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

Abstract

The utility model 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 filtering module, a bidirectional switch module, a three-phase rectification module and an output filtering module, the input filtering module comprises three input filtering inductors and three input filtering capacitors; one ends of the three input filter inductors are respectively connected to a three-phase alternating current power supply, and the other ends are respectively connected to one ends 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 ends of the three bidirectional controllable switches are respectively connected to connection points of the three input filter inductors and the three input filter capacitors, and the other ends of the three bidirectional controllable switches are respectively connected to an alternating current input end of the three-phase rectifier module; the output filter module is connected with the direct current output end of the three-phase rectifier module; and only three paths of driving signals need to be configured, so that control logic can be simplified, driving difficulty is reduced, driving circuits can be saved, and driving cost is reduced.

Description

Technical Field

[0001] The utility model 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

[0002] Active PFC circuits include Boost active PFC circuits and buck active PFC circuits. Currently, commonly used three-phase Boost active PFC circuits are as follows: Figure 1 As shown, the DC voltage on the load side of the circuit increases, which requires high-voltage power devices on the load side, increasing the cost. In addition, the wiring requires a higher clearance to meet safety requirements, resulting in an increase in product size. In addition, the high-voltage device loss is large, reducing system efficiency.

[0003] The three-phase buck active PFC circuit can reduce the DC voltage on the load side, thus avoiding the above problems. The commonly used three-phase buck active PFC circuit is as follows: Figure 2 As shown, the three bridge arms of the controllable rectifier bridge each include an upper switch tube and a lower switch tube, and there are 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. Utility Model Content

[0004] The purpose of the utility model is to solve at least one of the technical problems existing in the related art, and to provide a three-phase active PFC circuit, a circuit board, a controller and an air conditioner, which can simplify the control logic and reduce the driving difficulty, thereby saving the driving circuit and reducing the driving cost.

[0005] In a first aspect, an embodiment of the utility model 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:

[0006] 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;

[0007] The bidirectional switch module includes 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 end of the three bidirectional controllable switches is respectively connected to the AC input end of the three-phase rectifier module;

[0008] The output filter module includes 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.

[0009] According to some embodiments of the utility model, the three-phase active PFC circuit provided has at least the following beneficial effects: by arranging a bidirectional switch module between the input filter module and the three-phase rectifier module, power factor correction is achieved by controlling the on and off of 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 filter inductors are 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, and when the current flows into or out of a certain phase, the corresponding bidirectional controllable switch can be controlled to be on and off, and 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.

[0010] According to some embodiments of the present invention, 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.

[0011] According to some embodiments of the utility model, the three-phase active PFC circuit is provided, 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 with each other.

[0012] According to the three-phase active PFC circuit provided by some embodiments of the present invention, 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.

[0013] According to the three-phase active PFC circuit provided by some embodiments of the present invention, the implementation method of the bidirectional controllable switch includes the following cases:

[0014] Case 1: comprising 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 anti-parallel diodes;

[0015] Case 2: comprising a forward conducting branch and a reverse conducting branch connected in parallel, the forward conducting branch comprising a ninth switch tube and a seventh diode connected in series, and the reverse conducting branch comprising a tenth switch tube and an eighth diode connected in series;

[0016] Case 3: comprising 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 with each other;

[0017] Case 4: Including RB-IGBT devices.

[0018] According to the three-phase active PFC circuit provided by some embodiments of the present invention, the output filter module also 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.

[0019] According to the three-phase active PFC circuit provided by some embodiments of the present invention, the freewheeling module includes a thirteenth diode.

[0020] According to the three-phase active PFC circuit provided by some embodiments of the present invention, 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.

[0021] According to the three-phase active PFC circuit provided by some embodiments of the present invention, the bidirectional switch module alternately switches between a first state, a second state, a third state and a fourth state, the first state is that the three bidirectional controllable switches are all turned off, the second state is that 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 turned on at the same time, the third state is that the three bidirectional controllable switches are all turned on, and the fourth state is that one of the three bidirectional controllable switches is turned on.

[0022] In a second aspect, an embodiment of the utility model provides a circuit board, comprising the three-phase active PFC circuit as described in the embodiment of the first aspect above.

[0023] In a third aspect, an embodiment of the utility model provides a controller, comprising the circuit board as described in the embodiment of the second aspect above.

[0024] In a fourth aspect, an embodiment of the utility model 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.

[0025] Other features and advantages of the utility model will be described in the following description, and partly become apparent from the description, or understood by practicing the utility model. The purpose and other advantages of the utility model can be realized and obtained by the structures specifically pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings are used to provide a further understanding of the technical solution of the utility model and constitute a part of the specification. Together with the embodiments of the utility model, they are used to explain the technical solution of the utility model and do not constitute a limitation on the technical solution of the utility model.

[0027] The utility model is further described below in conjunction with the accompanying drawings and embodiments;

[0028] Figure 1 It is the circuit schematic diagram of the three-phase Boost active PFC circuit;

[0029] Figure 2 This is the circuit schematic of the three-phase Buck active PFC circuit;

[0030] Figure 3 It is a schematic diagram of the phase sequence and sector division of a three-phase AC power supply;

[0031] Figure 4a It is a circuit schematic diagram of a three-phase active PFC circuit provided in Embodiment 1 of the present utility model;

[0032] Figure 4b It is a circuit schematic diagram of a three-phase active PFC circuit provided in Embodiment 2 of the present utility model;

[0033] Figure 4c This is a circuit schematic diagram of a three-phase active PFC circuit provided in Embodiment 3 of the present utility model;

[0034] Figure 5a This is a circuit schematic diagram of a three-phase active PFC circuit provided in Embodiment 4 of the present utility model;

[0035] Figure 5b This is a circuit schematic diagram of a three-phase active PFC circuit provided in Embodiment 5 of the present utility model;

[0036] Figure 5c This is a circuit schematic diagram of a three-phase active PFC circuit provided in Embodiment 6 of the present utility model;

[0037] Figure 6This is a circuit schematic diagram of a three-phase active PFC circuit provided in Embodiment 7 of the present utility model;

[0038] Figure 7 This is a circuit schematic diagram of a three-phase active PFC circuit provided in Embodiment 8 of the present utility model;

[0039] Figure 8a It is a device principle diagram of the second implementation mode of the bidirectional controllable switch provided in the embodiment of the utility model;

[0040] Figure 8b It is a device principle diagram of the third implementation mode of the bidirectional controllable switch provided in the embodiment of the utility model;

[0041] Figure 8c It is a device principle diagram of a fourth implementation mode of a bidirectional controllable switch provided in an embodiment of the utility model;

[0042] Figure 8d It is a device principle diagram of the fifth implementation method of the bidirectional controllable switch provided in the embodiment of the utility model. DETAILED DESCRIPTION

[0043] This section will describe in detail the specific embodiments of the utility model. The preferred embodiments of the utility model 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 the overall technical solution of the utility model, but it cannot be understood as a limitation on the protection scope of the utility model.

[0044] In the description of the embodiments of the present utility model, "several" means one or more, "more" means more than two, "greater than", "less than", "exceed", etc. are understood to exclude the number itself, "above", "below", "within", etc. 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 there is a description of "first", "second", etc., it is only used for the purpose of distinguishing technical features, and cannot 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.

[0045] It should be noted that the words such as setting, installing, and connecting in the embodiments of the present invention should be understood in a broad sense, and the technical personnel in the relevant technical field can reasonably determine the specific meanings of the above words in the embodiments of the present invention in combination with the specific content of the technical solution. For example, the term "connection" can be a mechanical connection, an electrical connection, or mutual communication; it can be directly connected or indirectly connected through an intermediate medium.

[0046] It should be noted that the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0047] As the power grid's requirements for harmonics increase, power factor correction (PFC) circuits have become standard for all electrical products. There are two common methods of power factor correction: passive power factor correction and active power factor correction. Passive PFC mainly uses a large reactor in series at the power input to achieve current filtering, and generally has a low power factor. Compared with passive PFC, active PFC uses high-frequency switching devices to achieve a power factor of 0.99, and greatly reduces the size and weight of the reactor, effectively improving the power density of the product.

[0048] For active PFC circuits, the current industry generally adopts the Boost method to implement PFC. Three-phase active PFC circuits include three-phase Boost active PFC circuits and three-phase Buck active PFC circuits. The circuit topologies of three-phase Boost active PFC circuits are commonly two-level and three-level topologies. These two topologies will increase the DC voltage on the load side when implementing AC to DC conversion.

[0049] At present, the commonly used three-phase Boost active PFC circuit is as follows Figure 1 As shown in the figure, the circuit adopts the three-phase Vienna topology. The DC voltage on the load side increases, which requires high-voltage power devices on the load side, increasing the cost. In addition, the wiring requires a higher clearance to meet safety requirements, which increases the product size. In addition, the high-voltage device loss is large, which reduces the system efficiency. Specifically, when the line voltage of the three-phase AC power input is 380V, when PFC is turned on, if the A phase voltage v a >B phase voltage v b , the switch tubes T1 to T4 are turned on, and the current from phase A passes through the inductor L1, switch tube T1, switch tube T2, switch tube T4, switch tube T3, inductor L2 in sequence, and finally flows into phase B. In this stage, the inductor L1 and inductor L2 store energy; when the switch tubes T1 to T4 are turned off, the current from phase A passes through the inductor L1, diode D1, capacitor C1, capacitor C2, diode D4, inductor L2 in sequence, and finally flows into phase B. In this stage, the 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.

[0050] Therefore, it is proposed Figure 2 In the three-phase Buck active PFC circuit shown in FIG. 1 , the three bridge arms of the controllable rectifier bridge each include an upper switch tube and a lower switch tube, and there are a total of six controllable switch tubes that need to be controlled separately, that is, six independent drive circuits are required, which has a greater driving difficulty and a higher driving cost. Specifically, as Figure 2 As shown, the three-phase AC power supply is first filtered by LC. Figure 2 The inductor L1 and the capacitor C1, the inductor L2 and the capacitor C2, the inductor L3 and the capacitor C3 enter the controllable rectifier bridge. Each arm of the controllable rectifier bridge is a reverse resistance type, which is composed of a controllable switch device and a diode in series. Figure 2 The switch tube T1 and the diode D1, the switch tube T2 and the diode D2, the switch tube T3 and the diode D3, the switch tube T4 and the diode D4, the switch tube T5 and the diode D5, the switch tube T6 and the diode D6. After rectification, the output is filtered by LC, such as Figure 2 In the inductor L4, inductor L5 and capacitor C4, when the controlled rectifier bridge is turned off, the current on the inductor L4 and inductor L5 is continued through the diode D7. According to the characteristics of the voltage waveform of the three-phase AC power supply, such as Figure 3 As shown, in one cycle, it is divided into 12 sectors and controlled separately. For example, within the sector, v a >0, v b <v c <0, when the switch tube on the controllable rectifier bridge is turned on, the current flows from the A phase with a phase voltage greater than 0 to the B phase and the C phase with a phase voltage less than 0. Among them, when the A phase flows into the B phase, the A phase upper bridge switch tube T1 and the B phase lower bridge switch tube T4 are turned on, and the current flows from the A phase power supply through the inductor L1, the diode D1, the switch tube T1, the inductor L4, the capacitor C4, the inductor L5, the switch tube T4, the diode D4, 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; when the current flows from phase A to phase C, the upper bridge switch tube T1 of phase A and the lower bridge switch tube 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 tube T1, inductor L4, capacitor C4, inductor L5, switch tube T6, diode D6, and inductor L3 to the power supply of phase C. At this time, v AC -vL1 -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 +v L5 +v D7 -v o = 0. In this sector, the switch 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 6 controllable switch tubes including switch tube T1 to switch tube T6, and the six switch tubes are switched independently, so 6 independent drive circuits are required, which increases the difficulty and cost of driving.

[0051] Based on this, the embodiments of the utility model 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.

[0052] The following is a further description of the embodiments of the present invention in conjunction with the accompanying drawings.

[0053] Reference Figures 4a to 7 As shown, the first embodiment of the utility model 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:

[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; specifically, Figures 4a to 7 As shown, the three input filter inductors are respectively inductor L1, inductor L2 and inductor L3, and the three input filter capacitors are respectively 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.

[0055] The bidirectional switch module 200 includes three bidirectional controllable switches, one end of the three bidirectional controllable switches is respectively connected to the connection point of three input filter inductors and three input filter capacitors; the other end of the three bidirectional controllable switches is respectively connected to the AC input end of the three-phase rectifier module 300; specifically, Figures 4a to 7 As shown, 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 end of the first bidirectional controllable switch 210, the other end of the second bidirectional controllable switch 220 and the other end of 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 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 end 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 the connection relationship thereof is as follows: Figure 4b As shown or Figure 4c shown; reference Figure 4b , the positive electrode 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 electrode of the DC output terminal of the three-phase rectifier module 300; refer to Figure 4c , the positive electrode 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 other end of the first output filter inductor L4 is connected to the negative electrode of the DC output terminal of the three-phase rectifier module 300; in addition, refer to Figure 4a As shown, the output filter module 400 may also include a second output filter inductor L5, that is, the output filter module 400 simultaneously 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 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 inductor L5, and the other end of the second output filter inductor L5 is connected to the negative pole of the DC output end of the three-phase rectifier module 300.

[0057] According to the three-phase active PFC circuit provided by the embodiment of the utility model, a bidirectional switch module 200 is arranged 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 three bidirectional controllable switches in the bidirectional switch module 200. When the bidirectional switch module 200 is turned on, the current flows from a phase voltage greater than zero to a 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 the upper and lower bridge arms. When the 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.

[0058] Reference Figure 5a to Figure 5c In some embodiments of the present invention, the three-phase active PFC circuit further includes a freewheeling module 500, 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, referring to Figure 5a to Figure 5c As shown, the freewheeling module 500 includes a thirteenth diode D13 , the anode of the thirteenth diode D13 is connected to the cathode of the DC output terminal of the three-phase rectifier module 300 , and the cathode of the thirteenth diode D13 is connected to the cathode of the DC output terminal of the three-phase rectifier module 300 .

[0059] It is understandable that the freewheeling module 500 is provided so that when the bidirectional switch module 200 is turned off, the output filter module 400 can be freewheeled through the freewheeling module 500, thereby eliminating the need for freewheeling through the three-phase rectifier module 300. Compared with freewheeling through the three-phase rectifier module 300, the loop for freewheeling through the thirteenth diode D13 is shorter and has lower loss.

[0060] In the three-phase active PFC circuit provided in some embodiments of the present invention, 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, and the first bridge arm, the second bridge arm and the third bridge arm are connected in parallel. For example, referring to Figures 4a to 4c as well as Figure 5a to Figure 5cAs shown, the first bridge arm in 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, 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 connection point of the diode D1 and the diode D2, the other end of the second bidirectional controllable switch 220 is connected to the connection point of the diode D3 and the diode D4, and the other end of the third bidirectional controllable switch 230 is connected to the connection point of the diode D5 and the diode D6. It can be understood that the three-phase rectifier module 300 composed of diodes D1 to D6 is an uncontrolled rectifier.

[0061] In some other embodiments of the present invention, the three-phase active PFC circuit is provided: Figures 4a to 4c as well as Figure 5a to Figure 5c The first diode, the second diode, the third diode, the fourth diode, the fifth diode and the sixth diode included in the three-phase rectifier module 300 are respectively replaced by six switch tubes, or are respectively replaced by six switch tubes with anti-parallel diodes, for example, referring to Figure 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 in series, a second bridge arm formed by a third switch tube Q3 and a fourth switch tube Q4 in series, and a third bridge arm formed by a fifth switch tube Q5 and a sixth switch tube Q6 in series. The first bridge arm, the second bridge arm and the third bridge arm are connected in parallel to each other; the first switch tube Q1, the second switch tube Q2, the third switch tube Q3, the fourth switch tube Q4, the fifth switch tube Q5 and the sixth switch tube Q6 can be as follows Figure 7 As shown, the first switch tube Q1, the second switch tube Q2, the third switch tube Q3, the fourth switch tube Q4, the fifth switch tube Q5 and the sixth switch tube Q6 may not have anti-parallel diodes.

[0062] In addition, it can be understood that there are multiple implementations of the bidirectional controllable switch. In the three-phase active PFC circuit provided in some embodiments of the present invention, the implementation of the bidirectional controllable switch includes the following cases:

[0063] Case 1: including 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 anti-parallel diodes; for example, referring to Figure 4a The first bidirectional controllable switch 210 includes a switch tube T1 and a switch tube T2 connected in series; Figure 4a The second bidirectional controllable switch 220 includes a switch tube T3 and a switch tube T4 connected in series; Figure 4a The third bidirectional controllable switch 230 includes a switch tube T5 and a switch tube T6 connected in series; wherein, referring to Figure 4a The switch tubes T1 to T6 in the circuit are all provided with anti-parallel diodes;

[0064] Case 2: including a forward conducting branch and a reverse conducting branch connected in parallel, the forward conducting branch includes a ninth switch tube and a seventh diode connected in series, and the reverse conducting branch includes a tenth switch tube and an eighth diode connected in series; for example, referring to Figure 8a As shown, the forward conducting branch includes a switch tube T7 and a diode D7 connected in series, and the reverse conducting branch includes a switch tube T8 and a diode D8 connected in series; in addition, the positions of the switch tube T7 and the diode D7 in the forward conducting branch are interchanged, and the positions of the switch tube T8 and the diode D8 in the reverse conducting branch are interchanged, so as to obtain the following Figure 8b The bidirectional controllable switch shown;

[0065] Case 3: comprising 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 Figure 8c As shown, 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; 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 with each other;

[0066] Case 4: Including RB-IGBT devices, such as reference Figure 8d shown.

[0067] It should be noted that the above four situations are examples of some feasible implementation methods of the bidirectional controllable switch, and the bidirectional controllable switch in the bidirectional switch module 200 of the utility model is not limited to only the above four implementation methods. Any other circuit with bidirectional opening and closing controllable functions can be used, 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.

[0068] In the three-phase active PFC circuit provided in some embodiments of the present utility model, Figure 5a to Figure 5c The thirteenth diode D13 in the embodiment is replaced by a switch tube, or is replaced by a switch tube with an anti-parallel diode, for example, Figure 6 and Figure 7 As shown, the freewheeling module 500 includes a twelfth switch tube Q7. The twelfth switch tube Q7 can be Figure 6 and Figure 7 The twelfth switch tube Q7 is shown with an anti-parallel diode, but it may not be provided with an anti-parallel diode.

[0069] In the three-phase active PFC circuit provided by some embodiments of the present invention, the bidirectional switch module 200 alternately switches between the first state, the second state, the third state and the fourth state. The first state is that the three bidirectional controllable switches are all turned off, the second state is that 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 turned on at the same time, the third state is that the three bidirectional controllable switches are all turned on, and the fourth state is that one of the three bidirectional controllable switches is turned on. Specifically, Figure 5a The embodiment shown is used as an example to illustrate Figure 3 The phase sequence and sector division of the three-phase AC power supply shown 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 A phase whose phase voltage is greater than 0 to the B phase and the C phase whose phase voltage is less than 0 respectively; it can be understood that in this sector, the second state can include two situations, the first one 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, and 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 A is turned on, the second bidirectional controllable switch 220 corresponding to B is turned off, and the third bidirectional controllable switch 230 corresponding to C is turned on. 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 D6, the switch tube T6, the switch tube T5, and the inductor L3 to the C-phase 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 respectively freewheeling through the capacitors C1 to C3, 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 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, so voltage step-down rectification is achieved; and, 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, and when current flows into or out of a certain phase, the corresponding bidirectional controllable switch can be controlled to be on and off, and 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, it can simplify the control logic and reduce the driving difficulty, thereby saving the driving circuit and reducing the driving cost.

[0070] Understandably, Figure 5a The operation of the three-phase active PFC circuit shown 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.

[0071] In addition, the second aspect of the present invention provides a circuit board, including the three-phase active PFC circuit of the first aspect of the present invention, for example, including Figures 4a to 7 Any three-phase active PFC circuit in.

[0072] In addition, a third aspect of the present invention provides a controller, comprising the circuit board of the second aspect of the present invention.

[0073] In addition, a fourth aspect of the present invention provides an air conditioner, comprising a circuit board according to the second aspect or a controller according to the third aspect.

[0074] It will be appreciated by those skilled in the art that all or some of the steps and systems in the disclosed methods above may be implemented as software, firmware, hardware and appropriate combinations thereof. Some physical components or all physical components may be implemented as software executed by a processor, such as a central processing unit, a digital signal processor or a microprocessor, or implemented as hardware, or implemented as an integrated circuit, such as an application specific integrated circuit. Such software may be distributed on a computer-readable medium, which may include a computer storage medium or a non-transitory medium and a communication medium or a temporary medium. As known to those skilled in the art, the term computer storage medium 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 include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disk DVD or other optical disk storage, magnetic cassettes, magnetic tapes, disk storage or other magnetic storage devices, or any other medium that may be used to store desired information and may be accessed by a computer. Furthermore, it is well known to those skilled in the art that 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.

[0075] The embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments. Various changes can be made within the knowledge scope of ordinary technicians in the technical field without departing from the purpose of the present invention.

Claims

1. A three-phase active PFC circuit, It is characterized in that include: An 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 respectively connected to connection points of the three input filter inductors and the three input filter capacitors; 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; 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.

2. The three-phase active PFC circuit according to claim 1, It is characterized in that It also includes a freewheeling module, 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, It is characterized in that 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 with each other.

4. The three-phase active PFC circuit according to claim 1, It is characterized in that 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.

5. The three-phase active PFC circuit according to claim 1, It is characterized in that The implementation of the bidirectional controllable switch includes the following cases: Case 1: comprising 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 anti-parallel diodes; Case 2: comprising a forward conducting branch and a reverse conducting branch connected in parallel, the forward conducting branch comprising a ninth switch tube and a seventh diode connected in series, and the reverse conducting branch comprising a tenth switch tube and an eighth diode connected in series; Case 3: comprising 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 with each other; Case 4: Including RB-IGBT devices.

6. The three-phase active PFC circuit according to claim 1, It is characterized in that 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 claim 2, It is characterized in that The freewheeling module includes a thirteenth diode.

8. The three-phase active PFC circuit according to claim 2, It is characterized in that 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 claim 1, It is characterized in that The bidirectional switch module alternately switches between a first state, a second state, a third state and a fourth state. The first state is that the three bidirectional controllable switches are all turned off. The second state is that 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 turned on at the same time. The third state is that the three bidirectional controllable switches are all turned on. The fourth state is that one of the three bidirectional controllable switches is turned on.

10. A circuit board, It is characterized in that The three-phase active PFC circuit comprises the three-phase active PFC circuit according to any one of claims 1 to 9.

11. A controller, It is characterized in that Including the circuit board described in claim 10.

12. An air conditioner, It is characterized in that Includes the circuit board according to claim 10 or the controller according to claim 11.

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