Boost-buck driving circuit, method, air conditioner and computer readable storage medium

Abstract

The application provides a boost-buck driving circuit, a method, an air conditioner and a computer readable storage medium, wherein the boost-buck driving circuit comprises a totem pole circuit configured to perform power factor correction processing or rectification processing on a power supply signal, and a buck circuit, an input end of the buck circuit being connected to an output end of the totem pole circuit, the buck circuit comprising a first power tube and a second power tube, the first power tube and the second power tube being connected in series between a high-voltage output end and a low-voltage output end of the totem pole circuit, two ends of the second power tube being led out as a high-voltage bus and a low-voltage bus, wherein the first power tube and the second power tube are alternately turned on, a bus voltage between the high-voltage bus and the low-voltage bus decreases as a load running time increases, and the buck circuit is configured to perform voltage reduction processing or filtering processing on the power supply signal. Through the technical scheme provided by the application, the iron loss of the motor can be reduced, and the efficiency of the variable frequency motor can be improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electric machines, in particular to a boost-buck driving circuit, a boost-buck driving method, an air conditioner and a computer readable storage medium. BACKGROUND

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

[0003] For example, without entering the field weakening operation, the higher the direct current bus voltage, the greater the motor iron loss, and the lower the direct current bus voltage, the smaller the motor iron loss. Therefore, the direct current 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 step-down function. For example, passive PFC, single pulse and multi-pulse PFC do not have the function of adjusting the direct current bus voltage, and the typical boost PFC can only perform step-up regulation, but cannot perform step-down regulation.

[0005] In addition, any discussion of background techniques in the specification does not represent that the background techniques are necessarily prior art, and any discussion of prior art in the specification does not represent that the prior art is necessarily widely known or constitutes the general knowledge of those skilled in the art. SUMMARY

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

[0007] To this end, a first aspect of the present application provides a boost-buck driving circuit.

[0008] A second aspect of the present application provides a boost-buck driving method.

[0009] A third aspect of the present application provides an air conditioner.

[0010] A fourth aspect of the present application provides a computer readable storage medium.

[0011] Therefore, the first aspect of the present application provides a boost-buck driving circuit, comprising: a totem pole circuit configured to perform power factor correction processing or rectification processing on a power supply signal; and a buck-type circuit having an input end connected to an output end of the totem pole circuit, the buck-type circuit comprising: a first power tube and a second power tube connected in series between a high-voltage output end and a low-voltage output end of the totem pole circuit, both ends of the second power tube being led out as a high-voltage bus and a low-voltage bus, wherein the first power tube and the second power tube are controlled to be turned on alternately, a bus voltage between the high-voltage bus and the low-voltage bus decreases as a running time of a load increases, and the buck-type circuit is configured to perform voltage reduction processing or filtering processing on the power supply signal.

[0012] In the technical solution, the totem pole circuit and the buck-type circuit are arranged in the driving circuit to realize boost-buck adjustment of the bus voltage, so that the bus voltage can be higher than or lower than the peak value of the alternating voltage, thereby improving the motor efficiency and reliability, and in particular, for a permanent magnet synchronous motor, the bus voltage can be reduced to reduce the iron loss of the motor.

[0013] Specifically, a plurality of semiconductor switches are arranged in the totem pole circuit and the buck-type circuit, the semiconductor switches are controlled by a controller, the controller modulates the working state of the semiconductor switches according to at least one of the collected alternating current, alternating voltage, direct current bus voltage and direct current bus current, and adjusts the working state of the totem pole circuit and / or the buck-type circuit.

[0014] The power supply signal refers to a signal flowing through the driving circuit and driving the load to run, the input signal of the bridge-type circuit is an alternating signal, and the output is a bus direct current signal. Therefore, the alternating current and the alternating voltage are collected at the input end of the bridge-type circuit, and the direct current and the direct current bus voltage are collected at the output end of the bridge-type circuit.

[0015] In addition, the boost-buck driving circuit in the above technical solution provided by the present application can further have the following additional technical features:

[0016] In the above technical solution, further, the buck-type circuit comprises: a filter circuit connected in parallel with the second power tube, the filter circuit being configured to perform filtering processing on the power supply signal flowing through the high-voltage bus and the low-voltage bus.

[0017] In the technical solution, the buck-type circuit comprises the filter circuit, the filter circuit performs filtering processing on the bus direct current signal, and the first power tube and the second power tube of the buck-type circuit perform modulation work, thereby realizing voltage reduction processing on the bus direct current signal, which is conducive to improving the running efficiency of the load and reducing the iron loss and noise interference of the motor.

[0018] In the technical solution, further, the filter circuit comprises a first inductive element, a first capacitive element, the first end of the first inductive element is connected to the common end between the first power tube and the second power tube, the first end of the first capacitive element is connected to the second end of the first inductive element, and the second end of the first capacitive element is connected to the low-voltage bus.

[0019] In the technical solution, by setting the filter circuit comprising the first inductive element and the first capacitive element and connecting them in the above manner, the LC filter structure is connected at the load input end, the AC noise carried in the DC signal is filtered out, and the reliability of the load operation is further improved.

[0020] In the technical solution, further, the totem pole circuit comprises a second inductive element, a bridge circuit, and a second capacitive element, the second inductive element is configured to be connected to the power supply signal, any bridge arm of the bridge circuit is provided with a power tube, the input end of the bridge circuit is connected to the inductive element, the bridge circuit is configured to be capable of performing power factor correction processing or rectification processing on the power supply signal, and the second capacitive element is connected between the two output ends of the bridge circuit.

[0021] In the technical solution, by setting the second inductive element, the second capacitive element, and the bridge circuit and connecting them in the above manner, on the one hand, the bridge circuit can work as a power factor correction circuit, and on the other hand, the bridge circuit can work as a rectification circuit, which not only simplifies the circuit structure, but also effectively reduces the power consumption and delay of the circuit due to the power tube provided in each bridge arm of the bridge circuit.

[0022] In the technical solution, further, the third power tube, the fourth power tube, the fifth power tube, and the sixth power tube, the common end between the third power tube and the fourth power tube is connected to the first end of the second inductive element, the first end of the second inductive element, the first end of the power supply end is connected to the second end of the second inductive element, and the common end between the fifth power tube and the sixth power tube is connected to the second output end of the power supply end, wherein the common end of the third power tube and the fifth power tube serves as the high-voltage output end, and the common end of the fourth power tube and the sixth power tube serves as the low-voltage output end.

[0023] In the technical solution, by setting the bridge circuit comprising the above four power tubes and connecting them in the above manner, the AC signal can be rectified, and when the power tubes of the bridge circuit are modulated to boost at a specified duty ratio, the output bus DC signal is boosted.

[0024] In any of the above technical solutions, further comprising: a controller connected to the control end of the power tubes, the power tubes are each provided with a diode in anti-parallel, the controller drives the bridge circuit to work in a diode rectification mode, specifically comprising the following steps: the controller controls the power tubes in the bridge circuit to be all off, and the diodes in anti-parallel rectify the power supply signal.

[0025] In this technical solution, the controller controls the power tubes in the bridge circuit to be all off, and the diodes in anti-parallel rectify the power supply signal, and the bridge circuit is equivalent to a diode rectifier, so that the rectification processing of the alternating current signal is realized.

[0026] In any of the above technical solutions, further comprising: a controller connected to the control end of the power tubes, the power tubes are each provided with a diode in anti-parallel, the controller drives the bridge circuit to work in a synchronous rectification mode, specifically comprising the following steps: when the diodes in anti-parallel are turned on, the controller controls the corresponding power tubes to be turned on with a first duty ratio.

[0027] In this technical solution, when the diodes in anti-parallel are turned on, the corresponding power tubes are controlled by the controller to be turned on with a first duty ratio, so that the synchronous rectification processing is realized, the response time is short and the reliability is high.

[0028] In any of the above technical solutions, further comprising: a controller connected to the control end of the power tubes, the power tubes are each provided with a diode in anti-parallel, the controller drives the bridge circuit to work in a half-synchronous rectification mode, specifically comprising the following steps: the third power tube and the fourth power tube are controlled to be off, when the diode in anti-parallel of the fifth power tube is turned on, the controller controls the fifth power tube to be turned on, and when the diode in anti-parallel of the sixth power tube is turned on, the controller controls the sixth power tube to be turned on.

[0029] In this technical solution, the third power tube and the fourth power tube are controlled to be off, the diode in anti-parallel of the third power tube is turned on, and the diode in anti-parallel of the fourth power tube is turned on.

[0030] In addition, when the diode in anti-parallel of the fifth power tube is turned on, the controller controls the fifth power tube to be turned on at the same time, and when the diode in anti-parallel of the sixth power tube is turned on, the controller controls the sixth power tube to be turned on, that is, the fifth power tube and the sixth power tube are used for synchronous rectification processing.

[0031] In any of the above technical solutions, further comprising: a controller connected to the control end of the power tubes, the power tubes are each provided with an anti-parallel diode, the controller drives the bridge circuit to work in a half synchronous rectification mode, specifically comprising the following steps: controlling the fifth power tube and the sixth power tube to be cut off, when the anti-parallel diode of the third power tube is turned on, the controller controls the third power tube to be turned on, and when the anti-parallel diode of the fourth power tube is turned on, the controller controls the fourth power tube to be turned on.

[0032] In this technical solution, the fifth power tube and the sixth power tube are controlled to be cut off, that is, the anti-parallel diode of the fifth power tube is turned on, and the anti-parallel diode of the sixth power tube is turned on.

[0033] In addition, when the anti-parallel diode of the third power tube is turned on, the controller controls the third power tube to be turned on, and when the anti-parallel diode of the fourth power tube is turned on, the controller controls the fourth power tube to be turned on, that is, the third power tube and the fourth power tube are used for synchronous rectification processing.

[0034] In any of the above technical solutions, further comprising: a controller connected to the control end of the power tubes, the power tubes are each provided with an anti-parallel diode, the controller drives the bridge circuit to work in a power factor correction mode, specifically comprising the following steps: when the power supply signal flows to the common end between the third power tube and the fourth power tube, the third power tube and the fourth power tube are alternately turned on with a second duty ratio; when the anti-parallel diode of the fifth power tube has current flowing through, the controller controls the fifth power tube to be turned on with a third duty ratio, at the same time, the controller keeps the sixth power tube cut off; when the anti-parallel diode of the sixth power tube has current flowing through, the controller controls the sixth power tube to be turned on with a third duty ratio, at the same time, the controller keeps the fifth power tube cut off.

[0035] In this technical solution, when the power supply signal flows to the common end between the third power tube and the fourth power tube, the third power tube and the fourth power tube are alternately turned on with a second duty ratio, and when the anti-parallel diode of the sixth power tube has current flowing through, the controller controls the sixth power tube to be turned on with a third duty ratio, at the same time, the controller keeps the fifth power tube cut off, realizing power factor correction processing of the power supply signal.

[0036] Similarly, when the anti-parallel diode of the fifth power tube has current flowing through, the controller controls the fifth power tube to be turned on with a third duty ratio, at the same time, the controller keeps the sixth power tube cut off, realizing power factor correction processing of the power supply signal.

[0037] In any of the above technical solutions, further comprising: a controller connected to the control end of the power tube, the power tube being provided with an anti-parallel diode, the controller driving the bridge circuit to work in a power factor correction mode, specifically comprising the following steps: when the power supply signal flows into the common end between the fifth power tube and the sixth power tube, the fifth power tube and the sixth power tube are alternately turned on with a fourth duty cycle; when the anti-parallel diode of the third power tube has current flowing through, the controller controls the third power tube to be turned on with the fifth duty cycle, and at the same time, the controller keeps the fourth power tube off; when the anti-parallel diode of the fourth power tube has current flowing through, the controller controls the fourth power tube to be turned on with a fifth duty cycle, and at the same time, the controller keeps the third power tube off.

[0038] In this technical solution, when the power supply signal flows into the common end between the fifth power tube and the sixth power tube, the fifth power tube and the sixth power tube are alternately turned on with a fourth duty cycle, and when the anti-parallel diode of the fourth power tube has current flowing through, the controller controls the fourth power tube to be turned on with a fifth duty cycle, and at the same time, the controller keeps the third power tube off, thereby realizing power factor correction processing of the power supply signal.

[0039] Similarly, when the anti-parallel diode of the third power tube has current flowing through, the controller controls the third power tube to be turned on with the fifth duty cycle, and at the same time, the controller keeps the fourth power tube off, thereby realizing power factor correction processing of the power supply signal.

[0040] In any of the above technical solutions, further comprising: a controller connected to the control end of the switch tube, the second power tube being provided with an anti-parallel diode, the controller driving the step-down circuit to work in a filtering mode, specifically comprising the following steps: the controller controls the first power tube to be turned on, the controller controls the second power tube to be turned off or alternately turned on with the first power tube, and the filtering circuit filters the power supply signal.

[0041] In this technical solution, by controlling the second power tube to be turned off by the controller, the second power tube and its anti-parallel diode are both turned off, or the second power tube is alternately turned on with the first power tube, at this time, only the filtering circuit filters the power supply signal to filter out the interference of the noise signal to the load.

[0042] In any of the above technical solutions, further comprising: a controller connected to the control end of the switch tube, the controller drives the step-down circuit to work in a step-down mode, specifically comprising the following steps: the controller controls the first power tube to be turned on with a sixth duty ratio, and at the same time, the controller controls the second power tube to be turned on alternately with the first power tube.

[0043] In this technical solution, the first power tube and the second power tube are controlled by the controller to be turned on with a sixth duty ratio, and at the same time, the controller controls the second power tube to be turned on alternately with the first power tube, that is, the bus DC signal is modulated and step-down processed by the first power tube and the second power tube, so as to improve the efficiency of the load, and in addition, it is beneficial to reduce the iron loss of the motor.

[0044] The second aspect of the application provides a step-up and step-down driving method, comprising: determining an AC voltage input to the driving circuit and a bus voltage of the driving circuit; and controlling the step-down circuit to work in a filter mode or a step-down mode and controlling the totem pole circuit to work in a power factor correction mode or a rectification mode according to the AC voltage and the bus voltage.

[0045] In this technical solution, the totem pole circuit and the step-down circuit are arranged in the driving circuit, and the totem pole circuit is controlled to work in a rectification mode or a power factor correction mode and the step-down circuit is controlled to work in a step-down mode or a filter mode according to the AC voltage and the bus voltage, so as to realize step-up and step-down adjustment of the bus voltage, that is, the bus voltage can be higher than the peak value of the AC voltage or the bus voltage can be lower than the peak value of the AC voltage, so as to improve the efficiency and reliability of the motor, and especially for a permanent magnet synchronous motor, the iron loss of the motor can be reduced by reducing the bus voltage.

[0046] The power supply signal refers to a signal flowing through the driving circuit and driving the load to run, the input signal of the bridge circuit is an AC signal, and the output is a bus DC signal. Therefore, the AC current and the AC voltage are collected at the input end of the bridge circuit, and the DC current and the DC bus voltage are collected at the output end of the bridge circuit.

[0047] Specifically, a plurality of semiconductor switches are arranged in the totem pole circuit and the step-down circuit, the semiconductor switches are controlled by a controller, the controller modulates the working state of the semiconductor switches according to at least one signal of the collected AC voltage, AC current, DC bus voltage and DC bus current, and further adjusts the working state of the totem pole circuit and / or the step-down circuit.

[0048] In any of the above technical solutions, further, according to the AC voltage and the bus voltage, the step of controlling the step-down circuit to work in a rectification mode or a step-down mode and controlling the totem pole circuit to work in a step-up mode or a filtering mode, specifically includes: determining a voltage given value of the bus voltage to ; comparing the size relationship between the voltage given value and the AC voltage; according to the size relationship between the voltage given value and the AC voltage, controlling the step-down circuit to work in a rectification mode or a step-down mode and controlling the totem pole circuit to work in a step-up mode or a filtering mode.

[0049] In this technical solution, by controlling the step-down circuit to work in a rectification mode or a step-down mode and controlling the totem pole circuit to work in a step-up mode or a filtering mode according to the size relationship between the voltage given value and the AC voltage, in order to improve the working efficiency of the driving circuit, when the step-down circuit works in a step-down mode, the totem pole circuit works in a filtering mode, or when the totem pole circuit works in a step-up mode, the step-down circuit works in a rectification mode, in addition, when the step-down circuit works in a rectification mode, the totem pole circuit can work in a filtering mode.

[0050] In any of the above technical solutions, further, according to the AC voltage and the bus voltage, the step of controlling the step-down circuit to work in a filtering mode or a step-down mode and controlling the totem pole circuit to work in a power factor correction mode or a rectification mode, specifically includes: determining the product between the effective value of the AC voltage and a first voltage coefficient, and recording the product as a first voltage sampling value; detecting that the first voltage sampling value is greater than or equal to a given voltage value corresponding to the bus voltage, detecting the instantaneous value of the AC voltage; detecting that the instantaneous value of the AC voltage is less than the given voltage value corresponding to the bus voltage, controlling the totem pole circuit to work in a rectification mode and controlling the step-down circuit to work in a filtering mode; detecting that the instantaneous value of the AC voltage is greater than or equal to the given voltage value corresponding to the bus voltage, controlling the totem pole circuit to work in a rectification mode and controlling the step-down circuit to work in a step-down mode.

[0051] In this technical solution, by determining the product between the effective value of the AC voltage and a first voltage coefficient, and recording the product as a first voltage sampling value, if it is detected that the first voltage sampling value is greater than or equal to a given voltage value corresponding to the bus voltage, the instantaneous value of the AC voltage is detected, which indicates that the bus voltage is high enough to reliably drive the load to operate.

[0052] If the instantaneous value of the AC voltage is detected to be less than the given voltage value corresponding to the bus voltage, the totem-pole circuit is controlled to work in a rectification mode, and the step-down circuit is controlled to work in a filtering mode, without the need for step-up or step-down processing, and without the need for controlling the power tube, the first power tube and the second power tube to work in a modulation mode, thereby reducing the overall power consumption of the driving circuit.

[0053] Further, if the instantaneous value of the AC voltage is detected to be greater than or equal to the given voltage value corresponding to the bus voltage, the totem-pole circuit is controlled to work in a rectification mode, and the step-down circuit is controlled to work in a step-down mode.

[0054] In the voltage-uncontrolled mode, the totem-pole circuit works in a diode rectification or synchronous rectification state, and the step-down circuit works in a straight-through filtering state.

[0055] In any of the above technical solutions, further, according to the AC voltage and the bus voltage, the step-down circuit is controlled to work in a filtering mode or a step-down mode, and the totem-pole circuit is controlled to work in a power factor correction mode or a rectification mode, specifically including: determining the product between the effective value of the AC voltage and a first voltage coefficient, and recording the product as a first voltage sampling value; determining the product between the effective value of the AC voltage and a second voltage coefficient, and recording the product as a second voltage sampling value; detecting the instantaneous value of the AC voltage, if the first voltage sampling value is detected to be less than the given voltage value corresponding to the bus voltage, and the second voltage sampling value is detected to be greater than or equal to the given voltage value corresponding to the bus voltage; if the instantaneous value of the AC voltage is detected to be less than the given voltage value corresponding to the bus voltage, the totem-pole circuit is controlled to work in a power factor correction mode, and the step-down circuit is controlled to work in a filtering mode; and if the instantaneous value of the AC voltage is detected to be greater than or equal to the given voltage value corresponding to the bus voltage, the totem-pole circuit is controlled to work in a rectification mode, and the step-down circuit is controlled to work in a step-down mode.

[0056] In this technical solution, the first voltage sampling value is less than the second voltage sampling value, if the first voltage sampling value is detected to be less than the given voltage value corresponding to the bus voltage, and the second voltage sampling value is detected to be greater than or equal to the given voltage value corresponding to the bus voltage, the trend of the rising AC voltage is continuously predicted, and thus the instantaneous value of the AC voltage is continuously detected.

[0057] Further, if the instantaneous value of the AC voltage is detected to be less than the given voltage value corresponding to the bus voltage, the totem-pole circuit is controlled to work in a power factor correction mode, so as to improve the power supply efficiency, and in addition, the step-down circuit is controlled to work in a filtering mode, so as to further filter out the noise in the power supply signal, thereby improving the reliability of the load operation.

[0058] In any of the above technical solutions, further, the step of controlling the step-up and step-down circuit to work in a filtering mode or a step-down mode, and controlling the totem-pole circuit to work in a power factor correction mode or a rectification mode, specifically comprises: determining a product between the effective value of the alternating voltage and the second voltage coefficient, and recording the product as a second voltage sampling value; detecting that the second voltage sampling value is less than a given voltage value corresponding to the bus voltage, and controlling the totem-pole circuit to work in the power factor correction mode.

[0059] In this technical solution, detecting that the second voltage sampling value is less than the given voltage value corresponding to the bus voltage, and controlling the totem-pole circuit to work in the step-up mode, that is, reducing the possibility of the drop of the direct current bus voltage and the motor shutdown through timely step-up.

[0060] In the step-up mode, the step-up and step-down circuit is in a filtering state, and the totem-pole circuit works in a step-up modulation state.

[0061] In any of the above technical solutions, further, the motor is a permanent magnet synchronous motor, and the driving method further comprises: determining a rotational speed of the permanent magnet synchronous motor and a back electromotive force coefficient; and determining the given voltage value corresponding to the bus voltage according to the rotational speed and the back electromotive force coefficient.

[0062] In this technical solution, the given voltage value corresponding to the bus voltage is determined through the back electromotive force coefficient, which is beneficial to further improving the reliability and flexibility of the step-up and step-down adjustment of the direct current bus voltage.

[0063] The third aspect of the present application provides an air conditioner, comprising: a motor; and a step-up and step-down driving circuit as defined in any of the above technical solutions, the step-up and step-down driving circuit being configured to control the motor to operate.

[0064] In this technical solution, the air conditioner comprises the step-up and step-down driving circuit as defined in any of the above technical solutions, and therefore, the air conditioner comprises all the beneficial effects of the step-up and step-down driving circuit as defined in any of the above technical solutions, and therefore, no further description is given.

[0065] The fourth aspect of the present application provides a computer readable storage medium, the computer readable storage medium storing a computer program, the computer program being executed to implement the driving method as defined in any of the above technical solutions. BRIEF DESCRIPTION OF DRAWINGS

[0066] The above and / or additional aspects and advantages of the present application will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings, in which:

[0067] Figure 1 A structural diagram of a step-up and step-down driving circuit according to one embodiment of the present application is shown.

[0068] Figure 2 A configuration diagram of a step-up / down driving circuit according to another embodiment of the present application is shown;

[0069] Figure 3 A configuration diagram of a step-up / down driving circuit according to another embodiment of the present application is shown;

[0070] Figure 4 A configuration diagram of a step-up / down driving circuit according to another embodiment of the present application is shown;

[0071] Figure 5 A configuration diagram of a step-up / down driving circuit according to another embodiment of the present application is shown;

[0072] Figure 6 A configuration diagram of a step-up / down driving circuit according to another embodiment of the present application is shown;

[0073] Figure 7 A configuration diagram of a step-up / down driving circuit according to another embodiment of the present application is shown;

[0074] Figure 8 A timing diagram of a step-up / down driving method according to an embodiment of the present application is shown;

[0075] Figure 9 A timing diagram of a step-up / down driving method according to another embodiment of the present application is shown;

[0076] Figure 10 A timing diagram of a step-up / down driving method according to another embodiment of the present application is shown;

[0077] Figure 11 A timing diagram of a step-up / down driving method according to another embodiment of the present application is shown;

[0078] Figure 12 A timing diagram of a step-up / down driving method according to another embodiment of the present application is shown;

[0079] Figure 13 A timing diagram of a step-up / down driving method according to another embodiment of the present application is shown;

[0080] Figure 14 A timing diagram of a step-up / down driving method according to another embodiment of the present application is shown;

[0081] Figure 15 A timing diagram of a step-up / down driving method according to another embodiment of the present application is shown;

[0082] Figure 16A timing chart of a step-up / down driving method according to another embodiment of the present application is shown.

[0083] Figure 17 A timing chart of a step-up / down driving method according to another embodiment of the present application is shown.

[0084] Figure 18 A timing chart of a step-up / down driving method according to another embodiment of the present application is shown.

[0085] Figure 19 A timing chart of a step-up / down driving method according to another embodiment of the present application is shown.

[0086] Figure 20 A timing chart of a step-up / down driving method according to another embodiment of the present application is shown.

[0087] Figure 21 A timing chart of a step-up / down driving method according to another embodiment of the present application is shown.

[0088] Figure 22 A timing chart of a step-up / down driving method according to another embodiment of the present application is shown.

[0089] Figure 23 A schematic flow chart of a step-up / down driving method according to another embodiment of the present application is shown.

[0090] Figure 24 A schematic block diagram of an air conditioner according to an embodiment of the present application is shown.

[0091] Figure 25 A schematic block diagram of a computer readable storage medium according to an embodiment of the present application is shown.

[0092] Corresponding relationships between reference numerals in the above-described drawings and structures are as follows.

[0093] Alternating current signal AC, third power transistor T1, fourth power transistor T2, fifth power transistor T3, and sixth power transistor T4, first power transistor Q1, second power transistor Q2, load M, inverter IPM, first inductive element L1, second inductive element L2, first capacitive element C1, and second capacitive element C2. DETAILED DESCRIPTION

[0094] In order to more clearly understand the above-described purposes, features and advantages of the present application, the following further describes the present application with reference to 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.

[0095] Many specific details are set forth in the following description in order to provide a thorough understanding of the application. However, the application can be practiced according to other embodiments that can not be described in detail herein, and the scope of the present application is not limited to the specific embodiments described in this description.

[0096] The following description refers to the accompanying drawings. Figures 1 to 25 The application provides a boost-buck driving circuit, a method, an air conditioner and a computer readable storage medium.

[0097] As Figures 1 to 7 shown in the drawings, according to an embodiment of the application, a boost-buck driving circuit is provided, comprising: a totem pole circuit configured to perform power factor correction processing or rectification processing on a power supply signal; and a buck-type circuit, an input end of which is connected to an output end of the totem pole circuit, the buck-type circuit comprising: a first power tube Q1 and a second power tube Q2, which are connected in series in sequence between a high-voltage output end and a low-voltage output end of the totem pole circuit, and both ends of the second power tube Q2 are led out as a high-voltage bus and a low-voltage bus, wherein the first power tube Q1 and the second power tube Q2 are controlled to conduct alternately, a bus voltage between the high-voltage bus and the low-voltage bus decreases as a load running time increases, and the buck-type circuit is configured to perform voltage reduction processing or filtering processing on the power supply signal.

[0098] In the technical solution, by arranging the totem pole circuit and the buck-type circuit in the driving circuit, the boost-buck adjustment of the bus voltage is realized, which can make the bus voltage higher than the peak value of the alternating voltage or lower than the peak value of the alternating voltage, so as to improve the motor efficiency and reliability, and especially for the permanent magnet synchronous motor, the iron loss of the motor can be reduced by reducing the bus voltage.

[0099] Specifically, a plurality of semiconductor switches are arranged in the totem pole circuit and the buck-type circuit, the semiconductor switches are controlled by a controller, the controller modulates the working state of the semiconductor switches according to at least one signal of the collected alternating current, alternating voltage, direct current bus voltage and direct current bus current, and then adjusts the working state of the totem pole circuit and / or the buck-type circuit.

[0100] The power supply signal refers to a signal flowing through the driving circuit and driving the load to run, the input signal of the bridge-type circuit is an alternating current AC, and the output is a bus direct current signal. Therefore, the alternating current and the alternating voltage are collected at the input end of the bridge-type circuit, and the direct current and the direct current bus voltage are collected at the output end of the bridge-type circuit.

[0101] Hereinafter, the totem pole circuit of the driving control circuit can also be referred to as a BOOST circuit, and the buck-type circuit can also be referred to as a BUCK circuit.

[0102] AsFigure 2 and Figure 3 As shown, the load M can be an inverter IPM and the permanent magnet motor it drives.

[0103] like Figure 3 As shown, the main idea of ​​SVPWM is to use the ideal flux linkage circle of the stator of a three-phase symmetrical motor under three-phase symmetrical sinusoidal voltage supply as a reference standard, and to appropriately switch the three-phase inverter according to different switching modes to form a PWM wave. The resulting actual flux linkage vector is then used to track its accurate flux linkage circle. Traditional SPWM methods focus on the power supply to generate an adjustable frequency and voltage sinusoidal power supply, while SVPWM methods consider the inverter system and asynchronous motor as a whole. This results in a simpler model and facilitates real-time control by a microprocessor.

[0104] In addition, the buck-boost drive circuit in the above-mentioned technical solution provided by the present invention may also have the following additional technical features:

[0105] In the above technical solution, the step-down circuit further includes a filter circuit, which is connected in parallel with the second power transistor Q2. The filter circuit is used to filter the power supply signal flowing through the high-voltage bus and the low-voltage bus.

[0106] In this technical solution, by setting up a step-down circuit including a filter circuit, the filter circuit filters the DC signal of the bus. When the first power transistor Q1 and the second power transistor Q2 of the step-down circuit are modulated, the DC signal of the bus is stepped down, which not only helps to improve the operating efficiency of the load, but also helps to reduce the iron loss and noise interference of the motor.

[0107] In the above technical solution, the filter circuit further includes: a first inductive element L1, the first end of which is connected to the common terminal between the first power transistor Q1 and the second power transistor Q2; and a first capacitive element C1, the first end of which is connected to the second end of the first inductive element L1, and the second end of which is connected to the low-voltage bus.

[0108] In this technical solution, by setting a filter circuit including a first inductive element L1 and a first capacitive element C1 and connecting them in the manner described above, that is, by connecting an LC filter structure at the load input terminal, the AC noise carried in the DC signal is filtered out, thereby further improving the reliability of the load operation.

[0109] In the above technical solution, the totem pole circuit further includes: a second inductive element L2, which is configured to be connected to the power supply signal; a bridge circuit, wherein a power transistor is provided in any arm of the bridge circuit, the input terminal of the bridge circuit is connected to the inductive element, and the bridge circuit is configured to perform power factor correction or rectification processing on the power supply signal; and a second capacitive element C2, which is connected between the two output terminals of the bridge circuit.

[0110] In this technical solution, by setting a second inductive element L2, a second capacitive element C2, and a bridge circuit, and connecting them in the manner described above, it can function as a power factor correction circuit and a rectifier circuit. This not only simplifies the circuit structure, but also effectively reduces circuit power consumption and delay because each arm of the bridge circuit is equipped with a power transistor.

[0111] In the above technical solution, further, the third power transistor T1, the fourth power transistor T2, the fifth power transistor T3, and the sixth power transistor T4 are connected as follows: the common terminal between the third power transistor T1 and the fourth power transistor T2 is connected to the first terminal of the second inductive element L2; the first terminal of the power supply terminal is connected to the second terminal of the second inductive element L2; the common terminal between the fifth power transistor T3 and the sixth power transistor T4 is connected to the second output terminal of the power supply terminal; wherein, the common terminal between the third power transistor T1 and the fifth power transistor T3 serves as the high-voltage output terminal, and the common terminal between the fourth power transistor T2 and the sixth power transistor T4 serves as the low-voltage output terminal.

[0112] In this technical solution, by setting a bridge circuit specifically including the above four power transistors and connecting them in the above manner, the AC signal can be rectified. In addition, when the power transistors of the bridge circuit are modulated and boosted according to a specified duty cycle, the output bus DC signal is boosted.

[0113] like Figure 5 As can be seen from the equivalent circuit shown, in any of the above technical solutions, it further includes: a controller, the controller being connected to the control terminal of the power transistor, each of the power transistors being provided with anti-parallel diodes, the controller driving the bridge circuit to operate in diode rectification mode, specifically including the following steps: the controller controlling all power transistors in the bridge circuit to be turned off, and the anti-parallel diodes rectifying the power supply signal.

[0114] In the technical scheme, the controller controls the power tubes in the bridge circuit to be all cut off, the anti-parallel diode pair rectifies the power supply signal, the bridge circuit is equivalent to a diode rectifier, and therefore, the rectification processing of the alternating current signal AC is realized.

[0115] In any of the above technical schemes, further comprising: a controller connected to the control end of the power tubes, the power tubes are all provided with anti-parallel diodes, the controller drives the bridge circuit to work in a synchronous rectification mode, and specifically includes the following steps: when the anti-parallel diodes are turned on, the controller controls the corresponding power tubes to be turned on at a first duty ratio.

[0116] In the technical scheme, when the anti-parallel diodes are turned on, the corresponding power tubes are controlled by the controller to be turned on at a first duty ratio, so as to realize synchronous rectification processing, the response time is short and the reliability is high.

[0117] In any of the above technical schemes, further comprising: a controller connected to the control end of the power tubes, the power tubes are all provided with anti-parallel diodes, the controller drives the bridge circuit to work in a synchronous rectification mode, and specifically includes the following steps: controlling the third power tube T1 and the fourth power tube T2 to be cut off, when the anti-parallel diode of the fifth power tube T3 is turned on, the controller controls the fifth power tube T3 to be turned on, and when the anti-parallel diode of the sixth power tube T4 is turned on, the controller controls the sixth power tube T4 to be turned on.

[0118] In the technical scheme, by controlling the third power tube T1 and the fourth power tube T2 to be cut off, the anti-parallel diode of the third power tube T1 is turned on, and the anti-parallel diode of the fourth power tube T2 is turned on.

[0119] In addition, when the anti-parallel diode of the fifth power tube T3 is turned on, the controller controls the fifth power tube T3 to be turned on at the same time, and when the anti-parallel diode of the sixth power tube T4 is turned on, the controller controls the sixth power tube T4 to be turned on, that is, the fifth power tube T3 and the sixth power tube T4 are used for synchronous rectification processing.

[0120] In any of the above technical solutions, further comprising: a controller connected to the control end of the power tubes, the power tubes are each provided with an anti-parallel diode, the controller drives the bridge circuit to work in a half synchronous rectification mode, specifically comprising the following steps: controlling the fifth power tube T3 and the sixth power tube T4 to be cut off, when the anti-parallel diode of the third power tube T1 is turned on, the controller controls the third power tube T1 to be turned on, and when the anti-parallel diode of the fourth power tube T2 is turned on, the controller controls the fourth power tube T2 to be turned on.

[0121] In this technical solution, the fifth power tube T3 and the sixth power tube T4 are controlled to be cut off, that is, the anti-parallel diode of the fifth power tube T3 is turned on, and the anti-parallel diode of the sixth power tube T4 is turned on.

[0122] In addition, when the anti-parallel diode of the third power tube T1 is turned on, the controller controls the third power tube T1 to be turned on, and when the anti-parallel diode of the fourth power tube T2 is turned on, the controller controls the fourth power tube T2 to be turned on, that is, the third power tube T1 and the fourth power tube T2 are used for synchronous rectification processing.

[0123] As shown in the equivalent circuit, Figure 6 It can be known from the equivalent circuit that in any of the above technical solutions, further comprising: a controller connected to the control end of the power tubes, the power tubes are each provided with an anti-parallel diode, the controller drives the bridge circuit to work in a power factor correction mode, specifically comprising the following steps: when the power supply signal flows into the common end between the third power tube T1 and the fourth power tube T2, the third power tube T1 and the fourth power tube T2 are alternately turned on with a second duty ratio; when the anti-parallel diode of the fifth power tube T3 has current flowing through, the controller controls the fifth power tube T3 to be turned on with a third duty ratio, at the same time, the controller keeps the sixth power tube T4 cut off; when the anti-parallel diode of the sixth power tube T4 has current flowing through, the controller controls the sixth power tube T4 to be turned on with a third duty ratio, at the same time, the controller keeps the fifth power tube T3 cut off.

[0124] In this technical solution, when the power supply signal flows into the common end between the third power tube T1 and the fourth power tube T2, the third power tube T1 and the fourth power tube T2 are alternately turned on with a second duty ratio, and when the anti-parallel diode of the sixth power tube T4 has current flowing through, the controller controls the sixth power tube T4 to be turned on with a third duty ratio, at the same time, the controller keeps the fifth power tube T3 cut off, realizing the power factor correction processing of the power supply signal.

[0125] Similarly, when current flows through the anti-parallel diode of the fifth power transistor T3, the controller controls the fifth power transistor T3 to conduct with the third duty cycle. At the same time, the controller keeps the sixth power transistor T4 off, thus realizing the power factor correction processing of the power supply signal.

[0126] like Figure 6 As shown in the equivalent circuit, in any of the above technical solutions, it further includes: a controller connected to the control terminal of the power transistors, each power transistor having an anti-parallel diode; the controller drives the bridge circuit to operate in power factor correction mode, specifically including the following steps: when the power supply signal flows into the common terminal between the fifth power transistor T3 and the sixth power transistor T4, the fifth power transistor T3 and the sixth power transistor T4 are alternately turned on with a fourth duty cycle; when current flows through the anti-parallel diode of the third power transistor T1, the controller controls the third power transistor T1 to be turned on with the fifth duty cycle, while the controller keeps the fourth power transistor T2 off; when current flows through the anti-parallel diode of the fourth power transistor T2, the controller controls the fourth power transistor T2 to be turned on with the fifth duty cycle, while the controller keeps the third power transistor T1 off.

[0127] In this technical solution, when the power supply signal flows into the common terminal between the fifth power transistor T3 and the sixth power transistor T4, the controller controls the fifth power transistor T3 and the sixth power transistor T4 to conduct alternately with a fourth duty cycle. When current flows through the anti-parallel diode of the fourth power transistor T2, the controller controls the fourth power transistor T2 to conduct with a fifth duty cycle. At the same time, the controller keeps the third power transistor T1 off, thus realizing the power factor correction processing of the power supply signal.

[0128] Similarly, when current flows through the anti-parallel diode of the third power transistor T1, the controller controls the third power transistor T1 to conduct with the fifth duty cycle. At the same time, the controller keeps the fourth power transistor T2 off, thus realizing the power factor correction processing of the power supply signal.

[0129] like Figure 4 As can be seen from the equivalent circuit shown, in any of the above technical solutions, it further includes: a controller, the controller being connected to the control terminal of the switching transistor, the second power transistor Q2 having an anti-parallel diode, the controller driving the buck circuit to operate in filtering mode, specifically including the following steps: the controller controlling the first power transistor Q1 to be turned on, the controller controlling the second power transistor Q2 to be turned off or alternately turned on with the first power transistor Q1, and the filtering circuit filtering the power supply signal.

[0130] In the technical solution, the controller controls the second power tube Q2 to be cut off, the second power tube Q2 and the diode in anti-parallel connection thereof are both cut off, or the second power tube Q2 and the first power tube Q1 are alternately turned on, at this time, the filter circuit is used to filter the power supply signal to filter out the noise signal interference to the load.

[0131] In any of the above technical solutions, further comprising: a controller connected to the control end of the switch tube, the controller drives the step-down circuit to work in a step-down mode, specifically comprising the following steps: the controller controls the first power tube Q1 to be turned on at a sixth duty ratio, and simultaneously, the controller controls the second power tube Q2 and the first power tube Q1 to be alternately turned on.

[0132] In the technical solution, the controller controls the first power tube Q1 to be turned on at a sixth duty ratio, and simultaneously, the controller controls the second power tube Q2 and the first power tube Q1 to be alternately turned on, that is, the first power tube Q1 and the second power tube Q2 are used to modulate and step down the bus DC signal, so as to improve the efficiency of the load, and in addition, it is beneficial to reduce the iron loss of the motor.

[0133] It should be noted that, as shown in Figure 7 The application also includes the following alternative ways:

[0134] (1) The low-frequency switch control of one side bridge arm of the totem pole circuit is the fifth power tube T3 and the sixth power tube T4, which are respectively replaced by uncontrolled diodes D3 and D4, and do not need to be modulated and controlled.

[0135] (2) The second power tube Q2 of the BUCK circuit is replaced by an uncontrolled diode D2, which does not need to be modulated and controlled.

[0136] As shown in Figure 6 and Figure 7 The uncontrolled diode is used to replace the power tube or switch tube, which has lower cost, but will increase the diode conduction loss (in the case of medium and low load operation, the diode conduction voltage drop is greater than the MOSFET conduction voltage drop).

[0137] The above power tube and switch tube can be a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor, MOS tube for short) based on Si material, a MOSFET based on SiC material or a MOSFET based on GaN material, in addition, the four power tubes of the bridge circuit and the second power tube Q2 need to be provided with anti-parallel diodes, and the first power tube Q1 can not be provided with anti-parallel diodes.

[0138] AsFigures 8 to 25 As shown, according to the boost-buck driving method of another embodiment of the application, the method comprises: step S302, determining an AC voltage input to the driving circuit and a bus voltage of the driving circuit; step S304, controlling the buck circuit to work in a filter mode or a buck mode and controlling the totem pole circuit to work in a power factor correction mode or a rectification mode according to the AC voltage and the bus voltage.

[0139] In the technical solution, the totem pole circuit and the buck circuit are arranged in the driving circuit, and the totem pole circuit is controlled to work in a rectification mode or a power factor correction mode and the buck circuit is controlled to work in a buck mode or a filter mode according to the AC voltage and the bus voltage, so that the boost-buck adjustment of the bus voltage is realized, the bus voltage can be higher than the peak value of the AC voltage or lower than the peak value of the AC voltage, the motor efficiency and reliability are improved, and especially for the permanent magnet synchronous motor, the iron loss of the motor can be reduced by reducing the bus voltage.

[0140] The power supply signal refers to a signal flowing through the driving circuit and driving the load to run, the input signal of the bridge circuit is an AC signal, and the output is a bus DC signal. Therefore, the AC current and the AC voltage are collected at the input end of the bridge circuit, and the DC current and the DC bus voltage are collected at the output end of the bridge circuit.

[0141] Specifically, a plurality of semiconductor switches are arranged in the totem pole circuit and the buck circuit, the semiconductor switches are controlled by a controller, the controller modulates the working state of the semiconductor switches according to at least one signal of the collected AC voltage, AC current, DC bus voltage and DC bus current, and further adjusts the working state of the totem pole circuit and / or the buck circuit.

[0142] In any of the above technical solutions, further, according to the AC voltage and the bus voltage, the buck circuit is controlled to work in a rectification mode or a buck mode and the totem pole circuit is controlled to work in a boost mode or a filter mode, specifically including: determining a voltage given value of the bus voltage to the AC voltage; comparing the size relationship between the voltage given value and the AC voltage; according to the size relationship between the voltage given value and the AC voltage, the buck circuit is controlled to work in a rectification mode or a buck mode and the totem pole circuit is controlled to work in a boost mode or a filter mode.

[0143] In the technical solution, according to the magnitude relationship between the voltage given value and the AC voltage, the step-down circuit is controlled to work in a rectification mode or a step-down mode, and the totem-pole circuit is controlled to work in a step-up mode or a filtering mode, in order to improve the working efficiency of the driving circuit, when the step-down circuit works in the step-down mode, the totem-pole circuit works in the filtering mode, or when the totem-pole circuit works in the step-up mode, the step-down circuit works in the rectification mode, in addition, when the step-down circuit works in the rectification mode, the totem-pole circuit can work in the filtering mode.

[0144] In any of the above technical solutions, further, according to the AC voltage and the bus voltage, the step-down circuit is controlled to work in a filtering mode or a step-down mode, and the totem-pole circuit is controlled to work in a power factor correction mode or a rectification mode, specifically comprising: determining the product between the effective value of the AC voltage and a first voltage coefficient, and recording the product as a first voltage sampling value; detecting that the first voltage sampling value is greater than or equal to a given voltage value corresponding to the bus voltage, detecting the instantaneous value of the AC voltage; detecting that the instantaneous value of the AC voltage is less than the given voltage value corresponding to the bus voltage, controlling the totem-pole circuit to work in the rectification mode, and controlling the step-down circuit to work in the filtering mode; detecting that the instantaneous value of the AC voltage is greater than or equal to the given voltage value corresponding to the bus voltage, controlling the totem-pole circuit to work in the rectification mode, and controlling the step-down circuit to work in the step-down mode.

[0145] In the technical solution, by determining the product between the effective value of the AC voltage and a first voltage coefficient, and recording the product as a first voltage sampling value, if it is detected that the first voltage sampling value is greater than or equal to a given voltage value corresponding to the bus voltage, the instantaneous value of the AC voltage is detected, which indicates that the bus voltage is high enough to reliably drive the load to operate.

[0146] If it is detected that the instantaneous value of the AC voltage is less than the given voltage value corresponding to the bus voltage, the totem-pole circuit is controlled to work in the rectification mode, and the step-down circuit is controlled to work in the filtering mode, without the need for step-up or step-down processing, without the need for controlling the power tube, the first power tube and the second power tube to work in modulation, which is conducive to reducing the overall power consumption of the driving circuit.

[0147] Further, if it is detected that the instantaneous value of the AC voltage is greater than or equal to the given voltage value corresponding to the bus voltage, the totem-pole circuit is controlled to work in the rectification mode, and the step-down circuit is controlled to work in the step-down mode.

[0148] As shown in Figure 8 In the voltage non-control mode, the totem-pole circuit works in a diode rectification or synchronous rectification state, and the step-down circuit works in a straight-through filtering state.

[0149] As Figure 9 shown in any of the above technical solutions, further, according to the AC voltage and the bus voltage, the step of controlling the step-down circuit to work in a filtering mode or a step-down mode and controlling the totem pole circuit to work in a power factor correction mode or a rectification mode, specifically includes: determining the product between the effective value of the AC voltage and a first voltage coefficient, and recording the product as a first voltage sampling value; determining the product between the effective value of the AC voltage and a second voltage coefficient, and recording the product as a second voltage sampling value; detecting the instantaneous value of the AC voltage when the first voltage sampling value is less than the given voltage value corresponding to the bus voltage and the second voltage sampling value is greater than or equal to the given voltage value corresponding to the bus voltage; detecting the instantaneous value of the AC voltage when the instantaneous value of the AC voltage is less than the given voltage value corresponding to the bus voltage, controlling the totem pole circuit to work in the power factor correction mode, and controlling the step-down circuit to work in the filtering mode; and detecting the instantaneous value of the AC voltage when the instantaneous value of the AC voltage is greater than or equal to the given voltage value corresponding to the bus voltage, controlling the totem pole circuit to work in the rectification mode, and controlling the step-down circuit to work in the step-down mode.

[0150] In this technical solution, the first voltage sampling value is less than the second voltage sampling value, if the first voltage sampling value is detected to be less than the given voltage value corresponding to the bus voltage and the second voltage sampling value is detected to be greater than or equal to the given voltage value corresponding to the bus voltage, the trend of the rising of the AC voltage is continuously predicted, and thus the instantaneous value of the AC voltage is continuously detected.

[0151] Further, if the instantaneous value of the AC voltage is detected to be less than the given voltage value corresponding to the bus voltage, the totem pole circuit is controlled to work in the power factor correction mode to improve the power supply efficiency, and in addition, the step-down circuit is controlled to work in the filtering mode to further filter out the noise in the power supply signal, thereby improving the reliability of the load operation.

[0152] As Figure 10 shown in any of the above technical solutions, further, the step of controlling the step-down circuit to work in a filtering mode or a step-down mode and controlling the totem pole circuit to work in a power factor correction mode or a rectification mode, specifically includes: determining the product between the effective value of the AC voltage and a second voltage coefficient, and recording the product as a second voltage sampling value; and controlling the totem pole circuit to work in the power factor correction mode when the second voltage sampling value is detected to be less than the given voltage value corresponding to the bus voltage.

[0153] In this technical solution, if the second voltage sampling value is detected to be less than the given voltage value corresponding to the bus voltage, the totem pole circuit is controlled to operate in boost mode, that is, the possibility of DC bus voltage drop and motor shutdown is reduced by timely boosting.

[0154] In boost mode, the buck circuit is in filtering mode, while the totem pole circuit operates in boost modulation mode.

[0155] In any of the above technical solutions, the motor is a permanent magnet synchronous motor, and the driving method further includes: determining the speed and back electromotive force coefficient of the permanent magnet synchronous motor; and determining the given voltage value corresponding to the bus voltage based on the speed and the back electromotive force coefficient.

[0156] In this technical solution, the given voltage value corresponding to the bus voltage is determined by the back electromotive force coefficient, which helps to further improve the reliability and flexibility of DC bus voltage step-up and step-down regulation.

[0157] like Figure 11 and Figure 14 As shown, when the totem pole circuit operates in diode rectification and synchronous rectification states, the BUCK circuit can operate in either the pass-through filtering state or the BUCK buck control state; when the totem pole circuit operates in the boost PFC control state, the BUCK circuit can only operate in the pass-through filtering state.

[0158] The totem pole circuit operates in three modes: diode rectification, synchronous rectification, and boost PFC control.

[0159] In diode rectification mode, all four power switching transistors are in the off state, and rectification is performed using their anti-parallel diodes.

[0160] In synchronous rectification mode, all four power switches are in low-frequency switching mode. For one bridge arm (e.g., T1 and T2), the current power switch is turned on only when current flows through the anti-parallel diode of the power switch. For the other bridge arm (e.g., T3 and T4), the current power switch is turned on only when current flows through the anti-parallel diode of the power switch, or the current power switch is turned on during half a cycle when current flows through the anti-parallel diode of the power switch, and turned off during the other half cycle.

[0161] The boost PFC control state, one side bridge arm (for example, T1 and T2) is high-frequency switch control, realizes boost regulation function, and is closed-loop controlled according to the DC bus voltage given value and detection value, and AC input voltage detection and AC input current detection; the other side bridge arm (for example, T3 and T4) is low-frequency switch control, realizes synchronous rectification function, that is, when the antiparallel diode of the power switch tube has current flowing through, the current power switch tube is turned on, or when the antiparallel diode of the power switch tube has current flowing through in a half cycle, the current power switch tube is turned on for another half cycle time and is turned off.

[0162] As shown in Figure 12 , Figure 16 and Figure 21 , the half synchronous rectification one, that is, for one side bridge arm (for example, T1 and T2), the antiparallel diode is used for rectification when the bridge arm is in the off state; for the other side bridge arm (for example, T3 and T4), when the antiparallel diode of the power switch tube has current flowing through, the current power switch tube is turned on, or when the antiparallel diode of the power switch tube has current flowing through in a half cycle, the current power switch tube is turned on for another half cycle time and is turned off.

[0163] As shown in Figure 13 , Figure 17 and Figure 20 , the half synchronous rectification two, that is, for one side bridge arm (for example, T1 and T2), when the antiparallel diode of the power switch tube has current flowing through, the current power switch tube is turned on, or when the antiparallel diode of the power switch tube has current flowing through in a half cycle, the current power switch tube is turned on for another half cycle time and is turned off; for the other side bridge arm (for example, T3 and T4), the antiparallel diode is used for rectification when the bridge arm is in the off state.

[0164] The working state of the BUCK circuit includes the through filtering and the BUCK voltage reduction control.

[0165] As shown in Figure 19 , Figure 20 , Figure 21 and Figure 22 , the through filtering state, the first power tube Q1 is controlled to be continuously turned on, and the second power tube Q2 is controlled to be continuously turned off, so that the current is directly passed and filtered through LC.

[0166] The BUCK voltage reduction control state, the first power tube Q1 is controlled to realize the voltage reduction regulation function, and is closed-loop controlled according to the DC bus voltage given value and detection value. When the first power tube Q1 is turned on, the second power tube Q2 is controlled to be turned off; when the first power tube Q1 is turned off, the second power tube Q2 is controlled to be turned on or turned off.

[0167] As shown in Figure 15 and Figure 18As shown, in the voltage-uncontrolled mode, the totem pole circuit operates in diode rectification or synchronous rectification (secondary semi-synchronous rectification), and the BUCK circuit operates in pass-through filtering (equivalent to a Π-type filter).

[0168] In buck control mode, the totem pole circuit operates in diode rectification or synchronous rectification (secondary semi-synchronous rectification), and the BUCK circuit operates in BUCK buck control mode.

[0169] like Figure 23 As shown, in boost control mode, the totem pole circuit operates in boost PFC control state, and the BUCK circuit operates in pass-through filtering state (equivalent to a Π-type filter).

[0170] Based on the relationship between the DC bus voltage and the AC voltage, the operating mode switching within a cycle is determined, including the following methods:

[0171] 1) If the DC bus voltage setpoint is less than or equal to the effective value of the AC voltage multiplied by the first voltage coefficient: the instantaneous absolute value of the AC voltage is less than the DC bus voltage setpoint, the voltage is not controlled; otherwise, the voltage is reduced to the step-down control mode.

[0172] 2) If the effective value of AC voltage × first voltage coefficient ≤ DC bus voltage setpoint ≤ AC voltage effective value × second voltage coefficient: when the absolute value of instantaneous AC voltage is less than the DC bus voltage setpoint, enter boost control mode; otherwise, enter buck control mode.

[0173] 3) If the DC bus voltage is given ≥ AC voltage RMS value × second voltage coefficient: boost control mode, no mode switching.

[0174] 4) First voltage coefficient ≤ 1.4, second voltage coefficient ≥ 1.0, first voltage coefficient ≤ second voltage coefficient.

[0175] In applications where a permanent magnet synchronous motor is used as a load, the DC bus voltage setpoint is determined based on the speed of the permanent magnet synchronous motor and its phase voltage back EMF coefficient. The DC bus voltage setpoint = speed × phase voltage back EMF coefficient × third voltage coefficient.

[0176] Wherein, 1 ≤ third voltage coefficient ≤ 2.5; preferably, 1.5 ≤ third voltage coefficient ≤ 2.

[0177] like Figure 24 As shown, an air conditioner 400 according to an embodiment of the present invention includes: a motor 402; and a boost / buck driving circuit 404 as defined in any of the above technical solutions, the boost / buck driving circuit 404 being configured to control the operation of the motor 402.

[0178] In this technical solution, the air conditioner includes the boost / buck driving circuit as in any of the above technical solutions. Therefore, the air conditioner includes all the beneficial effects of the boost / buck driving circuit as in any of the above technical solutions, and will not be described again.

[0179] like Figure 25 As shown, a computer-readable storage medium 500 according to an embodiment of the present invention stores a computer program, which, when executed by an air conditioner 400, implements the driving method defined in any of the above technical solutions.

[0180] In the description of this invention, the term "multiple" refers to two or more. Unless otherwise explicitly defined, the terms "upper," "lower," etc., indicate the orientation or positional relationship based on the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. The terms "connection," "installation," "fixing," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances.

[0181] In the description of this invention, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this invention, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0182] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A boost-buck driving circuit, characterized by comprising: Comprise: Totem pole circuit, the totem pole circuit is configured to be able to carry out power factor correction processing or rectification processing to power supply signal; Buck circuit, the input end of the buck circuit is connected to the output end of the totem pole circuit, and the buck circuit comprises: First power tube and second power tube, in turn, are connected between the high-voltage output end and the low-voltage output end of the totem pole circuit, and the two ends of the second power tube are led out as high-voltage bus and low-voltage bus, Wherein, the buck circuit is configured to be able to carry out voltage reduction processing or filtering processing to the power supply signal; The totem pole circuit comprises a second inductive element and a bridge circuit, and one power tube is arranged in any bridge arm of the bridge circuit;The power supply end is configured to output the power supply signal to the drive circuit, and the bridge circuit comprises: the fifth power tube and the sixth power tube, and the common end between the fifth power tube and the sixth power tube is connected to the second output end of the power supply end; The fifth power tube and the sixth power tube are uncontrolled diodes; The buck circuit comprises: Filter circuit, the filter circuit is connected in parallel with the second power tube, and the filter circuit is used for filtering processing to the power supply signal flowing through the high-voltage bus and the low-voltage bus; Wherein, the first power tube and the second power tube are controlled to be turned on alternately, and the bus voltage between the high-voltage bus and the low-voltage bus decreases with the increase of the running time of the load.

2. The boost-buck driving circuit according to claim 1, wherein The filter circuit comprises: First inductive element, the first end of the first inductive element is connected to the common end between the first power tube and the second power tube; First capacitive element, the first end of the first capacitive element is connected to the second end of the first inductive element, and the second end of the first capacitive element is connected to the low-voltage bus.

3. The boost-buck drive circuit according to claim 1, wherein: The second inductive element is configured to be connected to the power supply signal; The input end of the bridge circuit is connected to the inductive element, and the bridge circuit is configured to be able to carry out power factor correction processing or rectification processing to the power supply signal; Second capacitive element, the second capacitive element is connected between the two output ends of the bridge circuit.

4. The boost-buck driving circuit according to claim 3, wherein The bridge circuit further comprises: Third power tube, fourth power tube, the common end between the third power tube and the fourth power tube is connected to the first end of the second inductive element, and the first end of the power supply end is connected to the second end of the second inductive element, Wherein, the common end of the third power tube and the fifth power tube serves as the high-voltage output end, and the common end of the fourth power tube and the sixth power tube serves as the low-voltage output end.

5. The boost-buck driving circuit according to claim 3, wherein Further comprising: Controller, the controller is connected to the control end of the power tube, and the power tube is provided with an anti-parallel diode, The controller drives the bridge circuit to work in diode rectification mode, specifically comprising the following steps: The controller controls the power tube in the bridge circuit to be cut off, and the anti-parallel diode rectifies the power supply signal.

6. The boost-buck driving circuit according to claim 4, wherein Further comprising: Controller, the controller is connected to the control end of the power tube, and the power tube is provided with an anti-parallel diode, The controller drives the bridge circuit to work in the synchronous rectification mode, specifically comprising the following steps: When the anti-parallel diode is turned on, the controller controls the corresponding power tube to be turned on with a first duty ratio.

7. The boost-buck driving circuit according to claim 4, wherein Further comprising: A controller connected to the control end of the power tube, the power tube is provided with an anti-parallel diode, The controller drives the bridge circuit to work in the half-synchronous rectification mode, specifically comprising the following steps: When the anti-parallel diode of the fifth power tube has current flowing through, the controller controls the fifth power tube to be turned on with a third duty ratio, and at the same time, the controller keeps the sixth power tube off; 8. The boost-buck driving circuit according to claim 4, wherein Further comprising: A controller connected to the control end of the power tube, the power tube is provided with an anti-parallel diode, The controller drives the bridge circuit to work in the half-synchronous rectification mode, specifically comprising the following steps: When the anti-parallel diode of the fifth power tube has current flowing through, the controller controls the fifth power tube to be turned on with a third duty ratio, and at the same time, the controller keeps the sixth power tube off; 9. The boost-buck driving circuit according to claim 4, wherein Further comprising: A controller connected to the control end of the power tube, the power tube is provided with an anti-parallel diode, The controller drives the bridge circuit to work in the power factor correction mode, specifically comprising the following steps: When the power supply signal flows to the common end between the third power tube and the fourth power tube, the third power tube and the fourth power tube are turned on alternately with a second duty ratio; When the anti-parallel diode of the fifth power tube has current flowing through, the controller controls the fifth power tube to be turned on with a third duty ratio, and at the same time, the controller keeps the sixth power tube off; When the anti-parallel diode of the sixth power tube has current flowing through, the controller controls the sixth power tube to be turned on with the third duty ratio, and at the same time, the controller keeps the fifth power tube off.

10. The boost-buck driving circuit according to claim 4, wherein Further comprising: A controller connected to the control end of the power tube, the power tube is provided with an anti-parallel diode, The controller drives the bridge circuit to work in the power factor correction mode, specifically comprising the following steps: When the power supply signal flows to the common end between the fifth power tube and the sixth power tube, the fifth power tube and the sixth power tube are turned on alternately with a fourth duty ratio; When the anti-parallel diode of the third power tube has current flowing through, the controller controls the third power tube to be turned on with a fifth duty ratio, and at the same time, the controller keeps the fourth power tube off; When the anti-parallel diode of the fourth power tube has current flowing through, the controller controls the fourth power tube to be turned on with the fifth duty ratio, and at the same time, the controller keeps the third power tube off.

11. The boost-buck driving circuit according to claim 1, wherein Further comprising: A controller connected to the control end of the power tube, the power tube is provided with an anti-parallel diode, The controller drives the step-down circuit to work in a filtering mode, specifically including the following steps: The controller controls the first power tube to be turned on, and controls the second power tube to be turned off or to be turned on alternately with the first power tube, and the filtering circuit filters the power supply signal.

12. The boost-buck driving circuit according to any one of claims 1 to 9, wherein Also comprising: A controller connected to the control end of the switch tube, the controller drives the step-down circuit to work in a step-down mode, specifically including the following steps: The controller controls the first power tube to be turned on with a sixth duty ratio, and controls the second power tube to be turned on alternately with the first power tube.

13. A method of boost-buck driving, characterized by, The driving method is suitable for the driving circuit as claimed in any one of claims 1 to 12, the driving circuit comprising a totem pole circuit and a step-down circuit connected in series, the driving method comprising: Determining an alternating voltage input to the driving circuit, and a bus voltage of the driving circuit; According to the alternating voltage and the bus voltage, controlling the step-down circuit to work in a filtering mode or a step-down mode, and controlling the totem pole circuit to work in a power factor correction mode or a rectification mode; According to the alternating voltage and the bus voltage, controlling the step-down circuit to work in a filtering mode or a step-down mode, and controlling the totem pole circuit to work in a power factor correction mode or a rectification mode, specifically including: Determining the product between the effective value of the alternating voltage and a first voltage coefficient, and recording the product as a first voltage sampling value; Determining the product between the effective value of the alternating voltage and a second voltage coefficient, and recording the product as a second voltage sampling value; Detecting the instantaneous value of the alternating voltage when the first voltage sampling value is less than a given voltage value corresponding to the bus voltage, and the second voltage sampling value is greater than or equal to the given voltage value corresponding to the bus voltage; Detecting the instantaneous value of the alternating voltage when the instantaneous value of the alternating voltage is less than the given voltage value corresponding to the bus voltage, controlling the totem pole circuit to work in a power factor correction mode, and controlling the step-down circuit to work in a filtering mode; Detecting the instantaneous value of the alternating voltage when the instantaneous value of the alternating voltage is greater than or equal to the given voltage value corresponding to the bus voltage, controlling the totem pole circuit to work in a rectification mode, and controlling the step-down circuit to work in a step-down mode.

14. The method of claim 13, wherein According to the alternating voltage and the bus voltage, controlling the step-down circuit to work in a filtering mode or a step-down mode, and controlling the totem pole circuit to work in a power factor correction mode or a rectification mode, specifically including: Determining a voltage given value of the bus voltage; Comparing the size relationship between the voltage given value and the alternating voltage; According to the size relationship between the voltage given value and the alternating voltage, controlling the step-down circuit to work in a filtering mode or a step-down mode, and controlling the totem pole circuit to work in a power factor correction mode or a rectification mode.

15. The method of claim 13, wherein According to the alternating voltage and the bus voltage, controlling the step-down circuit to work in a filtering mode or a step-down mode, and controlling the totem pole circuit to work in a power factor correction mode or a rectification mode, specifically including: determining a product between the effective value of the alternating voltage and a first voltage coefficient, and recording the product as a first voltage sampling value; detecting that the first voltage sampling value is greater than or equal to a given voltage value corresponding to the bus voltage, detecting an instantaneous value of the alternating voltage; detecting that the instantaneous value of the alternating voltage is less than the given voltage value corresponding to the bus voltage, controlling the totem-pole circuit to work in a rectification mode, and controlling the step-down circuit to work in a filtering mode; detecting that the instantaneous value of the alternating voltage is greater than or equal to the given voltage value corresponding to the bus voltage, controlling the totem-pole circuit to work in the rectification mode, and controlling the step-down circuit to work in a step-down mode.

16. The method of claim 13, wherein controlling the step-down circuit to work in the filtering mode or the step-down mode, and controlling the totem-pole circuit to work in a power factor correction mode or the rectification mode, specifically comprising: determining a product between the effective value of the alternating voltage and a second voltage coefficient, and recording the product as a second voltage sampling value; detecting that the second voltage sampling value is less than the given voltage value corresponding to the bus voltage, controlling the totem-pole circuit to work in the power factor correction mode, and simultaneously, controlling the step-down circuit to work in the filtering mode.

17. The method of any one of claims 13 to 16, wherein, the motor is a permanent magnet synchronous motor, and the driving method further comprises: determining a rotational speed of the permanent magnet synchronous motor and a back electromotive force coefficient; determining the given voltage value corresponding to the bus voltage according to the rotational speed and the back electromotive force coefficient.

18. An air conditioner characterized by comprising: comprise: a motor; the boost-buck driving circuit according to any one of claims 1 to 12, the driving circuit being configured to control the motor to operate.

19. A computer-readable storage medium, characterized in that, the computer readable storage medium has stored thereon a computer program, the computer program being executed to implement the boost-buck driving method according to any one of claims 13 to 17.

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