Three-phase active PFC circuit, circuit board, controller, and air conditioner

Abstract

Disclosed in the present application are a three-phase active PFC circuit, a circuit board, a controller, and an air conditioner. The three-phase active PFC circuit comprises an input filter module (100), a bidirectional switch module (200), a three-phase rectifier module (300) and an output filter module (400), wherein the input filter module (100) comprises three input filter inductors and three input filter capacitors; one end of each of the three input filter inductors is connected to a three-phase alternating-current power source, and the other end thereof is connected to one end of a respective one of the three input filter capacitors; the other ends of the three input filter capacitors are connected together; the bidirectional switch module (200) comprises three bidirectional controllable switches, one end of each of the three bidirectional controllable switches is connected to a connection point between a respective one of the three input filter inductors and a respective one of the three input filter capacitors, and the other end thereof is connected to an alternating-current input end of the three-phase rectifier module (300); and the output filter module (400) is connected to a direct-current output end of the three-phase rectifier module (300).

Description

Three-phase active PFC circuit, circuit board, controller and air conditioner

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese patent application number 202410388357.5 filed on April 1, 2024, entitled “Three-phase active PFC circuit, circuit board, controller and air conditioner”. The entire contents of the above patent application are incorporated into this application by reference. Technical Field

[0003] The present application relates to the technical field of air-conditioning circuits, and in particular to a three-phase active PFC circuit, a circuit board, a controller, and an air conditioner. Background Art

[0004] Active PFC circuits include boost active PFC and buck active PFC. Common three-phase boost active PFC circuits increase the DC voltage on the load side, requiring high-voltage power devices on the load side, increasing costs. Furthermore, higher clearances are required for traces to meet safety regulations, increasing product size. Furthermore, high losses in high-voltage devices reduce system efficiency.

[0005] Using a three-phase buck active PFC circuit can reduce the DC voltage on the load side, thereby avoiding the above problems. However, the three bridge arms of the controlled rectifier bridge of the commonly used three-phase buck active PFC circuit all include upper and lower switching tubes, with a total of six controllable switching tubes that need to be individually controlled. In other words, six independent drive circuits are required, which is more difficult and expensive to drive. Summary of the Invention

[0006] The purpose of the present application is to at least partially solve one of the technical problems existing in the related art, and to this end provide a three-phase active PFC circuit, a circuit board, a controller and an air conditioner.

[0007] In a first aspect, an embodiment of the present application provides a three-phase active PFC circuit, comprising an input filter module, a bidirectional switch module, a three-phase rectifier module and an output filter module, wherein the input filter module comprises three input filter inductors and three input filter capacitors; one end of the three input filter inductors is respectively connected to a three-phase AC power supply, and the other end is respectively connected to one end of the three input filter capacitors; the other ends of the three input filter capacitors are connected together; the bidirectional switch module comprises three bidirectional controllable switches, one end of the three bidirectional controllable switches is respectively connected to the connection points of the three input filter inductors and the three input filter capacitors; the other ends of the three bidirectional controllable switches are respectively connected to the AC input end of the three-phase rectifier module; and the output filter module comprises a first output filter inductor and a first output filter capacitor connected in series, and the output filter module is connected to the DC output end of the three-phase rectifier module.

[0008] According to some embodiments of the present application, the three-phase active PFC circuit further includes a freewheeling module, wherein the positive electrode of the freewheeling module is connected to the negative electrode of the DC output terminal of the three-phase rectifier module, and the negative electrode of the freewheeling module is connected to the positive electrode of the DC output terminal of the three-phase rectifier module.

[0009] According to some embodiments of the present application, a three-phase active PFC circuit is provided, wherein the three-phase rectifier module includes a first bridge arm formed by a first diode and a second diode connected in series, a second bridge arm formed by a third diode and a fourth diode connected in series, and a third bridge arm formed by a fifth diode and a sixth diode connected in series, and the first bridge arm, the second bridge arm, and the third bridge arm are connected in parallel to each other.

[0010] According to some embodiments of the present application, the three-phase active PFC circuit provided by the three-phase rectifier module includes a first bridge arm formed by a first switch tube and a second switch tube connected in series, a second bridge arm formed by a third switch tube and a fourth switch tube connected in series, and a third bridge arm formed by a fifth switch tube and a sixth switch tube connected in series. The first bridge arm, the second bridge arm and the third bridge arm are connected in parallel with each other, and the first switch tube, the second switch tube, the third switch tube, the fourth switch tube, the fifth switch tube and the sixth switch tube are provided with anti-parallel diodes or without anti-parallel diodes.

[0011] According to the three-phase active PFC circuit provided in some embodiments of the present application, the bidirectional controllable switch includes a seventh switch tube and an eighth switch tube connected in series, the seventh switch tube and the eighth switch tube have opposite conduction directions and are respectively provided with an anti-parallel diode.

[0012] According to some embodiments of the present application, the three-phase active PFC circuit provided by the bidirectional controllable switch includes a forward conducting branch and a reverse conducting branch connected in parallel, the forward conducting branch includes a ninth switching tube and a seventh diode connected in series, and the reverse conducting branch includes a tenth switching tube and an eighth diode connected in series.

[0013] According to some embodiments of the present application, the three-phase active PFC circuit provided by the bidirectional controllable switch includes a fourth bridge arm formed by a ninth diode and a tenth diode connected in series, a fifth bridge arm formed by an eleventh diode and a twelfth diode connected in series, and a sixth bridge arm formed by the eleventh switch tube, and the fourth bridge arm, the fifth bridge arm, and the sixth bridge arm are connected in parallel to each other.

[0014] According to the three-phase active PFC circuit provided by some embodiments of the present application, the bidirectional controllable switch includes a RB-IGBT device.

[0015] According to the three-phase active PFC circuit provided in some embodiments of the present application, the output filter module further includes a second output filter inductor, and the first output filter inductor, the first output filter capacitor and the second output filter inductor are connected in sequence.

[0016] According to the three-phase active PFC circuit provided by some embodiments of the present application, the freewheeling module includes a thirteenth diode.

[0017] According to the three-phase active PFC circuit provided in some embodiments of the present application, the freewheeling module includes a twelfth switch tube, and the twelfth switch tube is provided with an anti-parallel diode or is not provided with an anti-parallel diode.

[0018] According to some embodiments of the present application, the three-phase active PFC circuit is provided, and the bidirectional switch module alternately switches between a first state, a second state, a third state, and a fourth state. The first state is when all three bidirectional controllable switches are off, the second state is when one of the three bidirectional controllable switches whose corresponding phase voltage is greater than zero and one of the three bidirectional controllable switches whose corresponding phase voltage is less than zero are simultaneously turned on, the third state is when all three bidirectional controllable switches are turned on, and the fourth state is when one of the three bidirectional controllable switches is turned on.

[0019] In a second aspect, an embodiment of the present application provides a circuit board comprising the three-phase active PFC circuit as described in the embodiment of the first aspect above.

[0020] In a third aspect, an embodiment of the present application provides a controller comprising the circuit board described in the embodiment of the second aspect above.

[0021] In a fourth aspect, an embodiment of the present application provides an air conditioner, comprising the circuit board as described in the embodiment of the second aspect or the controller as described in the embodiment of the third aspect.

[0022] Other features and advantages of the present application will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present application. The purposes and other advantages of the present application can be realized and obtained through the structures particularly pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings are used to provide a further understanding of the technical solution of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of the present application and do not constitute a limitation on the technical solution of the present application.

[0024] The present application is further described below with reference to the accompanying drawings and embodiments;

[0025] FIG1 is a circuit diagram of a three-phase Boost active PFC circuit;

[0026] Figure 2 is a schematic diagram of a three-phase Buck active PFC circuit;

[0027] FIG3 is a schematic diagram of the phase sequence and sector division of a three-phase AC power supply;

[0028] FIG4 a is a circuit schematic diagram of a three-phase active PFC circuit provided in an embodiment of the present application;

[0029] FIG4 b is a circuit schematic diagram of a three-phase active PFC circuit provided in another embodiment of the present application;

[0030] FIG4 c is a circuit schematic diagram of a three-phase active PFC circuit provided in yet another embodiment of the present application;

[0031] FIG5 a is a circuit schematic diagram of a three-phase active PFC circuit provided in yet another embodiment of the present application;

[0032] FIG5 b is a circuit schematic diagram of a three-phase active PFC circuit provided in yet another embodiment of the present application;

[0033] FIG5 c is a circuit schematic diagram of a three-phase active PFC circuit provided in yet another embodiment of the present application;

[0034] FIG6 is a circuit schematic diagram of a three-phase active PFC circuit provided in yet another embodiment of the present application;

[0035] FIG7 is a circuit schematic diagram of a three-phase active PFC circuit provided in yet another embodiment of the present application;

[0036] FIG8 a is a device schematic diagram of an implementation of a bidirectional controllable switch provided in an embodiment of the present application;

[0037] FIG8 b is a device schematic diagram of another implementation of a bidirectional controllable switch provided in an embodiment of the present application;

[0038] FIG8 c is a device schematic diagram of another implementation of a bidirectional controllable switch provided in an embodiment of the present application;

[0039] FIG8 d is a device schematic diagram of another implementation of a bidirectional controllable switch provided in an embodiment of the present application. DETAILED DESCRIPTION

[0040] This section will describe the specific embodiments of the present application in detail. The preferred embodiments of the present application are shown in the accompanying drawings. The purpose of the accompanying drawings is to supplement the description of the text part of the specification with graphics, so that people can intuitively and vividly understand each technical feature and overall technical solution of the present application, but it cannot be understood as a limitation on the scope of protection of the present application.

[0041] In the description of the embodiments of this application, "several" means one or more, "more" means more than two, "greater than," "less than," and "exceed" are understood to exclude the number itself, and "above," "below," and "within" are understood to include the number itself. "At least one" means one or more, "at least one of the following" and similar expressions refer to any combination of these items, including any combination of single or plural items. If "first," "second," or the like is used in the description, it is only for the purpose of distinguishing technical features and is not to be understood as indicating or implying relative importance, or implicitly indicating the number of the indicated technical features, or implicitly indicating the order of the indicated technical features.

[0042] It should be noted that the terms "dispose," "install," and "connect" in the embodiments of this application should be interpreted broadly. Those skilled in the art can reasonably determine the specific meanings of these terms in the embodiments of this application based on the specific content of the technical solution. For example, the term "connect" can refer to mechanical connection, electrical connection, or communication; it can refer to direct connection or indirect connection through an intermediary.

[0043] It should be noted that the technical features involved in the various embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0044] As power grid requirements for harmonics increase, power factor correction (PFC) circuits have become standard for all electrical products. There are two common methods for power factor correction: passive and active. Passive PFC primarily uses a large reactor connected in series with the power input to filter the current, but generally results in a lower power factor. Compared to passive PFC, active PFC uses high-frequency switching devices, achieving a power factor of 0.99 while significantly reducing the size and weight of the reactor, effectively increasing the product's power density.

[0045] Boost is the most common approach in the industry for active PFC. Three-phase active PFC circuits include three-phase boost active PFC and three-phase buck active PFC. Common three-phase boost active PFC topologies include two-level and three-level. Both topologies boost the DC voltage on the load side when converting AC to DC.

[0046] Currently, the commonly used three-phase Boost active PFC circuit is shown in Figure 1. This circuit uses a three-phase Vienna topology. The DC voltage on the load side increases, which requires high-voltage power devices on the load side, increasing costs. In addition, the wiring requires a higher clearance to meet safety regulations, resulting in an increase in product size. In addition, the high-voltage device loss is large, reducing system efficiency. Specifically, when the line voltage of the three-phase AC power input is 380V, with PFC turned on, if the A phase voltage v a >B phase voltage v b , switch tubes T1 to T4 are turned on, and the current from phase A passes through inductor L1, switch tube T1, switch tube T2, switch tube T4, switch tube T3, inductor L2 in sequence, and finally flows into phase B. During this stage, inductor L1 and inductor L2 store energy; when switch tubes T1 to T4 are turned off, the current from phase A passes through inductor L1, diode D1, capacitor C1, capacitor C2, diode D4, inductor L2 in sequence, and finally flows into phase B. During this stage, inductor L1 and inductor L2 release energy, and the voltage loaded on capacitor C1 and capacitor C2 is the output voltage v o , then v AB +v L1 +v L2 -v o =0, in this mode, the switch tubes T1 to T4 are switched according to v AB (t) Real-time adjustment of the conduction duty cycle D(t), the output voltage Since 0≤D(t)<1, the output voltage v o ≥v AB In three-phase applications, the output voltage will reach over 600V. Such a high voltage is a great challenge for the devices on the load side.

[0047] Therefore, a three-phase Buck active PFC circuit as shown in Figure 2 is proposed, in which the three bridge arms of the controlled rectifier bridge each include an upper switch tube and a lower switch tube, with a total of six controllable switch tubes that need to be individually controlled. In other words, six independent drive circuits are required, which has great driving difficulty and high driving cost. Specifically, as shown in Figure 2, the three-phase AC power supply is first filtered by LC, such as inductor L1 and capacitor C1, inductor L2 and capacitor C2, inductor L3 and capacitor C3 in Figure 2, and then enters the controlled rectifier bridge. Each bridge arm of the controlled rectifier bridge is a reverse resistance type, consisting of a controllable switch device and a diode in series, such as switch tube T1 and diode D1, switch tube T2 and diode D2, switch tube T3 and diode D3, switch tube T4 and diode D4, switch tube T5 and diode D5, and switch tube T6 and diode D6 in Figure 2. After rectification, the current is filtered by LC and then output, as shown in the inductor L4, inductor L5 and capacitor C4 in Figure 2. When the controlled rectifier bridge is closed, the current in the inductor L4 and inductor L5 is freewheeling through the diode D7. According to the characteristics of the voltage waveform of the three-phase AC power supply, as shown in Figure 3, it is divided into 12 sectors within one cycle and controlled separately. For example, within the sector, v a >0, v b <v c <0, when the switch tube on the controlled rectifier bridge is turned on, the current flows from phase A (phase voltage greater than 0) to phase B and phase C (phase voltage less than 0). Among them, when phase A flows into phase B, the upper bridge switch tube T1 of phase A and the lower bridge switch tube T4 of phase B are turned on, and the current flows from the phase A power supply through the inductor L1, diode D1, switch tube T1, inductor L4, capacitor C4, inductor L5, switch tube T4, diode D4, inductor L2 and then flows into the phase B power supply. At this time, v AB -v L1 -v L4 -v L5 -v L2 -v o =0; when the current flows from phase A to phase C, the upper bridge switch T1 of phase A and the lower bridge switch T6 of phase C are turned on, and the current flows from the power supply of phase A through the inductor L1, diode D1, switch T1, inductor L4, capacitor C4, inductor L5, switch T6, diode D6, and inductor L3 to the power supply of phase C. At this time, v AC -v L1 -v L4 -v L5 -v L3 -v o =0; When the switch tubes T1 to T6 are all turned off, the inductors L1 to L3 continue to flow through the capacitors C1 to C3 respectively, while the inductors L4 and L5 continue to flow through the diode D7. At this time, v L4 +vL5 +v D7 -v o = 0. In this sector, the switch's on-duty cycle is D(t), and the output voltage is v o =v(t)×D(t), v(t)∈(v AB ,v AC ), since D(t) ≤ 1, the output voltage is lower than the input voltage. In this circuit topology, the controlled rectifier bridge consists of six controllable switches, T1 through T6, and these six switches switch independently. Therefore, six independent drive circuits are required, increasing the difficulty and cost of driving.

[0048] Based on this, the embodiments of the present application provide a three-phase active PFC circuit, circuit board, controller and air conditioner, which can simplify the control logic and reduce the driving difficulty, thereby saving the driving circuit and reducing the driving cost.

[0049] The embodiments of the present application are further described below with reference to the accompanying drawings.

[0050] 4a to 7 , a first embodiment of the present application provides a three-phase active PFC circuit, including an input filter module 100 , a bidirectional switch module 200 , a three-phase rectifier module 300 , and an output filter module 400 , wherein:

[0051] The input filter module 100 includes three input filter inductors and three input filter capacitors; one end of the three input filter inductors is respectively connected to the three-phase AC power supply, and the other end is respectively connected to one end of the three input filter capacitors; the other ends of the three input filter capacitors are connected together; specifically, as shown in Figures 4a to 7, the three input filter inductors are inductor L1, inductor L2 and inductor L3, and the three input filter capacitors are capacitor C1, capacitor C2 and capacitor C3; one end of the inductor L1 is connected to phase A of the three-phase AC power supply, and the other end of the inductor L1 is connected to one end of the capacitor C1; one end of the inductor L2 is connected to phase B of the three-phase AC power supply, and the other end of the inductor L2 is connected to one end of the capacitor C2; one end of the inductor L3 is connected to phase C of the three-phase AC power supply, and the other end of the inductor L3 is connected to one end of the capacitor C3; the other end of the capacitor C1, the other end of the capacitor C2 and the other end of the capacitor C3 are connected together.

[0052] The bidirectional switch module 200 includes three bidirectional controllable switches, one end of each of the three bidirectional controllable switches being connected to the connection point of the three input filter inductors and the three input filter capacitors, respectively; the other ends of each of the three bidirectional controllable switches being connected to the AC input end of the three-phase rectifier module 300, respectively. Specifically, as shown in Figures 4a to 7, the bidirectional switch module 200 includes a first bidirectional controllable switch 210, a second bidirectional controllable switch 220, and a third bidirectional controllable switch 230. One end of the first bidirectional controllable switch 210 is connected to the connection point of the inductor L1 and the capacitor C1, one end of the second bidirectional controllable switch 220 is connected to the connection point of the inductor L2 and the capacitor C2, and one end of the third bidirectional controllable switch 230 is connected to the connection point of the inductor L3 and the capacitor C3. The other ends of the first bidirectional controllable switch 210, the second bidirectional controllable switch 220, and the third bidirectional controllable switch 230 are respectively connected to the AC input end of the three-phase rectifier module 300, that is, respectively connected to the midpoints of the three rectifier bridge arms of the three-phase rectifier module 300.

[0053] The output filter module 400 includes a first output filter inductor and a first output filter capacitor connected in series, and the output filter module 400 is connected to the DC output terminal of the three-phase rectifier module 300. Specifically, the output filter module 400 includes a first output filter inductor L4 and a first output filter capacitor C4, and their connection relationship is shown in Figure 4b or Figure 4c; Referring to Figure 4b, the positive pole of the DC output terminal of the three-phase rectifier module 300 is connected to one end of the first output filter inductor L4, the other end of the first output filter inductor L4 is connected to one end of the first output filter capacitor C4, and the other end of the first output filter capacitor C4 is connected to the negative pole of the DC output terminal of the three-phase rectifier module 300; Referring to Figure 4c, the positive pole of the DC output terminal of the three-phase rectifier module 300 is connected to one end of the first output filter capacitor C4, the other end of the first output filter capacitor C4 is connected to one end of the first output filter inductor L4, and the first output filter inductor The other end of L4 is connected to the negative pole of the DC output terminal of the three-phase rectifier module 300; in addition, referring to Figure 4a, the output filter module 400 may also include a second output filter inductor L5, that is, the output filter module 400 also includes a first output filter inductor L4, a first output filter capacitor C4 and a second output filter inductor L5, the positive pole of the DC output terminal of the three-phase rectifier module 300 is connected to one end of the first output filter inductor L4, the other end of the first output filter inductor L4 is connected to one end of the first output filter capacitor C4, the other end of the first output filter capacitor C4 is connected to one end of the second output filter inductor L5, and the other end of the second output filter inductor L5 is connected to the negative pole of the DC output terminal of the three-phase rectifier module 300.

[0054] According to the three-phase active PFC circuit provided by some embodiments of the present application, a bidirectional switch module 200 is provided between the input filter module 100 and the three-phase rectifier module 300, and power factor correction is achieved by controlling the on and off of the three bidirectional controllable switches in the bidirectional switch module 200. When the bidirectional switch module 200 is turned on, the current flows from the phase voltage greater than zero to the phase voltage less than zero. When the bidirectional switch module 200 is turned off, the three input filter inductors are freewheeling through the three input filter capacitors. At the same time, the output filter module 400 can pass through the three-phase rectifier module 30 0 for freewheeling; since the three bidirectional controllable switches are connected in series between the input filter module 100 and the three-phase rectifier module 300, there is no distinction between upper and lower bridge arms. When current flows into or out of a phase, the corresponding bidirectional controllable switch can be controlled to be on or off. Only three drive signals need to be configured to control the three bidirectional controllable switches respectively, and there is no need to control the upper switch tubes and lower switch tubes of the three rectifier bridge arms respectively according to the current flow direction. That is, compared with the three-phase buck active PFC circuit in the related art, it can simplify the control logic, reduce the driving difficulty, thereby saving the driving circuit and reducing the driving cost.

[0055] 5a to 5c , the three-phase active PFC circuit provided in some embodiments of the present application further includes a freewheeling module 500, wherein the positive electrode of the freewheeling module 500 is connected to the negative electrode of the DC output terminal of the three-phase rectifier module 300, and the negative electrode of the freewheeling module 500 is connected to the positive electrode of the DC output terminal of the three-phase rectifier module 300. Specifically, as shown in FIG5a to 5c , the freewheeling module 500 includes a thirteenth diode D13, wherein the positive electrode of the thirteenth diode D13 is connected to the negative electrode of the DC output terminal of the three-phase rectifier module 300, and the negative electrode of the thirteenth diode D13 is connected to the positive electrode of the DC output terminal of the three-phase rectifier module 300.

[0056] It is understood that the provision of the freewheeling module 500 allows the output filter module 400 to freewheel through the freewheeling module 500 when the bidirectional switch module 200 is turned off, thereby eliminating the need for freewheeling through the three-phase rectifier module 300. Compared to freewheeling through the three-phase rectifier module 300, the freewheeling loop through the thirteenth diode D13 is shorter and has lower losses.

[0057] In some embodiments of the present application, a three-phase active PFC circuit is provided. The three-phase rectifier module 300 includes a first bridge arm formed by a first diode and a second diode connected in series, a second bridge arm formed by a third diode and a fourth diode connected in series, and a third bridge arm formed by a fifth diode and a sixth diode connected in series. The first, second, and third bridge arms are connected in parallel. For example, referring to Figures 4a to 4c and Figures 5a to 5c, the first bridge arm of the three-phase rectifier module 300 is formed by a diode D1 and a diode D2 connected in series, the second bridge arm is formed by a diode D3 and a diode D4 connected in series, and the third bridge arm is formed by a diode D5 and a diode D6 connected in series. The other end of the first bidirectional controllable switch 210 is connected to the junction point of the diode D1 and the diode D2, the other end of the second bidirectional controllable switch 220 is connected to the junction point of the diode D3 and the diode D4, and the other end of the third bidirectional controllable switch 230 is connected to the junction point of the diode D5 and the diode D6. It is understood that the three-phase rectifier module 300 formed using diodes D1 to D6 is an uncontrolled rectifier.

[0058] In some other embodiments of the present application, the three-phase active PFC circuits provided in the three-phase rectifier module 300 of FIG. 4a to FIG. 4c and FIG. 5a to FIG. 5c include the first diode, the second diode, the third diode, the fourth diode, the fifth diode, and the sixth diode respectively replaced by six switch tubes, or respectively replaced by six switch tubes with anti-parallel diodes. For example, referring to FIG. 7 , the three-phase rectifier module 300 includes a first bridge arm formed by a first switch tube Q1 and a second switch tube Q2 connected in series, a first bridge arm formed by a third switch tube Q3 and a fourth switch tube Q4 connected in series, and a first bridge arm formed by a third switch tube Q4 and a fourth switch tube Q5 connected in series. The second bridge arm formed by the series connection of the switching transistor Q4, the third bridge arm formed by the series connection of the fifth switching transistor Q5 and the sixth switching transistor Q6, the first bridge arm, the second bridge arm, and the third bridge arm are connected in parallel; the first switching transistor Q1, the second switching transistor Q2, the third switching transistor Q3, the fourth switching transistor Q4, the fifth switching transistor Q5, and the sixth switching transistor Q6 can be equipped with anti-parallel diodes as shown in FIG7, or the first switching transistor Q1, the second switching transistor Q2, the third switching transistor Q3, the fourth switching transistor Q4, the fifth switching transistor Q5, and the sixth switching transistor Q6 can also be equipped with anti-parallel diodes.

[0059] In addition, it is understandable that there are multiple implementations of the bidirectional controllable switch. In the three-phase active PFC circuit provided in some embodiments of the present application, the implementation of the bidirectional controllable switch includes the following:

[0060] Case 1: The seventh and eighth switching transistors are connected in series, and the conduction directions of the seventh and eighth switching transistors are opposite and they are respectively provided with anti-parallel diodes. For example, referring to the first bidirectional controllable switch 210 in FIG4 a , the switch 210 includes a switch T1 and a switch T2 connected in series; referring to the second bidirectional controllable switch 220 in FIG4 a , the switch 220 includes a switch T3 and a switch T4 connected in series; referring to the third bidirectional controllable switch 230 in FIG4 a , the switch 230 includes a switch T5 and a switch T6 connected in series; wherein, referring to FIG4 a , the switches T1 to T6 are all provided with anti-parallel diodes.

[0061] Case 2: including a forward conducting branch and a reverse conducting branch connected in parallel, the forward conducting branch including a ninth switch and a seventh diode connected in series, and the reverse conducting branch including a tenth switch and an eighth diode connected in series. For example, referring to FIG8 a , the forward conducting branch includes a switch T7 and a diode D7 connected in series, and the reverse conducting branch includes a switch T8 and a diode D8 connected in series. In addition, by swapping the positions of the switch T7 and the diode D7 in the forward conducting branch, and swapping the positions of the switch T8 and the diode D8 in the reverse conducting branch, a bidirectional controllable switch as shown in FIG8 b can be obtained.

[0062] Case 3: including a fourth bridge arm formed by a ninth diode and a tenth diode connected in series, a fifth bridge arm formed by an eleventh diode and a twelfth diode connected in series, and a sixth bridge arm formed by an eleventh switch tube; for example, referring to FIG8 c , the fourth bridge arm is formed by a diode D9 and a diode D10 connected in series; the fifth bridge arm is formed by a diode D11 and a diode D12 connected in series; and the sixth bridge arm is formed by a switch tube T9; the fourth bridge arm, the fifth bridge arm, and the sixth bridge arm are connected in parallel;

[0063] Case 4: including RB-IGBT devices, as shown in FIG. 8 d .

[0064] It should be noted that the above four situations are examples of some feasible embodiments of the bidirectional controllable switch, and do not limit the bidirectional controllable switch in the bidirectional switch module 200 of the invention to only adopt the above four implementation methods. Any other circuit with bidirectional opening and closing controllable functions can be adopted, as long as the bidirectional opening and closing controllable between the input filter module 100 and the three-phase rectifier module 300 can be achieved.

[0065] In the three-phase active PFC circuit provided in some embodiments of the present application, the thirteenth diode D13 in Figures 5a to 5c is replaced by a switch tube, or is replaced by a switch tube with an anti-parallel diode. For example, referring to Figures 6 and 7, the freewheeling module 500 includes a twelfth switch tube Q7. The twelfth switch tube Q7 may be provided with an anti-parallel diode as shown in Figures 6 and 7, or the twelfth switch tube Q7 may not be provided with an anti-parallel diode.

[0066] In the three-phase active PFC circuit provided in some embodiments of the present application, the bidirectional switch module 200 alternately switches between a first state, a second state, a third state, and a fourth state. In the first state, all three bidirectional controllable switches are off. In the second state, one of the three bidirectional controllable switches whose corresponding phase voltage is greater than zero and one of the three bidirectional controllable switches whose corresponding phase voltage is less than zero are both turned on. In the third state, all three bidirectional controllable switches are turned on. In the fourth state, one of the three bidirectional controllable switches is turned on. Specifically, the embodiment shown in FIG5a is used as an example for description. In combination with the phase sequence and sector division of the three-phase AC power supply shown in FIG3, in Inside the fan room, v a >0, v b <v c <0, when the bidirectional switch module 200 is turned on, the current flows from the phase A whose phase voltage is greater than 0 into the phase B and phase C whose phase voltage is less than 0 respectively; it can be understood that within this sector, the second state may include two situations. The first is that the first bidirectional controllable switch 210 corresponding to A and the second bidirectional controllable switch 220 corresponding to B are turned on, and the third bidirectional controllable switch 230 corresponding to C is turned off. The current flows from the A phase power supply through the inductor L1, the switch tube T1, the switch tube T2, the diode D1, the inductor L4, the capacitor C4, the inductor L5, the diode D4, the switch tube T4, the switch tube T3, and the inductor L2 to the B phase power supply. At this time, v AB -v L1 -v L4 -v L5 -v L2 -v o =0; In the second case, the first bidirectional controllable switch 210 corresponding to phase A is turned on, the second bidirectional controllable switch 220 corresponding to phase B is turned off, and the third bidirectional controllable switch 230 corresponding to phase C is turned on. The current flows from the phase A power supply through the inductor L1, the switch tube T1, the switch tube T2, the diode D1, the inductor L4, the capacitor C4, the inductor L5, the diode D6, the switch tube T6, the switch tube T5, and the inductor L3 and then flows into the phase C power supply. At this time, v AC -v L1 -v L4 -v L5 -v L3 -v o=0; In addition, in this sector, the third state is that the first bidirectional controllable switch 210 corresponding to A, the second bidirectional controllable switch 220 corresponding to B, and the third bidirectional controllable switch 230 corresponding to C are all turned on; the first state is that the first bidirectional controllable switch 210 corresponding to A, the second bidirectional controllable switch 220 corresponding to B, and the third bidirectional controllable switch 230 corresponding to C are all turned off, and the inductors L1 to L3 are freewheeling through the capacitors C1 to C3 respectively, while the inductors L4 and L5 are freewheeling through the diode D13. At this time, v L4 +v L5 +v D13 -v o = 0. In this sector, the switch's on-duty cycle is D(t), and the output voltage is v o =v(t)×D(t), v(t)∈(v AB ,v AC ), since D(t)≤1, the output voltage is lower than the input voltage, thus achieving voltage step-down rectification; moreover, since the three bidirectional controllable switches are connected in series between the input filter module 100 and the three-phase rectifier module 300, there is no distinction between upper and lower bridge arms. When current flows into or out of a certain phase, the corresponding bidirectional controllable switch can be controlled to be on or off. Only three drive signals need to be configured to control the three bidirectional controllable switches respectively, and there is no need to control the upper switch tubes and the lower switch tubes of the three rectifier bridge arms respectively according to the current flow direction. That is, compared with the three-phase buck active PFC circuit in the related art, the control logic can be simplified, the driving difficulty can be reduced, thereby saving the driving circuit and reducing the driving cost.

[0067] It is understandable that the working conditions of the three-phase active PFC circuit shown in FIG5a in other sectors can be determined based on the The working conditions in the fan room can be derived in the same way, so I will not go into details here.

[0068] In addition, a second embodiment of the present application provides a circuit board, including the three-phase active PFC circuit of the first embodiment, for example, including any one of the three-phase active PFC circuits in Figures 4a to 7.

[0069] In addition, a third embodiment of the present application provides a controller, comprising the circuit board of the second embodiment above.

[0070] In addition, the fourth embodiment of the present application provides an air conditioner, including the circuit board of the second embodiment or the controller of the third embodiment.

[0071] It will be understood by those skilled in the art that all or some of the steps and systems in the methods disclosed above can be implemented as software, firmware, hardware, and appropriate combinations thereof. Some or all of the physical components can be implemented as software executed by a processor, such as a central processing unit, a digital signal processor, or a microprocessor, or as hardware, or as an integrated circuit, such as an application-specific integrated circuit. Such software can be distributed on computer-readable media, which can include computer storage media or non-transitory media and communication media or transient media. As is well known to those skilled in the art, the term computer storage media includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information such as computer-readable instructions, data structures, program modules, or other data. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVDs) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store desired information and can be accessed by a computer. Furthermore, as is well known to those skilled in the art, communication media typically embodies computer-readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transport mechanism, and may include any information delivery media.

[0072] The embodiments of the present application are described in detail above in conjunction with the accompanying drawings, but the present application is not limited to the above embodiments. Various changes can be made within the scope of knowledge possessed by ordinary technicians in the technical field without departing from the purpose of the present application.

Claims

1. A three-phase active PFC circuit, comprising: Input filter module, including three input filter inductors and three input filter capacitors; One end of the three input filter inductors is respectively connected to a three-phase AC power supply, and the other end is respectively connected to one end of the three input filter capacitors; the other ends of the three input filter capacitors are connected together; a bidirectional switch module, comprising three bidirectional controllable switches, one end of each of the three bidirectional controllable switches being connected to a connection point between the three input filter inductors and the three input filter capacitors, respectively; A three-phase rectifier module, wherein the other ends of the three bidirectional controllable switches are respectively connected to the AC input ends of the three-phase rectifier module; and The output filter module includes a first output filter inductor and a first output filter capacitor connected in series. The output filter module is connected to the DC output end of the three-phase rectifier module.

2. The three-phase active PFC circuit according to claim 1, further comprising a freewheeling module, wherein: The positive pole of the freewheeling module is connected to the negative pole of the DC output terminal of the three-phase rectifier module, and the negative pole of the freewheeling module is connected to the positive pole of the DC output terminal of the three-phase rectifier module.

3. The three-phase active PFC circuit according to claim 1 or 2, wherein: The three-phase rectifier module includes a first bridge arm formed by a first diode and a second diode connected in series, a second bridge arm formed by a third diode and a fourth diode connected in series, and a third bridge arm formed by a fifth diode and a sixth diode connected in series. The first bridge arm, the second bridge arm and the third bridge arm are connected in parallel to each other.

4. The three-phase active PFC circuit according to any one of claims 1 to 3, wherein: The three-phase rectifier module includes a first bridge arm formed by a first switching tube and a second switching tube connected in series, a second bridge arm formed by a third switching tube and a fourth switching tube connected in series, and a third bridge arm formed by a fifth switching tube and a sixth switching tube connected in series. The first bridge arm, the second bridge arm, and the third bridge arm are connected in parallel to each other, and the first switching tube, the second switching tube, the third switching tube, the fourth switching tube, the fifth switching tube, and the sixth switching tube are provided with anti-parallel diodes or without anti-parallel diodes.

5. The three-phase active PFC circuit according to any one of claims 1 to 4, wherein: The implementation of the bidirectional controllable switch includes the following situations: Case 1: comprising a seventh switch tube and an eighth switch tube connected in series, wherein the seventh switch tube and the eighth switch tube have opposite conduction directions and are respectively provided with an anti-parallel diode; Case 2: comprising a forward conducting branch and a reverse conducting branch connected in parallel, wherein the forward conducting branch comprises a ninth switching tube and a seventh diode connected in series, and the reverse conducting branch comprises a tenth switching tube and an eighth diode connected in series; Case 3: including a fourth bridge arm formed by a ninth diode and a tenth diode connected in series, a fifth bridge arm formed by an eleventh diode and a twelfth diode connected in series, and a sixth bridge arm formed by an eleventh switch tube, wherein the fourth bridge arm, the fifth bridge arm, and the sixth bridge arm are connected in parallel; Case 4: Including RB-IGBT devices.

6. The three-phase active PFC circuit according to any one of claims 1 to 5, wherein: The output filter module further includes a second output filter inductor, and the first output filter inductor, the first output filter capacitor and the second output filter inductor are connected in sequence.

7. The three-phase active PFC circuit according to any one of claims 2 to 6, wherein: The freewheeling module includes a thirteenth diode.

8. The three-phase active PFC circuit according to any one of claims 2 to 7, wherein: The freewheeling module includes a twelfth switch tube, and the twelfth switch tube is provided with an anti-parallel diode or is not provided with an anti-parallel diode.

9. The three-phase active PFC circuit according to any one of claims 1 to 8, wherein: The bidirectional switch module alternately switches between a first state, a second state, a third state, and a fourth state. In the first state, all three bidirectional controllable switches are turned off. In the second state, one of the three bidirectional controllable switches whose corresponding phase voltage is greater than zero and one of the three bidirectional controllable switches whose corresponding phase voltage is less than zero are simultaneously turned on. In the third state, all three bidirectional controllable switches are turned on. In the fourth state, one of the three bidirectional controllable switches is turned on.

10. A circuit board comprising the three-phase active PFC circuit according to any one of claims 1 to 9.

11. A controller comprising the circuit board according to claim 10.

12. An air conditioner comprising the circuit board according to claim 10 or the controller according to claim 11.

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