Three-phase UPS system and power supply equipment

Abstract

The invention discloses a three-phase UPS system and power supply equipment, and relates to the technical field of three-phase UPS systems. Wherein one phase of the three-phase branch comprises a bidirectional PFC circuit, the other two phases of the three-phase branch comprise a double-BOOST PFC circuit, or one phase of the three-phase branch comprises the double-BOOST PFC circuit, and the other two phases of the three-phase branch comprise the bidirectional PFC circuit. Therefore, the three-phase branch can convert a three-phase power supply of a power grid into a direct-current power supply through the bidirectional PFC circuit and the double-BOOST PFC circuit and output the direct-current power supply to the UPS bus, and / or output a power supply of a battery to the UPS bus through the double-BOOST PFC circuit, and feed back redundant power supply on the UPS bus to the power grid through the bidirectional PFC circuit. Therefore, a battery discharge circuit does not need to be additionally configured, the circuit cost is saved, the electric energy on the UPS bus can be fed back to the power grid, and the feed energy can be effectively utilized.

Description

Technical Field

[0001] This application relates to the technical field of three-phase UPS systems, and particularly to a three-phase UPS system and a power supply device. Background Art

[0002] In the field of industrial automation, as a key power protection device, the three-phase UPS system undertakes the important task of providing stable electric energy for high-power loads. Especially in scenarios involving energy feedback loads, such as the application scenario where the UPS bus is connected to a four-quadrant frequency converter to drive a motor, the system not only needs to maintain continuous power supply but also needs to handle the energy feedback problem generated during the operation of the motor. Such loads are widely present in industrial equipment such as numerical control machine tools, hoisting machinery, and servo systems. During their operation, the motor dynamically switches between the electric and generating states, causing the four-quadrant frequency converter to feed back the regenerative energy to the UPS bus. If the UPS system lacks an effective energy processing mechanism, it will directly affect the continuity of industrial production and the safety of equipment operation.

[0003] Existing three-phase UPS systems have problems of energy waste and high hardware costs when dealing with energy feedback problems. In some UPS systems, an energy absorption resistor is used to convert the feedback energy into heat energy to avoid the situation where the UPS system shuts down and protects due to excessive bus voltage. However, this method will cause a large amount of electric energy to be converted into heat energy, resulting in energy waste. In other UPS systems, a bidirectional PFC circuit is used to transmit the feedback energy back to the power grid to achieve the purpose of energy recycling. Although this method can effectively recover energy, it requires an additional battery discharge circuit, so the circuit implementation cost is relatively high.

[0004] The above content is only used to assist in understanding the technical solution of this application and does not represent an admission that the above content is prior art. Summary of the Invention

[0005] The main purpose of this application is to provide a three-phase UPS system, aiming to solve the problems of energy waste and high hardware costs existing in the existing UPS systems when dealing with energy feedback problems.

[0006] To achieve the above purpose, the three-phase UPS system proposed in this application includes: Three-phase power supply access terminals, for accessing the power grid; three-phase branches, one of the three phases includes a bidirectional PFC circuit, and the other two phases include dual BOOST PFC circuits, or one of the three phases includes a dual BOOST PFC circuit, and the other two phases include bidirectional PFC circuits; wherein, the bidirectional PFC circuit is respectively connected to the three-phase power supply access terminals and the UPS bus of the three-phase UPS system, and the dual BOOST PFC circuit is respectively connected to the three-phase power supply access terminals, the battery, and the UPS bus of the three-phase UPS system; the three-phase branches are used to respectively convert the three-phase power supply of the power grid into a DC power supply through the bidirectional PFC circuit and the dual BOOST PFC circuit and output it to the UPS bus, and / or output the power of the battery to the UPS bus through the dual BOOST PFC circuit, and are used to feedback the excess power on the UPS bus to the power grid through the bidirectional PFC circuit.

[0007] In one embodiment, the dual BOOST PFC circuit includes a first inductor, a second inductor, a first diode, a second diode, a first switching tube integrated with an anti-parallel diode, a second switching tube integrated with an anti-parallel diode, a first capacitor and a second capacitor; one end of the first inductor and one end of the second inductor are respectively connected to one phase of the three-phase power supply access terminals and the battery, the other end of the first inductor, the first end of the first switching tube and the positive electrode of the first diode are connected, the second end of the first switching tube, the neutral point of the UPS bus, one end of the first capacitor and one end of the second capacitor are connected to the first end of the second switching tube, the other end of the second inductor, the second end of the second switching tube and the negative electrode of the second diode are connected, the negative electrode of the first diode and the other end of the first capacitor are connected to the positive electrode of the UPS bus, and the positive electrode of the second diode and the other end of the second capacitor are connected to the negative electrode of the UPS bus.

[0008] In one embodiment, the dual BOOST PFC circuit further includes a first rectification switching unit, a second rectification switching unit, a third rectification switching unit and a fourth rectification switching unit; the input end of the first rectification switching unit, the output end of the second rectification switching unit are connected to one phase of the three-phase power supply access terminals, the output end of the first rectification switching unit is connected to one end of the first inductor, and the input end of the second rectification switching unit is connected to one end of the second inductor; the input end of the third rectification switching unit is connected to the positive electrode of the battery, the output end of the fourth rectification switching unit is connected to the negative electrode of the battery, the output end of the third rectification switching unit is connected to one end of the first inductor, and the input end of the fourth rectification switching unit is connected to one end of the second inductor.

[0009] In one embodiment, the bidirectional PFC circuit includes a third inductor, a third switch tube integrated with an anti-parallel diode, a fourth switch tube integrated with an anti-parallel diode, a fifth switch tube integrated with an anti-parallel diode, a sixth switch tube integrated with an anti-parallel diode, a third capacitor and a fourth capacitor; one end of the third inductor is connected to one phase of the three-phase power supply access terminal, the other end of the third inductor, the first end of the fourth switch tube, the first end of the fifth switch tube are connected to the second end of the third switch tube, the second end of the fifth switch tube is connected to the second end of the sixth switch tube, the first end of the sixth switch tube, one end of the third capacitor, one end of the fourth capacitor are connected to the neutral terminal of the UPS bus, the first end of the third switch tube and the other end of the third capacitor are connected to the positive pole of the UPS bus, and the second end of the fourth switch tube and the other end of the fourth capacitor are connected to the negative pole of the UPS bus.

[0010] In one embodiment, when one phase of the three-phase branch includes a bidirectional PFC circuit and the other two phases include dual BOOST PFC circuits, the bidirectional PFC circuit further includes a first switch switching unit, one end of the first switch switching unit is connected to one phase of the three-phase power supply access terminal, and the other end of the first switch switching unit is connected to one end of the third inductor.

[0011] In one embodiment, when one phase of the three-phase branch includes a dual BOOST PFC circuit and the other two phases include bidirectional PFC circuits, the bidirectional PFC circuit further includes a second switch switching unit and a third switch switching unit; one end of the second switch switching unit is connected to one phase of the three-phase power supply access terminal, the other end of the second switch switching unit and one end of the third switch switching unit are connected to one end of the third inductor, and the other end of the third switch switching unit is connected to the battery.

[0012] In one embodiment, when the third switch switching unit closes the circuit between one end of the third inductor and the battery, the three-phase branch is further configured to output the power of the battery to the UPS bus through the bidirectional PFC circuit.

[0013] In one embodiment, the three-phase UPS system has a main circuit mode and a main circuit feedback mode. In one of the three-phase branches, a bidirectional PFC circuit is included, and in the other two phases, dual BOOST PFC circuits are included. In the main circuit mode, the bidirectional PFC circuit converts one phase of the three-phase power supply into a DC power supply and outputs it to the UPS bus, and the dual BOOST PFC circuits convert the other two phases of the three-phase power supply into DC power supplies respectively and output them to the UPS bus; in the main circuit feedback mode, in the main circuit feedback mode, the bidirectional PFC circuit feeds back the DC power supply on the UPS bus to one phase of the power grid; in one of the three-phase branches, a dual BOOST PFC circuit is included, and in the other two phases, bidirectional PFC circuits are included. In the main circuit mode, the dual BOOST PFC circuit converts one phase of the three-phase power supply into a DC power supply and outputs it to the UPS bus, and the bidirectional PFC circuits convert the other two phases of the three-phase power supply into DC power supplies respectively and output them to the UPS bus; in the main circuit feedback mode, the bidirectional PFC circuit feeds back the DC power supply on the UPS bus to two phases of the power grid.

[0014] In one embodiment, the three-phase UPS system has a battery positive-side discharge mode and a battery negative-side discharge mode; in one of the three-phase branches, a bidirectional PFC circuit is included, and in the other two phases, dual BOOST PFC circuits are included. In the battery positive-side discharge mode, the dual BOOST PFC circuits output the positive DC power supply of the battery to the UPS bus; in the battery negative-side discharge mode, the dual BOOST PFC circuits output the reverse DC power supply of the battery to the UPS bus; in one of the three-phase branches, a dual BOOST PFC circuit is included, and in the other two phases, bidirectional PFC circuits are included. One bidirectional PFC circuit of one phase is also connected to the positive electrode of the battery, and the bidirectional PFC circuit of the other phase is also connected to the negative electrode of the battery; in the battery positive-side discharge mode, the dual BOOST PFC circuits and / or the bidirectional PFC circuit of one phase output the positive DC power supply of the battery to the UPS bus; in the battery negative-side discharge mode, the dual BOOST PFC circuits and / or the bidirectional PFC circuit of the other phase output the reverse DC power supply of the battery to the UPS bus.

[0015] This application also provides a power supply device, including a battery and the three-phase UPS system as described above, and the battery is connected to the dual BOOST PFC circuit.

[0016] The technical solution of this application adopts a three-phase UPS system, which includes a three-phase power access terminal and three-phase branches. One of the three-phase branches includes a bidirectional PFC circuit, and the other two phases include double BOOST PFC circuits, or one of the three-phase branches includes a double BOOST PFC circuit, and the other two phases include bidirectional PFC circuits. Among them, the bidirectional PFC circuit is respectively connected to the three-phase power access terminal and the UPS bus of the three-phase UPS system, and the double BOOST PFC circuit is respectively connected to the three-phase power access terminal, the battery, and the UPS bus of the three-phase UPS system. When the power grid supplies power to the load, the three-phase branches can respectively convert the three-phase power of the power grid into DC power through the bidirectional PFC circuit and the double BOOST PFC circuit and output it to the UPS bus, and then provide power for the electrical load. And / or, when the battery supplies power to the load, the three-phase branches can output the power of the battery to the UPS bus through the double BOOST PFC circuit. When the load feeds power back to the power grid, the three-phase branches can feed back the redundant power on the UPS bus to the power grid through the bidirectional PFC circuit. In this way, this application can reuse the power devices of the bidirectional PFC circuit and the double BOOST PFC circuit in the three-phase branches, without additionally configuring a battery discharge circuit, thus saving hardware costs. Moreover, in the feeding application of an energy feedback type load, the electrical energy on the UPS bus can be fed back to the power grid, which can effectively save energy. Brief Description of the Drawings

[0017] In order to more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of this application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on the structures shown in these drawings.

[0018] Figure 1 Schematic diagram of the structure of an embodiment of the three-phase UPS system provided by this application; Figure 2 Electronic circuit diagram of an embodiment of the three-phase UPS system provided by this application; Figure 3 Electronic circuit diagram of another embodiment of the three-phase UPS system provided by this application; Figure 4 Electronic circuit diagram of an exemplary embodiment of the three-phase UPS system provided by this application; Figure 5 Electronic circuit diagram of another exemplary embodiment of the three-phase UPS system provided by this application; Figure 6 Energy flow diagram of the A-phase branch in the main path mode of an embodiment of the three-phase UPS system provided by this application; Figure 7 Another energy flow diagram of the A-phase branch in the main circuit mode of an embodiment of the three-phase UPS system provided by this application; Figure 8 An energy flow diagram of the B-phase branch in the main circuit mode of an embodiment of the three-phase UPS system provided by this application; Figure 9 Another energy flow diagram of the B-phase branch in the main circuit mode of an embodiment of the three-phase UPS system provided by this application; Figure 10 Another energy flow diagram of the A-phase branch in the main circuit mode of an embodiment of the three-phase UPS system provided by this application; Figure 11 Another energy flow diagram of the A-phase branch in the main circuit mode of an embodiment of the three-phase UPS system provided by this application; Figure 12 Another energy flow diagram of the B-phase branch in the main circuit mode of an embodiment of the three-phase UPS system provided by this application; Figure 13 Another energy flow diagram of the B-phase branch in the main circuit mode of an embodiment of the three-phase UPS system provided by this application; Figure 14 An energy flow diagram of the B-phase branch in the main circuit feedback mode of an embodiment of the three-phase UPS system provided by this application; Figure 15 Another energy flow diagram of the B-phase branch in the main circuit feedback mode of an embodiment of the three-phase UPS system provided by this application; Figure 16 Another energy flow diagram of the B-phase branch in the main circuit feedback mode of an embodiment of the three-phase UPS system provided by this application; Figure 17 Another energy flow diagram of the B-phase branch in the main circuit feedback mode of an embodiment of the three-phase UPS system provided by this application; Figure 18 An energy flow diagram of the A-phase branch in the battery positive side discharge mode of an embodiment of the three-phase UPS system provided by this application; Figure 19 Another energy flow diagram of the A-phase branch in the battery positive side discharge mode of an embodiment of the three-phase UPS system provided by this application; Figure 20 Energy flow diagram of the A-phase branch in the battery negative side discharge mode of an embodiment of the three-phase UPS system provided by this application; Figure 21 Another energy flow diagram of the A-phase branch in the battery negative side discharge mode of an embodiment of the three-phase UPS system provided by this application; Figure 22 Structural schematic diagram of another embodiment of the three-phase UPS system provided by this application; Figure 23 An energy flow diagram of the B-phase and A-phase branches in the main circuit mode of another embodiment of the three-phase UPS system provided by the present application; Figure 24 Another energy flow diagram of the B-phase and A-phase branches in the main circuit feedback mode of another embodiment of the three-phase UPS system provided by the present application; Figure 25 An energy flow diagram of the B-phase and A-phase branches in the main circuit feedback mode of another embodiment of the three-phase UPS system provided by the present application; Figure 26 An energy flow diagram of the B-phase and A-phase branches in the battery positive-side discharge mode of another embodiment of the three-phase UPS system provided by the present application; Figure 27 An energy flow diagram of the B-phase and A-phase branches in the battery negative-side discharge mode of another embodiment of the three-phase UPS system provided by the present application.

[0019] The realization of the purpose of the present application, functional characteristics and advantages will be further described with reference to the embodiments and the accompanying drawings. Specific embodiments

[0020] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0021] It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present application are only used to explain the relative position relationship and movement conditions between components in a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly.

[0022] In addition, the descriptions involving "first", "second", etc. in the present application are only for descriptive purposes, and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement them. When the combination of technical solutions appears to be contradictory or unable to be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present application.

[0023] Existing three-phase UPS systems face problems of energy waste and relatively high hardware costs when dealing with energy feedback. Some UPS systems use energy absorption resistors to convert the feedback energy into heat to avoid triggering the protection mechanism of the UPS system due to excessive bus voltage. For example, in one implementation (refer to Figure 4 ), an energy absorption resistor and a control switch can be added to the UPS bus. When energy is fed back to the UPS and causes the bus voltage to rise, the control switch will turn on the energy absorption resistor to absorb the excess energy on the bus, thus preventing the UPS from shutting down or being damaged due to excessive voltage. However, this method will cause a large amount of electrical energy to be converted into heat, resulting in energy waste.

[0024] In addition, some UPS systems use a bidirectional PFC circuit to transmit the feedback energy back to the power grid to achieve the effect of energy recycling. For example, in another implementation (refer to Figure 5 ), the PFC circuit in the UPS system can be replaced with a bidirectional PFC circuit. When the bus voltage is too high, the bidirectional PFC circuit can feed back the excess energy to the power grid. Although this method can effectively recover energy, since the bidirectional PFC circuit requires an additional battery discharge circuit, the hardware cost of the UPS system increases. Therefore, although energy feedback can be achieved, the added battery discharge circuit makes the overall cost relatively high.

[0025] This application proposes a three-phase UPS system.

[0026] Please refer to Figure 1 , in an embodiment of this application, the three-phase UPS system includes: A three-phase power supply access terminal for accessing the power grid; A three-phase branch. One of the three phases includes a bidirectional PFC circuit, and the other two phases include dual BOOST PFC circuits, or one of the three phases includes a dual BOOST PFC circuit, and the other two phases include bidirectional PFC circuits; wherein, the bidirectional PFC circuit is respectively connected to the three-phase power supply access terminal and the UPS bus of the three-phase UPS system, and the dual BOOST PFC circuit is respectively connected to the three-phase power supply access terminal, the battery, and the UPS bus of the three-phase UPS system; A three-phase branch for converting the three-phase power supply of the power grid into a DC power supply and outputting it to the UPS bus through the bidirectional PFC circuit and the dual BOOST PFC circuit respectively, and / or for outputting the power of the battery to the UPS bus through the dual BOOST PFC circuit, and for feeding back the excess power on the UPS bus to the power grid through the bidirectional PFC circuit.

[0027] In this embodiment, the bidirectional PFC circuit may include power devices such as switching transistors, inductors, capacitors, and diodes. When the UPS bus obtains electrical energy from the power grid, the bidirectional PFC circuit can convert one phase of the three-phase power supply into direct current and output it to the UPS bus. During this process, energy can be stored in the inductor when the switching transistor in the bidirectional PFC circuit is switched to the on state, and the energy stored in the inductor is released to the UPS bus when it is switched to the off state, so as to improve the power factor of the power supply output to the UPS bus. When the voltage of the UPS bus rises, the excess energy can be fed back to the power grid through the bidirectional PFC circuit. During this process, energy can be stored in the inductor when the switching transistor in the bidirectional PFC circuit is switched to the on state, and the energy stored in the inductor is released to the power grid when it is switched to the off state, so as to adjust the power factor of the power supply fed back to the power grid.

[0028] The dual BOOST PFC circuit may include two BOOST converters, and each BOOST converter includes power devices such as switching transistors, inductors, capacitors, and diodes. When the UPS bus obtains electrical energy from the power grid, the dual BOOST PFC circuit can convert one phase of the three-phase power supply into direct current and output it to the UPS bus. During this process, energy can be stored in the inductor when the switching transistor in the dual BOOST PFC circuit is switched to the on state, and the energy stored in the inductor is released to the UPS bus when it is switched to the off state, so as to improve the power factor of the power supply output to the UPS bus. When the UPS bus obtains electrical energy from the battery, the dual BOOST PFC circuit can obtain electrical energy from the battery and transmit the direct current output by the battery to the UPS bus. During this process, energy can be stored in the inductor when the switching transistor in the dual BOOST PFC circuit is switched to the on state, and the energy stored in the inductor is released to the UPS bus when it is switched to the off state, so as to improve the power factor of the power supply output to the UPS bus.

[0029] It should be noted that when one of the three phases includes a bidirectional PFC circuit and the other two phases include dual BOOST PFC circuits, the first end of the bidirectional PFC circuit is connected to the first phase of the three-phase power supply access terminal, and the second end is connected to the UPS bus; the first end of a dual BOOST PFC circuit is connected to the second phase of the three-phase power supply access terminal, the second end is connected to the battery, and the third end is connected to the UPS bus; the first end of the other dual BOOST PFC circuit is connected to the third phase of the three-phase power supply access terminal, the second end is connected to the battery, and the third end is connected to the UPS bus. When the power grid supplies power to the load, the bidirectional PFC circuit converts one phase of the three-phase power supply into a DC power supply and outputs it to the UPS bus, and the two dual BOOST PFC circuits convert the other two phases of the three-phase power supply into DC power supplies and output them to the UPS bus respectively; when the battery supplies power to the load, at least one of the two dual BOOST PFC circuits outputs the DC power supply of the battery to the UPS bus; when the load feeds power back to the power grid, the bidirectional PFC circuit feeds back the DC power supply on the UPS bus to one phase of the power grid. It should be noted that the UPS bus can obtain electrical energy from the power grid, or from the battery, or simultaneously from the power grid and the battery, and there is no limitation on this. This embodiment can reuse the power devices of the bidirectional PFC circuit and the dual BOOST PFC circuit in the three-phase branch, without the need to additionally configure a battery discharge circuit, thus saving hardware costs. Moreover, in the power feeding application of an energy feedback type load, the electrical energy on the UPS bus can be fed back to the power grid, which can effectively save energy.

[0030] When one of the three phases includes a dual BOOST PFC circuit and the other two phases include bidirectional PFC circuits, the first end of the dual BOOST PFC circuit is connected to the first phase of the three-phase power supply access terminal, the second end is connected to the battery, and the third end is connected to the UPS bus; the first end of a bidirectional PFC circuit is connected to the second phase of the three-phase power supply access terminal, and the second end is connected to the UPS bus; the first end of the other bidirectional PFC circuit is connected to the third phase of the three-phase power supply access terminal, and the second end is connected to the UPS bus. When the power grid supplies power to the load, the dual BOOST PFC circuit converts one phase of the three-phase power supply into a DC power supply and outputs it to the UPS bus, and the two bidirectional PFC circuits convert the other two phases of the three-phase power supply into DC power supplies and output them to the UPS bus respectively; and / or, when the battery supplies power to the load, the dual BOOST PFC circuit outputs the DC power supply of the battery to the UPS bus; when the load feeds power back to the power grid, at least one of the two bidirectional PFC circuits feeds the DC power supply on the UPS bus back to one phase of the power grid. It should be noted that the UPS bus can obtain electrical energy from the power grid, or from the battery, or from the power grid and the battery at the same time, and there is no restriction on this. This embodiment can reuse the power devices of the bidirectional PFC circuit and the dual BOOST PFC circuit in the three-phase branch, without additional configuration of a battery discharge circuit, thus saving hardware costs. Moreover, in the power feed application of an energy feedback type load, the electrical energy on the UPS bus can be fed back to the power grid, which can effectively save energy.

[0031] In this application, the three-phase UPS system includes a three-phase power access terminal and three-phase branches. Among them, one of the three-phase branches includes a bidirectional PFC circuit, and the other two phases include dual BOOST PFC circuits, or one of the three-phase branches includes a dual BOOST PFC circuit, and the other two phases include bidirectional PFC circuits. Among them, the bidirectional PFC circuit is respectively connected to the three-phase power access terminal and the UPS bus of the three-phase UPS system, and the dual BOOST PFC circuit is respectively connected to the three-phase power access terminal, the battery, and the UPS bus of the three-phase UPS system. When the power grid supplies power to the load, the three-phase branches can respectively convert the three-phase power of the power grid into DC power through the bidirectional PFC circuit and the dual BOOST PFC circuit and output it to the UPS bus, and then provide power for the electrical load. And / or, when the battery supplies power to the load, the three-phase branches can output the power of the battery to the UPS bus through the dual BOOST PFC circuit. When the load feeds power back to the power grid, the three-phase branches can feedback the redundant power on the UPS bus to the power grid through the bidirectional PFC circuit. It should be noted that the UPS bus can obtain electrical energy from the power grid, or from the battery, or simultaneously from the power grid and the battery, and there is no limitation on this. In this way, this application can reuse the power devices of the bidirectional PFC circuit and the dual BOOST PFC circuit in the three-phase branches, without the need to configure an additional battery discharge circuit, thus saving hardware costs. Moreover, in the power feedback application of an energy feedback type load, the electrical energy on the UPS bus can be fed back to the power grid, which can effectively save energy.

[0032] It should be noted that, in order to better describe the working principle of this application, the three-phase power access terminals of this application are respectively used to access the phase A, phase B, and phase C power supplies, corresponding to the phase A branch, phase B branch, and phase C branch in the three-phase branches.

[0033] In an embodiment of this application, the dual BOOST PFC circuit includes a first inductor, a second inductor, a first diode, a second diode, a first switching tube integrated with an anti-parallel diode, a second switching tube integrated with an anti-parallel diode, a first capacitor, and a second capacitor; One end of the first inductor and one end of the second inductor are respectively connected to one phase of the three-phase power access terminal and the battery. The other end of the first inductor, the first end of the first switching tube, and the positive pole of the first diode are connected. The second end of the first switching tube, the neutral point of the UPS bus, one end of the first capacitor, and one end of the second capacitor are connected to the first end of the second switching tube. The other end of the second inductor, the second end of the second switching tube, and the negative pole of the second diode are connected. The negative pole of the first diode, the other end of the first capacitor are connected to the positive pole of the UPS bus. The positive pole of the second diode, the other end of the second capacitor are connected to the negative pole of the UPS bus.

[0034] The bidirectional PFC circuit includes a third inductor, a third switch tube integrated with an anti-parallel diode, a fourth switch tube integrated with an anti-parallel diode, a fifth switch tube integrated with an anti-parallel diode, a sixth switch tube integrated with an anti-parallel diode, a third capacitor and a fourth capacitor; One end of the third inductor is connected to one phase of the three-phase power supply access terminal. The other end of the third inductor, the first end of the fourth switch tube, the first end of the fifth switch tube are connected to the second end of the third switch tube. The second end of the fifth switch tube is connected to the second end of the sixth switch tube. The first end of the sixth switch tube, one end of the third capacitor, and one end of the fourth capacitor are connected to the neutral terminal of the UPS bus. The first end of the third switch tube and the other end of the third capacitor are connected to the positive pole of the UPS bus. The second end of the fourth switch tube and the other end of the fourth capacitor are connected to the negative pole of the UPS bus.

[0035] It should be noted that in order to reduce the circuit volume and save capacitor components, the double BOOST PFC circuit and the bidirectional PFC circuit can share the capacitor C1 and the capacitor C2.

[0036] Please refer to Figure 2 , in an embodiment, one of the three-phase branches includes a bidirectional PFC circuit, and the other two phases include a double BOOST PFC circuit. For example, the A-phase branch and the C-phase branch include a double BOOST PFC circuit, and the B-phase branch includes a bidirectional PFC circuit. In this embodiment, taking the A-phase branch as an example, the double BOOST PFC circuit includes a first inductor L2, a second inductor L5, a first diode D1, a second diode D4, a first switch tube Q13 integrated with an anti-parallel diode, a second switch tube Q14 integrated with an anti-parallel diode, a first capacitor C1 and a second capacitor C2; One end of the first inductor L2 and one end of the second inductor L5 are respectively connected to the A phase of the three-phase power supply access terminal. One end of the first inductor L2 is also connected to the positive pole BAT+ of the battery. One end of the second inductor L5 is also connected to the negative pole BAT- of the battery. The other end of the first inductor L2, the first end of the first switch tube Q13 and the positive pole of the first diode D1 are connected. The second end of the first switch tube Q13, the neutral point Neutral of the UPS bus, one end of the first capacitor C1, one end of the second capacitor C2 and the first end of the second switch tube Q14 are connected. The other end of the second inductor L5, the second end of the second switch tube Q14 and the negative pole of the second diode D4 are connected. The negative pole of the first diode D1 and the other end of the first capacitor C1 are connected to the positive pole BUS+ of the UPS bus. The positive pole of the second diode D4 and the other end of the second capacitor C2 are connected to the negative pole BUS- of the UPS bus.

[0037] Similarly, the C-phase branch includes a first inductor L3, a second inductor L4, a first diode D2, a second diode D3, a first switching transistor Q15 with an integrated anti-parallel diode, a second switching transistor Q16 with an integrated anti-parallel diode, a first capacitor C1, and a second capacitor C2.

[0038] In the B-phase branch, the bidirectional PFC circuit includes a third inductor L1, a third switching transistor Q9 with an integrated anti-parallel diode, a fourth switching transistor Q10 with an integrated anti-parallel diode, a fifth switching transistor Q11 with an integrated anti-parallel diode, a sixth switching transistor Q12 with an integrated anti-parallel diode, a first capacitor C1, and a second capacitor C2; One end of the third inductor L1 is connected to the B phase of the three-phase power supply access terminal. The other end of the third inductor L1, the first end of the fourth switching transistor Q10, the first end of the fifth switching transistor Q11, and the second end of the third switching transistor Q9 are connected. The second end of the fifth switching transistor Q11 is connected to the second end of the sixth switching transistor Q12. The first end of the sixth switching transistor Q12, one end of the first capacitor C1, and one end of the second capacitor C2 are connected to the neutral terminal Neutral of the UPS bus. The first end of the third switching transistor Q9, the other end of the first capacitor C1 are connected to the positive terminal BUS+ of the UPS bus. The second end of the fourth switching transistor Q10, the other end of the second capacitor C2 are connected to the negative terminal BUS- of the UPS bus.

[0039] Please refer to Figure 3 , in another embodiment, one of the three-phase branches includes a dual BOOST PFC circuit, and the other two phases include bidirectional PFC circuits. For example, the A-phase branch and the C-phase branch include bidirectional PFC circuits, and the B-phase branch includes a dual BOOST PFC circuit. In this embodiment, taking the A-phase branch as an example, the bidirectional PFC circuit includes a third inductor L7, a third switching transistor Q25 with an integrated anti-parallel diode, a fourth switching transistor Q26 with an integrated anti-parallel diode, a fifth switching transistor Q27 with an integrated anti-parallel diode, a sixth switching transistor Q28 with an integrated anti-parallel diode, a first capacitor C3, and a second capacitor C4; One end of the third inductor L7 is connected to the A phase of the three-phase power supply access terminal. The other end of the third inductor L7, the first end of the fourth switching transistor Q26, the first end of the fifth switching transistor Q27, and the second end of the third switching transistor Q25 are connected. The second end of the fifth switching transistor Q29 is connected to the second end of the sixth switching transistor Q27. The first end of the sixth switching transistor Q27, one end of the first capacitor C3, and one end of the second capacitor C4 are connected to the neutral terminal Neutral of the UPS bus. The first end of the third switching transistor Q25, the other end of the first capacitor C3 are connected to the positive terminal BUS+ of the UPS bus. The second end of the fourth switching transistor Q26, the other end of the second capacitor C4 are connected to the negative terminal BUS- of the UPS bus.

[0040] Similarly, the C-phase branch includes a third inductor L8, a third switch Q23 integrated with an anti-parallel diode, a fourth switch Q24 integrated with an anti-parallel diode, a fifth switch Q29 integrated with an anti-parallel diode, a sixth switch Q30 integrated with an anti-parallel diode, a first capacitor C3, and a second capacitor C4.

[0041] In the B-phase branch, the dual BOOST PFC circuit includes a first inductor L6, a second inductor L9, a first diode D5, a second diode D6, a first switch Q21 integrated with an anti-parallel diode, a second switch Q22 integrated with an anti-parallel diode, a first capacitor C3, and a second capacitor C4; One end of the first inductor L6 and one end of the second inductor L9 are respectively connected to the B-phase of the three-phase power supply access terminal. One end of the first inductor L6 is also connected to the positive pole BAT+ of the battery, and one end of the second inductor L9 is also connected to the negative pole BAT- of the battery. The other end of the first inductor L6, the first end of the first switch Q21, and the positive pole of the first diode D5 are connected. The second end of the first switch Q21, the neutral point Neutral of the UPS bus (which can be regarded as a ground reference point here), one end of the first capacitor C3, one end of the second capacitor C4, and the first end of the second switch Q22 are connected. The other end of the second inductor L9, the second end of the second switch Q22, and the negative pole of the second diode D6 are connected. The negative pole of the first diode D5, the other end of the first capacitor C3, and the positive pole BUS+ of the UPS bus are connected. The positive pole of the second diode D6, the other end of the second capacitor C4, and the negative pole BUS- of the UPS bus are connected.

[0042] In this embodiment, by storing and releasing energy through the first inductor, the second inductor, and the third inductor, the current fluctuation can be smoothed, and the power factor of the output power supply can be improved. By controlling the conduction states of the first switch, the second switch, the third switch, and the fourth switch integrated with anti-parallel diodes, the bidirectional flow of energy can be achieved, converting the three-phase power supply into a DC power supply and transmitting it to the UPS bus, transmitting the power of the battery to the UPS bus, or feeding back the excess power on the UPS bus to the power grid.

[0043] Please refer to Figure 2 and Figure 3 In an embodiment of the present application, the dual BOOST PFC circuit further includes a first rectification switching unit, a second rectification switching unit, a third rectification switching unit, and a fourth rectification switching unit; The input end of the first rectification switching unit, the output end of the second rectification switching unit are connected to one phase of the three-phase power supply access terminal. The output end of the first rectification switching unit is connected to one end of the first inductor, and the input end of the second rectification switching unit is connected to one end of the second inductor; The input end of the third rectification switching unit is connected to the positive electrode of the battery, the output end of the fourth rectification switching unit is connected to the negative electrode of the battery, the output end of the third rectification switching unit is connected to one end of the first inductor, and the input end of the fourth rectification switching unit is connected to one end of the second inductor.

[0044] Please refer to Figure 2 , taking the A-phase branch of this embodiment as an example, the first rectification switching unit, the second rectification switching unit, the third rectification switching unit and the fourth rectification switching unit can be respectively set as thyristor Q1, thyristor Q8, thyristor Q4 and thyristor Q5. When the A-phase branch is powered by the power grid and in the positive half cycle of power supply, thyristor Q1 conducts, and other thyristors are turned off. When the A-phase branch is powered by the power grid and in the negative half cycle of power supply, thyristor Q8 conducts, and other thyristors are turned off. When the A-phase branch is powered by the battery and the battery discharges on the positive side, thyristor Q4 conducts, and other thyristors are turned off. When the A-phase branch is powered by the battery and the battery discharges on the negative side, thyristor Q5 conducts, and other thyristors are turned off. In this embodiment, the thyristor can switch from the off state to the on state within microseconds, can handle high voltage and large current, and has higher reliability and longer service life compared with mechanical switches. Thus, this embodiment can enhance the stability of the circuit. It should be noted that Figure 2 and Figure 3 the rectification switching unit of

[0045] Please refer to Figure 2 , in an embodiment of the present application, when one of the three-phase branches includes a bidirectional PFC circuit and the other two phases include dual BOOST PFC circuits, the bidirectional PFC circuit further includes a first switch switching unit. One end of the first switch switching unit is connected to one phase of the three-phase power access end, and the other end of the first switch switching unit is connected to one end of the third inductor.

[0046] In this embodiment, the first switch switching unit can be a relay, a contactor, MOS tubes connected back-to-back or a bidirectional thyristor. Please refer to Figure 2 , the first switch switching unit adopts relay RLY1. In this embodiment, the working mode of the circuit can be flexibly switched according to actual needs, enhancing the flexibility of the circuit. For example, when powered by the power grid or feeding power, relay RLY1 can be turned on, and when powered by the battery, relay RLY1 can be turned off.

[0047] Please refer to Figure 3, in an embodiment of the present application, when one phase of the three-phase branch includes a dual BOOST PFC circuit and the other two phases include a bidirectional PFC circuit, the bidirectional PFC circuit further includes a second switch switching unit and a third switch switching unit; One end of the second switch switching unit is connected to one phase of the three-phase power supply access terminal, the other end of the second switch switching unit and one end of the third switch switching unit are connected to one end of the third inductor, and the other end of the third switch switching unit is connected to the battery.

[0048] Please refer to Figure 22 , in an embodiment, the three-phase branch is further configured to output the power of the battery to the UPS bus through the bidirectional PFC circuit when the third switch switching unit turns on the circuit between one end of the third inductor and the battery.

[0049] In this embodiment, the second switch switching unit and the third switch switching unit can be relays, contactors or triacs. Please refer to Figure 3 , taking the A-phase branch as an example, the second switch switching unit can be relay RLY3 and relay RLY4, and the third switch switching unit can be relay RLY2 and relay RLY5. In the bidirectional PFC circuit of one phase, one end of relay RLY3 is connected to one phase of the three-phase power supply access terminal, the other end of relay RLY3 and one end of relay RLY2 are connected to one end of the third inductor L7, and the other end of relay RLY2 is connected to the positive pole of the battery; in the bidirectional PFC circuit of the other phase, one end of relay RLY4 is connected to one phase of the three-phase power supply access terminal, the other end of relay RLY4 and one end of relay RLY5 are connected to one end of the third inductor L8, and the other end of relay RLY5 is connected to the negative pole of the battery. Using two relays in the bidirectional PFC circuits of two phases can flexibly switch the working mode of the circuit according to actual needs, enhancing the flexibility of the circuit. For example, when powering through the grid or feeding power, relays RLY3 and RLY4 can be turned on and relays RLY2 and RLY5 can be turned off. When powering through the battery, it can be directly powered by the dual BOOST PFC circuit composed of the first inductor L6, the second inductor L9, the first diode D5, the second diode D6, the first switch tube Q21, the second switch tube Q22, the first capacitor C3 and the second capacitor C4, or relays RLY2 and RLY5 can be turned on and relays RLY3 and RLY4 can be turned off, and it can be powered by a bidirectional PFC circuit composed of the third inductor L7, the third switch tube Q25, the fourth switch tube Q26, the fifth switch tube Q27, the sixth switch tube Q28, the first capacitor C3 and the second capacitor C4, and another bidirectional PFC circuit composed of the third inductor L8, the third switch tube Q23, the fourth switch tube Q24, the fifth switch tube Q29, the sixth switch tube Q30, the first capacitor C3 and the second capacitor C4.

[0050] In an embodiment of the present application, the three-phase UPS system has a main path mode and a main path feedback mode; Among the three-phase branches, one phase includes a bidirectional PFC circuit, and the other two phases include dual BOOST PFC circuits. In the main path mode, the bidirectional PFC circuit converts one phase of the three-phase power supply into a DC power supply and outputs it to the UPS bus, and the dual BOOST PFC circuits convert the other two phases of the three-phase power supply into DC power supplies respectively and output them to the UPS bus; In the main path feedback mode, the bidirectional PFC circuit feeds back the DC power supply on the UPS bus to one phase of the power grid.

[0051] For the convenience of description, in the following embodiments, the rectifier switching unit is set as a thyristor. Among them, the rectifier switching unit of the dual BOOST PFC circuit can also be set as other units that can achieve rectifier switching, such as a relay in series with a diode, etc., which should not impose any limitations on the functions and application scopes of the embodiments of the present application. In this embodiment, taking the A-phase branch and the C-phase branch as dual BOOST PFC circuits and the B-phase branch as a bidirectional PFC circuit as an example, in the positive half cycle of the main path mode and when the commercial power supplies the load, please refer to Figure 6 and Figure 7 , the power supply process of the A-phase branch is as follows: The first switching tube Q13 is turned on. At this time, the grid energy passes through the thyristor Q1, the first inductor L2, the first switching tube Q13 to the Neutral terminal of the UPS bus, and the first inductor L2 stores energy. The first switching tube Q13 is turned off, and the grid energy passes through the thyristor Q1, the first inductor L2, the first diode D1, the first capacitor C1 to the Neutral terminal of the UPS bus, and the first inductor L2 releases energy to the UPS bus.

[0052] Please refer to Figure 8 and Figure 9 , the power supply process of the B-phase branch is as follows: The fifth switching tube Q11 and the sixth switching tube Q12 are turned on. The grid energy passes through the relay RLY1, the third inductor L1, the fifth switching tube Q11, the body diode of the sixth switching tube Q12 to the Neutral terminal of the UPS bus, and the third inductor L1 stores energy. The fifth switching tube Q11 and the sixth switching tube Q12 are turned off, and the grid energy passes through the relay RLY1, the third inductor L1, the body diode of the third switching tube Q9, the first capacitor C1 to the Neutral of the UPS bus, and the third inductor L1 releases energy to the first capacitor C1.

[0053] Similarly, the power supply process of the C-phase branch is as follows: The first switching transistor Q15 conducts. At this time, the grid energy passes through the thyristor Q2, the first inductor L3, the first switching transistor Q15 to the Neutral terminal of the UPS bus, and the first inductor L3 stores energy. The first switching transistor Q15 turns off. At this time, the grid energy passes through the thyristor Q2, the first inductor L3, the first diode D2, the first capacitor C1 to the Neutral terminal of the UPS bus, and the first inductor L3 releases energy to the UPS bus.

[0054] In the main circuit mode and during the negative half-cycle when the commercial power supplies the load, please refer to Figure 10 and Figure 11 , the power supply principle of the A-phase branch is as follows: The second switching transistor Q14 conducts. At this time, the grid energy goes from the Neutral terminal of the UPS bus, the second switching transistor Q14, the second inductor L5, the thyristor Q8 to the grid, and the second inductor L5 stores energy. The second switching transistor Q14 turns off. At this time, the grid energy goes from the Neutral terminal of the UPS bus, the second capacitor C2, the second diode D4, the second inductor L5, the thyristor Q8 to the grid, and the second inductor L5 releases energy to the second capacitor C2.

[0055] Please refer to Figure 12 and Figure 13 , the power supply principle of the B-phase branch is as follows: The fifth switching transistor Q11 and the sixth switching transistor Q12 conduct. The grid energy passes through the Neutral terminal of the UPS bus, the sixth switching transistor Q12, the body diode of the fifth switching transistor Q11, the third inductor L1, the relay RLY1 to the grid, and the third inductor L1 stores energy. The fifth switching transistor Q11 and the sixth switching transistor Q12 turn off. The grid energy passes through the Neutral terminal of the UPS bus, the second capacitor C2, the body diode of the fourth switching transistor Q10, the third inductor L1, the relay RLY1 to the grid, and the third inductor L1 releases energy to the second capacitor C2.

[0056] Similarly, the power supply process of the C-phase branch is as follows: The second switching transistor Q16 conducts. At this time, the grid energy goes from the Neutral terminal of the UPS bus, the second switching transistor Q16, the second inductor L4, the thyristor Q7 to the grid, and the second inductor L4 stores energy. The second switching transistor Q16 turns off. At this time, the grid energy goes from the Neutral terminal of the UPS bus, the second capacitor C2, the second diode D3, the second inductor L4, the thyristor Q7 to the grid, and the second inductor L4 releases energy to the second capacitor C2.

[0057] In the main circuit feedback mode and during the positive half-cycle when the UPS bus feeds back energy to the commercial power, please refer to Figure 14 and Figure 15 , the feeding process of the B-phase branch is as follows: The third switching transistor Q9 conducts, the fifth switching transistor Q11 and the sixth switching transistor Q12 turn off, and the energy of the first capacitor C1 passes through the third switching transistor Q9, the third inductor L1, the relay RLY1 to the B phase of the power grid. The third switching transistor Q9 turns off, the fifth switching transistor Q11 and the sixth switching transistor Q12 conduct, and the energy passes through the sixth switching transistor Q12, the body diode of the fifth switching transistor Q11, the third inductor L1, the relay RLY1 to the B phase of the power grid.

[0058] In the negative half-cycle of the main circuit feedback mode and the UPS bus feeding energy back to the commercial power, please refer to Figure 16 and Figure 17 , the feeding process of the B-phase branch is as follows: The fourth switching transistor Q10 conducts, the fifth switching transistor Q11 and the sixth switching transistor Q12 turn off, and the energy passes through the B phase of the power grid, the relay RLY1, the third inductor L1, the fifth switching transistor Q11, the body diode of the sixth switching transistor Q12 to the Neutral terminal of the UPS bus. The fourth switching transistor Q10 turns off, the fifth switching transistor Q11 and the sixth switching transistor Q12 conduct, and the energy passes through the B phase of the power grid, the relay RLY1, the third inductor L1, the body diodes of the fifth switching transistor Q11 and the sixth switching transistor Q12 to the Neutral terminal of the UPS bus.

[0059] In this way, this embodiment can realize the power supply of the A-phase, B-phase and C-phase branches, as well as the feeding of the B-phase branch, and can feed the electric energy on the UPS bus back to the power grid, saving energy.

[0060] In one of the three-phase branches, a dual BOOST PFC circuit is included, and the other two phases include a bidirectional PFC circuit. In the main circuit mode, the dual BOOST PFC circuit converts one phase of the three-phase power supply into a DC power supply and outputs it to the UPS bus, and the bidirectional PFC circuit converts the other two phases of the three-phase power supply into DC power supplies and outputs them to the UPS bus respectively; In the main circuit feedback mode, the bidirectional PFC circuit feeds back the DC power on the UPS bus to two phases of the power grid.

[0061] In this embodiment, taking the B-phase branch as a dual BOOST PFC circuit and the A-phase branch and the C-phase branch as bidirectional PFC circuits as an example, in the positive half-cycle of the main circuit mode and the commercial power supplying power to the load, please refer to Figure 23 , the power supply process of the B-phase branch is as follows: The first switching transistor Q21 conducts. At this time, the grid energy passes through the thyristor Q17, the first inductor L6, the first switching transistor Q21 to the Neutral terminal of the UPS bus, and the first inductor L6 stores energy. The first switching transistor Q21 turns off. At this time, the grid energy passes through the thyristor Q17, the first inductor L6, the first diode D5, the first capacitor C3 to the Neutral terminal of the UPS bus, and the first inductor L6 releases energy to the UPS bus.

[0062] Please refer to Figure 23 , and the power supply process of the A-phase branch is as follows: The fifth switching transistor Q27 and the sixth switching transistor Q28 conduct. The grid energy passes through the relay RLY3, the third inductor L7, the fifth switching transistor Q27, and the body diode of the sixth switching transistor Q28 to the Neutral terminal of the UPS bus, and the third inductor L7 stores energy. The fifth switching transistor Q27 and the sixth switching transistor Q28 turn off. The grid energy passes through the relay RLY3, the third inductor L7, the body diode of the third switching transistor Q25, and the first capacitor C3 to the Neutral of the UPS bus, and the third inductor L7 releases energy to the first capacitor C3.

[0063] Similarly, the power supply process of the C-phase branch is as follows: The fifth switching transistor Q29 and the sixth switching transistor Q30 conduct. The grid energy passes through the relay RLY4, the third inductor L8, the fifth switching transistor Q29, and the body diode of the sixth switching transistor Q30 to the Neutral terminal of the UPS bus, and the third inductor L8 stores energy. The fifth switching transistor Q29 and the sixth switching transistor Q30 turn off. The grid energy passes through the relay RLY4, the third inductor L8, the body diode of the fifth switching transistor Q29, and the first capacitor C3 to the Neutral of the UPS bus, and the third inductor L8 releases energy to the first capacitor C3.

[0064] In the negative half cycle when the main circuit mode is on and the commercial power supplies the load, please refer to Figure 24 , and the power supply principle of the B-phase branch is as follows: The second switching transistor Q22 conducts. At this time, the grid energy goes from the Neutral terminal of the UPS bus, the second switching transistor Q22, the second inductor L9, and the thyristor Q20 to the grid, and the second inductor L9 stores energy. The second switching transistor Q22 turns off. At this time, the grid energy goes from the Neutral terminal of the UPS bus, the second capacitor C4, the second diode D6, the second inductor L9, and the thyristor Q20 to the grid, and the second inductor L9 releases energy to the second capacitor C4.

[0065] Please refer to Figure 24 , and the power supply principle of the A-phase branch is as follows: The fifth switching transistor Q27 and the sixth switching transistor Q28 are turned on. The grid energy passes through the Neutral terminal of the UPS bus, the sixth switching transistor Q28, the body diode of the fifth switching transistor Q27, the third inductor L7, the relay RLY3 to the grid, and the third inductor L7 stores energy. The fifth switching transistor Q27 and the sixth switching transistor Q28 are turned off. The grid energy passes through the Neutral terminal of the UPS bus, the second capacitor C4, the body diode of the fourth switching transistor Q26, the third inductor L7, the relay RLY3 to the grid, and the third inductor L7 releases energy to the second capacitor C4.

[0066] Similarly, the power supply process of the C-phase branch is as follows: The fifth switching transistor Q29 and the sixth switching transistor Q30 are turned on. The grid energy passes through the Neutral terminal of the UPS bus, the sixth switching transistor Q30, the body diode of the fifth switching transistor Q29, the third inductor L8, the relay RLY4 to the grid, and the third inductor L8 stores energy. The fifth switching transistor Q29 and the sixth switching transistor Q30 are turned off. The grid energy passes through the Neutral terminal of the UPS bus, the second capacitor C4, the body diode of the fourth switching transistor Q24, the third inductor L8, the relay RLY4 to the grid, and the third inductor L8 releases energy to the second capacitor C4.

[0067] In the main circuit feedback mode and during the positive half-cycle of the UPS bus's feedback of mains energy, please refer to Figure 25 , the power feeding process of the A-phase branch is as follows: The third switching transistor Q25 is turned on, the fifth switching transistor Q27 and the sixth switching transistor Q28 are turned off. The energy of the first capacitor C3 passes through the third switching transistor Q25, the third inductor L7, the relay RLY3 to phase A of the grid. The third switching transistor Q25 is turned off, the fifth switching transistor Q27 and the sixth switching transistor Q28 are turned on, and the inductor continues to conduct current through the fifth switching transistor Q27 and the sixth switching transistor Q28. The energy passes from the body diodes of the sixth switching transistor Q28 and the fifth switching transistor Q27, the third inductor L7, the relay RLY3 to phase A of the grid.

[0068] Similarly, the power feeding process of the C-phase is as follows: The fourth switching transistor Q26 is turned on, the fifth switching transistor Q29 and the sixth switching transistor Q30 are turned off. The energy of the second capacitor C4 passes through the fourth switching transistor Q26, the third inductor L8, the relay RLY3 to phase C of the grid. The fourth switching transistor Q26 is turned off, the fifth switching transistor Q29 and the sixth switching transistor Q30 are turned on, and the inductor continues to conduct current through the fifth switching transistor Q29 and the sixth switching transistor Q30. The energy passes from the body diodes of the sixth switching transistor Q30 and the fifth switching transistor Q29, the third inductor L8, the relay RLY4 to phase C of the grid.

[0069] In the main circuit feedback mode and during the negative half-cycle of the UPS bus's feedback of mains energy, please refer to Figure 25, the power feeding process of the A-phase branch is as follows: The fourth switch tube Q26 conducts, the fifth switch tube Q27 and the sixth switch tube Q28 turn off. Energy passes through the A-phase of the power grid, relay RLY3, third inductor L7, fourth switch tube Q26 to the second capacitor C4, and the third inductor L7 stores energy. The fourth switch tube Q26 turns off, the fifth switch tube Q27 and the sixth switch tube Q28 conduct, and energy passes through the A-phase of the power grid, relay RLY3, third inductor L7, and the body diodes of the fifth switch tube Q27 and the sixth switch tube Q28 to the Neutral terminal of the UPS bus.

[0070] Similarly, the power feeding process of the C-phase is as follows: The fourth switch tube Q24 conducts, the fifth switch tube Q29 and the sixth switch tube Q30 turn off. Energy passes through the C-phase of the power grid, relay RLY4, third inductor L8, fourth switch tube Q24 to the second capacitor C4, and the third inductor L7 stores energy. The fourth switch tube Q24 turns off, the fifth switch tube Q29 and the sixth switch tube Q30 conduct, and energy passes through the A-phase of the power grid, relay RLY4, third inductor L8, and the body diodes of the fifth switch tube Q29 and the sixth switch tube Q30 to the Neutral terminal of the UPS bus.

[0071] In this way, this embodiment can convert the three-phase power supply of the power grid into a DC power supply and output it to the UPS bus, and feedback the redundant power on the UPS bus to the power grid through the bidirectional PFC circuit.

[0072] In an embodiment of the present application, the three-phase UPS system has a battery positive-side discharge mode and a battery negative-side discharge mode; In one of the three-phase branches, there is a bidirectional PFC circuit, and the other two phases include double BOOST PFC circuits. In the battery positive-side discharge mode, the double BOOST PFC circuit outputs the forward DC power of the battery to the UPS bus; in the battery negative-side discharge mode, the double BOOST PFC circuit outputs the reverse DC power of the battery to the UPS bus.

[0073] In this embodiment, one of the three-phase branches includes a bidirectional PFC circuit, and the other two phases include double BOOST PFC circuits. Taking the A-phase branch and the C-phase branch as double BOOST PFC circuits and the B-phase branch as a bidirectional PFC circuit as an example.

[0074] In the battery positive-side discharge mode, please refer to Figure 18 And Figure 19, taking the A-phase branch as an example, the wave generation of the C-phase branch and the A-phase branch can be synchronized or operate in a 180° staggered parallel connection. In the A-phase branch, when the first switch tube Q13 is turned on, the energy flows out from the positive terminal of the battery, passes through the thyristor Q4, the first inductor L2, the first switch tube Q13 to the Neutral terminal of the UPS bus, and the first inductor L2 stores energy. When the first switch tube Q13 is turned off, the energy flows out from the positive terminal of the battery, passes through the thyristor Q4, the first inductor L2, the first diode D1, the first capacitor C1 to the Neutral terminal of the UPS bus, and the first inductor L2 releases energy to the first capacitor C1.

[0075] In the battery negative-side discharge mode, please refer to Figure 20 and Figure 21 , taking the A-phase branch as an example, the wave generation of the C-phase branch and the A-phase branch can be synchronized or operate in a 180° staggered parallel connection. In the A-phase branch, when the second switch tube Q14 is turned on, the energy flows out from the Neutral terminal of the UPS bus, passes through the second switch tube Q14, the second inductor L5, the thyristor Q5 to the negative terminal of the battery, and the second inductor L5 stores energy. When Q14 is turned off, the energy flows out from the Neutral terminal of the UPS bus, passes through the second capacitor C2, the second diode D4, the second inductor L5, the thyristor Q5 to the negative terminal of the battery, and the second inductor L5 releases energy.

[0076] In this way, in a three-phase branch where one phase includes a bidirectional PFC circuit and the other two phases include a dual BOOST PFC circuit, the battery can be discharged through the dual BOOST PFC circuit.

[0077] In a three-phase branch where one phase includes a dual BOOST PFC circuit and the other two phases include a bidirectional PFC circuit, the bidirectional PFC circuit of one phase is also connected to the positive electrode of the battery, and the bidirectional PFC circuit of the other phase is also connected to the negative electrode of the battery; in the battery positive-side discharge mode, the dual BOOST PFC circuit and / or the bidirectional PFC circuit of one phase outputs the forward DC power supply of the battery to the UPS bus; in the battery negative-side discharge mode, the dual BOOST PFC circuit and / or the bidirectional PFC circuit of the other phase outputs the reverse DC power supply of the battery to the UPS bus.

[0078] In this embodiment, one phase of the three-phase branch includes a dual BOOST PFC circuit, and the other two phases include a bidirectional PFC circuit. Taking the B-phase branch as the dual BOOST PFC circuit and the A-phase branch and the C-phase branch as the bidirectional PFC circuits as an example.

[0079] In the battery positive-side discharge mode, please refer to Figure 26, in the B-phase branch, the first switching transistor Q21 conducts, and the energy flows out from the positive terminal of the battery, passes through the thyristor Q18, the first inductor L6, the first switching transistor Q21 to the Neutral terminal of the UPS bus, and the first inductor L6 stores energy. When the first switching transistor Q21 turns off, the energy flows out from the positive terminal of the battery, passes through the thyristor Q18, the first inductor L6, the first diode D5, the first capacitor C3 to the Neutral terminal of the UPS bus, and the first inductor L6 releases energy to the first capacitor C3.

[0080] In the A-phase branch, the fifth switching transistor Q27 and the sixth switching transistor Q28 conduct, and the energy flows out from the positive terminal of the battery, passes through the relay RLY2, the third inductor L7, the fifth switching transistor Q27, the sixth switching transistor Q28 to the Neutral terminal of the UPS bus, and the third inductor L7 stores energy. When the fifth switching transistor Q27 and the sixth switching transistor Q28 turn off, the energy flows out from the positive terminal of the battery, passes through the relay RLY2, the third inductor L7, the switching transistor Q25, the first capacitor C3 to the Neutral terminal of the UPS bus, and the third inductor L7 releases energy.

[0081] In the battery negative side discharge mode, please refer to Figure 27 , in the B-phase branch, the second switching transistor Q22 conducts, and the energy flows out from the Neutral terminal of the UPS bus, passes through the second switching transistor Q22, the second inductor L9, the thyristor Q19 to the negative terminal of the battery, and the second inductor L9 stores energy. When Q22 turns off, the energy flows out from the Neutral terminal of the UPS bus, passes through the second capacitor C4, the second diode D6, the second inductor L9, the thyristor Q19 to the negative terminal of the battery, and the second inductor L9 releases energy.

[0082] In the C-phase branch, the fifth switching transistor Q29 and the sixth switching transistor Q30 conduct, and the energy flows out from the Neutral terminal of the UPS bus, passes through the sixth switching transistor Q30, the fifth switching transistor Q29, the third inductor L8, the relay RLY5 to the negative terminal of the battery, and the third inductor L8 stores energy. When the fifth switching transistor Q29 and the sixth switching transistor Q30 turn off, the energy flows out from the Neutral terminal of the UPS bus, passes through the second capacitor C4, the switching transistor Q24, the third inductor L8, the relay RLY5 to the negative terminal of the battery, and the third inductor L8 releases energy.

[0083] In this way, in this embodiment, when one of the three-phase branches includes a dual BOOST PFC circuit and the other two phases include a bidirectional PFC circuit, the power of the battery can be output to the UPS bus through the dual BOOST PFC circuit, and when one of the three-phase branches includes a bidirectional PFC circuit and the other two phases include a dual BOOST PFC circuit, the power of the battery can be output to the UPS bus through the dual BOOST PFC circuit and / or the bidirectional PFC circuit.

[0084] The present application also provides a power supply device, which includes a battery and a three-phase UPS system. The battery is connected to the dual BOOST PFC circuit of the three-phase UPS system. For the specific structure of the three-phase UPS system, refer to the above embodiments. Since this power supply device adopts all the technical solutions of the above embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be elaborated here one by one.

[0085] The above description is only an exemplary embodiment of the present application and does not limit the patent scope of the present application. Any equivalent structural transformation made under the technical concept of the present application by using the content of the specification and drawings of the present application, or any direct / indirect application in other related technical fields is included in the patent protection scope of the present application.

Claims

1. A three-phase UPS system, characterized in that, Comprising: Three-phase power supply access terminals for accessing the power grid; Three-phase branches, where one of the three phases includes a bidirectional PFC circuit, and the other two phases include dual BOOST PFC circuits, or one of the three phases includes dual BOOST PFC circuits, and the other two phases include bidirectional PFC circuits; wherein, the bidirectional PFC circuit is respectively connected to the three-phase power supply access terminals and the UPS bus of the three-phase UPS system, and the dual BOOST PFC circuit is respectively connected to the three-phase power supply access terminals, the battery, and the UPS bus of the three-phase UPS system; The three-phase branches are used to convert the three-phase power supply of the power grid into a DC power supply and output it to the UPS bus respectively through the bidirectional PFC circuit and the dual BOOST PFC circuit, and / or output the power of the battery to the UPS bus through the dual BOOST PFC circuit, and are also used to feedback the excess power on the UPS bus to the power grid through the bidirectional PFC circuit.

2. The three-phase UPS system according to claim 1, wherein The dual BOOST PFC circuit includes a first inductor, a second inductor, a first diode, a second diode, a first switching tube integrated with an anti-parallel diode, a second switching tube integrated with an anti-parallel diode, a first capacitor and a second capacitor; One end of the first inductor and one end of the second inductor are respectively connected to one phase of the three-phase power supply access terminals and the battery. The other end of the first inductor, the first end of the first switching tube and the positive pole of the first diode are connected. The second end of the first switching tube, the neutral point of the UPS bus, one end of the first capacitor and one end of the second capacitor are connected to the first end of the second switching tube. The other end of the second inductor, the second end of the second switching tube and the negative pole of the second diode are connected. The negative pole of the first diode, the other end of the first capacitor are connected to the positive pole of the UPS bus. The positive pole of the second diode, the other end of the second capacitor are connected to the negative pole of the UPS bus.

3. The three-phase UPS system according to claim 2, wherein The dual BOOST PFC circuit further includes a first rectification switching unit, a second rectification switching unit, a third rectification switching unit and a fourth rectification switching unit; The input end of the first rectification switching unit, the output end of the second rectification switching unit are connected to one phase of the three-phase power supply access terminals. The output end of the first rectification switching unit is connected to one end of the first inductor. The input end of the second rectification switching unit is connected to one end of the second inductor; The input end of the third rectification switching unit is connected to the positive pole of the battery. The output end of the fourth rectification switching unit is connected to the negative pole of the battery. The output end of the third rectification switching unit is connected to one end of the first inductor. The input end of the fourth rectification switching unit is connected to one end of the second inductor.

4. The three-phase UPS system according to claim 1, characterized in that, The bidirectional PFC circuit includes a third inductor, a third switching tube integrated with an anti-parallel diode, a fourth switching tube integrated with an anti-parallel diode, a fifth switching tube integrated with an anti-parallel diode, a sixth switching tube integrated with an anti-parallel diode, a third capacitor and a fourth capacitor; One end of the third inductor is connected to one phase of the three-phase power supply access terminal. The other end of the third inductor, the first end of the fourth switching transistor, and the first end of the fifth switching transistor are connected to the second end of the third switching transistor. The second end of the fifth switching transistor is connected to the second end of the sixth switching transistor. The first end of the sixth switching transistor, one end of the third capacitor, and one end of the fourth capacitor are connected to the neutral terminal of the UPS bus. The first end of the third switching transistor and the other end of the third capacitor are connected to the positive terminal of the UPS bus. The second end of the fourth switching transistor and the other end of the fourth capacitor are connected to the negative terminal of the UPS bus.

5. The three-phase UPS system according to claim 4, characterized in that, When one phase of the three-phase branch includes a bidirectional PFC circuit and the other two phases include dual BOOST PFC circuits, the bidirectional PFC circuit further includes a first switch switching unit. One end of the first switch switching unit is connected to one phase of the three-phase power supply access terminal, and the other end of the first switch switching unit is connected to one end of the third inductor.

6. The three-phase UPS system according to claim 4, wherein, When one phase of the three-phase branch includes a dual BOOST PFC circuit and the other two phases include a bidirectional PFC circuit, the bidirectional PFC circuit further includes a second switch switching unit and a third switch switching unit; One end of the second switch switching unit is connected to one phase of the three-phase power supply access terminal. The other end of the second switch switching unit and one end of the third switch switching unit are connected to one end of the third inductor, and the other end of the third switch switching unit is connected to the battery.

7. The three-phase UPS system according to claim 6, wherein The three-phase branch is further configured to output the power of the battery to the UPS bus through the bidirectional PFC circuit when the third switch switching unit turns on the circuit between one end of the third inductor and the battery.

8. The three-phase UPS system according to any one of claims 1 to 7, characterized in that, The three-phase UPS system has a main path mode and a main path feedback mode; Among the three-phase branches, one phase includes a bidirectional PFC circuit and the other two phases include dual BOOST PFC circuits. In the main path mode, the bidirectional PFC circuit converts one phase of the three-phase power into a DC power supply and outputs it to the UPS bus, and the dual BOOST PFC circuits convert the other two phases of the three-phase power into DC power supplies and output them to the UPS bus respectively; In the main path feedback mode, the bidirectional PFC circuit feeds back the DC power supply on the UPS bus to one phase of the power grid; Among the three-phase branches, one phase includes a dual BOOST PFC circuit and the other two phases include a bidirectional PFC circuit. In the main path mode, the dual BOOST PFC circuit converts one phase of the three-phase power into a DC power supply and outputs it to the UPS bus, and the bidirectional PFC circuits convert the other two phases of the three-phase power into DC power supplies and output them to the UPS bus respectively; In the main path feedback mode, the bidirectional PFC circuit feeds back the DC power supply on the UPS bus to two phases of the power grid.

9. The three-phase UPS system according to any one of claims 1 to 7, characterized in that, The three-phase UPS system has a battery positive-side discharge mode and a battery negative-side discharge mode; In one of the three-phase branches includes a bidirectional PFC circuit, and the other two phases include dual BOOST PFC circuits, In the positive-side battery discharge mode, the dual BOOST PFC circuit outputs the forward DC power of the battery to the UPS bus; In the negative-side battery discharge mode, the dual BOOST PFC circuit outputs the reverse DC power of the battery to the UPS bus; In one of the three-phase branches includes a dual BOOST PFC circuit, and the other two phases include bidirectional PFC circuits, the bidirectional PFC circuit of one phase is also connected to the positive electrode of the battery, and the bidirectional PFC circuit of the other phase is also connected to the negative electrode of the battery; In the positive-side battery discharge mode, the dual BOOST PFC circuit and / or the bidirectional PFC circuit of one phase outputs the forward DC power of the battery to the UPS bus; In the negative-side battery discharge mode, the dual BOOST PFC circuit and / or the bidirectional PFC circuit of the other phase outputs the reverse DC power of the battery to the UPS bus.

10. A power supply device, characterized in that, Comprising a battery and a three-phase UPS system according to any one of claims 1 to 9, the battery is connected to the dual BOOST PFC circuit.

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