Rectifier circuit multiplexing uninterruptible power supply

Abstract

The invention provides an uninterruptible power supply for multiplexing a rectifying circuit. The uninterruptible power supply comprises a PFC boost circuit, the input end of which is used for connecting commercial power input and the target polarity end of a battery pack; the input end of the direct current bus is connected with the output end of the PFC booster circuit; the input end of the conversion circuit is connected with the output end of the direct-current bus, and the output end is connected with a load; a first port and a second port, corresponding to the battery side, of the battery bidirectional circuit are respectively used for connecting the positive electrode and the negative electrode of the battery pack, a third port and a fourth port, corresponding to the bus side, of the battery bidirectional circuit are respectively used for connecting a positive bus and a negative bus, and a fifth port is used for connecting a zero line; the balance bridge circuit is connected with the direct current bus and used for balancing the voltage difference between the positive capacitor and the negative capacitor; and in a battery power supply mode, the battery pack connected with the target polarity end charges the positive capacitor or the negative capacitor through the PFC booster circuit. According to the invention, the multiplexing rate of the circuit in the UPS can be improved, and the circuit cost is reduced.

Description

Technical Field

[0001] The present application relates to the field of power electronics technology, and in particular to an uninterruptible power supply with multiplexed rectifier circuits. Background Art

[0002] The basic structure of an uninterruptible power supply (UPS) includes a power factor correction (PFC) boost circuit, a battery bidirectional circuit, and a conversion circuit. When the AC power supplied by the mains is normal, the mains supplies power to the DC bus to enable the load to work normally. At the same time, the battery stores energy and maintains a normal charging voltage. When the mains power supply is interrupted, the battery supplies power to the DC bus to ensure that the load is not disconnected.

[0003] The circuits in the UPS that are powered by AC power and battery power are two independent circuits. When powered by battery, only the battery bidirectional circuit is used for power supply, and the PFC boost circuit is only used under AC power state. The circuit utilization rate is low, resulting in higher circuit costs. Summary of the invention

[0004] The embodiment of the present application provides an uninterruptible power supply with multiplexing rectifier circuits to improve the reuse rate of circuits in a UPS and reduce circuit costs.

[0005] In a first aspect, an embodiment of the present application provides an uninterruptible power supply with multiplexing of rectifier circuits, comprising:

[0006] A PFC boost circuit, whose input terminal is used to connect the mains input and the target polarity terminal of the battery pack;

[0007] A DC bus, whose input end is connected to the output end of the PFC boost circuit; wherein the DC bus includes a positive bus, a negative bus and a neutral line; a positive capacitor is connected between the positive bus and the neutral line, and a negative capacitor is connected between the neutral line and the negative bus;

[0008] A conversion circuit, whose input end is connected to the output end of the DC bus, and whose output end is used to connect to a load;

[0009] A battery bidirectional circuit, wherein the first port and the second port corresponding to the battery side are respectively used to connect the positive electrode and the negative electrode of the battery pack, the third port and the fourth port corresponding to the bus side are respectively used to connect the positive bus and the negative bus, and the fifth port is used to connect the neutral line;

[0010] A balancing bridge circuit, connected to the DC bus, for balancing the voltage difference between the positive capacitor and the negative capacitor;

[0011] In the battery power supply mode, the battery pack connected to the target polarity terminal charges the positive capacitor or the negative capacitor through a PFC boost circuit.

[0012] In a possible implementation, the battery pack is a dual battery pack, and the dual battery pack includes a first battery pack and a second battery pack connected in series;

[0013] The positive electrode of the first battery group serves as the positive electrode of the dual battery group;

[0014] The negative electrode of the first battery group is connected to the positive electrode of the second battery group, serving as the neutral line of the dual battery group, and is used to connect the neutral line and the fifth port of the battery bidirectional circuit;

[0015] The negative electrode of the second battery group serves as the negative electrode of the dual battery group;

[0016] In the battery power supply mode, when the target polarity end is the positive electrode of the dual battery pack, the first battery pack charges the positive capacitor through the PFC boost circuit, and the dual battery pack also charges the positive capacitor and the negative capacitor through the battery bidirectional circuit;

[0017] When the target polarity end is the negative electrode of the dual battery pack, the second battery pack charges the negative capacitor through the PFC boost circuit, and the dual battery pack also charges the positive capacitor and the negative capacitor through the battery bidirectional circuit.

[0018] In a possible implementation, the uninterruptible power supply further includes a first switch, a second switch, a third switch and a controller;

[0019] The input end of the PFC boost circuit is connected to the mains input through the first switch, and is connected to the target polarity end of the dual battery pack through the second switch;

[0020] The first port of the bidirectional battery circuit is connected to the positive electrode of the dual battery pack through the third switch;

[0021] The controller is used to:

[0022] When the AC power input from the mains is normal, controlling the first switch to be turned on, the second switch to be turned off, and the third switch to be turned on, so as to enter the mains power supply mode;

[0023] When the AC power input from the mains fails, the first switch is controlled to be disconnected, the second switch is controlled to be turned on, and the third switch is controlled to be turned on, and the battery power supply mode is entered; the battery power supply mode is: the battery group connected to the target polarity end in the dual battery group is controlled to charge the positive capacitor or the negative capacitor through the PFC boost circuit, the dual battery group is controlled to charge the positive capacitor and the negative capacitor through the battery bidirectional circuit, the balancing bridge circuit is controlled to balance the voltage difference between the positive capacitor and the negative capacitor, and the conversion circuit is controlled to convert the DC power and provide it to the load.

[0024] In a possible implementation, when the capacity difference between the two battery groups in the dual battery group is greater than a preset difference, and the capacity of the first battery group is greater than the capacity of the second battery group, the target polarity end is the positive electrode of the dual battery group;

[0025] When the capacity difference between the two battery groups in the dual battery group is greater than a preset difference, and the capacity of the first battery group is less than the capacity of the second battery group, the target polarity end is the negative electrode of the dual battery group.

[0026] In a possible implementation, the battery pack is a dual battery pack, the dual battery pack includes two battery packs with different capacities connected in series, and the target polarity end includes a positive electrode and a negative electrode of the dual battery pack;

[0027] The uninterruptible power supply also includes a second switch and a fourth switch;

[0028] The input end of the PFC boost circuit is connected to the positive electrode of the dual battery pack through the second switch, and is connected to the negative electrode of the dual battery pack through the fourth switch;

[0029] In the battery power supply mode, the dual battery pack charges the positive capacitor and the negative capacitor through a battery bidirectional circuit, and the battery pack with higher capacity in the dual battery pack charges the positive capacitor or the negative capacitor through a PFC boost circuit.

[0030] In a possible implementation, the battery bidirectional circuit includes a first inductor, a second inductor, a first switch tube, a second switch tube, a third switch tube and a fourth switch tube;

[0031] The first end of the first inductor serves as the first port of the battery bidirectional circuit, and is used to connect to the positive electrode of the dual battery pack;

[0032] The second end of the first inductor is respectively connected to the emitter of the first switch tube and the collector of the second switch tube;

[0033] The collector of the first switch tube serves as the third port of the battery bidirectional circuit, and is used to connect the positive bus;

[0034] The emitter of the second switch tube is connected to the collector of the third switch tube, and the emitter of the second switch tube serves as the fifth port of the battery bidirectional circuit, and is used to connect the neutral line of the dual battery group and the neutral line;

[0035] The first end of the second inductor serves as the second port of the battery bidirectional circuit, and is used to connect to the negative electrode of the dual battery pack;

[0036] The second end of the second inductor is respectively connected to the emitter of the third switch tube and the collector of the fourth switch tube;

[0037] The emitter of the fourth switch tube serves as the fourth port of the battery bidirectional circuit and is used to connect to the negative bus.

[0038] In a possible implementation, the battery bidirectional circuit includes a first inductor, a second inductor, a first switch tube, a second switch tube, a third switch tube and a fourth switch tube;

[0039] The first end of the first inductor and the first end of the third switch tube serve as the first port of the battery bidirectional circuit, and are used to connect the positive electrode of the battery pack;

[0040] The second end of the first inductor is respectively connected to the first end of the first switch tube and the first end of the second switch tube;

[0041] The second end of the first switch tube is connected to the first end of the second inductor, and the connection point serves as the second port and the fifth port of the battery bidirectional circuit, the second port is used to connect the negative electrode of the battery pack, and the fifth port is used to connect the neutral line;

[0042] The second end of the second switch tube serves as the third port of the battery bidirectional circuit, and is used to connect the positive bus;

[0043] The second end of the second inductor is respectively connected to the second end of the third switch tube and the first end of the fourth switch tube;

[0044] The second end of the fourth switch tube serves as a fourth port of the battery bidirectional circuit and is used to connect to the negative bus.

[0045] In a possible implementation, the mains input is three-phase alternating current, the uninterruptible power supply includes three first switches, three second switches and three PFC boost circuits, and each phase of the three-phase alternating current corresponds to a first switch, a second switch and a PFC boost circuit;

[0046] For each phase, the first end of the corresponding first switch is used to connect the AC power of the phase, and the second end of the corresponding first switch is connected to the input end of the PFC boost circuit of the phase;

[0047] An input end of the corresponding PFC boost circuit is also connected to the second end of the second switch of the phase, and an output end of the corresponding PFC boost circuit is connected to the bus;

[0048] The first end of each second switch is used to connect to the target polarity end of the battery pack.

[0049] In a possible implementation, the first switch includes a first thyristor and a second thyristor, and the second switch includes a third thyristor;

[0050] The PFC boost circuit includes a third inductor, a fourth inductor, a first diode, a second diode, a fifth switch tube and a sixth switch tube;

[0051] The anode of the first thyristor and the cathode of the second thyristor are connected and serve as the first end of the first switch; the cathode of the first thyristor serves as the first port of the second end of the first switch and is connected to the first end of the third inductor; the anode of the second thyristor serves as the second port of the second end of the first switch and is connected to the first end of the fourth inductor;

[0052] The second end of the third inductor is connected to the anode of the first diode and the collector of the fifth switch tube respectively; the cathode of the first diode is connected to the positive bus; the emitter of the fifth switch tube is used to connect to the neutral line;

[0053] The second end of the fourth inductor is connected to the emitter of the sixth switch tube and the cathode of the second diode respectively; the anode of the second diode is connected to the negative bus; the collector of the sixth switch tube is used to connect to the neutral line;

[0054] When the target polarity end is the positive electrode of the battery pack, the anode of the third thyristor serves as the first end of the second switch, and the cathode of the third thyristor is connected to the first end of the third inductor; when the target polarity end is the negative electrode of the battery pack, the cathode of the third thyristor serves as the first end of the second switch, and the anode of the third thyristor is connected to the first end of the fourth inductor.

[0055] In a possible implementation, the mains input is three-phase alternating current, the uninterruptible power supply includes three first switches, and each phase of the three-phase alternating current corresponds to one first switch;

[0056] For each phase, the first end of the corresponding first switch is used to connect the alternating current of the phase, the first port of the second end of the corresponding first switch is connected to the first end of the third inductor, and the second port of the second end of the corresponding first switch is connected to the first end of the fourth inductor.

[0057] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0058] In the embodiment of the present application, the battery pack is connected to the PFC boost circuit, and when there is a fault in the AC power input at the mains input end, that is, in the battery power supply mode, the electric energy of the battery pack can be discharged to the DC bus through the PFC boost circuit; the battery pack is also connected to the DC bus through the battery bidirectional circuit, and the electric energy in the battery pack is discharged to the DC bus through the battery bidirectional circuit, and the DC bus can be powered by the PFC boost circuit and the battery bidirectional circuit at the same time. That is, the DC bus can be powered by the PFC boost circuit and the battery bidirectional circuit at the same time, and the PFC boost circuit and the battery bidirectional circuit can be fully utilized in the mains power supply mode and the battery power supply mode to improve the reuse rate of the circuit; in addition, because when the battery pack is used for boosting, the PFC boost circuit is connected to one polarity end in the DC bus, and half of the DC bus is boosted, there is an imbalance problem between the two polarity ends in the DC bus, and the balancing bridge circuit is connected to the DC bus, and the voltage difference between the positive capacitor and the negative capacitor between the two polarity ends in the DC bus is balanced by the balancing bridge circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0060] Figure 1 It is a structural schematic diagram of an uninterruptible power supply with multiplexing of rectifier circuits provided in an embodiment of the present application;

[0061] Figure 2 It is a structural schematic diagram of a first dual-battery uninterruptible power supply provided in an embodiment of the present application;

[0062] Figure 3 is a schematic diagram of the structure of a second dual-battery uninterruptible power supply provided in an embodiment of the present application;

[0063] Figure 4 is a schematic diagram of the structure of a third dual-battery uninterruptible power supply provided in an embodiment of the present application;

[0064] Figure 5AIt is a structural schematic diagram of a first battery bidirectional circuit provided in an embodiment of the present application;

[0065] Figure 5B is a structural schematic diagram of a second battery bidirectional circuit provided in an embodiment of the present application;

[0066] Figure 5C is a structural schematic diagram of a third battery bidirectional circuit provided in an embodiment of the present application;

[0067] Figure 6 This is a circuit structure diagram of a first single-phase uninterruptible power supply provided in an embodiment of the present application;

[0068] Figure 7 is a first circuit structure diagram of a second single-phase uninterruptible power supply provided in an embodiment of the present application;

[0069] Figure 8 is a second circuit structure diagram of a second single-phase uninterruptible power supply provided in an embodiment of the present application;

[0070] Fig. 9 This is a circuit structure diagram of a first three-phase uninterruptible power supply provided in an embodiment of the present application;

[0071] Fig.10 It is a circuit structure diagram of a third single-phase uninterruptible power supply provided in an embodiment of the present application;

[0072] Fig.11 is a circuit structure diagram of a second three-phase uninterruptible power supply provided in an embodiment of the present application;

[0073] Fig.12 is a circuit structure diagram of a fourth single-phase uninterruptible power supply provided in an embodiment of the present application;

[0074] Fig.13 This is a schematic diagram of the operation of the first uninterruptible power supply provided by the embodiment of the present application through a PFC boost circuit;

[0075] Fig.14 This is a schematic diagram of the operation of the second uninterruptible power supply provided by the embodiment of the present application through the PFC boost circuit;

[0076] Fig.15 It is a schematic diagram of the operation of the uninterruptible power supply provided by an embodiment of the present application through a battery bidirectional circuit in a battery power supply mode. DETAILED DESCRIPTION

[0077] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.

[0078] It should be understood that when used in the present specification and the appended claims, the term "comprising" indicates the presence of described features, wholes, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or combinations thereof.

[0079] It should also be understood that the term “and / or” used in the specification and appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0080] In addition, in the description of the present application specification and the appended claims, the terms "first", "second", "third", etc. are only used to distinguish the descriptions and cannot be understood as indicating or implying relative importance.

[0081] References to "one embodiment" or "some embodiments" etc. described in the specification of this application mean that one or more embodiments of the present application include specific features, structures or characteristics described in conjunction with the embodiment. Therefore, the statements "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. that appear in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0082] In addition, the “plurality” mentioned in the embodiments of the present application should be interpreted as two or more.

[0083] The inventors have found that in the battery power supply mode, the UPS usually only uses the battery bidirectional circuit to supply power, and in the mains power supply mode, it usually uses the PFC boost circuit to supply power and uses the battery bidirectional circuit to charge the battery, which results in low utilization of the circuit in the UPS and high circuit cost. Therefore, it is necessary to consider an uninterruptible power supply.

[0084] In order to increase the reuse rate of circuits in UPS and reduce the size and cost, in the implementation mode of the present application, the battery pack and the PFC boost circuit are connected. In the battery power supply mode, the battery pack can be discharged to the DC bus through the PFC boost circuit, so that the PFC boost circuit can be used in the battery power supply mode and the AC power supply mode, thereby improving the utilization rate of the circuit and reducing the size and cost of the circuit.

[0085] In order to make the purpose, technical solutions and advantages of the present application clearer, specific embodiments will be described below in conjunction with the accompanying drawings.

[0086] Figure 1 A schematic diagram of the structure of an uninterruptible power supply with multiplexing of rectifier circuits provided in an embodiment of the present application, the uninterruptible power supply comprising:

[0087] The PFC boost circuit has an input end for connecting the mains input and the target polarity end of the battery pack. The polarity end of the battery pack includes a positive electrode BAT+ and a negative electrode BAT-, and the target polarity end can be the positive electrode BAT+ of the battery pack or the negative electrode BAT- of the battery pack.

[0088] Here, the PFC boost circuit can rectify and boost the AC power input from the mains, convert it into DC power, and input it into the DC bus; the PFC boost circuit can also boost the DC power input from the battery pack and discharge it to the positive bus or negative bus of the DC bus.

[0089] In addition, the battery pack can be a single battery pack or a double battery pack. The battery pack can be built into the UPS or placed outside the UPS.

[0090] A DC bus, whose input end is connected to the output end of the PFC boost circuit; wherein the DC bus includes a positive bus +BUS, a negative bus -BUS and a neutral line N; a positive capacitor C11 is connected between the positive bus +BUS and the neutral line N, and a negative capacitor C12 is connected between the neutral line N and the negative bus -BUS. Here, the "positive" and "negative" in the positive capacitor and the negative capacitor are only for the convenience of distinguishing the two capacitors, and are not a limitation on the capacitors.

[0091] The conversion circuit has an input end connected to the output end of the DC bus and an output end connected to the load. Here, the conversion circuit can be a direct current (DC)-to-DC conversion circuit or an inverter circuit. When the current required by the load is direct current, a DC-DC conversion circuit can be used to convert the direct current and provide it to the load; when the current required by the load is alternating current, an inverter circuit can be used to convert the direct current into alternating current and provide it to the load.

[0092] The battery bidirectional circuit has a first port D01 and a second port D02 on the battery side respectively used to connect the positive electrode BAT+ and the negative electrode BAT- of the battery pack, a third port D03 and a fourth port D04 on the bus side respectively used to connect the positive bus +BUS and the negative bus -BUS, and a fifth port D05 used to connect the neutral line N.

[0093] In this embodiment, in the AC power supply mode, the battery bidirectional circuit can charge the DC bus to the battery pack; in the battery power supply mode, the battery bidirectional circuit can discharge the electric energy of the battery pack to the DC bus.

[0094] The balancing bridge circuit is connected to the DC bus and is used to balance the voltage difference between the positive capacitor C11 and the negative capacitor C12, thereby realizing the power regulation between the positive bus +BUS and the negative bus -BUS, so that the DC bus meets the power needs of the load.

[0095] In the battery power supply mode, the battery pack connected to the target polarity terminal charges the positive capacitor C11 or the negative capacitor C12 through the PFC boost circuit.

[0096] Here, in the battery power supply mode, since the battery pack is connected to one polarity end of the DC bus through the PFC boost circuit, half of the boosted DC bus is charged to the positive capacitor C11 or the negative capacitor C12. Since the battery pack only boosts half of the DC bus through the PFC boost circuit, there will be an imbalance problem between the positive and negative buses in the DC bus, and accordingly, there is a voltage difference between the positive capacitor C11 and the negative capacitor C12. Therefore, by connecting the balancing bridge circuit to the DC bus, the balancing bridge circuit can be used to balance the positive capacitor C11 and the negative capacitor C12, thereby ensuring the normal and safe use of the UPS.

[0097] In addition, the battery pack can also be connected to the two polarity ends of the DC bus through the battery bidirectional circuit to boost the entire DC bus, that is, to charge the positive capacitor C11 and the negative capacitor C12. Here, the battery pack can be powered alternately through the PFC boost circuit and the battery bidirectional circuit, or can be powered simultaneously through the PFC boost circuit and the battery bidirectional circuit (such as when the battery pack is a dual battery pack).

[0098] In the embodiment of the present application, the battery pack is connected to the PFC boost circuit, and when there is a fault in the AC power input at the mains input end, that is, in the battery power supply mode, the electric energy of the battery pack can be discharged to the DC bus through the PFC boost circuit; the battery pack is also connected to the DC bus through the battery bidirectional circuit, and the electric energy in the battery pack is discharged to the DC bus through the battery bidirectional circuit, and the DC bus can be powered by the PFC boost circuit and the battery bidirectional circuit at the same time. That is, the DC bus can be powered by the PFC boost circuit and the battery bidirectional circuit at the same time, and the PFC boost circuit and the battery bidirectional circuit can be fully utilized in the mains power supply mode and the battery power supply mode to improve the reuse rate of the circuit; in addition, because when the battery pack is used for boosting, the PFC boost circuit is connected to one polarity end in the DC bus, and half of the DC bus is boosted, there is an imbalance problem between the two polarity ends in the DC bus, and the balancing bridge circuit is connected to the DC bus, and the voltage difference between the positive capacitor and the negative capacitor between the two polarity ends in the DC bus is balanced by the balancing bridge circuit.

[0099] The following is a specific description taking a dual battery pack as an example.

[0100] In some embodiments, the battery pack may be a dual battery pack, which includes a first battery pack and a second battery pack connected in series.

[0101] The positive electrode of the first battery group serves as the positive electrode BAT+ of the dual battery group; the negative electrode of the first battery group is connected to the positive electrode of the second battery group, serving as the neutral line of the dual battery group, and is used to connect the neutral line N and the fifth port D05 of the battery bidirectional circuit; the negative electrode of the second battery group serves as the negative electrode BAT- of the dual battery group. The neutral line of the dual battery group is directly connected to the neutral line N in the DC bus.

[0102] In battery-powered mode, see Figure 2 The structural schematic diagram of the uninterruptible power supply of the first dual battery pack is shown. When the target polarity end is the positive electrode BAT+ of the dual battery pack, the first battery pack corresponding to the positive electrode BAT+ of the dual battery pack can charge the positive capacitor C11 through the PFC boost circuit, and the dual battery pack can also charge the positive capacitor C11 and the negative capacitor C12 through the battery bidirectional circuit.

[0103] See also Figure 3 The structural schematic diagram of the uninterruptible power supply of the second dual battery pack is shown. When the target polarity end is the negative electrode BAT- of the dual battery pack, the second battery pack corresponding to the negative electrode BAT- of the dual battery pack can charge the negative capacitor C12 through the PFC boost circuit, and the dual battery pack can also charge the positive capacitor C11 and the negative capacitor C12 through the battery bidirectional circuit.

[0104] Here, in the battery power supply mode, when the DC bus is powered only by the battery bidirectional circuit, the power of the battery bidirectional circuit needs to meet the rated power of the UPS. The power of the electronic devices constituting the battery bidirectional circuit is relatively large, which is not conducive to reducing the volume and cost. Therefore, the dual battery pack can simultaneously power the DC bus through the PFC boost circuit and the battery bidirectional circuit to meet the rated power of the UPS, thereby reducing the power of the electronic devices selected in the battery bidirectional circuit, and then reducing the volume and cost of the circuit.

[0105] Optionally, the uninterruptible power supply of this embodiment further includes a first switch K1, a second switch K2, a third switch K3 and a controller.

[0106] The input end of the PFC boost circuit is connected to the mains input through the first switch K1, and is connected to the target polarity end of the dual battery pack through the second switch K2; the first port D01 of the bidirectional battery circuit is connected to the positive electrode BAT+ of the dual battery pack through the third switch K3.

[0107] The controller is used to:

[0108] When the AC power input from the mains is normal, the first switch is controlled to turn on K1, the second switch is turned off K2, and the third switch is turned on K3, and the mains power supply mode is entered. At this time, the AC power input from the mains is used to power the DC bus through the PFC boost circuit, that is, to charge the positive capacitor C11 and the negative capacitor C12, thereby realizing power supply for the load. At the same time, the battery bidirectional circuit is in a charging state, and the dual battery pack can also be charged through the battery bidirectional circuit.

[0109] When the AC power input from the mains fails, the first switch K1 is controlled to be disconnected, the second switch K2 is turned on, and the third switch K3 is turned on to enter the battery power supply mode; the battery power supply mode is: the battery pack connected to the target polarity end in the dual battery pack is controlled to charge the positive capacitor C11 or the negative capacitor C12 through the PFC boost circuit, the dual battery pack is controlled to charge the positive capacitor C11 and the negative capacitor C12 through the battery bidirectional circuit, the balancing bridge circuit is controlled to balance the voltage difference between the positive capacitor C11 and the negative capacitor C12, and the conversion circuit is controlled to convert the DC power and provide it to the load.

[0110] When the AC power input from the mains fails, the battery needs to be started to supply power to the load to maintain normal operation of the load. Therefore, the first switch K1 corresponding to the mains input can be disconnected, and the second switch K2 and the third switch K3 corresponding to the dual battery pack can be turned on.

[0111] Here, the controller may be physically multiple controllers, which respectively control different circuits in the uninterruptible power supply. For example, the uninterruptible power supply may include a first controller and a second controller, the first controller is used to control the PFC boost circuit and the battery bidirectional circuit, and the second controller is used to control the conversion circuit. Accordingly, the first controller may also control the first switch K1, the second switch K2, and the third switch K3. Specifically, one controller may be a control chip.

[0112] In addition, the inventor of the present application also found that since the battery pack connected to the target polarity end is discharged through the PFC boost circuit and the battery bidirectional circuit, while the other battery pack in the dual battery pack is discharged only through the battery bidirectional circuit, that is, the discharge speeds of the two battery packs in the dual battery pack are different, when the capacities of the two battery packs in the dual battery pack are the same, there will be a capacity difference between the two battery packs as the discharge time increases. Correspondingly, if there is a capacity difference between the two battery packs in the dual battery pack, the discharge speed of the battery pack with a higher capacity can be accelerated through the PFC boost circuit, thereby causing the capacities of the two battery packs in the dual battery pack to tend to balance, so as to fully utilize the capacities of the two battery packs in the dual battery pack.

[0113] That is, when the capacity difference between the two battery groups in the dual battery group is greater than the preset difference, and the capacity of the first battery group is greater than the capacity of the second battery group, the discharge speed of the first battery group needs to be accelerated, and the target polarity end can be the positive electrode BAT+ of the dual battery group, so that the first battery group can be discharged simultaneously through the PFC boost circuit and the battery bidirectional circuit.

[0114] When the capacity difference between the two battery groups in the dual battery group is greater than the preset difference, and the capacity of the first battery group is smaller than the capacity of the second battery group, the discharge speed of the second battery group needs to be accelerated, and the target polarity end can be the negative electrode BAT- of the dual battery group, so that the second battery group can be discharged simultaneously through the PFC boost circuit and the battery bidirectional circuit.

[0115] When the capacity difference between the two battery packs in the dual battery pack is less than or equal to the preset difference, it can be considered that the capacities of the two battery packs are the same. There is no need to speed up the discharge of one of the battery packs. The dual battery pack can be disconnected from the PFC boost circuit and the DC bus is powered only by the battery bidirectional circuit to ensure the balance between the two battery packs in the dual battery pack.

[0116] In other embodiments, see Figure 4 The structural schematic diagram of the third type of uninterruptible power supply with dual battery packs is shown, the battery pack is a dual battery pack, the dual battery pack includes two battery packs with different capacities connected in series, and the target polarity end includes the positive electrode BAT+ and the negative electrode BAT- of the dual battery pack.

[0117] The uninterruptible power supply also includes a second switch K2 and a fourth switch K4; the input end of the PFC boost circuit is connected to the positive electrode BAT+ of the dual battery pack through the second switch K2, and is connected to the negative electrode BAT- of the dual battery pack through the fourth switch K4.

[0118] In the battery power supply mode, the dual battery pack charges the positive capacitor C11 and the negative capacitor C12 through the battery bidirectional circuit, and the battery pack with higher capacity in the dual battery pack charges the positive capacitor C11 or the negative capacitor C12 through the PFC boost circuit.

[0119] In this embodiment, the positive electrode BAT+ and the negative electrode BAT- of the dual battery pack are respectively connected to the PFC boost circuit through switches. By controlling the switch corresponding to the battery pack with higher capacity in the dual battery pack to be turned on, the positive electrode BAT+ or the negative electrode BAT- of the dual battery pack can be connected to the input end of the PFC boost circuit.

[0120] Here, the UPS can be controlled by the controller to switch the working mode.

[0121] Specifically, the controller can be used to:

[0122] When the AC power input from the mains fails, the first switch K1 is controlled to be disconnected and the third switch K3 is turned on, entering the battery power supply mode. When the first switch K1 is turned on, the input end of the PFC boost circuit is disconnected from the mains input; when the third switch K3 is turned on, the dual battery pack is connected to the battery bidirectional circuit, and the dual battery pack can be discharged to the DC bus through the battery bidirectional circuit.

[0123] The battery power supply mode is specifically as follows: controlling the electric energy stored in the dual battery pack to be input into the battery bidirectional circuit, and controlling the battery bidirectional circuit to discharge the electric energy input by the dual battery pack to the DC bus; controlling the balancing bridge circuit to balance the voltage difference between the positive capacitor C11 and the negative capacitor C12, and controlling the conversion circuit to convert the DC power and provide it to the load.

[0124] And, the controller can determine whether the capacities of the two battery packs in the dual battery pack are the same, and determine the battery pack with higher capacity in the dual battery pack.

[0125] If the capacities of the two battery packs are different, and the battery pack with higher capacity in the dual battery pack is the battery pack corresponding to the positive electrode BAT+ of the dual battery pack, the second switch K2 is controlled to be turned on, and the fourth switch K4 is turned off.

[0126] If the capacities of the two battery packs are different, and the battery pack with higher capacity in the dual battery pack is the battery pack corresponding to the negative electrode BAT- of the dual battery pack, the second switch K2 is controlled to be disconnected, and the fourth switch K4 is controlled to be turned on.

[0127] In the battery power supply mode, the controller can be used to detect and judge the two battery packs in the dual battery pack, determine the battery pack with higher capacity in the dual battery pack, and determine whether the battery pack with higher capacity needs to be discharged faster.

[0128] In the above process, "controlling the electric energy stored in the dual battery pack to be input into the battery bidirectional circuit, and controlling the battery bidirectional circuit to discharge the electric energy input by the dual battery pack to the DC bus", and "determining whether the capacities of the two battery packs in the dual battery pack are the same, and determining the battery pack with higher capacity in the dual battery pack" can be carried out simultaneously or in steps.

[0129] Specifically, judging whether the capacities of the two battery packs in the dual battery pack are the same may be judging whether the capacity difference of the two battery packs in the dual battery pack is greater than a preset difference. If the capacity difference of the two battery packs in the dual battery pack is greater than the preset difference, it is considered that the capacities of the two battery packs are different. If the capacity difference of the two battery packs in the dual battery pack is less than or equal to the preset difference, it is considered that the capacities of the two battery packs are the same.

[0130] The above mainly introduces the battery power supply mode of UPS, and the following will continue to introduce the AC power supply mode.

[0131] In some embodiments, the controller is further used to: when the AC power input from the mains is normal, control the first switch K1 to be turned on, the second switch K2 to be turned off, the third switch K3 to be turned on, and the fourth switch K4 to be turned off, to enter the mains power supply mode.

[0132] The second switch K2 is disconnected and the fourth switch K4 is disconnected, so that the dual battery pack is disconnected from the PFC boost circuit. The first switch K1 is turned on, so that the AC power input from the mains is input to the DC bus through the PFC boost circuit, so that the load is powered by the mains input. The third switch K3 is turned on, and the dual battery pack can be charged through the battery bidirectional circuit to ensure that the UPS works in the battery power supply mode.

[0133] In addition, the working mode of the UPS also includes a bypass mode. In some embodiments, the uninterruptible power supply also includes a bypass and a fifth switch K5; the input end of the bypass is used to connect to the mains input, and the output end of the bypass is connected to the first end of the fifth switch K5; the second end of the fifth switch K5 is connected to the output end of the conversion circuit, and the third end of the fifth switch K5 is used to connect to the load.

[0134] By controlling the fifth switch K5, when bypass operation is required, the first end of the fifth switch K5 can be controlled to be turned on to turn on the bypass, and the AC power input from the mains can be directly provided to the load through the bypass; when the UPS is used normally, the second end of the fifth switch K5 can be controlled to be turned on to turn off the bypass.

[0135] The above article introduces the overall structure and working mode of UPS. The following article will continue to introduce the PFC boost circuit, battery bidirectional circuit, balance bridge circuit and conversion circuit in UPS respectively.

[0136] In some embodiments, see Figure 5A The structural schematic diagram of the first battery bidirectional circuit is shown, and the battery bidirectional circuit includes a first inductor L1, a second inductor L2, a first switch tube Q1, a second switch tube Q2, a third switch tube Q3 and a fourth switch tube Q4.

[0137] The first end of the first inductor L1 serves as the first port D01 of the battery bidirectional circuit, and is used to connect the positive electrode BAT+ of the dual battery pack; the second end of the first inductor L1 is respectively connected to the emitter of the first switch tube Q1 and the collector of the second switch tube Q2; the collector of the first switch tube Q1 serves as the third port D03 of the battery bidirectional circuit, and is used to connect the positive bus +BUS;

[0138] The emitter of the second switch tube Q2 is connected to the collector of the third switch tube Q3, and the emitter of the second switch tube Q2 serves as the fifth port D05 of the battery bidirectional circuit, which is used to connect the neutral line of the dual battery pack and the neutral line N in the DC bus (it can be seen that the fifth port D05 of the battery bidirectional circuit has two interfaces, and the neutral line of the dual battery pack and the neutral line N in the DC bus are connected).

[0139] The first end of the second inductor L2 serves as the second port D02 of the battery bidirectional circuit, and is used to connect the negative electrode BAT- of the dual battery pack; the second end of the second inductor L2 is respectively connected to the emitter of the third switch tube Q3 and the collector of the fourth switch tube Q4; the emitter of the fourth switch tube Q4 serves as the fourth port D04 of the battery bidirectional circuit, and is used to connect the negative bus -BUS.

[0140] Optional, see Figure 5B The schematic diagram of the structure of the second battery bidirectional circuit shown in FIG. 1 includes a first inductor L1, a second inductor L2, a first switch tube Q1, a second switch tube Q2, a third switch tube Q3 and a fourth switch tube Q4. The structure of the battery bidirectional circuit can also be as follows:

[0141] The collector of the first switch tube Q1 serves as the first port D01 of the battery bidirectional circuit, which is used to connect the positive electrode BAT+ of the dual battery pack; the emitter of the first switch tube Q1 is connected to the first end of the first inductor L1 and the collector of the second switch tube Q2; the emitter of the second switch tube Q2 serves as the fourth port D04 of the battery bidirectional circuit, which is used to connect the negative bus -BUS.

[0142] The second end of the first inductor L1 is connected to the first end of the second inductor L2, and the connection point thereof serves as the fifth port D05 of the battery bidirectional circuit, which is used to connect the neutral line of the dual battery pack and the neutral line N in the DC bus (it can be seen that the fifth port D05 of the battery bidirectional circuit has two interfaces, and the neutral line of the dual battery pack and the neutral line N in the DC bus are connected).

[0143] The emitter of the third switch tube Q3 serves as the second port D02 of the battery bidirectional circuit, and is used to connect the negative electrode BAT- of the dual battery pack; the collector of the third switch tube Q3 is connected to the second end of the second inductor L2 and the emitter of the fourth switch tube Q4; the collector of the fourth switch tube Q4 serves as the third port D03 of the battery bidirectional circuit, and is used to connect the positive bus +BUS.

[0144] In this embodiment, the first inductor L1, the first switch tube Q1 and the second switch tube Q2 constitute a first circuit, and the first battery group corresponding to the positive electrode BAT+ of the dual battery group can charge the negative capacitor C12 through the first circuit; the second inductor L2, the third switch tube Q3 and the fourth switch tube Q4 constitute a second circuit, and the second battery group corresponding to the negative electrode BAT- of the dual battery group can charge the positive capacitor C11 through the second circuit.

[0145] Both of the above-mentioned circuits are circuits that can be stepped up or down. For example, when the voltage of the first battery group is greater than the voltage of the negative capacitor C12, in the battery power supply mode, the first battery group can step down the voltage through the first circuit to charge the negative capacitor C12. In the AC power supply mode, the negative capacitor C12 can step up the voltage through the first circuit to charge the first battery group.

[0146] Correspondingly, when the voltage of the second battery pack is greater than the voltage of the positive capacitor C11, in the battery power supply mode, the second battery pack can be stepped down through the second circuit to charge the positive capacitor C11, and in the AC power supply mode, the positive capacitor C11 can be stepped up through the second circuit to charge the second battery pack.

[0147] The above describes two battery bidirectional circuits that can be used when the battery pack is a double battery pack. When the battery pack is a single battery pack, the above two battery bidirectional circuits can still be used. It should be noted that the fifth port D05 in the battery bidirectional circuit is only connected to the neutral line N in the DC bus.

[0148] In other embodiments, see Figure 5C As shown in the structural schematic diagram of the third battery bidirectional circuit, when the battery pack is a single battery pack (wherein the dual battery pack can also be regarded as a special single battery pack), the battery bidirectional circuit includes a first inductor L1, a second inductor L2, a first switch tube Q1, a second switch tube Q2, a third switch tube Q3 and a fourth switch tube Q4.

[0149] The first end of the first inductor L1 and the first end of the third switch tube Q3 serve as a first port D01 of the battery bidirectional circuit, and are used to connect to the positive electrode BAT+ of the battery pack.

[0150] The second end of the first inductor L1 is connected to the first end of the first switch tube Q1 and the first end of the second switch tube Q2 respectively.

[0151] The second end of the first switch tube Q1 is connected to the first end of the second inductor L2, and the connection point serves as the second port D02 and the fifth port D05 of the battery bidirectional circuit. The second port D02 is used to connect the negative electrode BAT- of the battery pack, and the fifth port D05 is used to connect the neutral line N (it can be seen that the second port D02 and the fifth port D05 of the battery bidirectional circuit are directly connected).

[0152] The second end of the second switch tube Q2 serves as the third port D03 of the battery bidirectional circuit, and is used to connect the positive bus +BUS; the second end of the second inductor L2 is respectively connected to the second end of the third switch tube Q3 and the first end of the fourth switch tube Q4; the second end of the fourth switch tube Q4 serves as the fourth port D04 of the battery bidirectional circuit, and is used to connect the negative bus -BUS.

[0153] In this embodiment, see Figure 6 In the circuit structure diagram of the first single-phase uninterruptible power supply shown in the figure, the first inductor L1, the first switch tube Q1 and the second switch tube Q2 in the battery bidirectional circuit form a first circuit, and the battery pack can charge the positive capacitor C11 through the first circuit; the second inductor L2, the third switch tube Q3 and the fourth switch tube Q4 form a second circuit, and the battery pack can charge the negative capacitor C12 through the second circuit. Thus, the battery pack can supply power to the entire DC bus through the battery bidirectional circuit.

[0154] Among them, the second circuit is a circuit that can be stepped up or down. When the voltage of the battery pack is greater than the voltage of the negative capacitor C12, in the battery power supply mode, the battery pack can step down the voltage through the second circuit to charge the negative capacitor C12. In the AC power supply mode, the negative capacitor C12 can step up the voltage through the second circuit to charge the battery pack.

[0155] Correspondingly, the first port D01 can be connected to the negative electrode BAT- of the battery pack, the second port D02 can be connected to the positive electrode BAT+ of the battery pack, the third port can be connected to the negative bus -BUS, and the fourth port can be connected to the positive bus +BUS. At this time, the second circuit that can be stepped up and down is connected to the positive capacitor C11. When the voltage of the battery pack is greater than the voltage of the positive capacitor C11, in the battery power supply mode, the battery pack can be stepped down through the second circuit to charge the positive capacitor C11. In the mains power supply mode, the positive capacitor C11 can be stepped up through the second circuit to charge the battery pack.

[0156] In addition, the battery pack can power the positive capacitor C11 through the first circuit of the battery bidirectional circuit, and power the negative capacitor C12 through the second circuit. Therefore, the battery pack only needs to meet half of the DC bus through the battery bidirectional circuit, and there is no need for the battery pack to meet the entire DC bus. The voltage stress in the battery bidirectional circuit can be reduced, the power and specifications of each device in the first circuit and the second circuit can be reduced, and the volume of the battery bidirectional circuit can be reduced.

[0157] So far, various specific structures of the battery bidirectional circuit have been introduced. When the battery bidirectional circuit realizes charging and discharging of the battery pack, it can also play the role of balancing the DC bus in the mains power supply mode, thereby saving the setting of the balancing bridge in the mains power supply mode. The details are as follows (wherein the battery pack can be a single battery pack or a double battery pack):

[0158] In the AC power supply mode, when there is a voltage difference between the positive capacitor C11 and the negative capacitor C12 in the DC bus, the capacitor with a higher voltage among the positive capacitor C11 and the negative capacitor C12 can be used to charge the battery pack, so that the capacitor with a higher voltage among the positive capacitor C11 and the negative capacitor C12 is discharged more, thereby making the positive capacitor C11 and the negative capacitor C12 tend to be balanced.

[0159] The positive capacitor C11 and the negative capacitor C12 can also be used to charge the battery pack, wherein in a charging cycle, the first charging energy is greater than the second charging energy, the first charging energy is the energy used by the capacitor with a higher voltage between the positive capacitor C11 and the negative capacitor C12 to charge the battery pack, and the second charging energy is the energy used by the capacitor with a lower voltage between the positive capacitor C11 and the negative capacitor C12 to charge the battery pack.

[0160] Furthermore, this can be achieved by controlling the on and off of the switch tube in the battery bidirectional circuit. Figure 5A For example, see the battery bidirectional circuit in Figure 7 In the first circuit structure diagram of the second single-phase uninterruptible power supply shown in the figure, when there is a voltage difference between the positive capacitor C11 and the negative capacitor C12, the two switch tubes of the circuit connected to the capacitor with a higher voltage in the battery bidirectional circuit are controlled to be alternately turned on, and the main switch tube of the circuit connected to the capacitor with a lower voltage in the battery bidirectional circuit is controlled to be turned off, so that the capacitor with a higher voltage among the positive capacitor C11 and the negative capacitor C12 charges the battery pack; the main switch tube of the first circuit is the first switch tube Q1, and the main switch tube of the second circuit is the fourth switch tube Q4.

[0161] For example, when the voltage of the positive capacitor C11 is greater than the voltage of the negative capacitor C12, the first switch tube Q1 and the second switch tube Q2 of the first circuit in the battery bidirectional circuit are controlled to be alternately turned on, and the fourth switch tube Q4 in the second circuit is controlled to be turned off.

[0162] When there is a voltage difference between the positive capacitor C11 and the negative capacitor C12, the first switch tube Q1 and the second switch tube Q2 can be controlled to be alternately turned on, and the third switch tube Q3 and the fourth switch tube Q4 can be controlled to be alternately turned on, wherein the first charging energy is greater than the second charging energy.

[0163] For example, when the voltage of the positive capacitor C11 is greater than the voltage of the negative capacitor C12, the first switch tube Q1 and the second switch tube Q2 of the first circuit in the battery bidirectional circuit are controlled to be alternately turned on, and the third switch tube Q3 and the fourth switch tube Q4 in the second circuit are controlled to be alternately turned on; and the first charging energy of the positive capacitor C11 to charge the battery pack through the alternating conduction of the first switch tube Q1 and the second switch tube Q2 is greater than the second charging energy of the negative capacitor C12 to charge the battery pack through the alternating conduction of the third switch tube Q3 and the fourth switch tube Q4.

[0164] In addition, the battery bidirectional circuit may further include a first Hall device HALL1 and a second Hall device HALL2. Figure 7 As shown, the first Hall device HALL1 is connected between the first port D01 and the first inductor L1 , and the second Hall device HALL2 is connected between the second port D02 and the second inductor L2 .

[0165] The above article introduces the battery bidirectional circuit. The following will continue to explain the specific structure of the PFC boost circuit.

[0166] In some embodiments, see Figure 7 In the first circuit structure diagram of the second single-phase uninterruptible power supply shown in the figure, the PFC boost circuit includes a third inductor L3, a first diode D1, a second diode D2, a fifth switch tube Q5 and a sixth switch tube Q6; the first end of the third inductor L3 serves as the input end of the PFC boost circuit; the second end of the third inductor L3 is respectively connected to the anode of the first diode D1, the cathode of the second diode D2 and the collector of the fifth switch tube; the cathode of the first diode D1 is used to connect to the positive bus +BUS; the anode of the second diode D2 is used to connect to the negative bus -BUS; the emitter of the fifth switch tube Q5 is connected to the emitter of the sixth switch tube, and the collector of the sixth switch tube Q6 is used to connect to the neutral line N.

[0167] Here, if Figure 8 As shown, the PFC boost circuit further includes a first current transformer CT1, a first end of the first current transformer CT1 serves as an input end of the PFC boost circuit, and a second end of the first current transformer CT1 is connected to a first end of the second inductor L2.

[0168] In addition, if Figure 7As shown, the third switch K3 may include a first relay RLY1, a second relay RLY2 and a first resistor R1; the second relay RLY2 is connected in series with the first resistor R1 and then connected in parallel with the first relay RLY1, which can reduce the starting current and loss.

[0169] Correspondingly, the fourth switch K4 includes a third relay RLY3, a fourth relay RLY4 and a second resistor R2; the fourth relay RLY4 is connected in series with the second resistor R2 and then connected in parallel with the third relay RLY3.

[0170] In the mains power supply mode, the AC power input by the mains can be three-phase AC power.

[0171] Optional, see Fig. 9 The circuit structure diagram of the first three-phase uninterruptible power supply shown in the figure, when the mains input is three-phase alternating current, the uninterruptible power supply includes three first switches K1, three second switches K2 and three PFC boost circuits, and each phase of the three-phase alternating current corresponds to a first switch, a second switch and a PFC boost circuit;

[0172] For each phase, the first end of the corresponding first switch K1 is used to connect the alternating current of the phase, and the second end of the corresponding first switch K1 is connected to the input end of the PFC boost circuit of the phase; an input end of the corresponding PFC boost circuit is also connected to the second end of the second switch K2 of the phase, and the output end of the corresponding PFC boost circuit is connected to the bus.

[0173] The first end of each second switch K2 is used to connect to the target polarity end of the battery pack (the positive electrode BAT+ or the negative electrode BAT− of the battery pack).

[0174] Correspondingly, when the PFC boost circuit is connected to two polarity ends of the battery pack respectively, when the mains input is three-phase AC power, three fourth switches K4 can be correspondingly provided, and each phase of AC power corresponds to one fourth switch K4.

[0175] For each phase, the first end of the corresponding second switch K2 is used to connect the positive electrode BAT+ of the battery pack, and the second end of the second switch K2 is connected to an input end of the corresponding PFC boost circuit; the first end of the corresponding fourth switch K4 is used to connect the negative electrode BAT- of the battery pack, and the second end of the fourth switch K4 is connected to an input end of the corresponding PFC boost circuit.

[0176] In this embodiment, in the mains power supply mode, each PFC boost circuit converts the corresponding one-phase AC power received into DC power and inputs the DC power into the DC bus.

[0177] Since a second switch K2 and a fourth switch K4 are respectively provided for each phase, in the battery power supply mode, the battery pack can be respectively connected to the PFC boost circuit of each phase through three second switches K2 or three fourth switches K4, and the three-phase PFC boost circuit can be used for power conversion at the same time. Thus, in the battery power supply mode, the battery pack can be discharged through the three-phase PFC boost circuit and the battery bidirectional circuit, thereby realizing four-way parallel discharge of the battery.

[0178] In other embodiments, see Fig.10 The circuit structure diagram of the third single-phase uninterruptible power supply, the first switch K1 includes a first thyristor SCR1 and a second thyristor SCR2, the second switch K2 includes a third thyristor SCR3. The PFC boost circuit includes a third inductor L3, a fourth inductor L4, a first diode D1, a second diode D2, a fifth switch tube Q5 and a sixth switch tube Q6.

[0179] The anode of the first thyristor SCR1 is connected to the cathode of the second thyristor SCR2 and serves as the first end of the first switch K1; the cathode of the first thyristor SCR1 serves as the first port of the second end of the first switch K1 and is connected to the first end of the third inductor L3; the anode of the second thyristor SCR2 serves as the second port of the second end of the first switch K1 and is connected to the first end of the fourth inductor L4.

[0180] Here, when the gate of the first thyristor SCR1 is subjected to a forward voltage, when the anode potential of the first thyristor SCR1 is higher than the cathode potential, the first thyristor SCR1 is turned on and can transmit current; when the cathode potential of the first thyristor SCR1 is higher than the anode potential, the first thyristor SCR1 is reversely blocked and cannot transmit current. That is, when the AC power input from the mains is a positive half-wave, it can be input into the PFC boost circuit through the first thyristor SCR1.

[0181] Correspondingly, when the gate of the second thyristor SCR2 is subjected to a forward voltage, when the anode potential of the second thyristor SCR2 is higher than the cathode potential, the second thyristor SCR2 is turned on and can transmit current; when the cathode potential of the second thyristor SCR2 is higher than the anode potential, the second thyristor SCR2 is reversely blocked and cannot transmit current. That is, when the AC input of the mains is a negative half-wave, the second thyristor SCR2 is turned on, and the PFC boost circuit is connected to the mains input.

[0182] In the PFC boost circuit, the second end of the third inductor L3 is respectively connected to the anode of the first diode D1 and the collector of the fifth switch tube Q5; the cathode of the first diode D1 is connected to the positive bus +BUS; the emitter of the fifth switch tube Q5 is used to connect to the neutral line N; the second end of the fourth inductor L4 is respectively connected to the emitter of the sixth switch tube Q6 and the cathode of the second diode D2; the anode of the second diode D2 is connected to the negative bus -BUS; the collector of the sixth switch tube Q6 is used to connect to the neutral line N.

[0183] In the second switch K2, when the target polarity end is the positive electrode BAT+ of the battery pack, the anode of the third thyristor SCR3 serves as the first end of the second switch K2, and the cathode of the third thyristor SCR3 is connected to the first end of the third inductor L3. When the gate of the third thyristor SCR3 is subjected to a forward voltage, the battery pack is discharged, the anode potential of the third thyristor SCR3 is higher than the cathode potential, the third thyristor SCR3 is turned on, and the battery pack is connected to the PFC boost circuit.

[0184] When the target polarity end is the negative electrode BAT- of the battery pack, the cathode of the third thyristor SCR3 serves as the first end of the second switch K2, and the anode of the third thyristor SCR3 is connected to the first end of the fourth inductor L4. When the gate of the third thyristor SCR3 is subjected to a forward voltage, the battery pack is discharged, the anode potential of the third thyristor SCR3 is higher than the cathode potential, the third thyristor SCR3 is turned on, and the battery pack is connected to the PFC boost circuit.

[0185] In addition, when the second switch K2 and the fourth switch K4 are provided at the same time, the second switch K2 includes a third thyristor SCR3, and the fourth switch K4 includes a fourth thyristor SCR4. The anode of the third thyristor SCR3 serves as the first end of the second switch K2, and the cathode of the third thyristor SCR3 is connected to the first end of the third inductor L3; the cathode of the fourth thyristor SCR4 serves as the first end of the second switch K2, and the anode of the fourth thyristor SCR4 is connected to the first end of the fourth inductor L4.

[0186] Here, the PFC boost circuit also includes a first current transformer CT1 and a second current transformer CT2, the first end of the first current transformer CT1 serves as an input end of the PFC boost circuit, and the second end of the first current transformer CT1 is connected to the first end of the third inductor L3; the first end of the second current transformer CT2 serves as an input end of the PFC boost circuit, and the second end of the second current transformer CT2 is connected to the first end of the fourth inductor L4.

[0187] Optional, see Fig.11 As shown in the circuit structure diagram of the second three-phase uninterruptible power supply, when the mains input is three-phase alternating current, the uninterruptible power supply includes three first switches K1, and each phase of the three-phase alternating current corresponds to a first switch K1.

[0188] For each phase, the first end of the corresponding first switch K1 is used to connect the alternating current of the phase, the first port of the second end of the corresponding first switch K1 is connected to the first end of the third inductor L3, and the second port of the second end of the corresponding first switch K1 is connected to the first end of the fourth inductor L4.

[0189] In this embodiment, in the mains power supply mode, each phase of AC power is input into the PFC boost circuit through the corresponding first switch K1 , and the PFC boost circuit converts the received three-phase AC power into DC power and inputs it into the DC bus.

[0190] Here, by setting three first switches K1, the three-phase AC power can be input into one PFC boost circuit, without setting three PFC boost circuits, which can reduce the components of the PFC boost circuit, reduce the circuit volume, and reduce the cost.

[0191] The above embodiments introduce the specific structures of two PFC boost circuits. The specific structures of the balanced bridge circuit and the conversion circuit will be further introduced below.

[0192] In some embodiments, Figure 6-Figure 11 As shown, the balanced bridge circuit includes a fifth inductor L5, a seventh switch tube Q7 and an eighth switch tube Q8; the first end of the fifth inductor L5 is used to connect to the neutral line N, and the second end of the fifth inductor L5 is respectively connected to the emitter of the seventh switch tube Q7 and the collector of the eighth switch tube; the collector of the seventh switch tube Q7 is used to connect to the positive bus +BUS; the emitter of the eighth switch tube Q8 is used to connect to the negative bus -BUS.

[0193] In this embodiment, the positive capacitor C11 stores the electric energy between the positive bus +BUS and the neutral line N, and the negative capacitor C12 stores the electric energy between the negative bus -BUS and the neutral line N. In the battery power supply mode, the battery pack with higher capacity in the dual battery pack is connected to the PFC boost circuit, the PFC boost circuit reuses the positive bus +BUS or the negative bus -BUS, the battery bidirectional circuit boosts the positive bus +BUS and the negative bus -BUS, the positive capacitor C11 and the negative capacitor C12 store different electric energies, therefore, it is necessary to use a balanced bridge circuit to transfer the electric energy of the capacitor with higher electric energy to the capacitor with lower electric energy, so that the electric energy stored in the positive capacitor C11 and the negative capacitor C12 are equal, and the voltage difference between the positive capacitor C11 and the negative capacitor C12 is balanced.

[0194] In actual use, the conversion circuit converts the electric energy stored in the positive capacitor C11 and the negative capacitor C12 into the direct current or alternating current required by the load. When the load adopts alternating current, the conversion circuit is an inverter circuit, which can convert the electric energy stored in the positive capacitor C11 into the positive half-wave of the output alternating current, and convert the electric energy stored in the negative capacitor C12 into the negative half-wave of the output alternating current.

[0195] In some embodiments, Figure 6-Figure 11 As shown, when the conversion circuit is an inverter circuit, an I-type inverter circuit can be used. The inverter circuit includes a third diode D3, a fourth diode D4, a first inverter switch tube Q91, a second inverter switch tube Q92, a third inverter switch tube Q93 and a fourth inverter switch tube Q94.

[0196] The anode of the third diode D3 is connected to the neutral line N, and the cathode of the third diode D3 is connected to the emitter of the first inverter switch tube Q91 and the collector of the second inverter switch tube Q92; the collector of the first inverter switch tube Q91 is connected to the positive bus +BUS, and the emitter of the second inverter switch tube Q92 serves as the output end of the inverter circuit.

[0197] The cathode of the fourth diode D4 is connected to the neutral line N, and the anode of the fourth diode D4 is connected to the emitter of the third inverter switch tube Q93 and the collector of the fourth inverter switch tube Q94; the collector of the third inverter switch tube Q93 serves as the output end of the inverter circuit, and the emitter of the fourth inverter switch tube Q94 is connected to the negative bus -BUS.

[0198] Optionally, the output end of the inverter circuit may be connected to a load via a sixth inductor L6.

[0199] Two current transformers may also be connected between the sixth inductor L6 and the load, such as the fourth current transformer CT4 and the fifth current transformer CT5 in the figure.

[0200] In addition, a fifth capacitor C5 may be connected between the live wire and the neutral wire of the output AC power to filter out high-frequency signals in the output AC power and prevent high-frequency interference from leaking from the output AC power and interfering with the load.

[0201] See also Fig.12 The circuit structure diagram of the fourth single-phase uninterruptible power supply is shown. In some embodiments, a common mode inductor can also be set in the uninterruptible power supply. The uninterruptible power supply also includes a first common mode inductor Lc1, a second common mode inductor Lc2 and a third common mode inductor Lc3. The AC power input from the mains is connected to the PFC boost circuit through the first common mode inductor Lc1; the dual battery pack is connected to one input end of the PFC boost circuit through the second common mode inductor Lc2, and the dual battery pack is connected to the battery bidirectional circuit through the second common mode inductor Lc2; the conversion circuit supplies power to the load through the third common mode inductor Lc3.

[0202] The above describes the working mode and specific structure of a rectifier circuit multiplexing uninterruptible power supply provided by the present application, see Figure 7 and Figure 8 The uninterruptible power supply shown in the figure takes the case of dual battery packs as an example to introduce the working process of the uninterruptible power supply in battery power supply mode.

[0203] For the convenience of description, the battery group corresponding to the positive electrode BAT+ of the dual battery group is referred to as the first battery group, and the battery group corresponding to the negative electrode BAT- of the dual battery group is referred to as the second battery group.

[0204] When the mains input fails, the uninterruptible power supply is in battery power mode. Figure 7 For example, the positive electrode BAT+ of the dual battery pack is used as the target polarity end, and the positive electrode BAT+ of the dual battery pack is connected to the input end of the PFC boost circuit through the second switch L2. Fig.13 The working schematic diagram of the first uninterruptible power supply powered by the PFC boost circuit is shown, the first switch K1 is disconnected, the second switch K2 is turned on, when the fifth switch tube Q5 is turned off, the current passes through the A path; when the fifth switch tube Q5 is turned on, the current passes through the B path.

[0205] Accordingly, Figure 8 For example, the negative electrode BAT- of the dual battery pack is used as the target polarity terminal, and the negative electrode BAT- of the dual battery pack is connected to the input terminal of the PFC boost circuit through the second switch L2. Fig.14 The working schematic diagram of the second uninterruptible power supply powered by the PFC boost circuit is shown, the first switch K1 is disconnected, the second switch K2 is turned on, when the sixth switch tube Q6 is turned on, the current passes through the A path; when the sixth switch tube Q6 is turned off, the current passes through the B path.

[0206] Also, see Fig.15 The uninterruptible power supply shown in the figure works in the battery power supply mode through the battery bidirectional circuit. The battery bidirectional circuit switches from the charging state to the discharging state, and discharges the electric energy stored in the dual battery pack to the DC bus. When the second switch tube Q2 and the third switch tube Q3 are turned on, the dual battery pack can charge the first inductor L1 and the second inductor L2. Fig.15 When the second switch tube Q2 and the third switch tube Q3 are turned off, the dual battery pack charges the positive capacitor C11 and the negative capacitor C12 through the battery bidirectional circuit, such as Fig.15 The A path in .

[0207] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0208] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0209] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0210] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. An uninterruptible power supply with multiplexed rectifier circuits, characterized in that: include: A PFC boost circuit, whose input terminal is used to connect the mains input and the target polarity terminal of the battery pack; A DC bus, whose input end is connected to the output end of the PFC boost circuit; wherein the DC bus includes a positive bus, a negative bus and a neutral line; a positive capacitor is connected between the positive bus and the neutral line, and a negative capacitor is connected between the neutral line and the negative bus; A conversion circuit, whose input end is connected to the output end of the DC bus, and whose output end is used to connect to a load; A battery bidirectional circuit, wherein the first port and the second port corresponding to the battery side are respectively used to connect the positive electrode and the negative electrode of the battery pack, the third port and the fourth port corresponding to the bus side are respectively used to connect the positive bus and the negative bus, and the fifth port is used to connect the neutral line; A balancing bridge circuit, connected to the DC bus, for balancing the voltage difference between the positive capacitor and the negative capacitor; In the battery power supply mode, the battery pack connected to the target polarity terminal charges the positive capacitor or the negative capacitor through a PFC boost circuit.

2. The uninterruptible power supply with multiplexed rectifier circuit according to claim 1, characterized in that: The battery pack is a dual battery pack, and the dual battery pack includes a first battery pack and a second battery pack connected in series; The positive electrode of the first battery group serves as the positive electrode of the dual battery group; The negative electrode of the first battery group is connected to the positive electrode of the second battery group, serving as the neutral line of the dual battery group, and is used to connect the neutral line and the fifth port of the battery bidirectional circuit; The negative electrode of the second battery group serves as the negative electrode of the dual battery group; In the battery power supply mode, when the target polarity end is the positive electrode of the dual battery pack, the first battery pack charges the positive capacitor through the PFC boost circuit, and the dual battery pack also charges the positive capacitor and the negative capacitor through the battery bidirectional circuit; When the target polarity end is the negative electrode of the dual battery group, the second battery group charges the negative capacitor through the PFC boost circuit, and the dual battery group also charges the positive capacitor and the negative capacitor through the battery bidirectional circuit.

3. The uninterruptible power supply with multiplexed rectifier circuit according to claim 2, characterized in that: The uninterruptible power supply also includes a first switch, a second switch, a third switch and a controller; The input end of the PFC boost circuit is connected to the mains input through the first switch, and is connected to the target polarity end of the dual battery pack through the second switch; The first port of the bidirectional battery circuit is connected to the positive electrode of the dual battery pack through the third switch; The controller is used to: When the AC power input from the mains is normal, controlling the first switch to be turned on, the second switch to be turned off, and the third switch to be turned on, so as to enter the mains power supply mode; When the AC power input from the mains fails, the first switch is controlled to be disconnected, the second switch is controlled to be turned on, and the third switch is controlled to be turned on, and the battery power supply mode is entered; the battery power supply mode is: the battery group connected to the target polarity end in the dual battery group is controlled to charge the positive capacitor or the negative capacitor through the PFC boost circuit, the dual battery group is controlled to charge the positive capacitor and the negative capacitor through the battery bidirectional circuit, the balancing bridge circuit is controlled to balance the voltage difference between the positive capacitor and the negative capacitor, and the conversion circuit is controlled to convert the DC power and provide it to the load.

4. The uninterruptible power supply with multiplexed rectifier circuit according to claim 2, characterized in that: When the capacity difference between the two battery groups in the dual battery group is greater than a preset difference, and the capacity of the first battery group is greater than the capacity of the second battery group, the target polarity end is the positive electrode of the dual battery group; When the capacity difference between the two battery groups in the dual battery group is greater than a preset difference, and the capacity of the first battery group is less than the capacity of the second battery group, the target polarity end is the negative electrode of the dual battery group.

5. The uninterruptible power supply with multiplexed rectifier circuit according to claim 1, characterized in that: The battery pack is a dual battery pack, the dual battery pack includes two battery packs with different capacities connected in series, and the target polarity end includes a positive electrode and a negative electrode of the dual battery pack; The uninterruptible power supply also includes a second switch and a fourth switch; The input end of the PFC boost circuit is connected to the positive electrode of the dual battery pack through the second switch, and is connected to the negative electrode of the dual battery pack through the fourth switch; In the battery power supply mode, the dual battery pack charges the positive capacitor and the negative capacitor through a battery bidirectional circuit, and the battery pack with higher capacity in the dual battery pack charges the positive capacitor or the negative capacitor through a PFC boost circuit.

6. A rectifier circuit multiplexing uninterruptible power supply according to any one of claims 2 to 5, characterized in that: The battery bidirectional circuit includes a first inductor, a second inductor, a first switch tube, a second switch tube, a third switch tube and a fourth switch tube; The first end of the first inductor serves as the first port of the battery bidirectional circuit, and is used to connect to the positive electrode of the dual battery pack; The second end of the first inductor is respectively connected to the emitter of the first switch tube and the collector of the second switch tube; The collector of the first switch tube serves as the third port of the battery bidirectional circuit, and is used to connect the positive bus; The emitter of the second switch tube is connected to the collector of the third switch tube, and the emitter of the second switch tube serves as the fifth port of the battery bidirectional circuit, and is used to connect the neutral line of the dual battery group and the neutral line; The first end of the second inductor serves as the second port of the battery bidirectional circuit, and is used to connect to the negative electrode of the dual battery pack; The second end of the second inductor is respectively connected to the emitter of the third switch tube and the collector of the fourth switch tube; The emitter of the fourth switch tube serves as the fourth port of the battery bidirectional circuit and is used to connect to the negative bus.

7. The uninterruptible power supply with multiplexed rectifier circuit according to claim 1, characterized in that: The battery bidirectional circuit includes a first inductor, a second inductor, a first switch tube, a second switch tube, a third switch tube and a fourth switch tube; The first end of the first inductor and the first end of the third switch tube serve as the first port of the battery bidirectional circuit, and are used to connect the positive electrode of the battery pack; The second end of the first inductor is respectively connected to the first end of the first switch tube and the first end of the second switch tube; The second end of the first switch tube is connected to the first end of the second inductor, and the connection point serves as the second port and the fifth port of the battery bidirectional circuit, the second port is used to connect the negative electrode of the battery pack, and the fifth port is used to connect the neutral line; The second end of the second switch tube serves as a third port of the battery bidirectional circuit, and is used to connect to the positive bus; The second end of the second inductor is respectively connected to the second end of the third switch tube and the first end of the fourth switch tube; The second end of the fourth switch tube serves as a fourth port of the battery bidirectional circuit and is used to connect to the negative bus.

8. A rectifier circuit multiplexing uninterruptible power supply according to any one of claims 1 to 4, characterized in that: The mains input is three-phase alternating current, the uninterruptible power supply comprises three first switches, three second switches and three PFC boost circuits, each phase of the three-phase alternating current corresponds to a first switch, a second switch and a PFC boost circuit; For each phase, the first end of the corresponding first switch is used to connect the AC power of the phase, and the second end of the corresponding first switch is connected to the input end of the PFC boost circuit of the phase; An input end of the corresponding PFC boost circuit is also connected to the second end of the second switch of the phase, and an output end of the corresponding PFC boost circuit is connected to the bus; The first end of each second switch is used to connect to the target polarity end of the battery pack.

9. The uninterruptible power supply with multiplexed rectifier circuit according to claim 3, characterized in that: The first switch includes a first thyristor and a second thyristor, and the second switch includes a third thyristor; The PFC boost circuit includes a third inductor, a fourth inductor, a first diode, a second diode, a fifth switch tube and a sixth switch tube; The anode of the first thyristor and the cathode of the second thyristor are connected and serve as the first end of the first switch; the cathode of the first thyristor serves as the first port of the second end of the first switch and is connected to the first end of the third inductor; the anode of the second thyristor serves as the second port of the second end of the first switch and is connected to the first end of the fourth inductor; The second end of the third inductor is connected to the anode of the first diode and the collector of the fifth switch tube respectively; the cathode of the first diode is connected to the positive bus; the emitter of the fifth switch tube is used to connect to the neutral line; The second end of the fourth inductor is connected to the emitter of the sixth switch tube and the cathode of the second diode respectively; the anode of the second diode is connected to the negative bus; the collector of the sixth switch tube is used to connect to the neutral line; When the target polarity end is the positive electrode of the battery pack, the anode of the third thyristor serves as the first end of the second switch, and the cathode of the third thyristor is connected to the first end of the third inductor; when the target polarity end is the negative electrode of the battery pack, the cathode of the third thyristor serves as the first end of the second switch, and the anode of the third thyristor is connected to the first end of the fourth inductor.

10. The uninterruptible power supply with multiplexed rectifier circuits according to claim 9, characterized in that: The mains inputs three-phase alternating current, and the uninterruptible power supply comprises three first switches, each phase of the three-phase alternating current corresponds to one first switch; For each phase, the first end of the corresponding first switch is used to connect the alternating current of the phase, the first port of the second end of the corresponding first switch is connected to the first end of the third inductor, and the second port of the second end of the corresponding first switch is connected to the first end of the fourth inductor.

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