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

Abstract

The present application discloses 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). The input filter module (100) comprises three input filter inductors and three input filter capacitors; one end of each of the three input filter capacitors is connected together to form an input filter neutral point; the bidirectional switch module (200) comprises three bidirectional controllable switches; the output filter module (400) comprises a first output filter capacitor and a second output filter capacitor which are connected in series, and the connection point between the first output filter capacitor and the second output filter capacitor serves as an output filter neutral point and is connected to the input filter neutral point.

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 202410386132.6 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] With increasing harmonic requirements in power grids, power factor correction (PFC) has become standard for all electrical products. There are two common methods for PFC: passive PFC and active PFC. Passive PFC primarily uses a large reactor connected in series with the power input to filter current, typically resulting in a lower power factor. Compared to passive PFC, active PFC uses high-frequency switching devices and adjusts the power factor via boost or buck circuits, achieving a power factor of 0.99 while significantly reducing the size and weight of the reactor and effectively increasing the product's power density. However, the introduction of high-frequency switching also causes the voltage across the device and the current flowing through it to change rapidly when the high-frequency switch is turned on and off rapidly, generating significant common-mode interference on the bus. This interference is coupled to the power input port through safety capacitors or parasitic capacitance to ground, causing the product's external interference to exceed standards and affecting its reliability. Summary of the Invention

[0005] The purpose of this application is to at least partially solve one of the technical problems existing in the prior art and to provide a three-phase active PFC circuit, circuit board, controller and air conditioner that can reduce external interference of the circuit and improve the reliability of the circuit.

[0006] In a first aspect, an embodiment of the present application provides a three-phase active PFC circuit, including an input filter module, a bidirectional switch module, a three-phase rectifier module, and an output filter module, wherein:

[0007] The input filter module includes 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 to form an input filter neutral point;

[0008] The bidirectional switch module includes three bidirectional controllable switches, one end of each of the three bidirectional controllable switches is connected to the connection point of the three input filter inductors and the three input filter capacitors respectively; the other end of each of the three bidirectional controllable switches is connected to the AC input end of the three-phase rectifier module respectively; and

[0009] The output filter module is connected to the DC output end of the three-phase rectifier module, and includes a first output filter capacitor and a second output filter capacitor connected in series. The connection point of the first output filter capacitor and the second output filter capacitor is connected to the input filter neutral point as an output filter neutral point.

[0010] According to some embodiments of the present application, the three-phase active PFC circuit provided has at least the following beneficial effects: by connecting the other ends of the three input filter capacitors in the input filter module together to form an input filter neutral point, and providing a first output filter capacitor and a second output filter capacitor in series in the output filter module, thereby forming an output filter neutral point at the connection point of the first output filter capacitor and the second output filter capacitor, and then connecting the output filter neutral point with the input filter neutral point, that is, connecting the midpoint of the filter capacitor of the output DC bus of the three-phase rectifier module to the filter midpoint before rectification, thereby constructing a minimum impedance loop for the high-frequency interference signal on the output DC bus of the three-phase rectifier module. The high-frequency interference signal on the output DC bus of the three-phase rectifier module returns to the input filter neutral point through the shortest path after passing through the first output filter capacitor or the second output filter capacitor, thereby avoiding the high-frequency interference signal from being coupled to the power input port, reducing external interference of the circuit, and improving the reliability of the circuit.

[0011] In addition, the three bridge arms of the controllable rectifier bridge in the commonly used three-phase Buck active PFC circuit all include an upper switch tube and a lower switch tube, with a total of six controllable switch tubes that need to be individually controlled, that is, six independent drive circuits are required, which has greater driving difficulty and high driving cost; the three-phase active PFC circuit provided by the embodiment of the present application realizes power factor correction by setting a bidirectional switch module between the input filter module and the three-phase rectifier module and controlling the on and off of the three bidirectional controllable switches in the bidirectional switch module. When the bidirectional switch module 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 is turned off, the three input The filter inductor is freewheeling through the three input filter capacitors, and the output filter module can be freewheeling through the three-phase rectifier module. Since the three bidirectional controllable switches are connected in series between the input filter module and the three-phase rectifier module, 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 and off. Only three drive signals need to be configured to control the three bidirectional controllable switches respectively. There is no need to control the upper 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 and reduce the driving difficulty, thereby saving the driving circuit and reducing the driving cost.

[0012] According to the three-phase active PFC circuit provided in some embodiments of the present application, a feedback filter capacitor is further provided on the connection line between the output filter neutral point and the input filter neutral point.

[0013] According to the three-phase active PFC circuit provided in some embodiments of the present application, the output filter module further includes a first output filter inductor arranged between the DC output end of the three-phase rectifier module and the first output filter capacitor.

[0014] 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 arranged between the DC output end of the three-phase rectifier module and the second output filter capacitor.

[0015] According to some embodiments of the present application, the three-phase active PFC circuit further includes a freewheeling device, wherein the positive electrode of the freewheeling device is connected to the negative electrode of the DC output terminal of the three-phase rectifier module, and the negative electrode of the freewheeling device is connected to the positive electrode of the DC output terminal of the three-phase rectifier module.

[0016] According to the three-phase active PFC circuit provided in some embodiments of the present application, the freewheeling device is a diode.

[0017] According to the three-phase active PFC circuit provided in some embodiments of the present application, the freewheeling device is a switch tube.

[0018] According to the three-phase active PFC circuit provided in some embodiments of the present application, the freewheeling device adopts a switch tube with an anti-parallel diode.

[0019] According to the three-phase active PFC circuit provided in some embodiments of the present application, the three-phase rectifier module includes a first bridge arm, a second bridge arm and a third bridge arm connected in parallel, and the first bridge arm, the second bridge arm and the third bridge arm are each formed by two diodes connected in series.

[0020] According to the three-phase active PFC circuit provided in some embodiments of the present application, the first bridge arm, the second bridge arm, and the third bridge arm are each formed by two switching tubes connected in series.

[0021] According to the three-phase active PFC circuit provided in some embodiments of the present application, the first bridge arm, the second bridge arm, and the third bridge arm are each formed by two switching tubes with anti-parallel diodes connected in series.

[0022] According to the three-phase active PFC circuit provided in some embodiments of the present application, the bidirectional controllable switch includes a first switch tube and a second switch tube connected in series, the first switch tube and the second switch tube have opposite conduction directions and are respectively provided with an anti-parallel diode.

[0023] According to some embodiments of the present application, a three-phase active PFC circuit is provided, wherein the bidirectional controllable switch includes a forward conducting branch and a reverse conducting branch connected in parallel, wherein the forward conducting branch includes a third switching tube and a first diode connected in series, and wherein the reverse conducting branch includes a fourth switching tube and a second diode connected in series.

[0024] 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 third diode and a fourth diode connected in series, a fifth bridge arm formed by a fifth diode and a sixth diode connected in series, and a sixth bridge arm formed by a fifth switch tube. The fourth bridge arm, the fifth bridge arm, and the sixth bridge arm are connected in parallel to each other.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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 above or comprising the controller as described in the embodiment of the third aspect above.

[0029] 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 achieved and obtained through the structures particularly pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] 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.

[0031] The present application is further described below with reference to the accompanying drawings and embodiments;

[0032] FIG1a is a circuit schematic diagram of a three-phase active PFC circuit provided in one embodiment of the present application;

[0033] FIG1b is a circuit schematic diagram of a three-phase active PFC circuit provided by another embodiment of the present application;

[0034] FIG1c is a circuit schematic diagram of a three-phase active PFC circuit provided in another embodiment of the present application;

[0035] FIG2 is a schematic diagram of the flow of high-frequency interference signals in an embodiment in which the output filter module is not provided with an output filter neutral point and is not connected to an input filter neutral point;

[0036] FIG3 is a schematic diagram of the flow of high-frequency interference signals in the three-phase active PFC circuit provided in the embodiment of FIG1a of the present application;

[0037] FIG4 is a circuit schematic diagram of a three-phase active PFC circuit provided in another embodiment of the present application;

[0038] FIG5 a is a circuit schematic diagram of a three-phase active PFC circuit provided in another embodiment of the present application;

[0039] FIG5 b is a circuit schematic diagram of a three-phase active PFC circuit provided in another embodiment of the present application;

[0040] FIG6 is a circuit diagram of another implementation of a three-phase rectifier module provided in an embodiment of the present application;

[0041] FIG7 a is a device schematic diagram of another implementation of a bidirectional controllable switch provided in an embodiment of the present application;

[0042] FIG7 b is a device schematic diagram of another implementation of a bidirectional controllable switch provided in an embodiment of the present application;

[0043] FIG7 c is a device schematic diagram of another implementation of a bidirectional controllable switch provided in an embodiment of the present application;

[0044] FIG7 d is a device schematic diagram of another implementation of a bidirectional controllable switch provided in an embodiment of the present application. DETAILED DESCRIPTION

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] With increasing harmonic requirements in power grids, power factor correction (PFC) has become standard for all electrical products. There are two common methods for PFC: passive PFC and active PFC. Passive PFC primarily uses a large reactor connected in series with the power input to filter current, typically resulting in a lower power factor. Compared to passive PFC, active PFC uses high-frequency switching devices and adjusts the power factor via boost or buck circuits, achieving a power factor of 0.99 while significantly reducing the size and weight of the reactor and effectively increasing the product's power density. However, the introduction of high-frequency switching also causes the voltage across the device and the current flowing through it to change rapidly when the high-frequency switch is turned on and off rapidly, generating significant common-mode interference on the bus. This interference is coupled to the power input port through safety capacitors or parasitic capacitance to ground, causing the product's external interference to exceed standards and affecting its reliability.

[0050] Active PFC circuits include boost and buck active PFC circuits. The three-phase boost active PFC circuit increases the DC voltage on the load side, requiring high-voltage power devices on the load side, increasing costs. Furthermore, wiring requires higher clearances to meet safety regulations, increasing product size. Furthermore, high losses in high-voltage devices reduce system efficiency. Using a three-phase buck active PFC circuit can reduce the DC voltage on the load side, thus avoiding these issues. However, the three arms of the controlled rectifier bridge in the commonly used three-phase buck active PFC circuit each include an upper and lower switching transistor, resulting in a total of six independently controlled switching transistors. This requires six independent drive circuits, making driving more difficult and costly.

[0051] Based on this, the embodiments of the present application provide a three-phase active PFC circuit, circuit board, controller and air conditioner, which can reduce external interference of the circuit, improve the reliability of the circuit, and simplify the control logic and reduce the driving difficulty, thereby saving the driving circuit and reducing the driving cost.

[0052] The embodiments of the present application are further described below with reference to the accompanying drawings.

[0053] 1a to 1c , a first embodiment of the present application provides a three-phase active PFC circuit, comprising an input filter module 100 , a bidirectional switch module 200 , a three-phase rectifier module 300 , and an output filter module 400 , wherein:

[0054] 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 to form an input filter neutral point; specifically, as shown in Figures 1a to 1c, 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 to form an input filter neutral point N'.

[0055] The bidirectional switch module 200 includes three bidirectional controllable switches, one end of each of which is 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 are connected to the AC input end of the three-phase rectifier module 300. Specifically, as shown in Figures 1a to 1c, 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.

[0056] The output filter module 400 is connected to the DC output end of the three-phase rectifier module 300, and includes a first output filter capacitor and a second output filter capacitor connected in series. The connection point of the first output filter capacitor and the second output filter capacitor is connected to the input filter neutral point as the output filter neutral point; specifically, as shown in Figure 1a, in addition to the first output filter capacitor C4 and the second output filter capacitor C5, the output filter module 400 also includes a first output filter inductor L4 arranged between the positive pole of the DC output end of the three-phase rectifier module 300 and the first output filter capacitor C4, and a second output filter inductor L5 arranged between the negative pole of the DC output end of the three-phase rectifier module 300 and the second output filter capacitor C5, that is, the positive pole of the DC output end 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 capacitor C5, the other end of the second output filter capacitor C5 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 The negative pole of the DC output terminal of the three-phase rectifier module 300; In addition, the output filter module 400 can also be shown in Figure 1b. In addition to the first output filter capacitor C4 and the second output filter capacitor C5, the output filter module 400 also includes a first output filter inductor L4 arranged between the positive pole of the DC output terminal of the three-phase rectifier module 300 and the first output filter capacitor C4. That is, the output filter module 400 in Figure 1b is less than the output filter module 400 in Figure 1a. The second output filter inductor L5; In addition, the output filter module 400 can also be shown in Figure 1c In addition to the first output filter capacitor C4 and the second output filter capacitor C5, the output filter module 400 also includes a second output filter inductor L5 arranged between the negative electrode of the DC output end of the three-phase rectifier module 300 and the second output filter capacitor C5. That is, the output filter module 400 in Figure 1c lacks the first output filter inductor L4 compared to the output filter module 400 in Figure 1a; continuing to refer to Figures 1a to 1c, the connection point between the first output filter capacitor C4 and the second output filter capacitor C5 serves as the output filter neutral point O and is connected to the input filter neutral point N'.

[0057] According to some embodiments of the present application, a three-phase active PFC circuit is provided. By connecting the other ends of the three input filter capacitors in the input filter module 100 together to form an input filter neutral point N', and providing a first output filter capacitor C4 and a second output filter capacitor C5 in series in the output filter module 400, an output filter neutral point O is formed at the connection point of the first output filter capacitor C4 and the second output filter capacitor C5. The output filter neutral point O is then connected to the input filter neutral point N'. In other words, the midpoint of the filter capacitor of the output DC bus of the three-phase rectifier module 300 is connected to the filter midpoint before rectification. This constructs a minimum impedance loop for high-frequency interference signals on the output DC bus of the three-phase rectifier module 300. The high-frequency interference signals on the output DC bus of the three-phase rectifier module 300 return to the input filter neutral point N' via the shortest path after passing through the first output filter capacitor C4 or the second output filter capacitor C5, thereby preventing the high-frequency interference signals from being coupled to the power input port, reducing external interference of the circuit, and improving circuit reliability.

[0058] Specifically, Figure 2 shows a schematic circuit diagram of a comparative embodiment in which the output filter module lacks an output filter neutral point O and is not connected to the input filter neutral point N'. During PFC operation, switches T1 through T6 operate rapidly, and current flows through the conducting switches, forming a loop. When switches T1 to T4 are turned on and the voltage of phase A is higher than the voltage of phase B, the load current flows from phase A through inductor L1, switch T1, switch T2, diode D1, the first output filter inductor L4, load R, the second output filter inductor L5, diode D4, switch T4, switch T3, inductor L2, and finally into phase B. Points P and N are the positive and negative DC output terminals of the three-phase rectifier module 300, respectively. Due to layout and design factors, parasitic capacitance exists between points P and N and the casing or ground, or safety capacitors are designed in. Their equivalent capacitances are Cpg and Cng. When the switches are switched at high frequency, the current changes rapidly, and parasitic parameters of the line exist, generating high-frequency interference signals Icmp and Icmn, which are coupled to the power input port through capacitors Cpg and Cng, causing external interference.

[0059] 3 , in the three-phase active PFC circuit provided in an embodiment of the present application, after the output filter neutral point O is connected to the input filter neutral point N', the high-frequency interference signal Icmp passes through the first output filter capacitor C4 and then returns from the output filter neutral point O to the input filter neutral point N' via the shortest path. The high-frequency interference signal Icmn passes through the second output filter capacitor C5 and then returns from the output filter neutral point O to the input filter neutral point N' via the shortest path, thereby preventing the interference signal from coupling to the power port, thereby preventing external interference.

[0060] In addition, the three bridge arms of the controllable rectifier bridge in the commonly used three-phase Buck active PFC circuit all include an upper switch tube and a lower switch tube, with a total of six controllable switch tubes that need to be individually controlled, that is, six independent drive circuits are required, which has greater driving difficulty and higher driving cost; the three-phase active PFC circuit provided by the embodiment of the present application realizes power factor correction by setting a bidirectional switch module 200 between the input filter module 100 and the three-phase rectifier module 300, and 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 bidirectional controllable switches are turned on and off. The input filter inductor is freewheeling through the three input filter capacitors, and at the same time, the output filter module 400 can be freewheeling through the three-phase rectifier module 300; 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 and 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 and reduce the driving difficulty, thereby saving the driving circuit and reducing the driving cost.

[0061] In addition, referring to Figure 4, in the three-phase active PFC circuit provided in some embodiments of the present application, a feedback filter capacitor Ccm is further provided on the connecting line between the output filter neutral point O and the input filter neutral point N', that is, the output filter neutral point O is connected to one end of the feedback filter capacitor Ccm, and the other end of the feedback filter capacitor Ccm is connected to the input filter neutral point N'.

[0062] It should be noted that providing a feedback filter capacitor Ccm on the connection line between the output filter neutral point O and the input filter neutral point N' can suppress currents other than the common mode current and prevent the main loop current from directly flowing back to the input filter neutral point N'.

[0063] 5a and 5b , the three-phase active PFC circuit provided in some embodiments of the present application further includes a freewheeling device 500, wherein the positive electrode of the freewheeling device 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 device 500 is connected to the positive electrode of the DC output terminal of the three-phase rectifier module 300. Specifically, referring to FIG5a , the freewheeling device 500 is 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.

[0064] It is understood that the provision of the freewheeling device 500 allows the output filter module 400 to freewheel through the freewheeling device 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.

[0065] It should be noted that in addition to using a diode, the freewheeling device 500 can also be implemented in other ways, such as using a switch tube, or a switch tube with an anti-parallel diode. The implementation method of using a switch tube with an anti-parallel diode can be shown in the switch tube Q7 in Figure 5b.

[0066] In the following, various implementations of the bidirectional controllable switches in the three-phase rectifier module 300 and the bidirectional switch module 200 are introduced in combination with the aforementioned embodiments.

[0067] Referring to Figures 1a to 1c and Figures 3 to 5b, 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, a second bridge arm, and a third bridge arm connected in parallel. The first bridge arm 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 midpoint of the first bridge arm, i.e., the connection point of the diodes D1 and D2; the other end of the second bidirectional controllable switch 220 is connected to the midpoint of the second bridge arm, i.e., the connection point of the diodes D3 and D4; and the other end of the third bidirectional controllable switch 230 is connected to the midpoint of the third bridge arm, i.e., the connection point of the diodes D5 and D6. It is understood that the three-phase rectifier module 300 formed by diodes D1 to D6 is an uncontrolled rectifier.

[0068] In the three-phase active PFC circuits provided in some other embodiments of the present application, the diodes D1 to D6 included in the three-phase rectifier module 300 in Figures 1a to 1c and Figures 3 to 5b can be replaced by six switching tubes, or replaced by six switching tubes with anti-parallel diodes, for example, as shown by the switching tubes Q1 to Q6 in Figure 6.

[0069] It is understandable that there are multiple ways to implement the bidirectional controllable switch. It can be implemented by a single bidirectional switch controllable device, or by a circuit composed of multiple controllable devices and uncontrolled devices.

[0070] 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 cases:

[0071] Case 1: including a first switching transistor and a second switching transistor connected in series, the first switching transistor and the second switching transistor having opposite conduction directions and each having an anti-parallel diode; for example, referring to Figures 1a to 1c and Figures 3 to 6, the first bidirectional controllable switch 210 includes a switching transistor T1 and a switching transistor T2 connected in series; the second bidirectional controllable switch 220 includes a switching transistor T3 and a switching transistor T4 connected in series; and the third bidirectional controllable switch 230 includes a switching transistor T5 and a switching transistor T6 connected in series; wherein the switching transistors T1 to T6 each have an anti-parallel diode;

[0072] Case 2: including a forward conducting branch and a reverse conducting branch connected in parallel, the forward conducting branch including a third switch and a first diode connected in series, and the reverse conducting branch including a fourth switch and a second diode connected in series. For example, referring to FIG7 a , the forward conducting branch includes a switch T9 and a diode D9 connected in series, and the reverse conducting branch includes a switch T10 and a diode D10 connected in series. In addition, by swapping the positions of the switch T9 and the diode D9 in the forward conducting branch, and swapping the positions of the switch T10 and the diode D10 in the reverse conducting branch, a bidirectional controllable switch as shown in FIG7 b can be obtained.

[0073] Case 3: including a fourth bridge arm formed by a third diode and a fourth diode in series, a fifth bridge arm formed by a fifth diode and a sixth diode in series, and a sixth bridge arm formed by a fifth switch tube. For example, referring to FIG. 7 c , the fourth bridge arm is formed by a diode D11 and a diode D12 in series; the fifth bridge arm is formed by a diode D13 and a diode D14 in series; and the sixth bridge arm is formed by a switch tube T11. The fourth bridge arm, the fifth bridge arm, and the sixth bridge arm are connected in parallel.

[0074] Case 4: including RB-IGBT devices, as shown in FIG. 7 d .

[0075] 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.

[0076] In addition, a second embodiment of the present application provides a circuit board, including the three-phase active PFC circuit of the first embodiment above, for example, including any one of the three-phase active PFC circuits in Figures 1a to 1c and Figures 3 to 6.

[0077] In addition, a third embodiment of the present application provides a controller, comprising the circuit board of the second embodiment above.

[0078] 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.

[0079] Those skilled in the art will appreciate 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.

[0080] 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 to form an input filter neutral point; 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 An output filter module is connected to the DC output end of the three-phase rectifier module, and includes a first output filter capacitor and a second output filter capacitor connected in series. The connection point of the first output filter capacitor and the second output filter capacitor is connected to the input filter neutral point as an output filter neutral point.

2. The three-phase active PFC circuit according to claim 1, wherein: A feedback filter capacitor is further provided on the connection line between the output filter neutral point and the input filter neutral point.

3. The three-phase active PFC circuit according to claim 1 or 2, wherein: The output filter module further includes a first output filter inductor arranged between the DC output end of the three-phase rectifier module and the first output filter capacitor.

4. The three-phase active PFC circuit according to any one of claims 1 to 3, wherein: The output filter module further includes a second output filter inductor arranged between the DC output end of the three-phase rectifier module and the second output filter capacitor.

5. The three-phase active PFC circuit according to any one of claims 1 to 4, further comprising a freewheeling device, wherein: The positive electrode of the freewheeling device is connected to the negative electrode of the DC output terminal of the three-phase rectifier module, and the negative electrode of the freewheeling device is connected to the positive electrode of the DC output terminal of the three-phase rectifier module.

6. The three-phase active PFC circuit according to claim 5, wherein: The implementation of the freewheeling device includes the following situations: Case 1: Using diodes; Case 2: Using a switch tube; Case 3: Use a switching tube with an anti-parallel diode.

7. The three-phase active PFC circuit according to any one of claims 1 to 6, wherein: The three-phase rectifier module includes a first bridge arm, a second bridge arm, and a third bridge arm connected in parallel. The implementation of the first bridge arm, the second bridge arm, and the third bridge arm includes the following situations: Case 1: Both are formed by two diodes connected in series; Case 2: Both are formed by two switching tubes connected in series; Case 3: Both are formed by two switching tubes with anti-parallel diodes connected in series.

8. The three-phase active PFC circuit according to any one of claims 1 to 7, wherein: The implementation of the bidirectional controllable switch includes the following situations: Case 1: comprising a first switching tube and a second switching tube connected in series, wherein the first switching tube and the second switching 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 third switch tube and a first diode connected in series, and the reverse conducting branch comprises a fourth switch tube and a second diode connected in series; Case 3: including a fourth bridge arm formed by a third diode and a fourth diode in series, a fifth bridge arm formed by a fifth diode and a sixth diode in series, and a sixth bridge arm formed by a fifth 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.

9. A circuit board comprising the three-phase active PFC circuit according to any one of claims 1 to 8.

10. A controller comprising the circuit board according to claim 9.

11. An air conditioner comprising the circuit board according to claim 9 or the controller according to claim 10.

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