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

Abstract

The invention 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 present application relates to the technical field of air conditioner circuit, and particularly relates to a three-phase active PFC circuit, a circuit board, a controller and an air conditioner. BACKGROUND

[0002] The active PFC circuit includes a Boost active PFC circuit and a buck active PFC circuit. Figure 1 As shown in FIG. 1, the load side DC voltage of the commonly used three-phase Boost active PFC circuit is raised, which leads to the need of high-voltage power devices on the load side, increases the cost, and requires a higher gap for the wiring to meet the safety requirements, which leads to the increase of product size, in addition, the high-voltage device has a large loss, which reduces the system efficiency.

[0003] The three-phase buck active PFC circuit can reduce the load side DC voltage, thereby avoiding the above problems, and the commonly used three-phase buck active PFC circuit is as shown in FIG. 2. Figure 2 As shown in FIG. 2, the three bridge arms of the controllable rectifier bridge each include an upper switch tube and a lower switch tube, and there are six controllable switch tubes that need to be controlled independently, that is, six independent driving circuits are needed, which has a large driving difficulty and a high driving cost. SUMMARY

[0004] The present application aims to at least solve one of the problems in the related art, and provides a three-phase active PFC circuit, a circuit board, a controller and an air conditioner, which can simplify the control logic, reduce the driving difficulty, thereby saving the driving circuit and reducing the driving cost.

[0005] In a first aspect, an embodiment of the present application provides a three-phase active PFC circuit, comprising an input filter module, a bidirectional switch module, a three-phase rectifier module and an output filter module, wherein:

[0006] The input filter module includes three input filter inductors and three input filter capacitors; one end of each of the three input filter inductors is connected to a three-phase alternating current power supply, and the other end is connected to one end of each 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 each of the three bidirectional controllable switches is connected to the connection point of each of the three input filter inductors and the three input filter capacitors; the other end of each of the three bidirectional controllable switches is connected to the alternating current 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 direct current output end of the three-phase rectifier module.

[0009] The three-phase active PFC circuit provided by some embodiments of the present application 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-off of three bidirectional controllable switches in the bidirectional switch module; when the bidirectional switch module is turned on, current flows from a phase voltage greater than zero to a phase voltage less than zero; when the bidirectional switch module is turned off, the three input filter inductors continue to flow through the three input filter capacitors, and at the same time, the output filter module can continue to flow 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 upper and lower bridge arm, and the corresponding bidirectional controllable switch can be controlled to turn on or off when current flows into or out of a certain phase, only three driving signals are needed to control the three bidirectional controllable switches, and the upper and lower switch tubes of the three rectifier bridge arms do not need to be controlled according to the current 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, the driving circuit can be saved, and the driving cost can be reduced.

[0010] The three-phase active PFC circuit provided by some embodiments of the present application further comprises a freewheeling module, a positive electrode of the freewheeling module is connected to a negative electrode of a direct current output end of the three-phase rectifier module, and a negative electrode of the freewheeling module is connected to a positive electrode of the direct current output end of the three-phase rectifier module.

[0011] The three-phase active PFC circuit provided by some embodiments of the present application comprises 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] The three-phase active PFC circuit provided by some embodiments of the present application comprises 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, and 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 are not provided with anti-parallel diodes.

[0013] The three-phase active PFC circuit provided by some embodiments of the present application has the following implementation modes of the bidirectional controllable switch:

[0014] Case one: including the seventh switch tube and the eighth switch tube in series, the seventh switch tube and the eighth switch tube are opposite in the conduction direction and respectively have anti-parallel diodes;

[0015] Case two: including a forward conduction branch and a reverse conduction branch in parallel, the forward conduction branch includes the ninth switch tube and the seventh diode in series, and the reverse conduction branch includes the tenth switch tube and the eighth diode in series;

[0016] Case three: including the fourth bridge arm formed by the ninth diode and the twelfth diode in series, the fifth bridge arm formed by the eleventh diode and the tenth diode in series, and the sixth bridge arm formed by the eleventh switch tube, the fourth bridge arm, the fifth bridge arm and the sixth bridge arm are parallel to each other;

[0017] Case four: including the RB-IGBT device.

[0018] According to some embodiments of the present application, the three-phase active PFC circuit 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.

[0019] According to some embodiments of the present application, the freewheeling module includes a thirteenth diode.

[0020] According to some embodiments of the present application, the freewheeling module includes a twelfth switch tube, and the twelfth switch tube has an anti-parallel diode or does not have an anti-parallel diode.

[0021] According to some embodiments of the present application, the bidirectional switch module is switched among a first state, a second state, a third state and a fourth state, the first state is that all the three bidirectional controllable switches are turned off, the second state is that one bidirectional controllable switch corresponding to a positive phase voltage and one bidirectional controllable switch corresponding to a negative phase voltage are turned on at the same time among the three bidirectional controllable switches, the third state is that all the three bidirectional controllable switches are turned on, and the fourth state is that one bidirectional controllable switch is turned on among the three bidirectional controllable switches.

[0022] In the second aspect, the embodiments of the present application provide a circuit board, including the three-phase active PFC circuit as described in the first aspect.

[0023] In the third aspect, the embodiments of the present application provide a controller, including the circuit board as described in the second aspect.

[0024] In a fourth aspect, an embodiment of the present invention provides an air conditioner, comprising the circuit board as described in the embodiment of the second aspect above or the controller as described in the embodiment of the third aspect above.

[0025] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present invention. The purposes and other advantages of the present invention can be realized and obtained by the structures particularly 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 present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the technical solution of the present invention and do not constitute a limitation to the technical solution of the present invention.

[0027] The present invention will be further described below with reference to the accompanying drawings and embodiments;

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

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

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

[0031] Figure 4a 1 is a circuit schematic diagram of a three-phase active PFC circuit provided in Example 1 of the present invention;

[0032] Figure 4b 1 is a circuit schematic diagram of a three-phase active PFC circuit provided in Embodiment 2 of the present invention;

[0033] Figure 4c 1 is a circuit schematic diagram of a three-phase active PFC circuit provided in Embodiment 3 of the present invention;

[0034] Figure 5a 1 is a circuit schematic diagram of a three-phase active PFC circuit provided in a fourth embodiment of the present invention;

[0035] Figure 5b 1 is a circuit schematic diagram of a three-phase active PFC circuit provided in Embodiment 5 of the present invention;

[0036] Figure 5c 1 is a circuit schematic diagram of a three-phase active PFC circuit provided in Example 6 of the present invention;

[0037] Figure 6 1 is a circuit schematic diagram of a three-phase active PFC circuit provided in Embodiment 7 of the present invention;

[0038] Figure 7 is a circuit schematic diagram of a three-phase active PFC circuit provided by an embodiment of the present application;

[0039] Figure 8a is a device schematic diagram of the second implementation mode of the bidirectional controllable switch provided by an embodiment of the present application;

[0040] Figure 8b is a device schematic diagram of the third implementation mode of the bidirectional controllable switch provided by an embodiment of the present application;

[0041] Figure 8c is a device schematic diagram of the fourth implementation mode of the bidirectional controllable switch provided by an embodiment of the present application;

[0042] Figure 8d is a device schematic diagram of the fifth implementation mode of the bidirectional controllable switch provided by an embodiment of the present application. DETAILED DESCRIPTION

[0043] This part will describe the specific embodiments of the present application in detail, and the preferred embodiments of the present application are shown in the accompanying drawings, which serve to supplement the description of the text part and enable people to intuitively and visually understand each technical feature and the overall technical scheme of the present application, but cannot be understood as a limitation on the protection scope of the present application.

[0044] In the description of the embodiments of the present application, one or more is meant to be one or more, more than two is meant to be two or more, greater than, less than, more than, etc. are understood as not including the number, above, below, within, etc. are understood as including the number, "at least one" means one or more, "at least one of the following" and the like means any combination of these items, including any combination of single or multiple items. If there is a description of "first", "second", etc., it is only used to distinguish technical features for the purpose, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features or implicitly indicating the sequence of indicated technical features.

[0045] It should be noted that the terms such as setting, installing and connecting in the embodiments of the present application should be understood broadly, and the person skilled in the art can reasonably determine the specific meaning of the above terms in the embodiments of the present application in combination with the specific content of the technical scheme. For example, the term "connection" can be mechanical connection, electrical connection or can communicate with each other; it can be directly connected or indirectly connected through an intermediate medium.

[0046] It should be noted that the technical features involved in each embodiment of the present application described below can be combined with each other as long as there is no conflict between them.

[0047] As power grid requirements for harmonics increase, power factor correction (PFC) circuits have become standard for all electrical products. There are two common methods for power factor correction: passive and active. Passive PFC primarily uses a large reactor connected in series with the power input to filter the current, but generally results in a lower power factor. Compared to passive PFC, active PFC uses high-frequency switching devices, achieving a power factor of 0.99 while significantly reducing the size and weight of the reactor, effectively increasing the product's power density.

[0048] Boost is the most common approach in the industry for active PFC. Three-phase active PFC circuits include three-phase boost active PFC and three-phase buck active PFC. Common three-phase boost active PFC topologies include two-level and three-level. Both topologies boost the DC voltage on the load side when converting AC to DC.

[0049] At present, the commonly used three-phase Boost active PFC circuit is as follows: Figure 1 As shown in the figure, this circuit adopts a 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 regulations, resulting in an increase in product size. In addition, the high-voltage device loss is large, reducing system efficiency. Specifically, when the line voltage of the three-phase AC power input is 380V, with PFC turned on, if the phase A voltage v a >B phase voltage v b , switch tubes T1 to T4 are turned on, and the current from phase A passes through inductor L1, switch tube T1, switch tube T2, switch tube T4, switch tube T3, inductor L2 in sequence, and finally flows into phase B. During this stage, inductor L1 and inductor L2 store energy; when switch tubes T1 to T4 are turned off, the current from phase A passes through inductor L1, diode D1, capacitor C1, capacitor C2, diode D4, inductor L2 in sequence, and finally flows into phase B. During this stage, inductor L1 and inductor L2 release energy, and the voltage loaded on capacitor C1 and capacitor C2 is the output voltage v o , then v AB +v L1 +v L2 -v o =0, in this mode, the switch tubes T1 to T4 are switched according to v AB (t) Real-time adjustment of the conduction duty cycle D(t), the output voltage Since 0≤D(t)<1, the output voltage v o ≥v ABIn three-phase applications, the output voltage will reach 600V or more, which is a great challenge for the devices on the load side.

[0050] Therefore, as shown in the three-phase Buck active PFC circuit Figure 2 , the three bridge arms of the controllable rectifier bridge each include an upper switch tube and a lower switch tube, a total of six controllable switch tubes that need to be controlled individually, that is, six independent driving circuits are needed, which has great driving difficulty and high driving cost. Specifically, as shown in Figure 2 , the three-phase AC power supply is first filtered by LC, such as Figure 2 inductance L1 and capacitance C1, inductance L2 and capacitance C2, inductance L3 and capacitance C3, into the controllable rectifier bridge. Each bridge arm of the controllable rectifier bridge is of the inverse blocking type and is composed of a controllable switching device and a diode in series, such as Figure 2 switch tube T1 and diode D1, switch tube T2 and diode D2, switch tube T3 and diode D3, switch tube T4 and diode D4, switch tube T5 and diode D5, and switch tube T6 and diode D6. After rectification, it is filtered by LC and output, such as Figure 2 inductance L4 and inductance L5 and capacitance C4. When the controllable rectifier bridge is off, the current on inductance L4 and inductance L5 flows through diode D7. According to the characteristics of the voltage waveform of the three-phase AC power supply, as shown in Figure 3 , it is divided into 12 sectors in a cycle and controlled respectively. Taking the sector as an example, in this 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 phase voltage greater than 0 A phase into the phase voltage less than 0 B phase and C phase respectively. Among them, when the current flows from A phase into B phase, A phase upper bridge switch tube T1 and B phase lower bridge switch tube T4 are turned on, the current flows from A phase power supply through inductance L1, diode D1, switch tube T1, inductance L4, capacitance C4, inductance L5, switch tube T4, diode D4, inductance L2 into 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 A phase into C phase, A phase upper bridge switch tube T1 and C phase lower bridge switch tube T6 are turned on, the current flows from A phase power supply through inductance L1, diode D1, switch tube T1, inductance L4, capacitance C4, inductance L5, switch tube T6, diode D6, inductance L3 into C phase power supply, at this time v AC -v L1 -v L4 -v L5 -vL3 -v o = 0; when the switch tubes T1-T6 are all closed, the inductors L1-L3 flow through the capacitors C1-C3 respectively, and the inductors L4 and L5 flow through the diode D7, at this time v L4 +v L5 +v D7 -v o = 0. In the sector, the conduction duty ratio of the switch tube is D(t), and the output voltage is v o = v(t) x D(t), v(t) e (v AB , v AC ), since D(t) <= 1, the output voltage is lower than the input voltage. In the circuit topology, the controllable rectifier bridge is composed of 6 controllable switch tubes including the switch tubes T1-T6, and the six switch tubes are independently switched, so 6 independent driving circuits are needed, which increases the driving difficulty and cost.

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

[0052] The embodiment of the present application will be further described below with reference to the drawings.

[0053] Referring to Figures 4a to 7 , the first aspect embodiment of the present application provides a three-phase active PFC circuit, which comprises 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 comprises three input filter inductors and three input filter capacitors; one end of the three input filter inductors is respectively connected to a three-phase alternating current power supply, and the other end is respectively connected to one end of the three input filter capacitors; the other end of the three input filter capacitors is connected together; specifically, as shown in Figures 4a to 7 , the three input filter inductors are inductors L1, L2 and L3 respectively, and the three input filter capacitors are capacitors C1, C2 and C3 respectively; one end of the inductor L1 is connected to phase A in the three-phase alternating current 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 in the three-phase alternating current 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 in the three-phase alternating current 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 each of the three bidirectional controllable switches being connected to a connection point of the three input filter inductors and the three input filter capacitors; the other end of each of the three bidirectional controllable switches being connected to an AC input end of the three-phase rectifier module 300; specifically, as shown in Figures 4a to 7 the bidirectional switch module 200 includes a first bidirectional controllable switch 210, a second bidirectional controllable switch 220, and a third bidirectional controllable switch 230; one end of the first bidirectional controllable switch 210 is connected to a connection point of the inductor L1 and the capacitor C1, one end of the second bidirectional controllable switch 220 is connected to a connection point of the inductor L2 and the capacitor C2, and one end of the third bidirectional controllable switch 230 is connected to a 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, are 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 a DC output end of the three-phase rectifier module 300. Specifically, the output filter module 400 includes the first output filter inductor L4 and the first output filter capacitor C4, and their connection relationship is as shown in Figure 4b or as shown in Figure 4c ; referring to Figure 4b , 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, and the other end of the first output filter capacitor C4 is connected to the negative pole of the DC output end of the three-phase rectifier module 300; referring to Figure 4c , 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 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 pole of the DC output end of the three-phase rectifier module 300; in addition, referring to Figure 4a , the output filter module 400 can also include a second output filter inductor L5, that is, the output filter module 400 simultaneously includes the first output filter inductor L4, the first output filter capacitor C4, and the 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 present invention, a bidirectional switch module 200 is provided between the input filter module 100 and the three-phase rectifier module 300, and power factor correction is achieved by controlling the on and off of the three bidirectional controllable switches in the bidirectional switch module 200. When the bidirectional switch module 200 is turned on, the current flows from the phase voltage greater than zero to the phase voltage less than zero. When the bidirectional switch module 200 is turned off, the three input filter inductors are freewheeling through the three input filter capacitors. At the same time, the output filter module 400 can pass through the three-phase rectifier module 300. For freewheeling; since the three bidirectional controllable switches are connected in series between the input filter module 100 and the three-phase rectifier module 300, there is no distinction between upper and lower bridge arms. When current flows into or out of a 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 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.

[0058] Reference Figures 5a to 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 Figures 5a to 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 anode of the DC output terminal of the three-phase rectifier module 300 .

[0059] It is understood that the provision of the freewheeling module 500 allows the output filter module 400 to freewheel through the freewheeling module 500 when the bidirectional switch module 200 is turned off, thereby eliminating the need for freewheeling through the three-phase rectifier module 300. Compared to freewheeling through the three-phase rectifier module 300, the freewheeling loop through the thirteenth diode D13 is shorter and has lower losses.

[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. 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 Figures 5a to 5cAs shown, the first bridge arm of the three-phase rectifier module 300 is formed by diodes D1 and D2 connected in series, the second bridge arm is formed by diodes D3 and D4 connected in series, and the third bridge arm is formed by diodes D5 and D6 connected in series. The other end of the first bidirectional controllable switch 210 is connected to the connection point of diodes D1 and D2, the other end of the second bidirectional controllable switch 220 is connected to the connection point of diodes D3 and D4, and the other end of the third bidirectional controllable switch 230 is connected to the connection point of diodes D5 and 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 Figures 5a to 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 replaced by six switch tubes, or are replaced by six switch tubes with anti-parallel diodes, for example, 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. 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 connected as follows: Figure 7 The embodiment shown in FIG1 is provided with anti-parallel diodes, but 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 also be provided with no anti-parallel diodes.

[0062] In addition, it is 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:

[0063] Case 1: including the seventh switch tube and the eighth switch tube connected in series, the conduction directions of the seventh switch tube and the eighth switch tube are opposite and each has an anti-parallel diode; 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 are all equipped with anti-parallel diodes;

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

[0065] Case three: including the fourth bridge arm formed by the ninth diode and the twelfth diode in series, the fifth bridge arm formed by the eleventh diode and the tenth diode in series, and the sixth bridge arm formed by the eleventh switch tube; for example, referring to Figure 8c , the fourth bridge arm is formed by the diode D9 and the diode D10 in series; the fifth bridge arm is formed by the diode D11 and the diode D12 in series; the sixth bridge arm is formed by the switch tube T9; the fourth bridge arm, the fifth bridge arm and the sixth bridge arm are parallel to each other;

[0066] Case four: including the RB-IGBT device; for example, referring to Figure 8d .

[0067] It should be noted that the above four cases 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 application to only the above four implementation manners, and any circuit with the function of bidirectional on and off controllable can be used, as long as the bidirectional on and off controllable between the input filter module 100 and the three-phase rectifier module 300 can be realized.

[0068] In the three-phase active PFC circuit provided in some embodiments of the application, Figures 5a to 5c , the thirteenth diode D13 is replaced by a switch tube, or is replaced by a switch tube with an anti-parallel diode; for example, referring to Figure 6 and Figure 7 , the freewheeling module 500 includes the twelfth switch tube Q7, and the twelfth switch tube Q7 can be provided with an anti-parallel diode as shown in Figure 6 and Figure 7 , or the twelfth switch tube Q7 can 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 a first state, a second state, a third state, and a fourth state. In the first state, all three bidirectional controllable switches are off. In the second state, one of the three bidirectional controllable switches whose corresponding phase voltage is greater than zero and one of the three bidirectional controllable switches whose corresponding phase voltage is less than zero are both turned on. In the third state, all three bidirectional controllable switches are turned on. In the fourth state, one of the three bidirectional controllable switches is turned on. Specifically, Figure 5a The embodiment shown is used as an example to illustrate the 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 phase A whose phase voltage is greater than 0 into the phase B and phase C whose phase voltage is less than 0 respectively; it can be understood that within this sector, the second state may include two situations. The first is that the first bidirectional controllable switch 210 corresponding to A and the second bidirectional controllable switch 220 corresponding to B are turned on, and the third bidirectional controllable switch 230 corresponding to C is turned off. The current flows from the A phase power supply through the inductor L1, the switch tube T1, the switch tube T2, the diode D1, the inductor L4, the capacitor C4, the inductor L5, the diode D4, the switch tube T4, the switch tube T3, and the inductor L2 to the B phase power supply. At this time, v AB -v L1 -v L4 -v L5 -v L2 -v o =0; In the second case, the first bidirectional controllable switch 210 corresponding to phase A is turned on, the second bidirectional controllable switch 220 corresponding to phase B is turned off, and the third bidirectional controllable switch 230 corresponding to phase C is turned on. The current flows from the phase A power supply through the inductor L1, the switch tube T1, the switch tube T2, the diode D1, the inductor L4, the capacitor C4, the inductor L5, the diode D6, the switch tube T6, the switch tube T5, and the inductor L3 and then flows into the phase C power supply. At this time, v AC -v L1 -v L4 -v L5 -v L3 -v o= 0; in addition, in the sector, the third state is that the first bidirectional controllable switch 210 corresponding to phase A, the second bidirectional controllable switch 220 corresponding to phase B, and the third bidirectional controllable switch 230 corresponding to phase C are all turned on; the first state is that the first bidirectional controllable switch 210 corresponding to phase A, the second bidirectional controllable switch 220 corresponding to phase B, and the third bidirectional controllable switch 230 corresponding to phase C are all turned off, and the inductors L1 to L3 flow through the capacitors C1 to C3, respectively, while the inductors L4 and L5 flow through the diode D13, at this time v L4 + v L5 + v D13 - v o = 0. In the sector, the on-duty ratio of the switch tube is D(t), and the output voltage is v o = v(t) x D(t), v(t) e (v AB , v AC ), since D(t)≤1, the output voltage is lower than the input voltage, so that voltage buck rectification is realized; moreover, since the three bidirectional controllable switches are connected in series between the input filter module 100 and the three-phase rectification module 300, there is no upper and lower bridge arm, when the current flows into and out of a phase, the corresponding bidirectional controllable switch is controlled to be turned on and off, only three driving signals are needed to control the three bidirectional controllable switches, without the need to control the upper and lower switch tubes of the three rectification bridge arms according to the current 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, so that the driving circuit can be saved, and the driving cost can be reduced.

[0070] It can be understood that Figure 5a the working conditions of the three-phase active PFC circuit shown in FIG. 1 in other sectors can be obtained according to the working conditions in the sector, and the same is true for the working conditions in other sectors, which will not be described in detail here.

[0071] In addition, the second aspect embodiment of the present application provides a circuit board, which comprises the three-phase active PFC circuit of the first aspect embodiment as described above, for example, comprising any one of the three-phase active PFC circuits in Figures 4a to 7 .

[0072] In addition, the third aspect embodiment of the present application provides a controller, which comprises the circuit board of the second aspect embodiment as described above.

[0073] In addition, the fourth aspect embodiment of the present application provides an air conditioner, which comprises the circuit board of the second aspect embodiment as described above or the controller of the third aspect embodiment as described above.

[0074] ​It will be understood by those skilled in the art that all or some of the steps and systems in the methods disclosed above can be implemented as software, firmware, hardware, and appropriate combinations thereof. Some or all of the physical components can be implemented as software executed by a processor, such as a central processing unit, a digital signal processor, or a microprocessor, or as hardware, or as an integrated circuit, such as an application-specific integrated circuit. Such software can be distributed on computer-readable media, which can include computer storage media or non-transitory media and communication media or transient media. As is well known to those skilled in the art, the term computer storage media includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information such as computer-readable instructions, data structures, program modules, or other data. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVDs) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store desired information and can be accessed by a computer. Furthermore, as is well known to those skilled in the art, communication media typically embodies computer-readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transport mechanism, and may include any information delivery media.

[0075] The embodiments of the present invention are described in detail above with reference to the accompanying drawings. However, the present invention 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 scope of the present invention.

Claims

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

2. The three-phase active PFC circuit according to claim 1, 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 end of the three-phase rectifier module, and the negative pole of the freewheeling module is connected to the positive pole of the DC output end of the three-phase rectifier module.

3. The three-phase active PFC circuit according to claim 1, 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. The first bridge arm, the second bridge arm and the third bridge arm are connected in parallel to each other.

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

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

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

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

10. A circuit board, 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, characterized in that: Including the circuit board according to claim 10.

12. An air conditioner, characterized in that: Including the circuit board according to claim 10 or the controller according to claim 11.

Images