Buck-boost driving circuit, air conditioner, method and computer readable storage medium

Abstract

The present invention provides a buck-boost driving circuit, an air conditioner, a method and a computer-readable storage medium, wherein the driving method includes: a buck circuit, the buck circuit is configured to be able to perform buck processing or rectification processing on the power supply signal, the buck circuit includes: a bridge circuit, two adjacent bridge arms of the bridge circuit are each provided with a bidirectional conducting power tube, and the other two adjacent bridge arms in the buck circuit are respectively provided with a first reverse blocking switch tube and a second reverse blocking switch tube; a third reverse blocking switch tube, the two ends of the third reverse blocking switch tube are connected to the output end of the bridge circuit; a boost circuit, the input end of the boost circuit is connected to the output end of the third reverse blocking switch tube, and the boost circuit is configured to be able to perform boost modulation on the power supply signal. Through the technical solution of the present invention, the DC bus voltage of the variable frequency motor is bucked and adjusted, so that the total loss of the motor is minimized, and high-efficiency control of the variable frequency compressor is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioners, and in particular to a buck-boost driving circuit, a buck-boost driving method, an air conditioner and a computer-readable storage medium. Background Art

[0002] Generally speaking, the driving motor of the high-efficiency variable frequency compressor of the variable frequency air conditioner is usually a permanent magnet motor. Therefore, the iron loss of the motor is mainly affected by the DC bus voltage of the variable frequency controller.

[0003] For example, without entering weak magnetic operation, the higher the DC bus voltage, the greater the motor iron loss, and the lower the DC bus voltage, the smaller the motor iron loss. Therefore, the DC voltage can be appropriately lowered to reduce the motor iron loss and improve the motor efficiency.

[0004] In the related art, the power factor correction (PFC) of the variable frequency air conditioner does not have a voltage reduction function. For example, passive PFC, single pulse and multi-pulse PFC do not have the function of adjusting the DC bus voltage, and the typical boost PFC can only perform voltage increase regulation but not voltage reduction regulation.

[0005] In addition, any discussion of background technology throughout the specification does not mean that the background technology is necessarily the prior art known to technicians in the relevant field, and any discussion of prior art throughout the specification does not mean that the prior art is necessarily widely known or necessarily constitutes common knowledge in the field. Summary of the invention

[0006] The present invention aims to solve at least one of the technical problems existing in the prior art or related art.

[0007] To this end, an object of the present invention is to provide a buck-boost driving circuit.

[0008] Another object of the present invention is to provide an air conditioner.

[0009] Another object of the present invention is to provide a buck-boost driving method.

[0010] Another object of the present invention is to provide a computer-readable storage medium.

[0011] In order to achieve the above-mentioned purpose, according to an embodiment of the first aspect of the present invention, there is provided a buck-boost driving circuit, comprising: a buck-type circuit, wherein the buck-type circuit is configured to be able to perform buck processing or rectification processing on a power supply signal, the buck-type circuit comprising: a bridge circuit, wherein two adjacent bridge arms of the bridge circuit are each provided with a bidirectional conducting power tube, and the other two adjacent bridge arms in the buck-type circuit are respectively provided with a first reverse blocking switch tube and a second reverse blocking switch tube; a third reverse blocking switch tube, wherein both ends of the third reverse blocking switch tube are connected to the output end of the bridge circuit; and a boost-type circuit, wherein the input end of the boost-type circuit is connected to the output end of the third reverse blocking switch tube, and the boost-type circuit is configured to be able to perform boost modulation on the power supply signal.

[0012] In this technical solution, by setting up a boost circuit and a buck circuit, the boost circuit is configured to be able to perform boost modulation or filtering on the power supply signal, and at the same time, the buck circuit can step down the voltage after rectification to flexibly adjust the bus voltage, which can not only make the bus voltage higher than the peak value of the AC voltage, but also make the bus voltage lower than the peak value of the AC voltage, that is, to increase or decrease the bus voltage according to the load operation requirements to improve the motor efficiency.

[0013] Among them, the AC signal is connected to the step-down circuit, the step-down circuit can step down or rectify the power supply signal and transmit it to the next-level boost circuit. The first reverse blocking switch tube and the second reverse blocking switch tube chop the power supply signal to reduce the bus voltage.

[0014] In addition, the boost circuit includes a first power tube and a second power tube, which are connected in series in the same direction at the output end of the buck circuit. The second power tube supplies power to the load, which can be a motor, or an inverter and a permanent magnet motor driven by it. The buck circuit can perform voltage reduction modulation to further improve the efficiency of the motor, which is also beneficial to reduce the iron loss of the motor.

[0015] In any of the above technical solutions, preferably, it also includes: an inductive element, a first end of the inductive element is connected to the high-voltage output end of the third reverse blocking switch tube, and a second end of the inductive element is connected to the high-voltage input end of the boost circuit.

[0016] In this technical solution, by setting up an inductive circuit, the first end of the inductive element is connected to the high-voltage output end of the third reverse blocking switch tube, and the second end of the inductive element is connected to the high-voltage input end of the boost circuit. On the one hand, the power supply signal can be filtered, and on the other hand, it is used as an inductive element of the power factor correction circuit, that is, it is multiplexed by the boost circuit to boost and modulate the power supply signal.

[0017] In addition, the boost circuit and the buck circuit share one inductive element.

[0018] In any of the above technical solutions, preferably, the boost circuit includes: a first power tube, connected between the second end of the inductive element and the low-voltage output end of the third reverse blocking switch tube; a second power tube, connected between the second end of the inductive element and the high-voltage input end of the load; a capacitive element, connected between the high-voltage input end of the load and the low-voltage output end of the third reverse blocking switch tube, the low-voltage output end of the third reverse blocking switch tube and the low-voltage input end of the load are common endpoints, wherein the first power tube and the second power tube are controlled to be alternately turned on to boost and modulate the power supply signal.

[0019] In this technical solution, a boost circuit is provided including a first power tube, a second power tube and a capacitive element, and connected in the above manner, so as to control the first power tube and the second power tube to be alternately turned on to perform boost modulation on the power supply signal, thereby improving the efficiency of the power supply signal and timely improving the amplitude of the power supply signal.

[0020] In any of the above technical solutions, preferably, the reverse blocking switch tube specifically includes: a first N-channel metal oxide semiconductor tube and a second N-channel metal oxide semiconductor tube, the drains of the two N-channel metal oxide semiconductor tubes are connected; a comparator, the source of the first N-channel metal oxide semiconductor tube is connected to the first input terminal of the comparator, and the source of the second N-channel metal oxide semiconductor tube is connected to the second input terminal of the comparator; a controller, the input terminal of the controller is connected to the output terminal of the comparator, and the output terminal of the controller is connected to the gate of the N-channel metal oxide semiconductor tube.

[0021] In this technical solution, the key components of the reverse blocking switch are a comparator and two anti-series metal oxide semiconductor tubes, wherein the source of the first N-channel metal oxide semiconductor tube is connected to the first input terminal of the comparator, and the source of the second N-channel metal oxide semiconductor tube is connected to the second input terminal of the comparator. The metal oxide semiconductor tube is controlled to be turned on or off by the output result of the comparator. Based on this, a reverse blocking switch is set to overcome the problems of large diode voltage drop and high power consumption, and the response efficiency is high.

[0022] In any of the above technical solutions, preferably, the reverse blocking switch tube includes: a first P-channel metal oxide semiconductor tube and a second P-channel metal oxide semiconductor tube, the sources of the two P-channel metal oxide semiconductor tubes are connected; a comparator, the drain of the first P-channel metal oxide semiconductor tube is connected to the first input terminal of the comparator, and the drain of the second P-channel metal oxide semiconductor tube is connected to the second input terminal of the comparator; a controller, the input terminal of the controller is connected to the output terminal of the comparator, and the output terminal of the controller is connected to the gate of the N-channel metal oxide semiconductor tube.

[0023] In this technical solution, the key components of the reverse blocking switch are a comparator and two anti-series metal oxide semiconductor tubes, wherein the source of the first P-channel metal oxide semiconductor tube is connected to the first input terminal of the comparator, and the source of the second P-channel metal oxide semiconductor tube is connected to the second input terminal of the comparator. The metal oxide semiconductor tube is controlled to be turned on or off by the output result of the comparator. Based on this, a reverse blocking switch is set to overcome the problems of large diode voltage drop and high power consumption, and the response efficiency is high.

[0024] In any of the above technical solutions, preferably, the reverse blocking switch tube comprises: a diode and a metal oxide semiconductor tube connected in series, the metal oxide semiconductor tube is provided with an anti-parallel diode, and the conduction direction of the diode is opposite to the conduction direction of the anti-parallel diode.

[0025] In this technical solution, a reverse blocking switch tube is provided including a diode and a metal oxide semiconductor tube connected in series. The metal oxide semiconductor tube is provided with an anti-parallel diode. The conduction direction of the diode is opposite to the conduction direction of the anti-parallel diode. When the metal oxide semiconductor tube is cut off, the series diode and the anti-parallel diode are also cut off because of their opposite conduction directions. Based on this, the problems of large diode voltage drop and high power consumption are overcome, and the response efficiency is high.

[0026] In any of the above technical solutions, preferably, the first reverse blocking switch tube and / or the second reverse blocking switch tube are diodes.

[0027] In any of the above technical solutions, preferably, the third reverse blocking switch tube is a diode.

[0028] In any of the above technical solutions, preferably, the second power tube is a diode.

[0029] According to the technical solution of the second aspect of the present invention, there is provided an air conditioner, comprising: a motor; as in the above-mentioned buck-boost driving method, the driving circuit is configured to control the operation of the motor.

[0030] According to the technical solution of the third aspect of the present invention, a buck-boost driving method is provided, comprising: determining an AC voltage input to the buck circuit, and a bus voltage input to the boost circuit; according to the AC voltage and the bus voltage, controlling the boost circuit to perform boost modulation, or controlling the buck circuit to perform buck modulation, or controlling the boost circuit and the buck circuit to alternately modulate the power supply signal.

[0031] In this technical solution, by controlling the boost circuit to perform boost modulation, or controlling the buck circuit to perform buck modulation, or controlling the boost circuit and the buck circuit to alternately modulate the power supply signal according to the AC voltage and the bus voltage, not only can the bus voltage be made higher than the peak value of the AC voltage, but also the bus voltage can be made lower than the peak value of the AC voltage, that is, the bus voltage can be increased or decreased according to the load operation requirements to improve the motor efficiency.

[0032] In any of the above technical solutions, preferably, according to the AC voltage and the bus voltage, the boost circuit is controlled to perform boost modulation, or the buck circuit is controlled to perform buck modulation, or the boost circuit and the buck circuit are controlled to alternately modulate the power supply signal, specifically including: comparing the magnitude relationship between a first voltage threshold and the bus voltage; when it is detected that the first voltage threshold is less than the bus voltage, controlling the buck circuit to stop modulation, and comparing the magnitude relationship between the bus voltage and the AC voltage; when it is detected that the bus voltage is greater than or equal to the AC voltage, controlling the boost circuit to perform boost modulation on the power supply signal.

[0033] In this technical solution, by detecting that the first voltage threshold is less than the bus voltage, the step-down circuit is controlled to stop modulation, and the magnitude relationship between the bus voltage and the AC voltage is compared. If it is detected that the bus voltage is greater than or equal to the AC voltage, the boost circuit is controlled to perform boost modulation on the power supply signal to improve the reliability of the power supply signal.

[0034] In any of the above technical solutions, preferably, according to the AC voltage and the bus voltage, the boost circuit is controlled to perform boost modulation, or the buck circuit is controlled to perform buck modulation, or the boost circuit and the buck circuit are controlled to alternately modulate the power supply signal, which specifically also includes: comparing the magnitude relationship between a second voltage threshold and the bus voltage; when it is detected that the second voltage threshold is greater than the bus voltage, controlling the boost circuit to stop modulation, and comparing the magnitude relationship between the bus voltage and the AC voltage; when it is detected that the bus voltage is less than or equal to the AC voltage, controlling the buck circuit to perform buck modulation on the power supply signal.

[0035] In this technical solution, the magnitude relationship between the second voltage threshold and the bus voltage is compared. Further, by detecting that the second voltage threshold is greater than the bus voltage, the boost circuit is controlled to stop modulation, and the magnitude relationship between the bus voltage and the AC voltage is compared. When it is detected that the bus voltage is less than or equal to the AC voltage, the buck circuit is controlled to perform buck modulation on the power supply signal to reduce the impact of the power supply signal on the subsequent circuit and improve the efficiency of the motor.

[0036] In any of the above technical solutions, preferably, according to the AC voltage and the bus voltage, the boost circuit is controlled to perform boost modulation, or the buck circuit is controlled to perform buck modulation, or the boost circuit and the buck circuit are controlled to alternately modulate the power supply signal, which specifically also includes: comparing the magnitude relationship between the first voltage threshold and the bus voltage, and comparing the magnitude relationship between the second voltage threshold and the bus voltage; detecting that the second voltage threshold is less than or equal to the bus voltage, and detecting that the first voltage threshold is greater than or equal to the bus voltage, controlling the boost circuit and the buck circuit to alternately modulate the power supply signal.

[0037] In this technical solution, by comparing the magnitude relationship between the first voltage threshold and the bus voltage, and comparing the magnitude relationship between the second voltage threshold and the bus voltage, if it is detected that the second voltage threshold is less than or equal to the bus voltage, and it is detected that the first voltage threshold is greater than or equal to the bus voltage, the boost circuit and the buck circuit are controlled to alternately modulate the power supply signal to further improve the motor efficiency.

[0038] In any of the above technical solutions, preferably, controlling the boost circuit and the buck circuit to alternately modulate the power supply signal specifically also includes: controlling the boost circuit to stop modulation, and comparing the magnitude relationship between the bus voltage and the AC voltage; when it is detected that the bus voltage is greater than the AC voltage, controlling the boost circuit to perform boost modulation on the power supply signal; when it is detected that the bus voltage is less than or equal to the AC voltage, controlling the buck circuit to perform buck modulation on the power supply signal.

[0039] In this technical solution, the boost circuit is controlled to stop modulation, and the magnitude relationship between the bus voltage and the AC voltage is compared. If it is detected that the bus voltage is greater than the AC voltage, the boost circuit is controlled to perform boost modulation on the power supply signal. Furthermore, if it is detected that the bus voltage is less than or equal to the AC voltage, the buck circuit is controlled to perform buck modulation on the power supply signal, so as to reduce the impact of the power supply signal on the subsequent circuit and improve the efficiency of the motor.

[0040] In any of the above technical solutions, preferably, controlling the buck circuit to perform buck modulation on the power supply signal specifically includes: controlling the first reverse blocking switch tube and the second reverse blocking switch tube to be alternately turned on according to the positive cycle and the negative cycle of the AC voltage, and controlling the third reverse blocking switch tube to be turned on.

[0041] In this technical solution, the first reverse blocking switch tube and the second reverse blocking switch tube are controlled to be alternately turned on according to the positive cycle and the negative cycle of the AC voltage, that is, the first reverse blocking switch tube and the second reverse blocking switch tube respectively work alternately in two consecutive half cycles of the AC voltage. In addition, by controlling the third reverse blocking switch tube to be turned on, the amplitude of the power supply signal input to the boost circuit is reduced.

[0042] In any of the above technical solutions, preferably, controlling the boost circuit to perform boost modulation on the power supply signal specifically includes: controlling the first power tube to be turned on or off according to a specified duty cycle, and controlling the third reverse blocking switch tube to be turned off; controlling the second power tube to be turned on alternately with the first power tube, or controlling the second power tube to be turned off.

[0043] In this technical solution, the power supply signal is boosted and modulated in a timely manner by controlling the first power tube to be turned on or off according to a specified duty cycle and controlling the third reverse blocking switch tube to be turned off.

[0044] In addition, during the process of modulation and voltage boosting of the first power tube, the second power tube and the first power tube are controlled to be turned on alternately, or the second power tube is controlled to be turned off, so as to avoid direct connection between the first power tube and the second power tube.

[0045] According to the technical solution of the fourth aspect of the present invention, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed, the buck-boost driving method as defined in any of the above technical solutions is implemented.

[0046] Additional aspects and advantages of the present invention will be given in part in the following description, and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0048] Figure 1 A schematic diagram of a buck-boost driving circuit according to an embodiment of the present invention is shown;

[0049] Figure 2A schematic diagram of a buck-boost driving circuit according to another embodiment of the present invention is shown;

[0050] Figure 3 A schematic diagram of a buck-boost driving circuit according to another embodiment of the present invention is shown;

[0051] Figure 4 A schematic diagram of a buck-boost driving circuit according to another embodiment of the present invention is shown;

[0052] Figure 5 A schematic diagram of an air conditioner according to an embodiment of the present invention is shown;

[0053] Figure 6 A schematic flow chart of a buck-boost driving method according to an embodiment of the present invention is shown;

[0054] Figure 7 A schematic block diagram of a computer-readable storage medium according to an embodiment of the present invention is shown;

[0055] Figure 8 shows a timing diagram of a buck-boost driving scheme according to an embodiment of the present invention;

[0056] Fig. 9 shows a timing diagram of a buck-boost driving scheme according to another embodiment of the present invention;

[0057] Fig.10 shows a timing diagram of a buck-boost driving scheme according to another embodiment of the present invention;

[0058] Fig.11 shows a timing diagram of a buck-boost driving scheme according to another embodiment of the present invention;

[0059] Fig.12 A schematic diagram of a PI controller of a buck-boost driving scheme according to an embodiment of the present invention is shown;

[0060] Fig.13 A schematic diagram of a PI controller of a buck-boost driving scheme according to another embodiment of the present invention is shown;

[0061] Fig.14 A schematic diagram of a PI controller of a buck-boost driving scheme according to another embodiment of the present invention is shown. DETAILED DESCRIPTION

[0062] In order to more clearly understand the above-mentioned purpose, features and advantages of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0063] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0064] Combine the following Figures 1 to 14 Embodiments of a buck-boost driving circuit, a method, an air conditioner, and a computer-readable storage medium according to embodiments of the present invention are described in detail.

[0065] like Figure 1 As shown, the buck-boost driving circuit 100 according to the first embodiment of the present invention includes: a buck-type circuit, which is configured to be able to perform buck processing or rectification processing on the power supply signal, and the buck-type circuit includes: a bridge circuit, two adjacent bridge arms of the bridge circuit are each provided with a bidirectional conducting power tube, and the other two adjacent bridge arms in the buck-type circuit are respectively provided with a first reverse blocking switch tube T1 and a second reverse blocking switch tube T2; a third reverse blocking switch tube T3, and both ends of the third reverse blocking switch tube T3 are connected to the output end of the bridge circuit; a boost-type circuit, the input end of the boost-type circuit is connected to the output end of the third reverse blocking switch tube T3, and the boost-type circuit is configured to be able to perform boost modulation on the power supply signal.

[0066] In this technical solution, by setting up a boost circuit and a buck circuit, the boost circuit is configured to be able to perform boost modulation or filtering on the power supply signal, and at the same time, the buck circuit can step down the voltage after rectification to flexibly adjust the bus voltage, which can not only make the bus voltage higher than the peak value of the AC voltage, but also make the bus voltage lower than the peak value of the AC voltage, that is, to increase or decrease the bus voltage according to the load operation requirements to improve the motor efficiency.

[0067] Among them, the AC signal AC is connected to the step-down circuit, the step-down circuit can step down or rectify the power supply signal and transmit it to the next-level boost circuit. The first reverse blocking switch tube T1 and the second reverse blocking switch tube T2 chop the power supply signal to reduce the bus voltage.

[0068] In addition, the bidirectional conducting power tubes include Figures 1 to 4 The first bidirectional conducting power tube M1 and the second bidirectional conducting power tube M2 are shown.

[0069] In addition, the boost circuit includes a first power tube Q1 and a second power tube Q2, which are connected in series in the same direction at the output end of the buck circuit. The second power tube Q2 supplies power to the load, which may be a motor, or an inverter and a permanent magnet motor driven by the inverter. The buck circuit can perform voltage reduction modulation to further improve the efficiency of the motor, which is also beneficial to reduce the iron loss of the motor.

[0070] In any of the above technical solutions, preferably, it also includes: an inductive element L, a first end of the inductive element L is connected to the high-voltage output end of the third reverse blocking switch tube T3, and a second end of the inductive element L is connected to the high-voltage input end of the boost circuit.

[0071] In this technical solution, by setting an inductive circuit, the first end of the inductive element L is connected to the high-voltage output end of the third reverse blocking switch tube T3, and the second end of the inductive element L is connected to the high-voltage input end of the boost circuit. On the one hand, the power supply signal can be filtered, and on the other hand, it is used as an inductive element of the power factor correction circuit, that is, it is multiplexed by the boost circuit to boost and modulate the power supply signal.

[0072] In addition, the boost circuit and the buck circuit share an inductive element L.

[0073] In any of the above technical solutions, preferably, the boost circuit includes: a first power tube Q1, connected between the second end of the inductive element L and the low-voltage output end of the third reverse blocking switch tube T3; a second power tube Q2, connected between the second end of the inductive element L and the high-voltage input end of the load; a capacitive element C, connected between the high-voltage input end of the load and the low-voltage output end of the third reverse blocking switch tube T3, the low-voltage output end of the third reverse blocking switch tube T3 and the low-voltage input end of the load are common terminals, wherein the first power tube Q1 and the second power tube Q2 are controlled to be alternately turned on to boost and modulate the power supply signal.

[0074] In this technical solution, a boost circuit is provided including a first power tube Q1, a second power tube Q2 and a capacitive element C, and connected in the above manner, so as to control the first power tube Q1 and the second power tube Q2 to be alternately turned on to perform boost modulation on the power supply signal, thereby improving the efficiency of the power supply signal and timely improving the amplitude of the power supply signal.

[0075] In any of the above technical solutions, preferably, the reverse blocking switch tube specifically includes: a first N-channel metal oxide semiconductor tube and a second N-channel metal oxide semiconductor tube, the drains of the two N-channel metal oxide semiconductor tubes are connected; a comparator, the source of the first N-channel metal oxide semiconductor tube is connected to the first input terminal of the comparator, and the source of the second N-channel metal oxide semiconductor tube is connected to the second input terminal of the comparator; a controller, the input terminal of the controller is connected to the output terminal of the comparator, and the output terminal of the controller is connected to the gate of the N-channel metal oxide semiconductor tube.

[0076] In this technical solution, the key components of the reverse blocking switch are a comparator and two anti-series metal oxide semiconductor tubes, wherein the source of the first N-channel metal oxide semiconductor tube is connected to the first input terminal of the comparator, and the source of the second N-channel metal oxide semiconductor tube is connected to the second input terminal of the comparator. The metal oxide semiconductor tube is controlled to be turned on or off by the output result of the comparator. Based on this, a reverse blocking switch is set to overcome the problems of large diode voltage drop and high power consumption, and the response efficiency is high.

[0077] In any of the above technical solutions, preferably, the reverse blocking switch tube includes: a first P-channel metal oxide semiconductor tube and a second P-channel metal oxide semiconductor tube, the sources of the two P-channel metal oxide semiconductor tubes are connected; a comparator, the drain of the first P-channel metal oxide semiconductor tube is connected to the first input terminal of the comparator, and the drain of the second P-channel metal oxide semiconductor tube is connected to the second input terminal of the comparator; a controller, the input terminal of the controller is connected to the output terminal of the comparator, and the output terminal of the controller is connected to the gate of the N-channel metal oxide semiconductor tube.

[0078] In this technical solution, the key components of the reverse blocking switch are a comparator and two anti-series metal oxide semiconductor tubes, wherein the source of the first P-channel metal oxide semiconductor tube is connected to the first input terminal of the comparator, and the source of the second P-channel metal oxide semiconductor tube is connected to the second input terminal of the comparator. The metal oxide semiconductor tube is controlled to be turned on or off by the output result of the comparator. Based on this, a reverse blocking switch is set to overcome the problems of large diode voltage drop and high power consumption, and the response efficiency is high.

[0079] In any of the above technical solutions, preferably, the reverse blocking switch tube comprises: a diode and a metal oxide semiconductor tube connected in series, the metal oxide semiconductor tube is provided with an anti-parallel diode, and the conduction direction of the diode is opposite to the conduction direction of the anti-parallel diode.

[0080] In this technical solution, a reverse blocking switch tube is provided including a diode and a metal oxide semiconductor tube connected in series. The metal oxide semiconductor tube is provided with an anti-parallel diode. The conduction direction of the diode is opposite to the conduction direction of the anti-parallel diode. When the metal oxide semiconductor tube is cut off, the series diode and the anti-parallel diode are also cut off because of their opposite conduction directions. Based on this, the problems of large diode voltage drop and high power consumption are overcome, and the response efficiency is high.

[0081] In any of the above technical solutions, preferably, the first reverse blocking switch tube T1 and / or the second reverse blocking switch tube T2 are diodes.

[0082] In any of the above technical solutions, preferably, the third reverse blocking switch tube T3 is a diode.

[0083] In any of the above technical solutions, preferably, the second power tube Q2 is a diode.

[0084] like Figure 5 As shown, the air conditioner 200 according to the embodiment of the present invention includes: a motor 202; and the buck-boost driving circuit 100 as described above, the buck-boost driving circuit 100 is configured to control the operation of the motor 202.

[0085] like Figure 6 As shown, the buck-boost driving method according to an embodiment of the present invention includes: step S302, determining the AC voltage input to the buck circuit and the bus voltage input to the boost circuit; step S304, controlling the boost circuit to perform boost modulation, or controlling the buck circuit to perform buck modulation, or controlling the boost circuit and the buck circuit to alternately modulate the power supply signal according to the AC voltage and the bus voltage.

[0086] In this technical solution, by controlling the boost circuit to perform boost modulation, or controlling the buck circuit to perform buck modulation, or controlling the boost circuit and the buck circuit to alternately modulate the power supply signal according to the AC voltage and the bus voltage, not only can the bus voltage be made higher than the peak value of the AC voltage, but also the bus voltage can be made lower than the peak value of the AC voltage, that is, the bus voltage can be increased or decreased according to the load operation requirements to improve the motor efficiency.

[0087] In any of the above technical solutions, preferably, according to the AC voltage and the bus voltage, the boost circuit is controlled to perform boost modulation, or the buck circuit is controlled to perform buck modulation, or the boost circuit and the buck circuit are controlled to alternately modulate the power supply signal, specifically including: comparing the magnitude relationship between a first voltage threshold and the bus voltage; when it is detected that the first voltage threshold is less than the bus voltage, controlling the buck circuit to stop modulation, and comparing the magnitude relationship between the bus voltage and the AC voltage; when it is detected that the bus voltage is greater than or equal to the AC voltage, controlling the boost circuit to perform boost modulation on the power supply signal.

[0088] In this technical solution, by detecting that the first voltage threshold is less than the bus voltage, the step-down circuit is controlled to stop modulation, and the magnitude relationship between the bus voltage and the AC voltage is compared. If it is detected that the bus voltage is greater than or equal to the AC voltage, the boost circuit is controlled to perform boost modulation on the power supply signal to improve the reliability of the power supply signal.

[0089] In any of the above technical solutions, preferably, according to the AC voltage and the bus voltage, the boost circuit is controlled to perform boost modulation, or the buck circuit is controlled to perform buck modulation, or the boost circuit and the buck circuit are controlled to alternately modulate the power supply signal, which specifically also includes: comparing the magnitude relationship between a second voltage threshold and the bus voltage; when it is detected that the second voltage threshold is greater than the bus voltage, controlling the boost circuit to stop modulation, and comparing the magnitude relationship between the bus voltage and the AC voltage; when it is detected that the bus voltage is less than or equal to the AC voltage, controlling the buck circuit to perform buck modulation on the power supply signal.

[0090] In this technical solution, the magnitude relationship between the second voltage threshold and the bus voltage is compared. Further, by detecting that the second voltage threshold is greater than the bus voltage, the boost circuit is controlled to stop modulation, and the magnitude relationship between the bus voltage and the AC voltage is compared. When it is detected that the bus voltage is less than or equal to the AC voltage, the buck circuit is controlled to perform buck modulation on the power supply signal to reduce the impact of the power supply signal on the subsequent circuit and improve the efficiency of the motor.

[0091] In any of the above technical solutions, preferably, according to the AC voltage and the bus voltage, the boost circuit is controlled to perform boost modulation, or the buck circuit is controlled to perform buck modulation, or the boost circuit and the buck circuit are controlled to alternately modulate the power supply signal, which specifically also includes: comparing the magnitude relationship between the first voltage threshold and the bus voltage, and comparing the magnitude relationship between the second voltage threshold and the bus voltage; detecting that the second voltage threshold is less than or equal to the bus voltage, and detecting that the first voltage threshold is greater than or equal to the bus voltage, controlling the boost circuit and the buck circuit to alternately modulate the power supply signal.

[0092] In this technical solution, by comparing the magnitude relationship between the first voltage threshold and the bus voltage, and comparing the magnitude relationship between the second voltage threshold and the bus voltage, if it is detected that the second voltage threshold is less than or equal to the bus voltage, and it is detected that the first voltage threshold is greater than or equal to the bus voltage, the boost circuit and the buck circuit are controlled to alternately modulate the power supply signal to further improve the motor efficiency.

[0093] In any of the above technical solutions, preferably, controlling the boost circuit and the buck circuit to alternately modulate the power supply signal specifically also includes: controlling the boost circuit to stop modulation, and comparing the magnitude relationship between the bus voltage and the AC voltage; when it is detected that the bus voltage is greater than the AC voltage, controlling the boost circuit to perform boost modulation on the power supply signal; when it is detected that the bus voltage is less than or equal to the AC voltage, controlling the buck circuit to perform buck modulation on the power supply signal.

[0094] In this technical solution, the boost circuit is controlled to stop modulation, and the magnitude relationship between the bus voltage and the AC voltage is compared. If it is detected that the bus voltage is greater than the AC voltage, the boost circuit is controlled to perform boost modulation on the power supply signal. Furthermore, if it is detected that the bus voltage is less than or equal to the AC voltage, the buck circuit is controlled to perform buck modulation on the power supply signal, so as to reduce the impact of the power supply signal on the subsequent circuit and improve the efficiency of the motor.

[0095] In any of the above technical solutions, preferably, controlling the buck circuit to perform buck modulation on the power supply signal specifically includes: controlling the first reverse blocking switch tube and the second reverse blocking switch tube to be alternately turned on according to the positive cycle and the negative cycle of the AC voltage, and controlling the third reverse blocking switch tube to be turned on.

[0096] In this technical solution, the first reverse blocking switch tube and the second reverse blocking switch tube are controlled to be alternately turned on according to the positive cycle and the negative cycle of the AC voltage, that is, the first reverse blocking switch tube and the second reverse blocking switch tube respectively work alternately in two consecutive half cycles of the AC voltage. In addition, by controlling the third reverse blocking switch tube to be turned on, the amplitude of the power supply signal input to the boost circuit is reduced.

[0097] In any of the above technical solutions, preferably, controlling the boost circuit to perform boost modulation on the power supply signal specifically includes: controlling the first power tube to be turned on or off according to a specified duty cycle, and controlling the third reverse blocking switch tube to be turned off; controlling the second power tube to be turned on alternately with the first power tube, or controlling the second power tube to be turned off.

[0098] In this technical solution, the power supply signal is boosted and modulated in a timely manner by controlling the first power tube to be turned on or off according to a specified duty cycle and controlling the third reverse blocking switch tube to be turned off.

[0099] In addition, during the process of modulation and voltage boosting of the first power tube, the second power tube and the first power tube are controlled to be turned on alternately, or the second power tube is controlled to be turned off, so as to avoid direct connection between the first power tube and the second power tube.

[0100] like Figure 7 As shown, according to the computer-readable storage medium 400 of an embodiment of the present invention, a computer program is stored on the computer-readable storage medium 400, and when the computer program is executed by the air conditioner 200, a buck-boost driving method as defined in any of the above technical solutions is implemented.

[0101] like Figures 1 to 4 As shown, the drive control circuit is composed of a boost circuit and a BUCK circuit. The BUCK circuit is an embodiment of a buck circuit. The input end of the boost circuit is connected to the output end of the BUCK circuit. The input of the buck circuit is connected to a single-phase AC power supply, and the output of the boost circuit is connected to a load.

[0102] Optionally, the load may be an inverter drive circuit and a permanent magnet motor driven by the inverter drive circuit.

[0103] The rectifier circuit includes a first reverse blocking switch tube T1 and a second reverse blocking switch tube T2, a first bidirectional conducting power tube M1 and a second bidirectional conducting power tube M2, and the above four power switch tubes form a bridge circuit.

[0104] The two ends of the AC power supply are connected to the middle connection points of the two side bridge arms of the bridge circuit. The high voltage output end and the low voltage output end of the bridge circuit are connected to the two ends of the first bidirectional conducting power tube M1 in the next level BUCK circuit to form the DC output of the rectifier circuit.

[0105] The first bidirectional conducting power tube M1 and the second bidirectional conducting power tube M2 may be replaced by diodes.

[0106] The BUCK circuit includes a third reverse blocking switch tube T3 and an inductive element L, and reuses the first reverse blocking switch tube T1 and the second reverse blocking switch tube T2 in the rectifier circuit. The drain of the third reverse blocking switch tube T3 is connected to one end of the inductive element L, the inductive element L is connected to the next-stage Boost circuit, and the source of the bidirectional conducting power switch tube is connected to the low-voltage end of the DC input.

[0107] The third reverse blocking switch tube T3 may be replaced by a diode.

[0108] The Boost circuit includes two bidirectionally conducting power switch tubes, namely, a second power tube Q2 and a first power tube Q1, and also includes a capacitive element C.

[0109] The drain of the second power tube Q2 is connected to the positive electrode of the capacitive element C, the source of the second power tube Q2 is connected to the drain of the first power tube Q1 , and the source of the first power tube Q1 is connected to the negative electrode of the capacitive element C.

[0110] The second power tube Q2 can be replaced by a diode.

[0111] The working process of PI controller is as follows Figures 8 to 11 As shown, Vout is the output bus voltage value, Vac is the input AC voltage, and Vin is the absolute value of the input voltage Vac. Figure 1 The buck-boost driving control method corresponding to the buck-boost driving circuit shown is:

[0112] like Figure 8 As shown, the step-down control is achieved by modulation control of the first reverse blocking switch tube T1 and the second reverse blocking switch tube T2, the step-up control is achieved by modulation control of the first power tube Q1 and the second power tube Q2, and the first bidirectional conducting power tube M1 and the second bidirectional conducting power tube M2 are used for rectification.

[0113] During buck-boost control, the first reverse blocking switch tube T1 and the second reverse blocking switch tube T2 perform PWM output at a certain duty cycle according to the positive and negative states of the input voltage Vac. When the first reverse blocking switch tube T1 or the second reverse blocking switch tube T2 is at a high level, the third reverse blocking switch tube T3 is at a low level. When the first reverse blocking switch tube T1 or the second reverse blocking switch tube T2 is at a low level, the third reverse blocking switch tube T3 is at a high level.

[0114] When the third reverse blocking switch tube T3 is replaced by a diode, only the first reverse blocking switch tube T1 and the second reverse blocking switch tube T2 are switched.

[0115] Ideally, the duty cycle D of the first reverse blocking switch tube T1 is T1 , the duty cycle D of the second reverse blocking switch tube T2 T2 , as shown in formulas (1-1) and (1-2) respectively:

[0116]

[0117]

[0118] Among them, when the duty cycle is 1, the first reverse blocking switch tube T1 or the second reverse blocking switch tube T2 is in the Boost step-up area and is in the fully on state; when the duty cycle is greater than 0 and less than 1, the first reverse blocking switch tube T1 or the second reverse blocking switch tube T2 is in the Buck step-down modulation area and is in the PWM modulation output state; when the duty cycle is 0, the first reverse blocking switch tube T1 or the second reverse blocking switch tube T2 is in the rectification mode and is in the fully off state.

[0119] During Boost control, the first power tube Q1 performs PWM output at a certain duty cycle, and the output of the second power tube Q2 is opposite to that of the first power tube Q1. When the second power tube Q2 is replaced by a diode, only the first power tube Q1 is switched.

[0120] In an ideal state, the duty cycle D of the first power tube Q1 is Q1 As shown in formula (1-3).

[0121]

[0122] Among them, when the duty cycle is 0, the first power tube Q1 is in the Buck step-down region and is fully off. When the duty cycle is greater than 0, Q1 is in the Boost step-up modulation region and is in the PWM modulation output state.

[0123] The first bidirectional conducting power tube M1 and the second bidirectional conducting power tube M2 are used for rectification.

[0124] The first bidirectional conducting power tube M1 performs on-off output according to the state of the input voltage Vac, and the output of the second bidirectional conducting power tube M2 is opposite to that of the first bidirectional conducting power tube M1.

[0125] The duty cycle D of the first bidirectional conducting power tube M1 M1 As shown in formula (1-4).

[0126]

[0127] like Figure 2 As shown, the rectifier circuit includes a first bidirectional conducting power tube M1, a second bidirectional conducting power tube M2, a first reverse blocking switch tube T1 and a second reverse blocking switch tube T2. The two ends of the AC power supply are connected to the middle connection points of the two side bridge arms of the bridge circuit (the second reverse blocking switch tube T2 and the second bidirectional conducting power tube M2 or the first reverse blocking switch tube T1 and the first bidirectional conducting power tube M1), and the high-voltage output end and the low-voltage output end of the bridge circuit are connected to the two ends of the third reverse blocking switch tube T3 in the BUCK circuit of the next stage, forming a DC output of the rectifier circuit.

[0128] The first reverse blocking switch tube T1 and the second reverse blocking switch tube T2 may be replaced by diodes.

[0129] The BUCK circuit includes a third reverse blocking switch tube T3 and an inductive element L, and reuses a first bidirectional conducting power tube M1 and a second bidirectional conducting power tube M2 in the rectifier circuit.

[0130] The drain of the third reverse blocking switch tube T3 is connected to one end of the inductive element L, the inductive element L is connected to the Boost circuit of the next stage, and the source of the bidirectional conducting power switch tube is connected to the low voltage end of the DC input.

[0131] The third reverse blocking switch tube T3 may be replaced by a diode.

[0132] The Boost circuit includes a second power tube Q2, a first power tube Q1 and a capacitive element C.

[0133] The drain of the second power tube Q2 is connected to the positive electrode of the capacitive element C, the source of the second power tube Q2 is connected to the drain of the first power tube Q1, and the source of the first power tube Q1 is connected to the negative electrode of the capacitive element C. The second power tube Q2 can be replaced by a diode.

[0134] Figure 2 The buck-boost drive control method corresponding to the circuit shown is as follows:

[0135] The step-down control is achieved by modulation control of the first bidirectional conducting power tube M1 and the second bidirectional conducting power tube M2, the step-up control is achieved by modulation control of the first power tube Q1 and the second power tube Q2, and the first reverse blocking switch tube T1 and the second reverse blocking switch tube T2 are used for rectification.

[0136] Vout is the output bus voltage value, Vac is the input AC voltage, and Vin is the absolute value of the input voltage Vac.

[0137] During buck-boost control, the first reverse blocking switch tube T1 and the second reverse blocking switch tube T2 perform PWM output at a certain duty cycle according to the positive and negative states of the input voltage Vac. When the first bidirectional conducting power tube M1 or the second bidirectional conducting power tube M2 is at a high level, the third reverse blocking switch tube T3 is at a low level. When the first bidirectional conducting power tube M1 or the second bidirectional conducting power tube M2 is at a low level, the third reverse blocking switch tube T3 is at a high level.

[0138] When the third reverse blocking switch tube T3 is replaced by a diode, only the first bidirectional conducting power tube M1 and the second bidirectional conducting power tube M2 are switched.

[0139] In an ideal state, the duty ratios of the first reverse blocking switch tube T1 and the second reverse blocking switch tube T2 are as shown in formulas (2-1) and (2-2):

[0140]

[0141]

[0142] like Fig. 9 As shown, when the duty cycle is 1, the first bidirectional conductive power tube M1 or the second bidirectional conductive power tube M2 is in the Boost step-up region and is in the fully on state; when the duty cycle is greater than 0 and less than 1, the first bidirectional conductive power tube M1 or the second bidirectional conductive power tube M2 is in the Buck step-down modulation region and is in the PWM modulation output state; when the duty cycle is 0, the first bidirectional conductive power tube M1 or the second bidirectional conductive power tube M2 is in the rectification mode and is in the fully off state.

[0143] During Boost control, the first power tube Q1 performs PWM output at a certain duty cycle, and the output of the second power tube Q2 is opposite to that of the first power tube Q1.

[0144] When the second power tube Q2 is replaced by a diode, only the first power tube Q1 is controlled to switch.

[0145] Under ideal conditions, the duty cycle of the first power tube Q1 output is as shown in formula (2-3).

[0146]

[0147] Among them, when the duty cycle is 0, the first power tube Q1 is in the Buck step-down region and is fully off; when the duty cycle is greater than 0, Q1 is in the Boost step-up modulation region and is in the PWM modulation output state.

[0148] The first bidirectional conducting power tube M1 and the second bidirectional conducting power tube M2 are used for rectification.

[0149] The first bidirectional conducting power tube M1 performs on-off output according to the state of the input voltage Vac, and the output of the second bidirectional conducting power tube M2 is opposite to that of the first bidirectional conducting power tube M1.

[0150] The duty cycle D of the first bidirectional conducting power tube M1 T3 As shown in formula (2-4).

[0151]

[0152] like Figure 3 As shown, the rectifier circuit includes a first reverse blocking switch tube T1 and a first bidirectional conducting power tube M1, and a second reverse blocking switch tube T2 and a second bidirectional conducting power tube M2. The two ends of the AC power supply are connected to the middle connection points of the two side bridge arms of the bridge circuit, and the high voltage output end and the low voltage output end of the bridge circuit are connected to the two ends of the third reverse blocking switch tube T3 in the next stage BUCK circuit, forming the DC output of the rectifier circuit.

[0153] The first bidirectional conducting power tube M1 and the second bidirectional conducting power tube M2 may be replaced by diodes.

[0154] The BUCK circuit includes a third reverse blocking switch tube T3 and an inductive element L, and reuses the first reverse blocking switch tube T1 and the first bidirectional conducting power tube M1 in the rectifier circuit. The drain of the third reverse blocking switch tube T3 of the bidirectional conducting power switch tube is connected to one end of the inductive element L, the inductive element L is connected to the Boost circuit of the next stage, and the source of the bidirectional conducting power switch tube is connected to the low voltage end of the DC input. The third reverse blocking switch tube T3 can be replaced by a diode.

[0155] The Boost circuit includes a second power tube Q2, a first power tube Q1 and a capacitive element C.

[0156] The drain of the second power tube Q2 is connected to the positive electrode of the capacitive element C, the source of the second power tube Q2 is connected to the drain of the bidirectional conductive power switch tube first power tube Q1, and the source of the bidirectional conductive power switch tube first power tube Q1 is connected to the negative electrode of the capacitive element C. The second power tube Q2 can be replaced by a diode.

[0157] Figure 3 The buck-boost driving control method corresponding to the buck-boost driving circuit shown is as follows:

[0158] The step-down control is achieved by modulation control of the first reverse blocking switch tube T1 and the first bidirectional conducting power tube M1, and the step-up control is achieved by modulation control of the first power tube Q1 and the second power tube Q2. The second reverse blocking switch tube T2 and the second bidirectional conducting power tube M2 are used for rectification.

[0159] Vout is the output bus voltage value, Vac is the input AC voltage, and Vin is the absolute value of the input voltage Vac.

[0160] like Fig.10 During the buck-boost control shown in the figure, the first reverse blocking switch tube T1 and the first bidirectional conducting power tube M1 perform PWM output at a certain duty cycle according to the positive and negative states of the input voltage Vac, and the output of the third reverse blocking switch tube T3 is opposite to the first reverse blocking switch tube T1 or the first bidirectional conducting power tube M1 (when the first reverse blocking switch tube T1 or the first bidirectional conducting power tube M1 is at a high level, the third reverse blocking switch tube T3 is at a low level, and when the first reverse blocking switch tube T1 or the first bidirectional conducting power tube M1 is at a low level, the third reverse blocking switch tube T3 is at a high level).

[0161] When the third reverse blocking switch tube T3 is replaced by a diode, only the first reverse blocking switch tube T1 and the first bidirectional conducting power tube M1 are switched.

[0162] In an ideal state, the duty ratios of the first reverse blocking switch tube T1 and the first bidirectional conducting power tube M1 are as shown in formulas (3-1) and (3-2):

[0163]

[0164]

[0165] Among them, when the duty cycle is 1, the first bidirectional conductive power tube M1 or the second bidirectional conductive power tube M2 is in the Boost boost region and is in the fully on state; when the duty cycle is greater than 0 and less than 1, the first bidirectional conductive power tube M1 or the second bidirectional conductive power tube M2 is in the Buck step-down modulation region and is in the PWM modulation output state; when the duty cycle is 0, the first bidirectional conductive power tube M1 or the second bidirectional conductive power tube M2 is in the rectification mode and is in the fully off state.

[0166] During Boost control, the first power tube Q1 performs PWM output at a certain duty cycle, and the output of the second power tube Q2 is opposite to that of the first power tube Q1.

[0167] When the second power tube Q2 is replaced by a diode, only the first power tube Q1 is controlled to switch.

[0168] In an ideal state, the duty cycle D of the first power tube Q1 is Q1 As shown in formula (3-3).

[0169]

[0170] Among them, when the duty cycle is 0, the first power tube Q1 is in the Buck step-down region and is fully off; when the duty cycle is greater than 0, Q1 is in the Boost step-up modulation region and is in the PWM modulation output state.

[0171] The second reverse blocking switch tube T2 and the second bidirectional conducting power tube M2 are used for rectification. The second reverse blocking switch tube T2 performs on-off output according to the state of the input voltage Vac, and the output of the second bidirectional conducting power tube M2 is opposite to that of the second reverse blocking switch tube T2. The output of the second reverse blocking switch tube T2 is shown in formula (3-4).

[0172]

[0173] like Figure 4 As shown, the rectifier circuit includes a second reverse blocking switch tube T2, a second bidirectional conducting power tube M2, a first reverse blocking switch tube T1, and a first bidirectional conducting power tube M1. The four power switch tubes form a bridge circuit. The two ends of the AC power supply are connected to the middle connection points of the bridge arms on both sides of the bridge circuit, and the high-voltage output end and the low-voltage output end of the bridge circuit are connected to the two ends of the third reverse blocking switch tube T3 in the BUCK circuit of the next level, forming the DC output of the rectifier circuit.

[0174] The second reverse blocking switch tube T2 and the second bidirectional conducting power tube M2 may be replaced by diodes.

[0175] The BUCK circuit includes a third reverse blocking switch tube T3, an inductive element L, and reuses the second reverse blocking switch tube T2 and the second bidirectional conducting power tube M2 in the rectifier circuit. The drain of the third reverse blocking switch tube T3 of the bidirectional conducting power switch tube is connected to one end of the inductive element L, the inductive element L is connected to the Boost circuit of the next stage, and the source of the bidirectional conducting power switch tube is connected to the low voltage end of the DC input.

[0176] The third reverse blocking switch tube T3 may be replaced by a diode.

[0177] The Boost circuit includes a second power tube Q2, a first power tube Q1 and a capacitive element C.

[0178] The drain of the second power tube Q2 is connected to the positive electrode of the capacitive element C, the source of the second power tube Q2 is connected to the drain of the bidirectional conductive power switch tube first power tube Q1, and the source of the bidirectional conductive power switch tube first power tube Q1 is connected to the negative electrode of the capacitive element C.

[0179] The second power tube Q2 can be replaced by a diode.

[0180] Figure 4The buck-boost driving control method corresponding to the buck-boost driving circuit shown is as follows:

[0181] like Fig.11 As shown, the step-down control is achieved by modulation control of the second reverse blocking switch tube T2 and the second bidirectional conducting power tube M2, and the step-up control is achieved by modulation control of the first power tube Q1 and the second power tube Q2. The first reverse blocking switch tube T1 and the first bidirectional conducting power tube M1 are used for rectification.

[0182] Vout is the output bus voltage value, Vac is the input AC voltage, and Vin is the absolute value of the input voltage Vac.

[0183] During buck-boost control, the second reverse blocking switch tube T2 and the second bidirectional conducting power tube M2 perform PWM output at a certain duty cycle according to the positive and negative states of the input voltage Vac, and the output of the third reverse blocking switch tube T3 is opposite to the second reverse blocking switch tube T2 or the second bidirectional conducting power tube M2 (when the second reverse blocking switch tube T2 or the second bidirectional conducting power tube M2 is at a high level, the third reverse blocking switch tube T3 is at a low level, and when the second reverse blocking switch tube T2 or the second bidirectional conducting power tube M2 is at a low level, the third reverse blocking switch tube T3 is at a high level).

[0184] When the third reverse blocking switch tube T3 is replaced by a diode, only the second reverse blocking switch tube T2 and the second bidirectional conducting power tube M2 are switched.

[0185] Ideally, the duty cycle D of the second reverse blocking switch tube T2 is T2 and the duty cycle D of the second bidirectional conducting power tube M2 M2 , as shown in formulas (4-1) and (4-2) respectively:

[0186]

[0187]

[0188] Among them, when the duty cycle is 1, the second reverse blocking switch tube T2 or the second bidirectional conducting power tube M2 is in the Boost boost area and is in the fully on state; when the duty cycle is greater than 0 and less than 1, the second reverse blocking switch tube T2 or the second bidirectional conducting power tube M2 is in the Buck step-down modulation area, which is the PWM modulation output state; when the duty cycle is 0, the second reverse blocking switch tube T2 or the second bidirectional conducting power tube M2 is in the rectification mode and is in the fully off state.

[0189] During Boost control, the first power tube Q1 performs PWM output at a certain duty cycle, and the output of the second power tube Q2 is opposite to that of the first power tube Q1. When the second power tube Q2 is replaced by a diode, only the first power tube Q1 is switched.

[0190] In an ideal state, the duty cycle D of the first power tube Q1 is Q1 As shown in formula (4-3).

[0191]

[0192] Among them, when the duty cycle is 0, the first power tube Q1 is in the Buck step-down region and is fully off; when the duty cycle is greater than 0, Q1 is in the Boost step-up modulation region and is in the PWM modulation output state.

[0193] The first reverse blocking switch tube T1 and the first bidirectional conducting power tube M1 are used for rectification. The first reverse blocking switch tube T1 performs on-off output according to the state of the input voltage Vac, and the output of the first bidirectional conducting power tube M1 is opposite to that of the first reverse blocking switch tube T1.

[0194] The duty cycle D of the first reverse blocking switch tube T1 T1 As shown in formula (4-4).

[0195]

[0196] When the bus voltage value Vout is within the peak value of the input voltage Vin, the system has a Buck modulation area and a Boost modulation area; when it is higher than the peak value of the input voltage Vin, the system is in the Boost modulation area throughout.

[0197] When switching between Buck mode and Boost mode, the buffer modulation interval can also be set within the range of Vout±Vbuf (0≤Vbuf<Vout). In this interval, Buck and Boost modes work alternately every n modulation cycles to keep the current and voltage stable during mode switching. Among them, Vbuf and n are set according to the actual debugging situation.

[0198] Combine the following Figure 12 to Figure 14 The modulation implementation method is described in detail.

[0199] In order to realize the step-up and step-down control of the bus voltage, it is necessary to set the bus voltage set value Vcmd.

[0200] The Buck and Boost operating modes are determined based on the relationship between Vcmd and Vin. When the system is in Boost modulation, the specific modulation drive mode is as follows: Fig.12As shown in the figure, the Boost Duty of the Boost circuit is determined; when the system is in Buck modulation, the specific modulation driving mode is as follows Figure 4 As shown in the figure, the duty cycle of the Buck circuit can be determined.

[0201] exist Fig.12 and Fig.13 In the embodiment, the duty cycle output is realized by a controller (PI controller is used as an example in the figure) so that the actual bus voltage Vout approaches the voltage set value Vcmd.

[0202] Among them, Status is a binary state quantity, which is 1 in Buck modulation and 0 in Boost modulation. When Status changes, the corresponding initial duty cycle Pre Duty is calculated according to the duty cycle formula of the corresponding mode and updated to the controller as the initial quantity (such as the initial value of the integral in the PI controller) to improve the responsiveness of the initial state of the controller, reduce the fluctuation amplitude at the switching moment, and improve the modulation stability.

[0203] Fig.14 Another way to determine Pre Duty is given.

[0204] At the moment when the Buck mode is switched to the Boost mode, the complementary value of the output duty cycle in the Buck mode (1-Dbuck) is updated to the controller as the initial value of the Boost mode (such as the initial value of the integral in the PI controller); at the moment when the Boost mode is switched to the Buck mode, the complementary value of the output duty cycle in the Boost mode (1-Dboost) is updated to the controller as the initial value of the Buck mode (such as the initial value of the integral in the PI controller). This method can also achieve modulation stability during switching.

[0205] The technical solution of the present invention is described in detail above in conjunction with the accompanying drawings. The present invention provides a buck-boost driving circuit, method, air conditioner and computer-readable storage medium. By setting a boost circuit and a buck circuit, the boost circuit is configured to be able to perform boost modulation or filtering processing on the power supply signal, and the buck circuit can perform buck modulation on the rectified voltage to flexibly adjust the bus voltage, which can not only make the bus voltage higher than the peak value of the AC voltage, but also make the bus voltage lower than the peak value of the AC voltage, that is, to increase or decrease the bus voltage according to the load operation requirements to improve the motor efficiency.

[0206] The steps in the method of the present invention can be adjusted in order, combined or deleted according to actual needs.

[0207] The units in the circuit of the present invention can be combined, divided and deleted according to actual needs.

[0208] Those skilled in the art can understand that all or part of the steps in the various methods of the above embodiments can be completed by instructing related hardware through a program, and the program can be stored in a computer-readable storage medium, and the storage medium includes a read-only memory (ROM), a random access memory (RAM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), a one-time programmable read-only memory (OTPROM), an electronically erasable rewritable read-only memory (EEPROM), a compact disc (CD-ROM) or other optical disc storage, magnetic disk storage, magnetic tape storage, or any other computer-readable medium that can be used to carry or store data.

[0209] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A buck-boost driving method, It is characterized in that The invention is applicable to a buck-boost driving circuit, wherein the buck-boost driving circuit comprises a buck type circuit and a boost type circuit which are electrically connected. The step-down circuit is configured to be able to perform step-down processing or rectification processing on the power supply signal, and the step-down circuit includes: A bridge circuit, wherein two adjacent bridge arms of the bridge circuit are each provided with a bidirectional conducting power tube, and two adjacent bridge arms in the buck circuit are respectively provided with a first reverse blocking switch tube and a second reverse blocking switch tube; a third reverse blocking switch tube, wherein two ends of the third reverse blocking switch tube are connected to the output end of the bridge circuit; The input end of the boost circuit is connected to the output end of the third reverse blocking switch tube, and the boost circuit is configured to perform boost modulation on the power supply signal; The buck-boost driving method comprises: Determining an AC voltage input to the step-down circuit and a bus voltage input to the step-up circuit; According to the AC voltage and the bus voltage, control the boost circuit to perform boost modulation, or control the buck circuit to perform buck modulation, or control the boost circuit and the buck circuit to alternately modulate the power supply signal; According to the AC voltage and the bus voltage, controlling the boost circuit to perform boost modulation, or controlling the buck circuit to perform buck modulation, or controlling the boost circuit and the buck circuit to alternately modulate the power supply signal, specifically includes: Comparing the magnitude relationship between the first voltage threshold and the bus voltage; Detecting that the first voltage threshold is less than the bus voltage, controlling the step-down circuit to stop modulation, and comparing the magnitude relationship between the bus voltage and the AC voltage; When it is detected that the bus voltage is greater than or equal to the AC voltage, the boost circuit is controlled to perform boost modulation on the power supply signal.

2. The buck-boost driving method according to claim 1, It is characterized in that According to the AC voltage and the bus voltage, the boost circuit is controlled to perform boost modulation, or the buck circuit is controlled to perform buck modulation, or the boost circuit and the buck circuit are controlled to alternately modulate the power supply signal, specifically including: Comparing the magnitude relationship between the second voltage threshold and the bus voltage; Detecting that the second voltage threshold is greater than the bus voltage, controlling the boost circuit to stop modulation, and comparing the magnitude relationship between the bus voltage and the AC voltage; When it is detected that the bus voltage is less than or equal to the AC voltage, the step-down circuit is controlled to perform step-down modulation on the power supply signal.

3. The buck-boost driving method according to claim 1, It is characterized in that According to the AC voltage and the bus voltage, the boost circuit is controlled to perform boost modulation, or the buck circuit is controlled to perform buck modulation, or the boost circuit and the buck circuit are controlled to alternately modulate the power supply signal, specifically including: Comparing the magnitude relationship between the first voltage threshold and the bus voltage, and comparing the magnitude relationship between the second voltage threshold and the bus voltage; It is detected that the second voltage threshold is less than or equal to the bus voltage, and it is detected that the first voltage threshold is greater than or equal to the bus voltage, and the boost circuit and the buck circuit are controlled to alternately modulate the power supply signal.

4. The buck-boost driving method according to claim 1, It is characterized in that Controlling the boost circuit and the buck circuit to alternately modulate the power supply signal specifically includes: Controlling the boost circuit to stop modulation, and comparing the magnitude relationship between the bus voltage and the AC voltage; When it is detected that the bus voltage is greater than the AC voltage, controlling the boost circuit to perform boost modulation on the power supply signal; When it is detected that the bus voltage is less than or equal to the AC voltage, the step-down circuit is controlled to perform step-down modulation on the power supply signal.

5. The buck-boost driving method according to any one of claims 1 to 4, It is characterized in that Controlling the step-down circuit to perform step-down modulation on the power supply signal specifically includes: According to the positive cycle and the negative cycle of the AC voltage, the first reverse blocking switch tube and the second reverse blocking switch tube are controlled to be alternately turned on, and the third reverse blocking switch tube is controlled to be turned on.

6. The buck-boost driving method according to any one of claims 1 to 4, It is characterized in that Controlling the boost circuit to perform boost modulation on the power supply signal specifically includes: Controlling the first power tube to be turned on or off according to a specified duty cycle, and controlling the third reverse blocking switch tube to be turned off; The second power tube and the first power tube are controlled to be turned on alternately, or the second power tube is controlled to be turned off.

7. A computer-readable storage medium, It is characterized in that The computer-readable storage medium stores a computer program, and when the computer program is executed, the buck-boost driving method according to any one of claims 1 to 4 is implemented.

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