaged, while the remaining second transformers can continue to operate and provide power to their respective first loads, thereby improving the reliability of the medium-voltage power equipment.

[0023] In conjunction with the first aspect, in one embodiment, the medium-voltage power unit further includes a maintenance bypass connected in parallel with the first electronic switch. The controller is also configured to control the simultaneous closing of the first electronic switch and the second automatic switch when the medium-voltage power unit is ready for maintenance. The controller is further configured to control the first electronic switch to open and the maintenance bypass to close after controlling the simultaneous closing of the first electronic switch and the second automatic switch. The controller is further configured to control the second automatic switch to open after controlling the closing of the maintenance bypass.

[0024] Based on this scheme, compared with the first electronic switch, the mechanical and electrical structure of the second automatic switch is relatively stable. The closing of the second automatic switch serves as an intermediate state, transitioning to the maintenance bypass closing, which can ensure the continuity of power supply, provide more reliable circuit on / off control, and improve the reliability of medium-voltage power devices.

[0025] A second aspect of this application provides a power supply system including a medium-voltage power device, which is the medium-voltage power device described in the first aspect or any embodiment of the first aspect.

[0026] The description of the second aspect in this application can be referred to the detailed description of the first aspect; and the beneficial effects of the second aspect can be referred to the analysis of the beneficial effects of the first aspect, which will not be repeated here. Attached Figure Description

[0027] Figure 1 A schematic diagram of the circuit topology of a power supply system;

[0028] Figure 2 A schematic diagram of the circuit topology for another power supply system;

[0029] Figure 3 A schematic diagram illustrating an application scenario of a medium-voltage power device provided in an embodiment of this application;

[0030] Figure 4 A circuit topology diagram of a medium-voltage power device provided in this application embodiment;

[0031] Figure 5 A schematic diagram of another medium-voltage power device provided in the embodiments of this application;

[0032] Figure 6 A circuit topology diagram of another medium-voltage power device provided in the embodiments of this application;

[0033] Figure 7 This is a schematic diagram of the circuit topology of another medium-voltage power device provided in an embodiment of this application. Detailed Implementation

[0034] The following sections will discuss the fabrication and use of various embodiments in detail. However, it should be understood that many applicable inventive concepts provided in this application can be implemented in a variety of specific environments. The specific embodiments discussed are merely illustrative of specific ways of implementing and using this description and technology, and do not limit the scope of this application.

[0035] Unless otherwise defined, all technical terms used herein have the same meaning as commonly known to one of ordinary skill in the art.

[0036] Each circuit or other component may be described or referred to as "for" performing one or more tasks. In this context, "for" is used to imply a structure by indicating that the circuit / component includes a structure (e.g., a circuit system) that performs one or more tasks during operation. Therefore, even when the specified circuit / component is currently inoperable (e.g., not turned on), it can still be referred to as "for performing that task." Circuits / components used with the term "for" include hardware, such as circuits that perform operations.

[0037] The technical solutions of the embodiments of this application will now be described with reference to the accompanying drawings. In this application, "multiple" refers to two or more, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship. Furthermore, in the embodiments of this application, the words "first," "second," etc., do not limit the quantity or order.

[0038] In this application, the word "for example" is used to indicate that something is being described as an example, illustration, or illustration. Any embodiment or design described as "for example" in this application should not be construed as being more preferred or advantageous than other embodiments or design options. Rather, the use of the word "for example" is intended to present the relevant concepts in a specific manner.

[0039] Before introducing the embodiments of this application, the background technology involved in this application will be introduced first.

[0040] like Figure 1 The diagram shows a circuit topology of a power supply system 100. This power supply system 100 is used to provide power to loads in a data center, such as servers. The power supply system 100 includes a storage battery 110, a converter 120, a first transformer T1, a second transformer T2, an uninterruptible power supply (UPS) 130, and a backup battery 140. The electrodes of the storage battery 110 are connected to the DC side of the converter 120, and the AC side of the converter 120 is connected to the low-voltage side of the first transformer T1. The high-voltage sides of the first transformer T1 and the second transformer T2 are connected to a first power grid 200. The low-voltage side of the second transformer T2 is connected to the AC input terminal of the UPS 130, and the DC terminal of the UPS 130 is connected to the electrodes of the backup battery 140. The AC output terminal of the UPS 130 is connected to a load 300, which can be a server in the data center.

[0041] The first transformer T1 and the second transformer T2 are used to step down the high-voltage AC power output from the first power grid 200, for example, stepping down the 10kV AC power output from the first power grid 200 to 220V AC power. The converter 120 is used to convert the stepped-down AC power into DC power to charge the energy storage battery 110. The converter 120 is also used to convert the DC power output from the energy storage battery 110 into AC power, and the first transformer T1 is also used to step up the AC power to provide power to the first power grid 200 or the uninterruptible power supply 130. Thus, the energy storage battery 110 can be charged during off-peak hours and discharged during peak hours, achieving peak-valley arbitrage and saving electricity costs. The uninterruptible power supply 130 is used to perform power conversion on the stepped-down AC power to provide power to the load 300, or to perform power conversion on the stepped-down AC power to charge the backup battery 140. In the event of a power outage in the first power grid 200, the uninterruptible power supply 130 is used to convert the DC power output from the backup battery 140 to provide uninterrupted power to the load 300.

[0042] The energy storage battery 110 is typically placed outdoors, while the backup battery 140 is typically placed indoors near the uninterruptible power supply 130. The energy storage battery 110 is used for long-term energy storage, referring to energy storage lasting more than four hours. This battery is designed to address prolonged power supply and demand imbalances, ensuring a continuous and stable power supply. The backup battery 140 is used for short-term energy storage, rapidly responding to short-term power fluctuations and sudden power demands, ensuring power can be supplied to the load 300 in emergencies.

[0043] However, placing the backup battery 140 indoors poses a safety hazard, occupies indoor space, and is not conducive to the subsequent expansion and flexible evolution of the load 300. Furthermore, as the capacity of the load 300 increases, the power distribution will become very complex.

[0044] like Figure 2 The diagram shown is a circuit topology diagram of another power supply system 100, which is similar to the one described above. Figure 1 Compared to the circuit topology diagram of the power supply system 100 shown, the difference is that the backup battery 140 is placed at the far end of the uninterruptible power supply 130, outdoors. This avoids the safety hazards that may exist when the backup battery 140 is placed indoors. In addition, the backup battery 140 does not occupy indoor space, which is conducive to the subsequent expansion and flexible evolution of the load 300. Power distribution is easier when the capacity of the load 300 increases.

[0045] However, the low-voltage energy transmission between the backup battery 140 and the uninterruptible power supply 130 requires thicker cables or multiple cables to reduce resistance and power loss. This results in higher cable costs, more difficult cabling, and parasitic inductance due to the longer cables. This parasitic inductance can generate induced electromotive force, interfering with normal voltage in the circuit, causing voltage fluctuations, and affecting the reliability of the power supply system 100. Therefore, how to provide power to the data center in a way that reduces safety hazards, does not occupy indoor space, facilitates subsequent load expansion and flexible evolution, and is convenient in power distribution and cabling, low in cost, and highly reliable has become an urgent problem to be solved.

[0046] Based on this, this application provides a medium-voltage power device that integrates a backup battery and an energy storage battery. The integrated battery is placed outdoors, thereby reducing safety hazards, not occupying indoor space, facilitating subsequent load expansion and flexible evolution, and making power distribution convenient as the load capacity increases. Furthermore, the integrated battery does not use low-voltage long cables to transmit energy, thus not increasing cable costs and avoiding voltage fluctuations caused by parasitic inductance of long cables. When this medium-voltage power device is applied to a power supply system, it can improve the operational reliability of the power supply system.

[0047] In one implementation, such as Figure 3 As shown, the medium-voltage power device 400 provided in this embodiment can be a standalone device. The medium-voltage power device 400 can be placed in a container or in a fixed energy building; this embodiment does not limit its placement in this regard.

[0048] In one implementation, such as Figure 3 The diagram shown illustrates an application scenario of a medium-voltage power device 400 provided in this application embodiment. The medium-voltage power device 400 can be applied to a power supply system 500, which also includes a second transformer T2. The input and output terminals of the medium-voltage power device 400 are connected to a first power grid 200, and the output terminal of the medium-voltage power device 400 is connected to the high-voltage side of the second transformer T2. The low-voltage side of the second transformer T2 is connected to a first load 600.

[0049] In one implementation, the power supply system 500 can be applied to a data center, or it can be applied to fields that require uninterrupted power supply, such as high-end manufacturing, for example, a semiconductor manufacturing plant.

[0050] Reference Figure 3The medium-voltage power device 400 provided in this application embodiment includes a first electronic switch S1, a first battery 410, a first converter 420, a first transformer T1, and a first automatic switch K1. The first terminal of the first electronic switch S1 is connected to a first power grid 200. The electrode of the first battery 410 is connected to the DC side of the first converter 420. The AC side of the first converter 420 is connected to the low-voltage side of the first transformer T1. The high-voltage side of the first transformer T1 is connected to one end of the first automatic switch K1. The other end of the first automatic switch K1 and the second terminal of the first electronic switch S1 are connected to the high-voltage side of a second transformer T2. The low-voltage side of the second transformer T2 is connected to a first load 600.

[0051] The first battery 410 is used to provide power to the first load 600 in the event of a power outage in the first power grid 200, and is also used to charge during off-peak hours and discharge during peak hours.

[0052] In one embodiment, the first battery 410 may be a box-level battery, a cluster-level battery, or a single battery, wherein the box-level battery includes multiple cluster-level batteries, and the box-level battery may also be referred to as an energy storage box. The specific type of the first battery 410 is not limited in the embodiments of this application.

[0053] Specifically, refer to Figure 3 The circuit consisting of the first battery 410, the first converter 420, the first transformer T1 and the first automatic switch K1 can be called the power supply branch. Under normal working conditions, the first automatic switch K1 is always in the closed state. Under the fault of the power supply branch, the first automatic switch K1 is open.

[0054] When the first power grid 200 is functioning normally, the first electronic switch S1 and the first automatic switch K1 are closed. The first transformer T1 is used to step down the high-voltage AC power output from the first power grid 200, for example, stepping down the 10kV AC power output from the first power grid 200 to 220V AC power. The first converter 420 is used to convert the stepped-down AC power into DC power to charge the first battery 410. The first converter 420 is also used to convert the DC power output from the first battery 410 into AC power, and the first transformer T1 is also used to step up the AC power to provide power to the first power grid 200 or the first load 600. Thus, the first battery 410 can be charged during off-peak hours and discharged during peak hours, achieving peak-valley arbitrage and saving on electricity costs.

[0055] When the first power grid 200 is functioning normally, the first electronic switch S1 is closed, and the second transformer T2 is used to step down the high-voltage AC power output from the first power grid 200. When the first power grid 200 is de-energized, the first electronic switch S1 is opened, the first automatic switch K1 is closed, the first converter 420 is used to convert the DC power output from the first battery 410 into AC power, the first transformer T1 is used to step up the AC power, and the second transformer T2 is used to step down the AC power after it has been stepped up by the first transformer T1 to provide power to the first load 600. Thus, the first battery 410 can provide uninterrupted power to the first load 600 even when the first power grid 200 is de-energized.

[0056] In one embodiment, the types of the first electronic switch S1 and other electronic switches in the following embodiments include: metal-oxide-semiconductor field-effect transistor (MOSFET), which can also be simply referred to as MOS, insulated-gate bipolar transistor (IGBT), thyristor, or integrated gate commutated thyristor (IGCT). The specific type of the first electronic switch S1 is not limited in the embodiments of this application.

[0057] In one embodiment, the types of the first automatic switch K1 and other automatic switches in the following embodiments include: circuit breaker, automatic air switch, automatic reclosing switch or electromagnetic type dual-power supply (ATS). The embodiments of this application do not limit the specific type of automatic switch.

[0058] The medium-voltage power device 400 provided in this application embodiment integrates a backup battery and an energy storage battery into a first battery 410. The first battery 410 is used to realize the functions of an energy storage battery and a backup battery. The DC power output by the first battery 410 is converted into AC power by the first converter 420 and can be stepped up by the first transformer T1 to transmit energy at high voltage. Therefore, the first battery 410 can be placed outdoors at a certain distance from the load (first load 600) to achieve long-distance power supply, thereby reducing safety hazards, not occupying indoor space, facilitating subsequent load expansion and flexible evolution, and making power distribution convenient as the load capacity increases. In addition, the first battery 410 does not use low-voltage long cables to transmit energy, which will not increase cable costs and can avoid voltage fluctuations caused by parasitic inductance of long cables. When the medium-voltage power device 400 is applied to the power supply system 500, it can improve the operational reliability of the power supply system 500.

[0059] In one implementation, such as Figure 4 The diagram shown is a circuit topology diagram of a medium-voltage power device 400 provided in an embodiment of this application. The medium-voltage power device 400 also includes a second automatic switch K2, which is connected in parallel with the first electronic switch S1.

[0060] In one implementation, reference Figure 4 The medium-voltage power device 400 may include multiple power supply branches. In this embodiment of the application, the specific number of power supply branches included in the medium-voltage power device 400 is not limited.

[0061] In one implementation, reference is made to Figure 4 The medium-voltage power unit 400 may further include a maintenance bypass 430 and a controller 440. The maintenance bypass 430 is connected in parallel with the first electronic switch S1. The controller 440 is also used to control the simultaneous closing of the first electronic switch S1 and the second automatic switch K2 when the medium-voltage power unit 400 is ready for maintenance. After controlling the simultaneous closing of the first electronic switch S1 and the second automatic switch K2, the controller 440 is also used to control the opening of the first electronic switch S1 and the closing of the maintenance bypass 430. The controller 440 is also used to control the opening of the second automatic switch K2 after controlling the closing of the maintenance bypass 430. Compared with the first electronic switch S1, the mechanical and electrical structure of the second automatic switch K2 is relatively stable. The closing of the second automatic switch K2 serves as an intermediate state, transitioning to the closing of the maintenance bypass 430, which can ensure the continuity of power supply, provide more reliable circuit on / off control, and improve the reliability of the medium-voltage power unit 400.

[0062] The medium-voltage power device 400 provided in this application embodiment has several advantages. First, in the event of a failure of the first electronic switch S1, the second automatic switch K2 can remain closed, allowing the first power grid 200 to continue supplying power to the first load 600, thus improving the reliability of the medium-voltage power device 400. Second, during the startup process of the first transformer T1 or the second transformer T2, the first automatic switch K1 and the first electronic switch S1 can simultaneously bear the current, thereby reducing the burden on a single switch, reducing transformer inrush current, and further improving the reliability of the medium-voltage power device 400.

[0063] In one implementation, such as Figure 5 The diagram shown illustrates the circuit topology of another medium-voltage power device 400 provided in this embodiment of the application. This medium-voltage power device 400 further includes a second electronic switch S2, a second battery 450, a second converter 460, a third transformer T3, and a third automatic switch K3. The first terminal of the first electronic switch S1 is connected to the output terminal of the first medium-voltage distribution cabinet 700, and the first input terminal of the first medium-voltage distribution cabinet 700 is connected to the first power grid 200. The first terminal of the second electronic switch S2 is connected to the output terminal of the second medium-voltage distribution cabinet 800, and the first input terminal of the second medium-voltage distribution cabinet 800 is connected to the second power grid 900. The input and output terminals of the second medium-voltage distribution cabinet 800 are connected to one end of the fourth automatic switch K4, and the input and output terminals of the first medium-voltage distribution cabinet 700 are connected to the other end of the fourth automatic switch K4. The electrodes of the second battery 450 are connected to the DC side of the second converter 460. The AC side of the second converter 460 is connected to the low-voltage side of the third transformer T3. The high-voltage side of the third transformer T3 is connected to one end of the third automatic switch K3. The other end of the third automatic switch K3 and the second end of the second electronic switch S2 are used to connect to the high-voltage side of the fourth transformer T4. The low-voltage side of the second transformer T2 is used to connect to the input terminal of the first low-voltage distribution cabinet 1000. The output terminal of the first low-voltage distribution cabinet 1000 is used to connect to the first load 600. The low-voltage side of the fourth transformer T4 is used to connect to the input terminal of the second low-voltage distribution cabinet 1100. The output terminal of the second low-voltage distribution cabinet 1100 is used to connect to the second load 1200. The input and output terminals of the first low-voltage distribution cabinet 1000 are used to connect to one end of the fifth automatic switch K5. The input and output terminals of the second low-voltage distribution cabinet 1100 are used to connect to the other end of the fifth automatic switch K5.

[0064] The first battery 410 is also used to provide power to the second load 1200 in the event of a power outage of the second power grid 900.

[0065] The second battery 450 is used to provide power to the first load 600 or the second load 1200 in the event of a power outage in the first power grid 200 or the second power grid 900. It is also used to charge during off-peak hours and discharge during peak hours. The specific functions of the second electronic switch S2, the second battery 450, the second converter 460, the third transformer T3, the third automatic switch K3, and the fourth transformer T4 can be found in the descriptions of the first electronic switch S1, the first battery 410, the first converter 420, the first transformer T1, the first automatic switch K1, and the second transformer T2. These descriptions will not be repeated here.

[0066] In one embodiment, the second battery 450 can be a box-level battery, a cluster-level battery, or a single battery. The box-level battery includes multiple cluster-level batteries, and the box-level battery can also be called an energy storage box. The specific type of the second battery 450 is not limited in the embodiments of this application.

[0067] In one implementation, the first load 600 and the second load 1200 can be the same load.

[0068] In one implementation, reference is made to Figure 5 The circuit consisting of the second battery 450, the second converter 460, the second transformer T2 and the third automatic switch K3 can be called a power supply branch. The medium-voltage power device 400 may include multiple power supply branches. In this application embodiment, the specific number of power supply branches included in the medium-voltage power device 400 is not limited.

[0069] In one implementation, such as Figure 6 The diagram shown is a circuit topology diagram of another medium-voltage power device 400 provided in this application embodiment. The medium-voltage power device 400 may further include a sixth automatic switch K6, which is connected in parallel with the second electronic switch S2. The function of the sixth automatic switch K6 can be referred to the relevant description of the second automatic switch K2 described above, and will not be repeated here in this application embodiment.

[0070] In one implementation, reference is made to Figure 5The medium-voltage power device 400 provided in this application embodiment also includes a controller 440. The controller 440 is used to control the first electronic switch S1 and the second automatic switch K2 to open when the first power grid 200 is de-energized, and simultaneously control the first converter 420 to operate, so that the first battery 410 provides power to the first load 600 through the first converter 420, the first transformer T1, the first automatic switch K1, the second transformer T2, and the first low-voltage distribution cabinet 1000. It also controls the fourth automatic switch K4 to close, so that the AC power provided by the second power grid 900 reaches the first terminal of the first electronic switch S1 through the second medium-voltage distribution cabinet 800, the fourth automatic switch K4, and the first medium-voltage distribution cabinet 700. The controller 440 is also used to control the phase of the output voltage of the first converter 420 to be the same as the phase of the voltage of the second power grid 900 after controlling the first converter 420 to operate and the first battery 410 to provide power to the first load 600. For example, the controller 440 can use phase-shift control to make the phase of the output voltage of the first converter 420 the same as the phase of the voltage of the second power grid 900. The controller 440 is also used to control the first electronic switch S1 to close when the phase of the output voltage of the first converter 420 is the same as the phase of the voltage of the second power grid 900, so that the first battery 410 and the second power grid 900 simultaneously supply power to the first load 600. The controller 440 is also used to control the first converter 420 to slowly stop operating after controlling the first electronic switch S1 to close, so that the second power grid 900 supplies power to the first load 600. Therefore, in the event of a power outage in the first power grid 200, power can be supplied to the first load 600 uninterruptedly, improving the power supply reliability of the medium-voltage power unit 400.

[0071] In one implementation, reference is made to Figure 6The second input terminals of the first medium-voltage distribution cabinet 700 and the second input terminals of the second medium-voltage distribution cabinet 800 are used to connect to the output terminal of the diesel generator 1300. The controller 440 is used to control the first electronic switch S1 and the second automatic switch K2 to open when both the first power grid 200 and the second power grid 900 are de-energized. Simultaneously, it controls the first converter 420 to operate, so that the first battery 410 provides power to the first load 600 through the first converter 420, the first transformer T1, the first automatic switch K1, the second transformer T2, and the first low-voltage distribution cabinet 1000. It also controls the diesel generator 1300 to start operating, so that the AC power provided by the diesel generator 1300 reaches the first terminal of the first electronic switch S1 through the first medium-voltage distribution cabinet 700. The controller 440 is also used to control the phase of the output voltage of the first converter 420 to be the same as the phase of the output voltage of the diesel generator 1300 after controlling the first converter 420 to operate and the first battery 410 to provide power to the first load 600. The controller 440 is also configured to close the first electronic switch S1 when the phase of the output voltage of the first converter 420 is the same as the phase of the output voltage of the diesel generator 1300, so that the first battery 410 and the diesel generator 1300 simultaneously supply power to the first load 600. The controller 440 is also configured to slowly stop the first converter 420 after closing the first electronic switch S1, so that the diesel generator 1300 supplies power to the first load 600. Therefore, even when both the first power grid 200 and the second power grid 900 are de-energized, power can be supplied to the first load 600 uninterruptedly, improving the power supply reliability of the medium-voltage power unit 400.

[0072] In one implementation, reference is made to Figure 5 The controller 440 is used to control the fifth automatic switch K5 to close in the event of an open-circuit fault in the second transformer T2, so that the second power grid 900 or the second battery 450 can supply power to the first load 600. Therefore, in the event of an open-circuit fault in the second transformer T2, power can be supplied to the first load 600 uninterruptedly, improving the power supply reliability of the medium-voltage power unit 400.

[0073] In one implementation, Figure 4 On the basis of, such as Figure 7 The diagram shown is a circuit topology diagram of another medium-voltage power device 400 provided in an embodiment of this application. The medium-voltage power device 400 may also include a plurality of sixth automatic switches K6. The second end of the first electronic switch S1 is connected to one end of the plurality of sixth automatic switches K6. The other ends of the plurality of sixth automatic switches K6 are respectively used to connect to the high-voltage side of the plurality of second transformers T2. The low-voltage side of the plurality of second transformers T2 is used to connect to the plurality of first loads 600.

[0074] Reference Figure 7 The controller 440 is also used to close the second automatic switch K2 and open the sixth automatic switch K6 corresponding to the short-circuited transformer T2 in the event of a short-circuit fault in any of the second transformers T2. The controller 440 is also used to open the second automatic switch K2 after opening the sixth automatic switch K6 corresponding to the short-circuited transformer T2. Compared to the first electronic switch S1, the second automatic switch K2 has higher withstand voltage and current values, thus preventing damage to the first electronic switch S1 in the event of a short-circuit fault in any of the multiple second transformers T2. Simultaneously, the remaining second transformers T2 can continue to operate and supply power to their respective first loads 600, thereby improving the reliability of the medium-voltage power unit 400.

[0075] The medium-voltage power device 400 provided in this application embodiment can continuously supply power to the load (first load 600 or second load 1200) in the event of a single power grid failure, a power grid failure, or a transformer open-circuit or short-circuit fault on the load side, thereby improving the power supply reliability of the medium-voltage power device 400.

[0076] Based on this, such as Figure 3 As shown in the figure, this application embodiment also provides a power supply system 500, which includes a medium-voltage power device 400 and a second transformer T2. The circuit topology of the medium-voltage power device 400 is as follows: Figures 3-7 The circuit topology of the medium-voltage power device 400 shown in any of the accompanying drawings, as well as the specific functions of the medium-voltage power device 400 and the second transformer T2, can be referred to the above description, and will not be repeated here in the embodiments of this application.

[0077] In one embodiment, the power supply system 500 may further include a fourth transformer T4, a first low-voltage distribution cabinet 1000, a second low-voltage distribution cabinet 1100, and a fifth automatic switch K5. The circuit topology of the power supply system 500 may be as follows: Figure 5 The circuit topology of the power supply system 500 is shown.

[0078] The above detailed description of the medium-voltage power device 400 and the analysis of its beneficial effects can be applied to the power supply system 500, and will not be repeated here in the embodiments of this application.

[0079] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A medium-voltage power supply device, characterized in that, The medium-voltage power device includes a first electronic switch, a first battery, a first converter, a first transformer, and a first automatic switch; The first terminal of the first electronic switch is used to connect to the first power grid, the electrode of the first battery is connected to the DC side of the first converter, the AC side of the first converter is connected to the low-voltage side of the first transformer, the high-voltage side of the first transformer is connected to one terminal of the first automatic switch, the other terminal of the first automatic switch and the second terminal of the first electronic switch are used to connect to the high-voltage side of the second transformer, and the low-voltage side of the second transformer is used to connect to the first load. The first battery is used to provide power to the first load in the event of a power outage in the first power grid.

2. The medium-voltage power supply device according to claim 1, characterized in that, The medium-voltage power device also includes a second automatic switch, which is connected in parallel with the first electronic switch.

3. The medium-voltage power supply device according to claim 2, characterized in that, The medium-voltage power unit also includes a second electronic switch, a second battery, a second converter, a third transformer, and a third automatic switch; The first terminal of the first electronic switch is used to connect to the output terminal of the first medium-voltage distribution cabinet, the first input terminal of the first medium-voltage distribution cabinet is used to connect to the first power grid, the first terminal of the second electronic switch is used to connect to the output terminal of the second medium-voltage distribution cabinet, the first input terminal of the second medium-voltage distribution cabinet is used to connect to the second power grid, the input and output terminals of the second medium-voltage distribution cabinet are used to connect to one terminal of the fourth automatic switch, and the input and output terminals of the first medium-voltage distribution cabinet are used to connect to the other terminal of the fourth automatic switch. The electrodes of the second battery are connected to the DC side of the second converter, the AC side of the second converter is connected to the low-voltage side of the third transformer, the high-voltage side of the third transformer is connected to one end of the third automatic switch, and the other end of the third automatic switch and the second end of the second electronic switch are used to connect to the high-voltage side of the fourth transformer. The low-voltage side of the second transformer is used to connect to the input terminal of the first low-voltage distribution cabinet, the output terminal of the first low-voltage distribution cabinet is used to connect to the first load, the low-voltage side of the fourth transformer is used to connect to the input terminal of the second low-voltage distribution cabinet, the output terminal of the second low-voltage distribution cabinet is used to connect to the second load, the input and output terminals of the first low-voltage distribution cabinet are used to connect to one end of the fifth automatic switch, and the input and output terminals of the second low-voltage distribution cabinet are used to connect to the other end of the fifth automatic switch. The first battery is also used to provide power to the second load in the event of a power outage in the second power grid; The second battery is used to provide power to the first load or the second load in the event of a power outage in the first grid or the second grid, and is also used to charge during off-peak hours and discharge during peak hours.

4. The medium-voltage power supply device according to claim 3, characterized in that, The medium-voltage power device also includes a sixth automatic switch, which is connected in parallel with the second electronic switch.

5. The medium-voltage power supply device according to claim 3 or 4, characterized in that, The medium-voltage power device also includes a controller, and the first automatic switch is always in a closed state when the first battery, the first converter and the first transformer are working normally. The controller is used to control the first electronic switch and the second automatic switch to open when the first power grid is de-energized, and at the same time control the first inverter to operate so that the first battery provides power to the first load, and control the fourth automatic switch to close. The controller is further configured to, after controlling the first converter to operate and the first battery to provide power to the first load, control the phase of the output voltage of the first converter to be the same as the phase of the second grid voltage. The controller is further configured to control the first electronic switch to close when the phase of the output voltage of the first converter is the same as the phase of the voltage of the second grid, so that the first battery and the second grid simultaneously provide power to the first load. The controller is also configured to, after controlling the first electronic switch to close, control the first converter to slowly stop working, so that the second power grid can provide power to the first load.

6. The medium-voltage power supply device according to claim 3 or 4, characterized in that, The second input terminal of the first medium-voltage distribution cabinet and the second input terminal of the second medium-voltage distribution cabinet are used to connect to the output terminal of the diesel generator. The medium-voltage power device also includes a controller. The first automatic switch is always in a closed state when the first battery, the first converter and the first transformer are working normally. The controller is used to control the first electronic switch and the second automatic switch to disconnect when both the first power grid and the second power grid are de-energized, and at the same time control the first converter to operate so that the first battery provides power to the first load, and control the diesel generator to start working. The controller is further configured to, after controlling the first converter to operate and the first battery to provide power to the first load, control the phase of the output voltage of the first converter to be the same as the phase of the output voltage of the diesel generator. The controller is further configured to control the first electronic switch to close when the phase of the output voltage of the first converter is the same as the phase of the output voltage of the diesel generator, so that the first battery and the diesel generator simultaneously provide power to the first load. The controller is also configured to, after controlling the first electronic switch to close, control the first converter to slowly stop working, so that the diesel generator can provide power to the first load.

7. The medium-voltage power supply device according to claim 3 or 4, characterized in that, The medium-voltage power unit also includes a controller; The controller is used to control the fifth automatic switch to close in the event of an open circuit fault in the second transformer, so that the second power grid or the second battery can provide power to the first load.

8. The medium-voltage power supply unit according to any one of claims 2-7, characterized in that, The medium-voltage power device also includes a plurality of sixth automatic switches. The second end of the first electronic switch is connected to one end of the plurality of sixth automatic switches. The other ends of the plurality of sixth automatic switches are respectively used to connect to the high-voltage side of a plurality of second transformers. The low-voltage side of the plurality of second transformers is used to connect to a plurality of first loads. The controller is also configured to, in the event of a short-circuit fault in any of the second transformers, control the second automatic switch to close and control the sixth automatic switch corresponding to the second transformer that has experienced a short-circuit fault to open. The controller is further configured to control the second automatic switch to open after the sixth automatic switch corresponding to the second transformer that has experienced a short-circuit fault has opened.

9. The medium-voltage power supply unit according to any one of claims 2-8, characterized in that, The medium-voltage power unit also includes a maintenance bypass, which is connected in parallel with the first electronic switch; The controller is also used to control the first electronic switch and the second automatic switch to close simultaneously when the medium-voltage power device is ready for maintenance; The controller is further configured to, after controlling the first electronic switch and the second automatic switch to close simultaneously, control the first electronic switch to open and control the maintenance bypass to close. The controller is also configured to control the second automatic switch to open after controlling the maintenance bypass to close.

10. A power supply system, characterized in that, The power supply system includes a medium-voltage power device, which is the medium-voltage power device as described in any one of claims 1-9.

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