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 bridge circuit, the bridge circuit is configured to rectify the power supply signal; a buck-type circuit, the buck-type circuit includes: a first reverse blocking power tube and a first power tube, which are sequentially connected in series between the high-voltage output end and the low-voltage output end of the bridge circuit; an inductive element, the first end of the inductive element is connected to the common end between the first reverse blocking power tube and the first power tube, wherein the first reverse blocking power tube is controlled to be turned on or off according to a specified duty cycle, and the first power tube is opposite to the on state of the first reverse blocking power tube or remains in the off state, so as to perform buck modulation on the power supply signal. Through the technical solution of the present invention, the DC bus voltage of the variable frequency motor is buck-boosted, 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 a DC bus voltage adjustment function, and a 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, a buck-boost driving circuit is provided, comprising: a bridge circuit, wherein the bridge circuit is configured to rectify a power supply signal; a buck-type circuit, wherein the buck-type circuit comprises: a first reverse blocking power tube and a first power tube, which are sequentially connected in series between a high voltage output terminal and a low voltage output terminal of the bridge circuit; an inductive element, wherein a first end of the inductive element is connected to a common terminal between the first reverse blocking power tube and the first power tube, wherein the first reverse blocking power tube is controlled to be turned on or off according to a specified duty cycle, and the first power tube is opposite to the on state of the first reverse blocking power tube or remains in an off state, so as to buck-modulate the power supply signal.

[0012] In this technical solution, a bridge circuit is set up to rectify the power supply signal, and the buck circuit can step down and modulate the rectified voltage, so that the bus voltage can be made lower than the peak value of the AC voltage. That is, the bus voltage is reduced according to the load operation requirements to improve the motor efficiency. At the same time, it is also beneficial to reduce the iron loss of the motor to comprehensively improve the reliability of the motor.

[0013] Among them, the AC signal is connected to the bridge circuit, the bridge circuit can rectify the power supply signal and transmit it to the next-level buck circuit, the first reverse blocking power tube can chop the power supply signal, that is, the buck circuit can step down the power supply signal, and the power supply signal after the step-down processing continues to be transmitted to the next-level boost circuit to step up the power supply signal.

[0014] In addition, the buck circuit includes a first power tube and a first reverse blocking power tube, which are connected in series in the same direction at the output end of the bridge circuit. The first 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 buck modulation to further improve the efficiency of the motor.

[0015] In addition, the step-up circuit and the step-down circuit share one inductive element.

[0016] In any of the above technical solutions, preferably, it also includes: a boost circuit, which includes: a second power tube, connected between the second end of the inductive element and the low-voltage output end; a third 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, the low-voltage output end and the low-voltage input end of the load are common ends, wherein the second power tube and the third power tube are controlled to be alternately turned on to boost and modulate the power supply signal.

[0017] In this technical solution, by setting up a boost circuit including a second power tube, a third power tube and a capacitive element, not only can the power supply signal be boosted and modulated, but the efficiency of the power supply signal can also be improved. In addition, the power supply signal can also be filtered to reduce the noise signal input to the load.

[0018] 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.

[0019] 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.

[0020] 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 P-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 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.

[0022] 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.

[0023] 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.

[0024] In any of the above technical solutions, preferably, the first reverse blocking power tube and / or the second power tube is a diode.

[0025] In any of the above technical solutions, preferably, the third power tube is a diode.

[0026] In any of the above technical solutions, preferably, the second power tube is a diode.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[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, 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.

[0033] 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.

[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 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.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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 power tube and the second power tube to be alternately turned on according to the positive cycle and the negative cycle of the AC voltage, and controlling the third power tube to be turned on.

[0039] In this technical solution, the first reverse blocking power tube and the second power 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 power tube and the second power tube respectively work alternately in two consecutive half cycles of the AC voltage. In addition, by controlling the conduction of the third power tube, the amplitude of the power supply signal input to the boost circuit is reduced.

[0040] 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 power 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.

[0041] 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 power tube to be turned off.

[0042] 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.

[0043] 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.

[0044] 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

[0045] 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:

[0046] Figure 1 A schematic diagram of a buck-boost driving circuit according to an embodiment of the present invention is shown;

[0047] Figure 2 A schematic diagram of an air conditioner according to another embodiment of the present invention is shown;

[0048] Figure 3 A schematic flow chart of a buck-boost driving method according to an embodiment of the present invention is shown;

[0049] Figure 4 A schematic block diagram of a computer-readable storage medium according to an embodiment of the present invention is shown;

[0050] Figure 5 shows a timing diagram of a buck-boost driving scheme according to an embodiment of the present invention;

[0051] Figure 6 shows a timing diagram of a buck-boost driving scheme according to another embodiment of the present invention;

[0052] Figure 7 shows a timing diagram of a buck-boost driving scheme according to another embodiment of the present invention;

[0053] Figure 8 A schematic diagram showing the operation of a controller according to a buck-boost driving scheme according to an embodiment of the present invention is shown;

[0054] Fig. 9 A schematic diagram showing the operation of a controller according to a buck-boost driving scheme according to another embodiment of the present invention is shown;

[0055] Fig.10 A working schematic diagram of a controller of a buck-boost driving scheme according to another embodiment of the present invention is shown. DETAILED DESCRIPTION

[0056] 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.

[0057] 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.

[0058] Combine the following Figures 1 to 10 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.

[0059] like Figure 1As shown, the buck-boost driving circuit 100 according to the first embodiment of the present invention includes: a bridge circuit, which is configured to rectify the power supply signal; a buck circuit, which includes: a first reverse blocking power tube Q1 and a first power tube Q2, which are connected in series between the high voltage output end and the low voltage output end of the bridge circuit in sequence; an inductive element L, wherein the first end of the inductive element L is connected to the common end between the first reverse blocking power tube and the first power tube, wherein the first reverse blocking power tube Q1 is controlled to be turned on or off according to a specified duty cycle, and the first power tube Q2 is opposite to the on state of the first reverse blocking power tube Q1 or remains in the off state, so as to buck-modulate the power supply signal.

[0060] In this technical solution, a bridge circuit is set up to rectify the power supply signal, and the buck circuit can step down and modulate the rectified voltage, so that the bus voltage can be made lower than the peak value of the AC voltage. That is, the bus voltage is reduced according to the load operation requirements to improve the motor efficiency. At the same time, it is also beneficial to reduce the iron loss of the motor to comprehensively improve the reliability of the motor.

[0061] Among them, the AC signal AC is connected to the bridge circuit, the bridge circuit can rectify the power supply signal and transmit it to the next-level buck circuit, the first reverse blocking power tube Q1 can chop the power supply signal, that is, the buck circuit can step down the power supply signal, and the power supply signal after the step-down processing continues to be transmitted to the next-level boost circuit to step up the power supply signal.

[0062] In addition, the buck circuit includes a first power tube Q2 and a first reverse blocking power tube Q1. The first power tube Q2 and the first reverse blocking power tube Q1 are connected in series in the same direction at the output end of the bridge circuit. The first power tube Q2 supplies power to the load. The load can be a motor, or an inverter and a permanent magnet motor driven by it. The buck circuit can perform buck modulation to further improve the efficiency of the motor.

[0063] In addition, the boost circuit and the buck circuit share the same inductive element L.

[0064] In any of the above technical solutions, preferably, it also includes: a boost circuit, which includes: a second power tube Q4, connected between the second end of the inductive element L and the low-voltage output end; a third power tube Q3, 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, and the low-voltage output end and the low-voltage input end of the load are common ends, wherein the second power tube Q4 and the third power tube Q3 are controlled to be alternately turned on to boost and modulate the power supply signal.

[0065] In this technical solution, by setting a boost circuit including a second power tube Q4, a third power tube Q3 and a capacitive element C, not only can the power supply signal be boosted and modulated, but the efficiency of the power supply signal can also be improved. In addition, the power supply signal can also be filtered to reduce the noise signal input to the load.

[0066] 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.

[0067] 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.

[0068] 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 P-channel metal oxide semiconductor tube.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] In any of the above technical solutions, preferably, the first reverse blocking power tube and / or the second power tube is a diode.

[0073] In any of the above technical solutions, preferably, the third power tube is a diode.

[0074] In any of the above technical solutions, preferably, the second power tube Q4 is a diode.

[0075] like Figure 2 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.

[0076] like Figure 3 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.

[0077] 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.

[0078] 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.

[0079] 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.

[0080] 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.

[0081] 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.

[0082] 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.

[0083] 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.

[0084] 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.

[0085] 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.

[0086] 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 power tube and the second power tube to be alternately turned on according to the positive cycle and the negative cycle of the AC voltage, and controlling the third power tube to be turned on.

[0087] In this technical solution, the first reverse blocking power tube and the second power 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 power tube and the second power tube respectively work alternately in two consecutive half cycles of the AC voltage. In addition, by controlling the conduction of the third power tube, the amplitude of the power supply signal input to the boost circuit is reduced.

[0088] 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 power 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.

[0089] 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 power tube to be turned off.

[0090] 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.

[0091] like Figure 4 As shown, a computer-readable storage medium 400 is provided, on which a computer program is stored. When the computer program is executed by the air conditioner 200, the steps of the buck-boost driving method as defined in any of the above technical solutions are implemented, specifically including: determining the AC voltage input to the buck circuit and the 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.

[0092] 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.

[0093] 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.

[0094] 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.

[0095] 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.

[0096] 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.

[0097] 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.

[0098] 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.

[0099] 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.

[0100] 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.

[0101] 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 power tube and the second power tube to be alternately turned on according to the positive cycle and the negative cycle of the AC voltage, and controlling the third power tube to be turned on.

[0102] In this technical solution, the first reverse blocking power tube and the second power 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 power tube and the second power tube respectively work alternately in two consecutive half cycles of the AC voltage. In addition, by controlling the conduction of the third power tube, the amplitude of the power supply signal input to the boost circuit is reduced.

[0103] 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 power 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.

[0104] 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 power tube to be turned off.

[0105] 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.

[0106] like Figure 1 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 output of the boost circuit is directly connected to the input of the BUCK circuit. The input of the boost circuit is connected to a single-phase AC power supply, and the output of the BUCK circuit is connected to a load.

[0107] Optionally, the load may be an inverter drive circuit and a permanent magnet motor driven by the inverter drive circuit.

[0108] The rectifier circuit includes four bidirectional conduction power switch tubes, which are respectively recorded as the fourth power tube T1, the fifth power tube T2, the sixth power tube T3 and the seventh power tube T4. The above four bidirectional conduction power switch tubes form a bridge circuit. The bridge circuit performs rectification and can be replaced by diodes. The two ends of the AC power supply are connected to the middle connection points of the two side bridge arms (T2T4 or T1T3) of the bridge circuit. The high-voltage output end and the low-voltage output end of the bridge circuit are connected to the BUCK circuit of the next level to form the DC output of the rectifier circuit.

[0109] The fourth power tube T1 , the fifth power tube T2 , the sixth power tube T3 and the seventh power tube T4 may all be replaced by diodes.

[0110] The BUCK circuit includes a first reverse blocking power tube Q1, a first power tube Q2 (bidirectional conduction power switch tube), and an inductive element L. The drain of the first reverse blocking power tube Q1 is connected to the high voltage end of the DC input, the source of the first reverse blocking power tube Q1 is connected to the drain of the first power tube Q2 (bidirectional conduction power switch tube) and one end of the inductive element L, the inductive element L is connected to the next-level Boost circuit, and the source of the bidirectional conduction power switch tube is connected to the low voltage end of the DC input.

[0111] The first power tube Q2 can be replaced by a diode.

[0112] The Boost circuit includes two bidirectionally conducting power switch tubes, which are respectively denoted as the third power tube Q3, the second power tube Q4 and the capacitive element C.

[0113] The drain of the third power tube Q3 is connected to the positive electrode of the capacitive element C, the source of the third power tube Q3 is connected to the drain of the second power tube Q4, and the source of the second power tube Q4 is connected to the negative electrode of the capacitive element C.

[0114] The third power tube Q3 can be replaced by a diode.

[0115] like Figure 1 The buck-boost drive control method corresponding to the circuit shown is as follows:

[0116] The step-down control is achieved by modulation control of the first power tube Q2 and the first reverse blocking power tube Q1, and the step-up control is achieved by modulation control of the third power tube Q3 and the second power tube Q4.

[0117] Control methods such as Figure 5 , Figure 6 and Figure 7 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.

[0118] During Buck step-down control, the first reverse blocking power tube Q1 performs PWM output with a certain duty cycle, and the output of the first power tube Q2 is opposite to the first reverse blocking power tube Q1 (when the first reverse blocking power tube Q1 is at a high level, the first power tube Q2 is at a low level, and when the first reverse blocking power tube Q1 is at a low level, the first power tube Q2 is at a high level).

[0119] When the first power tube Q2 is replaced by a diode, only the first reverse blocking power tube Q1 is switched.

[0120] Ideally, the duty cycle D of the first reverse blocking power tube Q1 is Q1 As shown in formula (1):

[0121]

[0122] Among them, when the duty cycle is 1, the first reverse blocking power tube Q1 is in the Boost boost region and is in a fully on state; when the duty cycle is less than 1, the first reverse blocking power tube Q1 is in the Buck step-down modulation region and is in a PWM modulation output state.

[0123] During Boost control, the second power tube Q4 performs PWM output at a certain duty cycle, and the output of the third power tube Q3 is opposite to that of the second power tube Q4. When the third power tube Q3 is replaced by a diode, only the second power tube Q4 is switched.

[0124] Ideally, the duty cycle D of the second power tube Q4 is Q4 As shown in formula (2).

[0125]

[0126] Among them, when the duty cycle is 0, the second power tube Q4 is in the Buck step-down region and is fully off; when the duty cycle is greater than 0, the first reverse blocking power tube Q1 is in the Boost step-up modulation region and is in the PWM modulation output state.

[0127] The fourth power tube T1 performs synchronous on-off output according to the state of the input voltage Vac. The output of the seventh power tube T4 is the same as that of the fourth power tube T1. The outputs of the fifth power tube T2 and the sixth power tube T3 are opposite to those of the fourth power tube T1. The duty cycle D of the fourth power tube T1 T1 As shown in formula (3).

[0128]

[0129] 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.

[0130] In order to realize the buck-boost control of bus voltage and further reduce the switching loss of power switch components, the present invention proposes an improved modulation method of Buck and Boost based on the given value Vcmd of bus voltage (actually determined by Vout, Vout≈Vcmd): set the upper threshold voltage Vbck of Buck buck modulation and the lower threshold voltage Vbst of Boost boost modulation. Generally, Vbck>Vbst. According to the set value of Vcmd, the following three modulation modes are performed:

[0131] When Vcmd > Vbck, the Buck buck modulation is turned off, and only the Boost boost modulation is performed when Vcmd is higher than Vin.

[0132] When Vcmd < Vbst, the Boost modulation is turned off, and only the Buck buck modulation is performed when Vcmd is lower than Vin.

[0133] When Vcmd is between Vbck and Vbst, the Buck buck modulation and the Boost boost modulation work alternately according to the magnitude change of Vcmd and Vin. When Vcmd is higher than Vin, the Boost boost modulation is performed. When Vcmd is lower than Vin, the Buck buck modulation is performed.

[0134] When switching between the Buck mode and the Boost mode, a buffer modulation interval can also be set within the range of Vout ± Vbuf (0 ≤ Vbuf < Vout). Within this interval, every n modulation cycles, the Buck and Boost modes work alternately to keep the current and voltage stable during mode switching. Among them, Vbuf and n are set according to the actual debugging situation. To achieve the buck-boost control of the bus voltage, it is necessary to set the bus voltage given value Vcmd.

[0135] Determine the working modes of Buck and Boost according to the relationship between Vcmd and Vin.

[0136] When Vcmd is lower than Vin, the system is in the Boost boost modulation mode. The specific Boost modulation drive is as Figure 8 shown.

[0137] When Vcmd is higher than Vin, the system is in the Buck buck modulation mode. The Buck modulation drive is as Fig.10 shown.

[0138] As Figure 8 and Fig. 9 shown, the duty cycle output is realized through a controller (taking the PI controller as an example in the figure) to make the actual bus voltage Vout approach the voltage given value Vcmd.

[0139] Among them, Status is a binary status quantity, which is 1 during Buck modulation and 0 during Boost modulation. When the status of 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 an initial quantity (such as the integral initial value in the PI controller) to improve the responsiveness of the initial state of the controller and reduce the fluctuation amplitude at the switching moment, thus enhancing the modulation stability.

[0140] Fig.10Another way to determine Pre Duty is shown. At the moment when Buck mode switches to Boost mode, the complementary value of the output duty cycle in Buck mode (1-Dbuck) is updated to the controller as the initial value of Boost mode (such as the initial value of integration in PI controller). At the moment when Boost mode switches to Buck mode, the complementary value of the output duty cycle in Boost mode (1-Dboost) is updated to the controller as the initial value of Buck mode (such as the initial value of integration in PI controller). This method can also achieve modulation stability during switching.

[0141] 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 rectification 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.

[0142] The steps in the method of the present invention can be adjusted in order, combined or deleted according to actual needs.

[0143] The units in the circuit of the present invention can be combined, divided and deleted according to actual needs.

[0144] A person 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 the relevant 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 programmable read-only memory (EEPROM), a compact disc read-only memory (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. The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For a person skilled in the art, the present invention can have various modifications and changes. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A buck-boost driving circuit, characterized in that: include: A bridge circuit, wherein the bridge circuit is configured to rectify the power supply signal; A step-down circuit, the step-down circuit comprising: The first reverse blocking power tube and the first power tube are sequentially connected in series between the high voltage output end and the low voltage output end of the bridge circuit; an inductive element, wherein a first end of the inductive element is connected to a common end between the first reverse blocking power tube and the first power tube, The first reverse blocking power tube is controlled to be turned on or off according to a specified duty cycle, and the first power tube is in a conduction state opposite to that of the first reverse blocking power tube or remains in an off state, so as to perform voltage reduction modulation on the power supply signal; The first reverse blocking power tube specifically includes: A first N-channel metal oxide semiconductor tube and a second N-channel metal oxide semiconductor tube, wherein drain electrodes of the two N-channel metal oxide semiconductor tubes are connected; A comparator, wherein the source of the first N-channel metal oxide semiconductor transistor is connected to a first input terminal of the comparator, and the source of the second N-channel metal oxide semiconductor transistor is connected to a second input terminal of the comparator; A controller, wherein an input end of the controller is connected to an output end of the comparator, and an output end of the controller is connected to a gate of the N-channel metal oxide semiconductor tube; or The first reverse blocking power tube comprises: A first P-channel metal oxide semiconductor tube and a second P-channel metal oxide semiconductor tube, wherein the sources of the two P-channel metal oxide semiconductor tubes are connected; A comparator, wherein 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, wherein an input end of the controller is connected to an output end of the comparator, and an output end of the controller is connected to a gate of the P-channel metal oxide semiconductor tube; The first power tube is a diode or a bidirectional conducting power tube.

2. The buck-boost driving circuit according to claim 1, characterized in that: Also includes: A boost circuit, the boost circuit comprising: A second power tube connected between the second end of the inductive element and the low voltage output end; a third power tube connected between the second end of the inductive element and the high voltage input end of the load; A capacitive element is connected between the high voltage input terminal of the load and the low voltage output terminal, wherein the low voltage output terminal and the low voltage input terminal of the load are common terminals. The second power tube and the third power tube are controlled to be turned on alternately to perform voltage boost modulation on the power supply signal.

3. The buck-boost driving circuit according to claim 2, characterized in that: The third power tube is a diode or a bidirectional conducting power tube.

4. The buck-boost driving circuit according to claim 2, characterized in that: The first power tube and / or the third power tube are provided with anti-parallel diodes.

5. An air conditioner, characterized in that: include: Motor; The buck-boost drive circuit according to any one of claims 1 to 4, wherein the drive circuit is configured to control the operation of the motor.

6. A buck-boost driving method, characterized in that: The buck-boost driving circuit according to any one of claims 1 to 4, wherein the driving circuit comprises a buck-type circuit and a boost-type circuit electrically connected, and the 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; or 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; or 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.

7. The buck-boost driving method according to claim 6, 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.

8. The buck-boost driving method according to claim 6 or 7, 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 power tube and the second power tube are controlled to be alternately turned on, and the third power tube is controlled to be turned on.

9. The buck-boost driving method according to claim 6 or 7, 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 power 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.

10. A computer-readable storage medium, 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 6 to 9 is implemented.

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