Uninterruptible power supply

Abstract

The embodiment of the utility model discloses an uninterruptible power supply, relates to the technical field of power electronics, and solves the problem of how to ensure the continuity of power supply for a load end and protect a switching device on a line from being damaged in the process of switching between a main circuit and a bypass. According to the specific scheme, the uninterruptible power supply equipment comprises a main circuit, a bypass and a load end, and the main circuit and the bypass are used for supplying power to the load end. An inverter circuit and a switch are arranged on the main circuit, the output end of the inverter circuit is connected with the switch, and the switch is used for controlling connection or disconnection between the output end of the inverter circuit and the load end. The two-way conduction device is connected with the fuse in series, the two-way conduction device and the fuse which are connected in series are connected with the switch in parallel, the fuse is used for being disconnected when fault current flows through the two-way conduction device and the fault current is larger than a first current threshold value, and the two-way conduction device is used for being connected when power supply of the load end by the bypass is switched to power supply of the load end by the main circuit.

Description

Technical Field

[0001] This application relates to the field of power electronics technology, and particularly to an uninterruptible power supply. Background Art

[0002] An uninterruptible power supply (UPS) includes a main path, a bypass path, and a load terminal. The main path and the bypass path are used to supply power to the load terminal. Among them, an inverter circuit and a relay are provided on the main path. The relay is used to disconnect when the main path is abnormal, controlling the disconnection between the output terminal of the inverter circuit and the load terminal. At this time, the bypass path is used to supply power to the load terminal. The relay is also used to close when the main path returns to normal, controlling the conduction between the output terminal of the inverter circuit and the load terminal. At this time, the main path is used to supply power to the load terminal.

[0003] However, there is a mechanical action delay when the relay closes or disconnects. And the fault current on the main path can also cause damage to the switching devices. Therefore, in the process of switching between the main path and the bypass path, how to ensure the continuity of power supply to the load terminal while protecting the switching devices on the line from damage has become an urgent problem to be solved. Summary of the Utility Model

[0004] The embodiments of this application provide an uninterruptible power supply, which solves the problem of how to ensure the continuity of power supply to the load terminal while protecting the switching devices on the line from damage in the process of switching between the main path and the bypass path.

[0005] To achieve the above object, the embodiments of this application adopt the following technical solutions:

[0006] In the first aspect of the embodiments of this application, an uninterruptible power supply is provided. The uninterruptible power supply device includes a main path, a bypass path, and a load terminal. Both the main path and the bypass path are used to supply power to the load terminal. An inverter circuit and a switch are provided on the main path. The output terminal of the inverter circuit is connected to the switch. The switch is used to control the conduction or disconnection between the output terminal of the inverter circuit and the load terminal. A bidirectional conduction device is connected in series with a fuse, and the series-connected bidirectional conduction device and fuse are connected in parallel with the switch. The fuse is used to disconnect when a fault current flows through the bidirectional conduction device and the fault current is greater than the first current threshold. The bidirectional conduction device is used to conduct when the power supply to the load terminal is switched from the bypass path to the main path.

[0007] In a possible embodiment, the ampere-square-second of the fuse is less than the explosion ampere-square-second of the bidirectional conduction device. The explosion ampere-square-second of the bidirectional conduction device refers to the ampere-square-second when the bidirectional conduction device is about to explode, which can be determined through experimental tests.

[0008] Based on this solution, by setting a bidirectional conduction device in parallel with the switch, the bidirectional conduction device is used to conduct when the power supply to the load terminal is switched from the bypass to the main path. Compared with the switching speed of the switch, the switching speed of the bidirectional conduction device is faster, so that rapid switching between the bypass and the main path can be achieved, and the continuity of the power supply to the load terminal can be ensured. At the same time, by setting a fuse in series with the bidirectional conduction device, the fuse is used to disconnect when a fault current flows through the bidirectional conduction device and the fault current is greater than the first current threshold, so that when the uninterruptible power supply fails, the explosion and damage of the bidirectional conduction device can be avoided, and the reliability of the uninterruptible power supply can be improved.

[0009] In combination with the first aspect, in a possible implementation manner, the fuse in series with the bidirectional conduction device is the first fuse, and the switch is in series with a second fuse. The second fuse is used to disconnect when the current flowing through the switch is greater than the second current threshold, and the second current threshold is greater than the first current threshold.

[0010] Based on this solution, by setting a second fuse in series with the switch, the second fuse is used to disconnect when the current flowing through the switch is greater than the second current threshold, and the switch is protected against overcurrent, so that when the uninterruptible power supply fails, the damage of the switch can be avoided, and the reliability of the uninterruptible power supply can be improved.

[0011] In combination with the first aspect, in a possible implementation manner, the bidirectional conduction device includes two thyristors. The fuse in series with the bidirectional conduction device is the first fuse, and the two thyristors are reversely connected in parallel and then connected in series with the first fuse.

[0012] In a possible embodiment, the ampere-seconds of the first fuse is less than the explosion ampere-seconds of any one of the two thyristors.

[0013] Based on this solution, the two thyristors in the bidirectional conduction device are protected by the first fuse, so that when the uninterruptible power supply fails, the explosion and damage of the two thyristors can be avoided, and the reliability of the uninterruptible power supply can be improved.

[0014] In combination with the first aspect, in a possible implementation manner, the fusing of the first fuse is used to protect the bidirectional conduction device.

[0015] In combination with the first aspect, in a possible implementation manner, the fusing of the second fuse is used to protect the switch.

[0016] In combination with the first aspect, in a possible implementation manner, the bidirectional conduction device includes two thyristors, and the fuse in series with the bidirectional conduction device includes two fuses. The two thyristors are respectively connected in series with one of the fuses and then reversely connected in parallel.

[0017] In a possible embodiment, the ampere-second of each of the two fuses is respectively less than the explosion ampere-second of the thyristor connected in series with each fuse. The explosion ampere-second of each thyristor refers to the ampere-second when the thyristor is about to explode, which can be determined through experimental tests.

[0018] Based on this solution, the bidirectional conduction device includes two thyristors, and the fuse connected in series with the bidirectional conduction device includes two fuses. The two thyristors are respectively connected in series with one of the fuses and then reversely paralleled, so that when a fault occurs in the uninterruptible power supply, the explosion and damage of the two thyristors can be avoided, and the reliability of the uninterruptible power supply can be improved.

[0019] Combined with the first aspect, in a possible implementation manner, the direction of the fault current is opposite to the direction of the current output from the output end of the inverter circuit.

[0020] Based on this solution, by setting a fuse connected in series with the bidirectional conduction device, the fuse is used to disconnect when the fault current flows through the bidirectional conduction device and the fault current is greater than the first current threshold, so that when a fault occurs in the uninterruptible power supply and the direction of the fault current is opposite to the direction of the current output from the output end of the inverter circuit, the explosion and damage of the bidirectional conduction device can be avoided, and the reliability of the uninterruptible power supply can be improved.

[0021] Combined with the first aspect, in a possible implementation manner, the fuse includes a plurality of sub-fuses connected in parallel.

[0022] Based on this solution, by equivalently replacing a fuse with a plurality of sub-fuses connected in parallel, compared with using one fuse, the plurality of sub-fuses connected in parallel share the current, so that the service life of each sub-fuse in the plurality of sub-fuses can be extended. Description of the Drawings

[0023] Figure 1 It is a circuit topology schematic diagram of a modular UPS;

[0024] Figure 2 It is a circuit topology schematic diagram of another modular UPS;

[0025] Figure 3 It is a circuit topology schematic diagram of yet another modular UPS;

[0026] Figure 4 It is a circuit topology schematic diagram of an application scenario of an uninterruptible power supply provided by an embodiment of the present application;

[0027] Figure 5 It is a circuit topology schematic diagram of an uninterruptible power supply provided by an embodiment of the present application;

[0028] Figure 6Another circuit topology schematic diagram of the uninterruptible power supply provided by the embodiment of the present application;

[0029] Figure 7 Another circuit topology schematic diagram of the uninterruptible power supply provided by the embodiment of the present application;

[0030] Figure 8 Another circuit topology schematic diagram of the uninterruptible power supply provided by the embodiment of the present application;

[0031] Figure 9 Another circuit topology schematic diagram of the uninterruptible power supply provided by the embodiment of the present application;

[0032] Figure 10 Another circuit topology schematic diagram of the uninterruptible power supply provided by the embodiment of the present application;

[0033] Figure 11 Another circuit topology schematic diagram of the uninterruptible power supply provided by the embodiment of the present application;

[0034] Figure 12 Another circuit topology schematic diagram of the uninterruptible power supply provided by the embodiment of the present application. Detailed implementation manners

[0035] The fabrication and use of the embodiments will be discussed in detail below. It should be understood that many applicable utility model concepts provided by the present application can be implemented in a variety of specific environments. The specific embodiments discussed are merely illustrative of the specific ways of implementing and using this description and this technology, and do not limit the scope of the present application.

[0036] Unless otherwise defined, all scientific and technical terms used herein have the same meaning as commonly understood by those of ordinary skill in the art.

[0037] Each circuit or other component may be described or referred to as "configured to" perform one or more tasks. In this case, "configured to" is used to imply a structure by indicating that the circuit / component includes a structure (such as a circuit system) that performs one or more tasks during operation. Thus, even when the specified circuit / component is currently inoperable (e.g., not turned on), the circuit / component can still be referred to as configured to perform the task. A circuit / component used in conjunction with the phrase "configured to" includes hardware, such as a circuit that performs the operation, etc.

[0038] The following will describe the technical solutions in the embodiments of the present application with reference to the accompanying drawings in the embodiments of the present application. In the present application, "at least one" means one or more, and "a plurality" means two or more. "And / or" describes the association relationship of associated objects and indicates that three relationships may exist. For example, A and / or B may represent: A exists alone, A and B exist simultaneously, and B exists alone, where A and B may be singular or plural. The character " / " generally represents an "or" relationship between the associated objects before and after. "At least one (item)" or similar expressions thereof refer to any combination of these items, including any combination of single item (item) or plural items (items). For example, at least one (item) of a, b, or c may represent: a, b, c, a and b, a and c, b and c, or a, b, and c, where a, b, and c may be single or multiple. Additionally, in the embodiments of the present application, words such as "first" and "second" do not limit the quantity and order.

[0039] In the present application, words such as "exemplary" or "for example" are used to give examples, illustrations, or explanations. Any embodiment or design solution described as "exemplary" or "for example" in the present application should not be construed as being more preferred or having more advantages than other embodiments or design solutions. Rather, the use of words such as "exemplary" or "for example" is intended to present relevant concepts in a specific manner.

[0040] Before introducing the embodiments of the present application, the technical terms and background technology related to the present application will be introduced first.

[0041] Silicon controlled rectifier (SCR): It can be abbreviated as thyristor and can also be called thyristor. This thyristor can be used as a switch in a circuit and has advantages such as small volume, high efficiency, and long lifespan. The types of thyristors include single-phase thyristors and triple alternating current semiconductor switches (Triac), and this triple alternating current semiconductor switch can also be called a bidirectional thyristor, which can be used to replace two single-phase thyristors connected in antiparallel (also called two single-phase thyristors connected in reverse parallel).

[0042] As Figure 1As shown, it is a schematic diagram of the circuit topology of a modular UPS100. The modular UPS100 includes a bypass 110, a load terminal H, and multiple main paths 120. The bypass 110 can also be referred to as a bypass module or a bypass device, and the main path 120 can also be referred to as a power module or a power conversion device. The input end of the bypass 110 and the first input ends of the multiple main paths 120 are used to connect to the input power supply 200. The second input ends of the multiple main paths 120 are used to connect to the energy storage device 400. The output end of the bypass 110 and the output ends of the multiple main paths 120 are connected to the load terminal H, and the load terminal H is used to connect to the load 300.

[0043] Referring to Figure 1 , each main path 120 includes a rectifier circuit 121 (which can also be referred to as a rectifier), a DC conversion circuit 122 (which can also be referred to as a battery discharger), and an inverter circuit 123 (which can also be referred to as an inverter). The input end of the rectifier circuit 121 is the first input end of the main path 120, and the input end of the rectifier circuit 121 is used to connect to the input power supply 200. The input end of the DC conversion circuit 122 is the second input end of the main path 120, and the input end of the DC conversion circuit 122 is used to connect to the energy storage device 400. The output end of the rectifier circuit 121 and the output end of the DC conversion circuit 122 are connected to the input end of the inverter circuit 123. The output end of the inverter circuit 123 is the output end of the main path 120, and the output end of the inverter circuit 123 is used to connect to the load terminal H.

[0044] When the input power supply 200 is normal, the rectifier circuit 121 in the main path 120 is used to convert the alternating current provided by the input power supply 200 into a stable direct current voltage, and the inverter circuit 123 is used to convert the stable direct current voltage into a stable alternating current voltage to supply power to the load 300 through the load terminal H.

[0045] When the input power supply 200 is abnormal, the DC conversion circuit 122 in the main path 120 is used to convert the direct current voltage provided by the energy storage device 400 into a stable direct current voltage, and the inverter circuit 123 is used to convert the stable direct current voltage into a stable alternating current voltage to supply power to the load 300 through the load terminal H.

[0046] When the input power supply 200 is normal and all the main paths 120 in the modular UPS100 fail, the bypass 110 is used to transmit the alternating current provided by the input power supply 200 to the load 300 to supply power to the load 300 through the load terminal H, ensuring the power supply continuity of the load 300.

[0047] Referring to Figure 1, each main path 120 further includes a relay 124 and a fuse 125 corresponding to each phase output terminal of the inverter circuit 123. The first end of the relay 124 is connected to a phase output terminal of the inverter circuit 123, the second end of the relay 124 is connected to the first end of the fuse 125, and the second end of the fuse 125 is used to connect to the load 300. Thus, when a fault occurs in the main path 120, the main path 120 can be isolated through the relay 124, and the fuse 125 is used for overcurrent protection of the relay 124, which can improve the reliability of the main path 120.

[0048] However, when the relay 124 is closed or opened, there is a mechanical action delay, and during the switching process between the bypass 110 and the main path 120, the power supply continuity of the load 300 cannot be ensured.

[0049] To solve this problem, continue to refer to Figure 1 , each main path 120 further includes a first unidirectional SCR 126 and a second unidirectional SCR 127 corresponding to each phase output terminal of the inverter circuit 123. The cathode of the first unidirectional SCR 126 and the anode of the second unidirectional SCR 127 are connected to the first end of the relay 124, and the anode of the first unidirectional SCR 126 and the cathode of the second unidirectional SCR 127 are connected to the second end of the relay 124.

[0050] During the switching process between the bypass 110 and the main path 120, first control the first unidirectional SCR 126 and the second unidirectional SCR 127 to conduct, and at the same time control the relay 124 to close. After the relay 124 is closed, then control the first unidirectional SCR 126 and the second unidirectional SCR 127 to turn off. Compared with the switching speed of the relay 124, the switching speeds of the first unidirectional SCR 126 and the second unidirectional SCR 127 are faster, so that the fast switching between the bypass 110 and the main path 120 can be realized, and the power supply continuity of the load 300 can be ensured.

[0051] It can be understood that during the operation of the main path 120, the relay 124 and the fuse 125 pass a large current for a long time, and the first unidirectional SCR 126 and the second unidirectional SCR 127 do not pass a large current for a long time, and the current flowing through the first unidirectional SCR 126 and the second unidirectional SCR 127 is small. In this main path 120, the fuse 125 is matched with the relay 124. When a fault occurs in the modular UPS 100 and the fault current flows through the fuse 125 and the relay 124, the fuse 125 can quickly disconnect, so the relay 124 can be protected.

[0052] However, the fuse 125 does not match the first unidirectional SCR 126 or the second unidirectional SCR 127. When the modular UPS 100 fails and a large current flows through the first unidirectional SCR 126, the second unidirectional SCR 127, and the fuse 125, the fuse 125 cannot provide overcurrent protection for the first unidirectional SCR 126 or the second unidirectional SCR 127, and the first unidirectional SCR 126 or the second unidirectional SCR 127 will be damaged by explosion, resulting in low reliability of the main circuit 120.

[0053] For example, as Figure 2 shown, when the fault point is between the modular UPS 100 and the load 300, for instance, when the output cable of the modular UPS 100 is damaged and touches the shell of the modular UPS 100, causing a short circuit, the current flowing through the first unidirectional SCR 126 and the second unidirectional SCR 127 is as shown by the line A in Figure 2 , and this current will cause the first unidirectional SCR 126 or the second unidirectional SCR 127 to be damaged by explosion.

[0054] To solve this problem, when the fault point is outside the main circuit 120, such as when the output cable of the modular UPS 100 is damaged and short-circuited as described above, the current-limiting protection function of the inverter circuit 123 can be used to limit the current flowing through the first unidirectional SCR 126 and the second unidirectional SCR 127, so as to avoid damage to the first unidirectional SCR 126 and the second unidirectional SCR 127.

[0055] However, as Figure 3 shown, when the fault point is inside the main circuit 120, for example, when the inverter circuit 123 is short-circuited and the current output by the rest of the main circuit 120 is reversely input into the faulty main circuit 120, the current flowing through the first unidirectional SCR 126 and the second unidirectional SCR 127 is as shown by the line B in Figure 3 . The inverter circuit 123 in the faulty main circuit 120 cannot perform current-limiting protection, and at the same time, the inverter circuits 123 in the other main circuits 120 cannot perform current-limiting protection either. The fuse 125 cannot protect the first unidirectional SCR 126 and the second unidirectional SCR 127, which will cause the first unidirectional SCR 126 or the second unidirectional SCR 127 to be damaged by explosion, resulting in low reliability of the faulty main circuit 120.

[0056] In summary, in the modular UPS 100, there is a mechanical action delay when the relay 124 closes and opens. Also, the fault current on the main path 120 can cause the first unidirectional SCR 126 or the second unidirectional SCR 127 to explode and be damaged. Therefore, during the switching process between the bypass 110 and the main path 120, how to ensure the continuity of power supply to the load terminal H while protecting the first unidirectional SCR 126 or the second unidirectional SCR 127 located on the line from being damaged has become an urgent problem to be solved. Based on this, the embodiment of the present application provides an uninterruptible power supply. By setting a fuse in series with the bidirectional conduction device to provide overcurrent protection for the bidirectional conduction device, the explosion and damage of the bidirectional conduction device can be avoided. Moreover, the series-connected bidirectional conduction device and fuse are connected in parallel with the switch. Thus, during the switching process between the main path and the bypass, the continuity of power supply to the load terminal can be ensured, and the reliability of the uninterruptible power supply can be improved.

[0057] As Figure 4 shown, it is a circuit topology schematic diagram of an application scenario of an uninterruptible power supply 500 provided by the embodiment of the present application. Specifically, the uninterruptible power supply 500 may include a bypass 510, a load terminal H, and at least one main path 520. Both the bypass 510 and the at least one main path 520 are used to supply power to the load terminal H. The bypass 510 may also be referred to as a bypass module or a bypass device, and the main path 520 may also be referred to as a power module or a power conversion device. The embodiment of the present application does not limit the specific number of main paths 520 included in the uninterruptible power supply 500. In the following embodiments of the present application, an example is given with the uninterruptible power supply 500 including one main path 520 for illustrative purposes. The input end of the bypass 510 and the first input end of the at least one main path 520 are connected to the first input end of the uninterruptible power supply 500, the second input end of the at least one main path 520 is connected to the second input end of the uninterruptible power supply 500, the output end of the bypass 510 and the output end of the at least one main path 520 are connected to the load terminal H. The first input end of the uninterruptible power supply 500 is used to connect to the input power supply 200, the second input end of the uninterruptible power supply 500 is used to connect to the energy storage device 400, and the load terminal H is used to connect to the load 300.

[0058] The uninterruptible power supply 500 can be applied to systems such as large data centers, large communication centers, large enterprise computer rooms, financial system computer rooms, industrial automation centers, and dispatching centers. The embodiment of the present application does not limit the specific systems to which the uninterruptible power supply 500 is applied.

[0059] In a possible embodiment, when the uninterruptible power supply 500 is applied to the above system, it can be applied to the above system individually. "Individually" means that a single uninterruptible power supply 500 is applied to the above system. Alternatively, multiple uninterruptible power supplies 500 can be applied to the above system in parallel. "In parallel" means that multiple uninterruptible power supplies 500 are connected in parallel and then applied to the above system. The embodiments of the present application do not limit this, such as Figure 4 As shown, the embodiments of the present application take the individual application of the uninterruptible power supply 500 to the above system as an example for illustrative description.

[0060] Referring to Figure 4 , the first input end of the uninterruptible power supply 500 is connected to the input power supply 200 through the input power distribution cabinet 600. The input power supply 200 may include the commercial power 210 or the fuel generator set 220. The second input end of the uninterruptible power supply 500 is connected to the energy storage device 400 through the battery busbar box 700. The energy storage device 400 may include battery packs 1 to battery packs N. The N battery packs can be connected in series, in parallel, or some of them are connected in series and the rest are connected in parallel. N is a positive integer greater than or equal to 1. The load end H of the uninterruptible power supply 500 is connected to the load 300 through the output power distribution cabinet 800. The load 300 may include multiple loads. The uninterruptible power supply 500 is also connected to the management system 900 through a communication cable. The management system 900 is used to manage and control the uninterruptible power supply 500. The management system 900 can also manage and control the input power distribution cabinet 600, the battery busbar box 700, the energy storage device 400, and the output power distribution cabinet 800 through the communication cable between the uninterruptible power supply 500 and other devices.

[0061] In a possible embodiment, when the uninterruptible power supply 500 is applied to the above system, it can be installed against the wall or not installed against the wall. The embodiments of the present application do not limit this.

[0062] As Figure 5 shown, it is a circuit topology schematic diagram of an uninterruptible power supply 500 provided by the embodiments of the present application. The uninterruptible power supply 500 includes a bypass 510, a load end H, and a main path 520. Among them, an inverter circuit 521 and a switch K are provided on the main path 520. The output end of the inverter circuit 521 is connected to the switch K. The switch K is used to control the conduction or disconnection between the output end of the inverter circuit 521 and the load end H. The bidirectional conduction device 522 is connected in series with the fuse 523, and the series-connected bidirectional conduction device 522 and fuse 523 are connected in parallel with the switch K. The fuse 523 is used to disconnect when a fault current flows through the bidirectional conduction device 522 and the fault current is greater than the first current threshold. The embodiments of the present application do not limit the specific value of the first current threshold. The bidirectional conduction device 522 is used to conduct when switching from the bypass 510 to supply power to the load end H to the main path 520 to supply power to the load end H.

[0063] Optionally, the type of switch K includes a relay or a contactor, and the embodiments of the present application do not limit the specific type of switch K.

[0064] Optionally, the bidirectional conduction device 522 includes a triac, or the bidirectional conduction device 522 includes two unidirectional thyristors connected in reverse parallel. The embodiments of the present application do not limit this, for example Figure 5 in which the bidirectional conduction device 522 includes a triac TRIAC is taken as an example for illustrative description.

[0065] Optionally, the type of fuse 523 includes a fuse wire or a fast fuse. The embodiments of the present application do not limit this, for example Figure 5 in which the fuse 523 includes a first fuse wire FU1 is taken as an example for illustrative description.

[0066] Compared with the modular UPS100 shown above Figure 1 in the main path 520 of the uninterruptible power supply 500, by providing a bidirectional conduction device 522 connected in parallel with the switch K, the bidirectional conduction device 522 is used to conduct when switching from the bypass 510 to supply power to the load terminal H to supplying power to the load terminal H by the main path 520. Compared with the switching speed of the switch K, the switching speed of the bidirectional conduction device 522 is faster, so that the fast switching between the bypass 510 and the main path 520 can be realized, and the continuity of power supply to the load terminal H can be ensured. Compared with the modular UPS100 shown above Figure 2 in the main path 520 of the uninterruptible power supply 500, by providing a fuse 523 connected in series with the bidirectional conduction device 522, the fuse 523 is used to disconnect when a fault current flows through the bidirectional conduction device 522 and the fault current is greater than the first current threshold. Therefore, when the uninterruptible power supply 500 fails, the explosion and damage of the bidirectional conduction device 522 can be avoided, and the reliability of the uninterruptible power supply 500 can be improved.

[0067] In a possible embodiment, the direction of the above-mentioned fault current is opposite to the direction of the output current at the output terminal of the inverter circuit 521. In the main path 520 of the uninterruptible power supply 500, by providing a fuse 523 connected in series with the bidirectional conduction device 522, the fuse 523 is used to disconnect when a fault current flows through the bidirectional conduction device 522 and the fault current is greater than the first current threshold. Therefore, when the uninterruptible power supply 500 fails and the direction of the fault current is opposite to the direction of the output current at the output terminal of the inverter circuit 521, the explosion and damage of the bidirectional conduction device 522 can be avoided, and the reliability of the uninterruptible power supply 500 can be improved.

[0068] In a possible embodiment, referring to Figure 5, the main circuit 520 further includes a rectification circuit 524 (which can also be referred to as a rectifier) and a DC conversion circuit 525 (which can also be referred to as a battery discharger). The input end of the rectification circuit 524 is used to connect to the input power supply 200, and the input end of the DC conversion circuit 525 is used to connect to the energy storage device 400. The output end of the rectification circuit 524 and the output end of the DC conversion circuit 525 are connected to the input end of the inverter circuit 521.

[0069] Optionally, the inverter circuit 521 may include a single-phase output terminal or a three-phase output terminal, and the embodiments of the present application do not limit this. When the inverter circuit 521 includes a single-phase output terminal, the circuit topology schematic diagram of the uninterruptible power supply 500 is as Figure 5 shown. When the inverter circuit 521 includes a three-phase output terminal, the circuit topology schematic diagram of the uninterruptible power supply 500 is as Figure 6 shown. Referring to Figure 6 , when the inverter circuit 521 includes a three-phase output terminal, the main circuit 520 further includes a bidirectional conduction device 522, a switch K, and a fuse 523 that are respectively connected to each phase output terminal of the inverter circuit 521. In the following embodiments of the present application, an example is given with the inverter circuit 521 including a single-phase output terminal for illustrative purposes.

[0070] In a possible embodiment, when the inverter circuit 521 includes a single-phase output terminal, the uninterruptible power supply 500 can be referred to as a single-phase uninterruptible power supply. When the inverter circuit 521 includes a three-phase output terminal, the uninterruptible power supply 500 can be referred to as a three-phase uninterruptible power supply.

[0071] In a possible embodiment, the fuse 523 includes a plurality of sub-fuses connected in parallel. By equivalently replacing one fuse with a plurality of sub-fuses connected in parallel, compared with using one fuse, the plurality of sub-fuses connected in parallel share the current, thereby extending the life of each sub-fuse in the plurality of sub-fuses.

[0072] The following introduces various possible circuit topologies of the uninterruptible power supply 500:

[0073] In a possible embodiment, referring to Figure 5 , the bidirectional conduction device 522 includes a triac, and the fuse 523 includes a first fuse FU1, and the first fuse FU1 is matched with the triac. When a fault occurs in the main circuit 520 and the fault current flows through the triac and the first fuse FU1, the first fuse FU1 melts in time to provide overcurrent protection for the triac, which can prevent the triac from exploding and being damaged, and can improve the reliability of the uninterruptible power supply 500.

[0074] In a possible embodiment, the matching of the first fuse FU1 with the TRIAC means that the ampere-square second (I 2 t) of the first fuse FU1 is less than the explosion ampere-square second of the TRIAC. The explosion ampere-square second of the TRIAC refers to the ampere-square second when the TRIAC is about to explode, which can be determined through experimental tests.

[0075] In a possible embodiment, as Figure 7 shown, the bidirectional conduction device 522 includes a first thyristor 5221 (which can also be called a thyristor) and a second thyristor 5222 connected in reverse parallel. The fuse 523 includes a first fuse FU1, and the first fuse FU1 is matched with the first thyristor 5221 and the second thyristor 5222. When a fault occurs in the main circuit 520 and the fault current flows through the first fuse FU1, the first thyristor 5221, and the second thyristor 5222, the first fuse FU1 melts in time to provide overcurrent protection for the first thyristor 5221 and the second thyristor 5222, which can prevent the first thyristor 5221 and the second thyristor 5222 from exploding and being damaged, and can improve the reliability of the uninterruptible power supply 500.

[0076] In a possible embodiment, the matching of the first fuse FU1 with the first thyristor 5221 and the second thyristor 5222 means that the ampere-square second of the first fuse FU1 is less than the explosion ampere-square second of the first thyristor 5221, and the ampere-square second of the first fuse FU1 is less than the explosion ampere-square second of the second thyristor 5222.

[0077] In a possible embodiment, as Figure 8As shown, the bidirectional conduction device 522 includes a first unidirectional thyristor 5221 and a second unidirectional thyristor 5222. The fuse 523 includes two fuses. The first unidirectional thyristor 5221 and the second unidirectional thyristor 5222 are respectively connected in series with one of the fuses and then connected in reverse parallel. The two fuses include a second fuse FU2 and a third fuse FU3. The second fuse FU2 is matched with the first unidirectional thyristor 5221, and the third fuse FU3 is matched with the second unidirectional thyristor 5222. When a fault occurs in the uninterruptible power supply 500 and the fault current flows through the first unidirectional thyristor 5221 and the second fuse FU2, the second fuse FU2 melts in time to provide overcurrent protection for the first unidirectional thyristor 5221, which can prevent the first unidirectional thyristor 5221 from exploding and being damaged, and can improve the reliability of the uninterruptible power supply 500. When a fault occurs in the uninterruptible power supply 500 and the fault current flows through the second unidirectional thyristor 5222 and the third fuse FU3, the third fuse FU3 melts in time to provide overcurrent protection for the second unidirectional thyristor 5222, which can prevent the second unidirectional thyristor 5222 from exploding and being damaged, and can improve the reliability of the uninterruptible power supply 500.

[0078] In a possible embodiment, the second fuse FU2 being matched with the first unidirectional thyristor 5221 and the third fuse FU3 being matched with the second unidirectional thyristor 5222 means that the ampere-square-second of the second fuse FU2 is less than the explosion ampere-square-second of the first unidirectional thyristor 5221, and the ampere-square-second of the third fuse FU3 is less than the explosion ampere-square-second of the second unidirectional thyristor 5222.

[0079] The uninterruptible power supply 500 provided by the embodiment of the present application, by providing a bidirectional conduction device 522 connected in parallel with the switch K, the bidirectional conduction device 522 is used to conduct when switching from the bypass 510 to supply power to the load terminal H to switching from the main path 520 to supply power to the load terminal H. Compared with the switching speed of the switch K, the switching speed of the bidirectional conduction device 522 is faster, so that the rapid switching between the bypass 510 and the main path 520 can be realized, and the continuity of power supply to the load terminal H can be ensured. By providing a fuse 523 connected in series with the bidirectional conduction device 522, the fuse 523 is used to disconnect when the fault current flows through the bidirectional conduction device 522 and the fault current is greater than the first current threshold, so that when a fault occurs in the uninterruptible power supply 500, the explosion and damage of the bidirectional conduction device 522 can be avoided, and the reliability of the uninterruptible power supply 500 can be improved.

[0080] In a possible embodiment, in combination with Figure 5 , such as Figure 9As shown, the fuse 523 in series with the bidirectional conduction device 522 is the first fuse, and the fuse 526 in series with the switch K is the second fuse. The fuse 526 is used to disconnect when the current flowing through the switch K is greater than the second current threshold, and the second current threshold is greater than the above-mentioned first current threshold. The specific value of the second current threshold in the embodiments of the present application is not limited. Among them, the fusing of the fuse 523 (the first fuse) is used to protect the bidirectional conduction device 522, and the fusing of the fuse 526 (the second fuse) is used to protect the switch K.

[0081] In a possible embodiment, as Figure 9 shown, the fuse 526 includes a fourth fuse FU4, which is matched with the switch K, and the fourth fuse FU4 is used to perform overcurrent protection on the switch K.

[0082] Optionally, referring to Figure 9 , the fourth fuse FU4 can be arranged between the connection point M and the load end H, or can be arranged between the switch K and the connection point M. The embodiments of the present application do not limit this, and the possible circuit topologies are exemplarily described below:

[0083] In a possible embodiment, in combination with Figure 5 , when the fuse 526 is arranged between the connection point M and the load end H, the circuit topology schematic diagram of the uninterruptible power supply 500 is as Figure 9 shown. Or, in combination with Figure 8 , when the fuse 526 is arranged between the connection point M and the load end H, the circuit topology schematic diagram of the uninterruptible power supply 500 is as Figure 10 shown.

[0084] In a possible embodiment, in combination with Figure 5 , when the fuse 526 is arranged between the switch K and the connection point M, the circuit topology schematic diagram of the uninterruptible power supply 500 is as Figure 11 shown. Or, in combination with Figure 8 , when the fuse 526 is arranged between the switch K and the connection point M, the circuit topology schematic diagram of the uninterruptible power supply 500 is as Figure 12 shown.

[0085] In a possible embodiment, when the inverter circuit 521 includes three-phase output terminals, the main circuit 520 further includes fuses 526 respectively connected to each phase output terminal of the inverter circuit 521. The specific connection method can refer to the circuit topology schematic diagram of the uninterruptible power supply 500 shown in any of the above Figures 9 to 12 figures, and the embodiments of the present application will not be elaborated here.

[0086] The embodiment of the present application provides an uninterruptible power supply 500. The main circuit 520 further includes a fuse 526, which is matched with the switch K. The fuse 526 is used for overcurrent protection of the switch K, so that when a fault occurs in the uninterruptible power supply 500, damage to the switch K can be avoided, and the reliability of the uninterruptible power supply 500 can be improved.

[0087] As described above, the above are only specific embodiments of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions within the technical scope disclosed in the present application should be covered by the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. An uninterruptible power supply, characterized in that: The uninterruptible power supply device comprises a main circuit, a bypass circuit and a load end, wherein the main circuit and the bypass circuit are both used to supply power to the load end; The main circuit is provided with an inverter circuit and a switch, the output end of the inverter circuit is connected to the switch, and the switch is used to control the conduction or disconnection between the output end of the inverter circuit and the load end; A bidirectional conductive device is connected in series with a fuse, and the bidirectional conductive device and the fuse in series are connected in parallel with the switch, the fuse is used to disconnect when a fault current flows through the bidirectional conductive device and the fault current is greater than a first current threshold, and the bidirectional conductive device is used to conduct when the power supply from the bypass to the load end is switched to the main circuit to the load end.

2. The uninterruptible power supply according to claim 1, characterized in that: The fuse connected in series with the bidirectional conductive device is a first fuse, and the switch is connected in series with a second fuse, and the second fuse is used to disconnect when the current flowing through the switch is greater than a second current threshold, and the second current threshold is greater than the first current threshold.

3. The uninterruptible power supply according to claim 1 or 2, characterized in that: The bidirectional conducting device comprises two thyristors, the fuse connected in series with the bidirectional conducting device is a first fuse, and the two thyristors are connected in series with the first fuse after being reversely connected in parallel.

4. The uninterruptible power supply according to claim 2, characterized in that: The blowing of the first fuse is used to protect the bidirectional conducting device.

5. The uninterruptible power supply according to claim 2 or 4, characterized in that: The melting of the second fuse is used to protect the switch.

6. The uninterruptible power supply according to claim 1 or 2, characterized in that: The bidirectional conductive device comprises two thyristors, and the fuse connected in series with the bidirectional conductive device comprises two fuses. The two thyristors are respectively connected in series with one of the fuses and then connected in reverse parallel.

7. The uninterruptible power supply according to claim 1 or 2, characterized in that: The direction of the fault current is opposite to the direction of the output current at the output end of the inverter circuit.

8. The uninterruptible power supply according to claim 1 or 2, characterized in that: The fuse includes a plurality of sub-fuses connected in parallel.

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