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

Abstract

The utility model discloses a three-phase BUCK active PFC circuit, a circuit board, a controller and an air conditioner, and relates to the technical field of circuits, the three-phase BUCK active PFC circuit comprises an input filtering module, a rectification module and a voltage absorption module, the input filtering module is connected with a three-phase AC power supply; the rectification module is connected with the input filtering module; the voltage absorption module comprises a one-way conduction branch, a capacitance absorption branch and a resistance absorption branch, one end of the one-way conduction branch is connected with the positive electrode of the output end of the rectification module, and the other end of the one-way conduction branch is connected to one end of the capacitance absorption branch and one end of the resistance absorption branch; the other end of the capacitance absorption branch circuit and the other end of the resistance absorption branch circuit are connected to the negative electrode of the output end of the rectification module, the one-way conduction branch circuit or the resistance absorption branch circuit is provided with a first device used for reducing the heating value of the resistance absorption branch circuit, peak voltage can be absorbed, and the heating value is low.

Description

Technical Field

[0001] The utility model relates to the technical field of circuits, and in particular to a three-phase BUCK active PFC circuit, a circuit board, a controller and an air conditioner. Background Art

[0002] The three-phase BUCK active PFC circuit can achieve step-down control and has a lower bus voltage, which provides a larger voltage space for the selection of the inverter switch in the later stage and is widely used in high-power occasions. When the load carried by the three-phase BUCK active PFC circuit is light, the current of the inductor set on the DC bus is in a discontinuous state. At the moment when the inductor current drops to zero, the two ends of the freewheeling diode will resonate due to the inductance on the DC bus and the parasitic capacitance of the bridge arm of the rectifier module, thereby generating a higher peak voltage.

[0003] At present, the common solution is to use an RCD absorption circuit across the positive and negative DC bus to absorb the peak voltage. However, the voltage across the capacitor in the RCD absorption circuit is basically equal to the voltage between the positive and negative DC bus, which causes the resistor in the RCD absorption circuit to heat up seriously. Utility Model Content

[0004] The utility model aims to solve at least one of the technical problems existing in the prior art, and provides a three-phase BUCK active PFC circuit, a circuit board, a controller and an air conditioner, which can absorb peak voltage and have lower heat generation.

[0005] In a first aspect, an embodiment of the utility model provides a three-phase BUCK active PFC circuit, including an input filter module, a rectifier module and a voltage absorption module, wherein:

[0006] The input filter module is connected to a three-phase AC power supply;

[0007] The rectifier module is connected to the input filter module;

[0008] The voltage absorption module comprises a unidirectional conduction branch, a capacitor absorption branch and a resistor absorption branch, one end of the unidirectional conduction branch is connected to the positive electrode of the output end of the rectifier module, the other end of the unidirectional conduction branch is connected to one end of the capacitor absorption branch and one end of the resistor absorption branch, and the other end of the capacitor absorption branch and the other end of the resistor absorption branch are connected to the negative electrode of the output end of the rectifier module;

[0009] The unidirectional conducting branch or the resistive absorbing branch is provided with a first device for reducing the heat generated by the resistive absorbing branch.

[0010] The three-phase BUCK active PFC circuit provided by the embodiment of the utility model has at least the following beneficial effects: by arranging a voltage absorption module between the positive electrode of the output end and the negative electrode of the output end of the rectifier module, when a peak voltage appears, it is transmitted to the capacitor absorption branch and the resistor absorption branch through the unidirectional conduction branch, and the capacitor absorption branch and the resistor absorption branch absorb the peak voltage, and a first device is further arranged in the unidirectional conduction branch or the resistor absorption branch to reduce the heat generated by the resistor absorption branch, so that the three-phase BUCK active PFC circuit can absorb the peak voltage and has a lower heat generation.

[0011] According to the three-phase BUCK active PFC circuit provided by some embodiments of the present utility model, the unidirectional conduction branch includes a first diode, the capacitor absorption branch includes a first capacitor, the resistor absorption branch includes a first voltage regulator and a first resistor, the first device is the first voltage regulator, the positive electrode of the output end of the rectifier module is connected to the anode of the first diode, the cathode of the first diode is connected to one end of the first capacitor and the cathode of the first voltage regulator, the anode of the first voltage regulator is connected to one end of the first resistor, and the other end of the first resistor and the other end of the first capacitor are connected to the negative electrode of the output end of the rectifier module.

[0012] According to the three-phase BUCK active PFC circuit provided by some embodiments of the present utility model, the unidirectional conduction branch includes a first switch tube and a first diode, the capacitor absorption branch includes a first capacitor, the resistor absorption branch includes a first resistor, the first device is the first switch tube, the positive electrode of the output end of the rectifier module is connected to a switch pin of the first switch tube, the other switch pin of the first switch tube is connected to the anode of the first diode, the cathode of the first diode is connected to one end of the first capacitor and one end of the first resistor, and the other end of the first resistor and the other end of the first capacitor are connected to the negative electrode of the output end of the rectifier module.

[0013] According to the three-phase BUCK active PFC circuit provided by some embodiments of the present utility model, the unidirectional conduction branch includes a first switch tube and a TVS tube, the capacitor absorption branch includes a first capacitor, the resistor absorption branch includes a first resistor, the first device is the TVS tube, the positive electrode of the output end of the rectifier module is connected to the anode of the first diode, the cathode of the first diode is connected to the cathode of the TVS tube, the anode of the TVS tube is connected to one end of the first capacitor and one end of the first resistor, and the other end of the first resistor and the other end of the first capacitor are connected to the negative electrode of the output end of the rectifier module.

[0014] According to the three-phase BUCK active PFC circuit provided by some embodiments of the present invention, a plurality of the first voltage regulator tubes connected in series are arranged in the resistance absorption branch.

[0015] According to the three-phase BUCK active PFC circuit provided by some embodiments of the present invention, the first switch tube is turned on when the output current of the positive electrode of the output end of the rectifier module is less than a preset current value, and is turned off when at least two-phase bridge arms of the rectifier module are turned on.

[0016] According to the three-phase BUCK active PFC circuit provided by some embodiments of the present invention, the rectifier module includes a first bridge arm formed by a second diode and a third diode connected in series, a second bridge arm formed by a fourth diode and a fifth diode connected in series, a third bridge arm formed by a sixth diode and a seventh diode connected in series, and three bidirectional controllable switches, the first bridge arm, the second bridge arm and the third bridge arm are connected in parallel to each other, the input filter module is respectively connected to one end of the three bidirectional controllable switches, and the other ends of the three bidirectional controllable switches are respectively connected to the midpoint of the first bridge arm, the midpoint of the second bridge arm and the midpoint of the third bridge arm.

[0017] In a second aspect, an embodiment of the present invention provides a circuit board, comprising the three-phase BUCK active PFC circuit as described in the embodiment of the first aspect above.

[0018] In a third aspect, an embodiment of the present invention provides a controller, comprising the circuit board as described in the embodiment of the second aspect above.

[0019] 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 comprising the controller as described in the embodiment of the third aspect above.

[0020] 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

[0021] 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.

[0022] The utility model is further described below in conjunction with the accompanying drawings and embodiments;

[0023] Figure 1 This is a commonly used three-phase BUCK active PFC circuit diagram provided by the embodiment of the utility model;

[0024] Figure 2 It is a control sector distribution diagram provided by an embodiment of the utility model;

[0025] Figure 3 This is a voltage waveform diagram when the DC inductance provided by the embodiment of the utility model is continuous;

[0026] Figure 4 It is a voltage waveform diagram when the DC inductor is intermittent provided by the embodiment of the utility model;

[0027] Figure 5 It is a schematic diagram of a traditional RCD voltage absorption circuit provided by an embodiment of the utility model;

[0028] Figure 6a This is an improved three-phase BUCK active PFC circuit diagram provided by an embodiment of the utility model;

[0029] Figure 6b This is another improved three-phase BUCK active PFC circuit diagram provided by an embodiment of the utility model;

[0030] Figure 7a This is another improved three-phase BUCK active PFC circuit diagram provided by an embodiment of the utility model;

[0031] Figure 7b This is another improved three-phase BUCK active PFC circuit diagram provided by an embodiment of the utility model;

[0032] Figure 8 This is another improved three-phase BUCK active PFC circuit diagram provided by an embodiment of the utility model;

[0033] Fig. 9 It is a voltage waveform diagram after clamping provided by an embodiment of the utility model;

[0034] Fig.10 This is a possible combination diagram of the first switch tube provided in an embodiment of the utility model. DETAILED DESCRIPTION

[0035] 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.

[0036] In the description of the utility model, if there is a description of first and second, it is only for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0037] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0038] At present, the commonly used three-phase BUCK active PFC circuit diagram is as follows Figure 1 As shown, the circuit includes an input filter module 100 and a rectifier module 200, which can realize voltage reduction control and has a lower bus voltage, thus providing a larger voltage space for the selection of the subsequent inverter switch and is widely used in high-power occasions.

[0039] Under normal circumstances, the DC bus inductor connected to the output end of the rectifier module 200 in the circuit is always working continuously, and the inductor current set on the DC bus and the voltage at the output end of the rectifier module 200 are sampled. Figure 1 As shown in the position between PN in the figure, point P corresponds to the position of the positive electrode of the output end of the rectifier module 200, and point N corresponds to the position of the negative electrode of the output end of the rectifier module 200. After sampling, the inductor current and the voltage of the output end of the rectifier module 200 are analyzed, as shown in FIG. Figure 3 As shown, the inductor current Sample Current on the DC bus is always in a continuous state, and the corresponding output voltage Vpn of the rectifier module 200 is relatively flat.

[0040] However, when the load of the three-phase BUCK active PFC circuit is light, the sampling position is still the same as Figure 1 As shown in , the inductor current is analyzed after sampling, such as Figure 4 As shown, it can be seen that the inductor current DC-Inductor Current is in a discontinuous state. At the moment when the inductor current drops to zero, the two ends of the freewheeling diode will resonate due to the inductance on the DC bus and the parasitic capacitance of the bridge arm of the rectifier module 200, causing the corresponding output voltage Vpn of the rectifier module 200 to have a spike phenomenon.

[0041] At present, a common solution is to use an RCD absorption circuit 1000 connected across the positive and negative DC busbars to absorb the peak voltage. Figure 5As shown in the RCD absorption circuit 1000 in the figure, however, the voltage across the capacitor in the RCD absorption circuit 1000 is substantially equal to the voltage between the positive and negative DC bus bars, causing serious heating of the resistor in the RCD absorption circuit 1000.

[0042] Based on this, the embodiments of the utility model provide a three-phase BUCK active PFC circuit, a circuit board, a controller and an air conditioner, which can absorb peak voltage and have lower heat generation.

[0043] The following is a further description of the embodiments of the present invention in conjunction with the accompanying drawings.

[0044] Reference Figure 6a-Figure 8 As shown, in the first aspect, the embodiment of the utility model provides a three-phase BUCK active PFC circuit, including an input filter module 100, a rectifier module 200 and a voltage absorption module 300, wherein:

[0045] The input filter module 100 is connected to a three-phase AC power supply; the rectifier module 200 is connected to the input filter module 100; the voltage absorption module 300 includes a unidirectional conduction branch 310, a capacitor absorption branch 320 and a resistor absorption branch 330, one end of the unidirectional conduction branch 310 is connected to the positive electrode of the output end of the rectifier module 200, the other end of the unidirectional conduction branch 310 is connected to one end of the capacitor absorption branch 320 and one end of the resistor absorption branch 330, and the other end of the capacitor absorption branch 320 and the other end of the resistor absorption branch 330 are connected to the negative electrode of the output end of the rectifier module 200;

[0046] The unidirectional conducting branch 310 or the resistive absorbing branch 330 is provided with a first device for reducing the heat generated by the resistive absorbing branch 330 .

[0047] According to the characteristics of the voltage waveform of the three-phase AC power supply, refer to Figure 2 , within one cycle, it is divided into 12 sectors and controlled separately. Taking the second sector as an example, the voltage characteristics of the second sector are: |Vc|>|Va|>|Vb|, Va>Vb>0>Vc.

[0048] Understandably, Figure 6a-Figure 8 The working conditions of the three-phase BUCK active PFC circuit shown in other sectors can be derived similarly based on the working conditions in the second sector, and will not be described in detail here.

[0049] It should be noted that 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 6a to 8As shown, the three input filter inductors are inductor L1, inductor L2 and inductor L3, and the three input filter capacitors are capacitor C2, capacitor C3 and capacitor C4; 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 C4; 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 C3; 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 C2; the other end of the capacitor C2, the other end of the capacitor C3 and the other end of the capacitor C4 are connected together.

[0050] According to the three-phase BUCK active PFC circuit provided by the embodiment of the utility model, by arranging the voltage absorption module 300 between the positive electrode of the output end and the negative electrode of the output end of the rectifier module 200, when a peak voltage appears, it is transmitted to the capacitor absorption branch 320 and the resistor absorption branch 330 through the unidirectional conduction branch 310, and the capacitor absorption branch 320 and the resistor absorption branch 330 absorb the peak voltage. In addition, a first device is arranged in the unidirectional conduction branch 310 or the resistor absorption branch 330 to reduce the heat generated by the resistor absorption branch 330, so that the three-phase BUCK active PFC circuit can absorb the peak voltage and has a lower heat generation.

[0051] According to the three-phase BUCK active PFC circuit provided by some embodiments of the present invention, refer to Figure 6a The unidirectional conduction branch 310 includes a first diode D1, the capacitor absorption branch 320 includes a first capacitor C1, and the resistor absorption branch 330 includes a first voltage regulator Z1 and a first resistor R1. The first device is the first voltage regulator Z1. The positive electrode of the output end of the rectifier module 200 is connected to the anode of the first diode D1, the cathode of the first diode D1 is connected to one end of the first capacitor C1 and the cathode of the first voltage regulator Z1, the anode of the first voltage regulator Z1 is connected to one end of the first resistor R1, and the other end of the first resistor R1 and the other end of the first capacitor C1 are connected to the negative electrode of the output end of the rectifier module 200.

[0052] It can be understood that, compared with the technical solution in which only the first resistor R1 is provided in the resistance absorption branch 330, a first voltage-stabilizing tube Z1 is additionally provided in the resistance absorption branch 330, and the first voltage-stabilizing tube Z1 is connected in series with the first resistor R1. The first voltage-stabilizing tube Z1 can divide the voltage for the first resistor R1, and by setting the first voltage-stabilizing tube Z1 with different working voltages, the voltage across the first resistor R1 can be reasonably adjusted. The cost is low and only a simple selection of the first voltage-stabilizing tube Z1 is required to reduce the voltage across the first resistor R1, thereby avoiding severe heating of the first resistor R1.

[0053] According to the three-phase BUCK active PFC circuit provided by some embodiments of the present invention, a plurality of first voltage regulator tubes Z1 connected in series are arranged in the resistance absorption branch 330. Figure 6b .

[0054] It can be understood that by adjusting the number of first voltage-stabilizing tubes Z1 connected in series, the voltage across the first resistor R1 can be reasonably adjusted, thereby preventing the first resistor R1 from being severely heated.

[0055] According to the three-phase BUCK active PFC circuit provided by some embodiments of the present invention, refer to Figure 7a-Figure 7b The unidirectional conduction branch 310 includes a first switch tube S1 and a first diode D1, the capacitor absorption branch 320 includes a first capacitor C1, the resistor absorption branch 330 includes a first resistor R1, the first device is the first switch tube S1, the positive electrode of the output end of the rectifier module 200 is connected to a switch pin of the first switch tube S1, the other switch pin of the first switch tube S1 is connected to the anode of the first diode D1, the cathode of the first diode D1 is connected to one end of the first capacitor C1 and one end of the first resistor R1, and the other end of the first resistor R1 and the other end of the first capacitor C1 are connected to the negative electrode of the output end of the rectifier module 200.

[0056] It can be understood that, compared with the technical solution of only setting the first diode D1 in the unidirectional conductive branch 310, the first switch tube S1 is additionally set in the unidirectional conductive branch 310, and the first switch tube S1 is connected in series with the first diode D1. When the first switch tube S1 is turned on, the resistance absorption branch 330 and the capacitor absorption branch 320 start working. When the first switch tube S1 is turned off, the resistance absorption branch 330 and the capacitor absorption branch 320 stop working. By controlling the on and off of the first switch tube S1, the working time of the resistance absorption branch 330 and the capacitor absorption branch 320 can be reduced, thereby avoiding the situation where the first resistor R1 is seriously heated due to long-term operation.

[0057] According to the three-phase BUCK active PFC circuit provided by some embodiments of the present invention, the first switch tube S1 is turned on when the output current of the positive electrode of the output end of the rectifier module 200 is less than a preset current value, and is turned off when at least two-phase bridge arms of the rectifier module 200 are turned on.

[0058] It should be noted that by sampling the current at the positive pole of the output end of the rectifier module 200, the current at the positive pole of the output end of the rectifier module 200 is obtained. At the same time, the current at the positive pole of the output end of the rectifier module 200 is also the inductor current. By sampling the voltage between the positive pole of the output end of the rectifier module 200 and the negative pole of the output end of the rectifier module 200, the voltage obtained is the output voltage of the rectifier module 200.

[0059] It should be noted that the preset current value is set to 0. When the output current of the positive electrode of the output terminal of the first switch tube S1 of the rectifier module 200 is less than 0, that is, the inductor current is interrupted, refer to Fig. 9 When the inductor current is 0, it corresponds to the moment a. If the first switch tube S1 is turned off at this time, the output voltage of the rectifier module 200 will have a peak phenomenon (such as Figure 4 By turning on the first switch tube S1, the capacitor absorption branch 320 and the resistor absorption branch 330 will start to work and absorb the peak voltage until at least two phases of the bridge arm of the rectifier module 200 are turned on and the output voltage of the rectifier module 200 is clamped to the line voltage Vdamp (as shown in FIG. Fig. 9 The output voltage Vpn of the rectifier module 200 corresponding to point a is shown in FIG.

[0060] It should be noted that, refer to Figure 4 , Figure 4 This corresponds to the voltage waveform of the inductor before adding the voltage absorption circuit. When the inductor current drops to 0, Figure 4 The voltages of phases A and C corresponding to point a are 0, and the voltage of phase B is not 0. The first bridge arm and the third bridge arm connected to phases A and C in the rectifier module 200 are both cut off, and the second bridge arm connected to phase B is turned on. The output voltage Vpn of the rectifier module 200 has a peak. When the inductor current starts to rise from 0, Figure 4 The B phase and the C phase corresponding to the point b are not 0, the A phase is 0, the first bridge arm and the third bridge arm connecting the B phase and the C phase in the rectifier module 200 are both turned on, and the second bridge arm connected to the A phase is turned off. The corresponding output voltage Vpn of the rectifier module 200 has been reduced from the peak voltage to the line voltage Vdamp.

[0061] It can be understood that before the voltage absorption module 300 is added to the three-phase BUCK active PFC circuit, if at least two phase bridge arms in the rectifier module 200 are turned on, for example, when the bridge arms corresponding to phases B and C are both turned on, the peak voltage disappears and the output voltage of the corresponding rectifier module 200 is reduced to the line voltage Vdamp.

[0062] Furthermore, after the voltage absorption module 300 is added to the three-phase BUCK active PFC circuit, the first switch tube S1 is turned on when the output current of the positive electrode of the output end of the rectifier module 200 is less than the preset current value, and is turned off when at least two-phase bridge arms of the rectifier module 200 are turned on. When the preset current value is 0, that is, during the period corresponding to the time point a when the inductor current value drops to 0 to the time point b when the inductor current starts to rise from 0, the first switch tube S1 is precisely controlled. Compared with the solution in which the voltage absorption module 300 is always in a working state, the heating time of the first resistor R1 in the resistance absorption branch 330 is reduced, the heat generation thereof is reduced, and at the same time, the peak voltage can be better absorbed.

[0063] It should be noted that the first switch tube S1 can be selected as follows: Fig.10 The transistor shown on the left (1), or Fig.10 The MOS tube shown in the middle (2) or the Fig.10 The IGBT tube shown on the right (3).

[0064] It should be noted that the first diode D1 is provided in the unidirectional conducting branch 310 to prevent current backflow, re-inducing resonance and avoiding damage to the first switch tube S1.

[0065] According to the three-phase BUCK active PFC circuit provided by some embodiments of the present invention, refer to Figure 8 The unidirectional conduction branch 310 includes a first switch tube S1 and a TVS tube K1, the capacitor absorption branch 320 includes a first capacitor C1, the resistor absorption branch 330 includes a first resistor R1, the first device is the TVS tube K1, the positive electrode of the output end of the rectifier module 200 is connected to the anode of the first diode D1, the cathode of the first diode D1 is connected to the cathode of the TVS tube K1, the anode of the TVS tube K1 is connected to one end of the first capacitor C1 and one end of the first resistor R1, and the other end of the first resistor R1 and the other end of the first capacitor C1 are connected to the negative electrode of the output end of the rectifier module 200.

[0066] It can be understood that, compared with the technical solution of only providing the first diode D1 in the unidirectional conduction branch 310, a TVS tube K1 is additionally provided in the unidirectional conduction branch 310, the cathode of the first diode D1 is connected to the cathode of the TVS tube K1, and the anode of the TVS tube K1 is connected to one end of the first capacitor C1 and one end of the first resistor R1. The breakdown voltage design of the TVS tube K1 can achieve partial absorption of the peak voltage. Specifically, the TVS tube K1 has an extremely fast response time and can quickly change from high impedance to low impedance when the voltage exceeds its specific breakdown voltage. When the TVS tube K1 enters the low impedance state, most of the energy will be quickly absorbed. In this way, the first resistor R1 in the resistance absorption branch 330 does not need to absorb too much energy, thereby reducing the heat generation.

[0067] According to the three-phase BUCK active PFC circuit provided by some embodiments of the present invention, refer to Figure 6a , Figure 6b , Figure 7a , Figure 8 As shown, the rectifier module 200 includes a first bridge arm formed by a second diode D2 and a third diode D3 connected in series, a second bridge arm formed by a fourth diode and a fifth diode D5 connected in series, a third bridge arm formed by a sixth diode and a seventh diode D7 connected in series, and three bidirectional controllable switches. The first bridge arm, the second bridge arm and the third bridge arm are connected in parallel to each other, and the input filter module 100 is respectively connected to one end of the three bidirectional controllable switches, and the other ends of the three bidirectional controllable switches are respectively connected to the midpoint of the first bridge arm, the midpoint of the second bridge arm and the midpoint of the third bridge arm.

[0068] It should be noted that, refer to Figure 7a The three-phase BUCK active PFC circuit also includes a freewheeling module 500 and an output filter module 400, the freewheeling module 500 includes an eighth diode D8, and the output filter module 400 includes an inductor L4, a capacitor C5 and an inductor L5 connected in series, wherein the freewheeling module 500 and the output filter module 400 are connected in parallel with the rectifier module 200.

[0069] It should be noted that, in some embodiments, referring to Figure 7b As shown, the rectifier module 200 includes a first bridge arm, a second bridge arm and a third bridge arm. The first bridge arm, the second bridge arm and the third bridge arm all include an upper switch tube and a lower switch tube. There are a total of six controllable switch tubes that need to be individually controlled. Each bridge arm is composed of a controllable switch device and a diode in series. Specifically, as shown in the figure, the upper bridge arm of the first bridge arm is composed of a switch tube T1 and a second diode D2 in series, the lower bridge arm of the first bridge arm is composed of a switch tube T2 and a third diode D3 in series, the upper bridge arm of the second bridge arm is composed of a switch tube T3 and a fourth diode D4 in series, the lower bridge arm of the second bridge arm is composed of a switch tube T4 and a fifth diode D5 in series, the upper bridge arm of the third bridge arm is composed of a switch tube T5 and a sixth diode D6 in series, the lower bridge arm of the third bridge arm is composed of a switch tube T6 and a seventh diode D7 in series, the first bridge arm, the second bridge arm and the third bridge arm are connected in parallel to each other, and the input filter module 100 is connected to the midpoint of the first bridge arm, the midpoint of the second bridge arm and the midpoint of the third bridge arm, respectively.

[0070] It should be noted that, by providing a voltage absorption module 300 between the positive electrode of the output terminal and the negative electrode of the output terminal of the rectifier module 200, when a peak voltage occurs, it is transmitted to the capacitor absorption branch 320 and the resistor absorption branch 330 through the unidirectional conduction branch 310, and the capacitor absorption branch 320 and the resistor absorption branch 330 absorb the peak voltage, so that the output terminal voltage of the rectifier module 200 is clamped to the line voltage Vdamp (such as when the inductor current is in a discontinuous state). Fig. 9 As shown), it is possible to effectively protect other components in the circuit from the impact of the spike voltage. In addition, a first device is provided in the unidirectional conducting branch 310 or the resistance absorbing branch 330. Specifically, referring to Figure 6a-Figure 8 As shown, by adding one or more first voltage regulator tubes Z1 to the resistance absorption branch 330, or adding a first switch tube S1 to the unidirectional conduction branch 310, or adding a TVS tube K1 to the unidirectional conduction branch 310, the heat generated by the first resistor R1 in the resistance absorption branch 330 can be reduced well.

[0071] In a second aspect, an embodiment of the present invention provides a circuit board, comprising the three-phase BUCK active PFC circuit of the embodiment of the first aspect above.

[0072] In a third aspect, an embodiment of the present invention provides a controller, comprising a circuit board as described in the embodiment of the second aspect above.

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

[0074] 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.

[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 BUCK active PFC circuit, characterized in that: include: An input filter module is connected to a three-phase AC power supply; A rectifier module connected to the input filter module; A voltage absorption module, comprising a unidirectional conduction branch, a capacitor absorption branch and a resistor absorption branch, wherein one end of the unidirectional conduction branch is connected to the positive electrode of the output end of the rectifier module, the other end of the unidirectional conduction branch is connected to one end of the capacitor absorption branch and one end of the resistor absorption branch, and the other end of the capacitor absorption branch and the other end of the resistor absorption branch are connected to the negative electrode of the output end of the rectifier module; The unidirectional conducting branch or the resistive absorbing branch is provided with a first device for reducing the heat generated by the resistive absorbing branch.

2. The three-phase BUCK active PFC circuit according to claim 1, characterized in that: The unidirectional conducting branch includes a first diode, the capacitive absorption branch includes a first capacitor, the resistive absorption branch includes a first voltage regulator and a first resistor, the first device is the first voltage regulator, the positive electrode of the output end of the rectifier module is connected to the anode of the first diode, the cathode of the first diode is connected to one end of the first capacitor and the cathode of the first voltage regulator, the anode of the first voltage regulator is connected to one end of the first resistor, and the other end of the first resistor and the other end of the first capacitor are connected to the negative electrode of the output end of the rectifier module.

3. The three-phase BUCK active PFC circuit according to claim 1, characterized in that: The unidirectional conduction branch includes a first switch tube and a first diode, the capacitor absorption branch includes a first capacitor, the resistor absorption branch includes a first resistor, the first device is the first switch tube, the positive pole of the output end of the rectifier module is connected to a switch pin of the first switch tube, the other switch pin of the first switch tube is connected to the anode of the first diode, the cathode of the first diode is connected to one end of the first capacitor and one end of the first resistor, and the other end of the first resistor and the other end of the first capacitor are connected to the negative pole of the output end of the rectifier module.

4. The three-phase BUCK active PFC circuit according to claim 3, characterized in that: The unidirectional conduction branch includes a first switching tube and a TVS tube, the capacitor absorption branch includes a first capacitor, the resistor absorption branch includes a first resistor, the first device is the TVS tube, the positive electrode of the output end of the rectifier module is connected to the anode of the first diode, the cathode of the first diode is connected to the cathode of the TVS tube, the anode of the TVS tube is connected to one end of the first capacitor and one end of the first resistor, and the other end of the first resistor and the other end of the first capacitor are connected to the negative electrode of the output end of the rectifier module.

5. The three-phase BUCK active PFC circuit according to claim 2, characterized in that: The resistance absorption branch is provided with a plurality of the first voltage regulator tubes connected in series.

6. The three-phase BUCK active PFC circuit according to claim 3, characterized in that: The first switch tube is turned on when the output current of the positive electrode of the output end of the rectifier module is less than a preset current value, and is turned off when at least two-phase bridge arms of the rectifier module are turned on.

7. The three-phase BUCK active PFC circuit according to claim 1, characterized in that: The rectifier module includes a first bridge arm formed by a second diode and a third diode connected in series, a second bridge arm formed by a fourth diode and a fifth diode connected in series, a third bridge arm formed by a sixth diode and a seventh diode connected in series, and three bidirectional controllable switches, the first bridge arm, the second bridge arm and the third bridge arm are connected in parallel to each other, the input filter module is respectively connected to one end of the three bidirectional controllable switches, and the other ends of the three bidirectional controllable switches are respectively connected to the midpoint of the first bridge arm, the midpoint of the second bridge arm and the midpoint of the third bridge arm.

8. A circuit board, characterized in that: A three-phase BUCK active PFC circuit comprising any one of claims 1 to 7.

9. A controller, characterized in that: Including the circuit board described in claim 8.

10. An air conditioner, characterized in that: Includes the circuit board described in claim 8 or includes the controller described in claim 9.

Images