Motor drive control circuit, drive method, circuit board and air conditioner

Abstract

The present application discloses a drive control circuit, a drive method, a circuit board and an air conditioner. Among them, the motor drive control circuit includes a first power module and a second power module connected to both sides of an open-winding motor, a first switch group, a controller, a totem-pole PFC circuit and a buck switch circuit. The controller is connected to the totem-pole PFC circuit to control the totem-pole PFC circuit to reach at least one of the following states: a diode rectification state, a low-frequency switching state, and a high-frequency switching state. Matching the diode rectification mode and the low-frequency switching mode of the totem-pole PFC circuit, the controller controls the buck switch circuit to perform buck output to provide a voltage suitable for low-frequency operation for the first power module, so as to obtain a higher energy efficiency ratio in the state of low-frequency operation of the open-winding motor, improve the operation efficiency of the device at low frequencies, and meet the energy-saving requirements.

Description

Technical Field

[0001] The present application relates to the technical field of motor drive control, and particularly relates to a motor drive control circuit, a drive method, a circuit board, and an air conditioner. Background Art

[0002] Variable-frequency motors are widely used in various variable-frequency devices, such as variable-frequency air conditioners. The variable-frequency motor outputs a driving voltage that matches the current load size, thereby improving the operating efficiency of the variable-frequency device and achieving the purpose of energy conservation. To meet the high-frequency working requirements of variable-frequency devices, some variable-frequency motors adopt an open-winding motor structure, which can achieve high torque and power in the case of high-power drive. However, compared with the motor winding structure of a single inverter, the open-winding motor structure has a dual inverter. Therefore, the operating efficiency of the open-winding motor at low frequencies is not high and cannot meet the growing energy-saving needs of users. Summary of the Invention

[0003] The present application aims to at least solve one of the technical problems existing in the prior art. For this purpose, the present application provides a drive control circuit, a drive method, a circuit board, and an air conditioner, which can improve the operating efficiency of an open-winding motor at low frequencies on the premise of ensuring that the open-winding motor can operate at high frequencies by switching to different working states.

[0004] The motor drive control circuit according to the first aspect embodiment of the present application is used to drive an open-winding motor with three-phase windings. One end of each phase of the winding forms a first three-phase lead-out wire group, and the other end of each phase of the winding forms a second three-phase lead-out wire group. The motor drive control circuit includes:

[0005] A first power module connected to the first three-phase lead-out wire group;

[0006] A second power module connected to the second three-phase lead-out wire group;

[0007] A first switch group connected to the second three-phase lead-out wire group for switching the three-phase windings between star connection and open-winding connection;

[0008] A controller respectively connected to the first power module, the second power module, and the first switch group;

[0009] A totem-pole PFC circuit, and the controller is connected to the totem-pole PFC circuit to control the totem-pole PFC circuit to reach at least one of the following states:

[0010] Diode rectification state, low-frequency switching state, and high-frequency switching state;

[0011] Buck switching circuit, the totem-pole PFC circuit, the buck switching circuit and the three-phase winding are connected in sequence, and the controller is connected to the buck switching circuit to control the output voltage of the buck switching circuit.

[0012] The motor drive control circuit according to the first aspect embodiment of the present application has at least the following beneficial effects: Based on the open-winding motor, by controlling the switching of the first switch group, the working state switching of the totem PFC circuit, and the working state switching of the buck switching circuit, different driving methods can be realized corresponding to various loads of the open-winding motor. For example, when the open-winding motor operates at low frequency, by closing the first switch group, the connection mode of the three-phase winding is switched to star connection, and at the same time, the totem-pole PFC circuit is controlled to operate in the diode rectification state or the low-frequency switching state, and the buck switching circuit is controlled to operate in the buck output state. In this way, the access loss of the second power module can be avoided, and the first power module can also obtain a lower supply voltage, thereby reducing the inverter conversion loss in the first power module, enabling the open-winding motor to obtain a higher energy efficiency ratio under the low-frequency operation state and meeting the energy-saving requirements.

[0013] According to some embodiments of the first aspect of the present application, the totem-pole PFC circuit further includes a first inductor, a first capacitor and a bridge circuit. The AC input terminal, the first inductor, the bridge circuit and the first capacitor are connected in sequence, and the controller is connected to the bridge circuit.

[0014] According to some embodiments of the first aspect of the present application, the bridge circuit includes a first bridge arm unit and a second bridge arm unit. The first bridge arm unit includes a first rectifying component and a second rectifying component connected in series in the same direction. The second bridge arm unit includes a third rectifying component and a fourth rectifying component connected in series in the same direction. The first capacitor is connected to the output terminal of the bridge circuit and is in parallel with the first bridge arm unit. The first rectifying component, the second rectifying component, the third rectifying component and the fourth rectifying component are respectively connected to the controller.

[0015] According to some embodiments of the first aspect of the present application, the first rectifying component, the second rectifying component, the third rectifying component and the fourth rectifying component are semiconductor switching devices, and reverse-parallel diodes are provided for the first rectifying component, the second rectifying component, the third rectifying component and the fourth rectifying component.

[0016] According to some embodiments of the first aspect of the present application, the buck switching circuit includes a buck chopper circuit, and the buck chopper circuit includes a fifth switching device, a sixth freewheeling device, a second inductor, and a second capacitor. The output terminal of the totem-pole PFC circuit, the fifth switching device, the sixth freewheeling device, and the reference ground are connected in sequence. The connection point between the fifth switching device and the sixth freewheeling device, the second inductor, the second capacitor, and the reference ground are connected in sequence. The connection point between the second inductor and the second capacitor is connected to the first power module.

[0017] A motor drive control circuit according to another embodiment of the first aspect of the present application is used to drive an open-winding motor with three-phase windings. One end of each phase of the winding forms a first three-phase lead-out wire group, and the other end of each phase of the winding forms a second three-phase lead-out wire group. The motor drive control circuit includes:

[0018] A first power module connected to the first three-phase lead-out wire group;

[0019] A second power module connected to the second three-phase lead-out wire group;

[0020] A first switch group connected to the second three-phase lead-out wire group for switching the three-phase windings between star connection and open-winding connection;

[0021] A totem-pole PFC circuit includes a first inductor, a first capacitor, and a bridge circuit. The first inductor, the bridge circuit, and the first capacitor are connected in sequence. The bridge circuit includes a first bridge arm unit and a second bridge arm unit. The first bridge arm unit includes a first rectifying component and a second rectifying component connected in series in the same direction. The second bridge arm unit includes a third rectifying component and a fourth rectifying component connected in series in the same direction. The first capacitor is connected to the output terminal of the bridge circuit and is in parallel with the first bridge arm unit;

[0022] A buck switching circuit. The totem-pole PFC circuit, the buck switching circuit, and the three-phase windings are connected in sequence. The buck switching circuit includes a buck chopper circuit. The buck chopper circuit includes a fifth switching device, a sixth freewheeling device, a second inductor, and a second capacitor. The output terminal of the totem-pole PFC circuit, the fifth switching device, the sixth freewheeling device, and the reference ground are connected in sequence. The connection point between the fifth switching device and the sixth freewheeling device, the second inductor, the second capacitor, and the reference ground are connected in sequence. The connection point between the second inductor and the second capacitor is connected to the first power module.

[0023] According to some embodiments of the first aspect of the present application, it further includes a second switch group, the second switch group is respectively connected to the first three-phase lead-out wire group and the second three-phase lead-out wire group, the first switch group is opened, the second switch group is closed, and the three-phase winding is switched to a delta connection.

[0024] According to some embodiments of the first aspect of the present application, the buck switch circuit further includes a short-circuit switch, and the short-circuit switch is connected in parallel with the buck chopper circuit.

[0025] According to the driving method of the second aspect embodiment of the present application, it is used to drive an open-winding motor with a three-phase winding. One end of each winding forms a first three-phase lead-out wire group, and the other end of each winding forms a second three-phase lead-out wire group. It is characterized in that the motor drive control circuit includes:

[0026] A first power module, connected to the first three-phase lead-out wire group;

[0027] A second power module, connected to the second three-phase lead-out wire group;

[0028] A first switch group, connected to the second three-phase lead-out wire group, for switching the three-phase winding between a star connection and an open-winding connection;

[0029] A totem-pole PFC circuit, for achieving at least one of the following states:

[0030] A diode rectification state, a low-frequency switching state, and a high-frequency switching state;

[0031] A buck switch circuit, the totem-pole PFC circuit, the buck switch circuit, and the three-phase winding are connected in sequence;

[0032] The driving method includes:

[0033] According to the load of the open-winding motor, control the first switch group to close to switch the three-phase winding to a star connection, control the totem-pole PFC circuit to enter a diode rectification state or a low-frequency switching state, and control the buck switch circuit to perform buck output.

[0034] According to the driving method of the second aspect embodiment of the present application, it has at least the following beneficial effects: Based on the open-winding motor, by controlling the switching of the first switch group, the switching of the operating state of the totem pole PFC circuit, and the switching of the operating state of the buck switch circuit, different driving methods can be realized corresponding to various loads of the open-winding motor. For example, when the open-winding motor operates at a low frequency, the connection mode of the three-phase windings is switched to star connection by closing the first switch group, and at the same time, the totem pole PFC circuit is controlled to operate in the diode rectification state or the low-frequency switching state, and the buck switch circuit is controlled to operate in the buck output state. In this way, the access loss of the second power module can be avoided, and the first power module can also obtain a lower supply voltage, thereby reducing the inverter conversion loss in the first power module, so that the open-winding motor can obtain a higher energy efficiency ratio under the low-frequency operation state and meet the energy-saving requirements.

[0035] According to some embodiments of the second aspect of the present application, the totem pole PFC circuit further includes a bridge circuit, the bridge circuit includes a first bridge arm unit and a second bridge arm unit, the first bridge arm unit includes a first rectifying component and a second rectifying component connected in series in the same direction, the second bridge arm unit includes a third rectifying component and a fourth rectifying component connected in series in the same direction, and the first capacitor is connected to the output end of the bridge circuit and is in parallel with the first bridge arm unit;

[0036] Controlling the totem pole PFC circuit to enter the diode rectification state includes:

[0037] Continuously turning off the first rectifying component, the second rectifying component, the third rectifying component, and the fourth rectifying component.

[0038] According to some embodiments of the second aspect of the present application, the totem pole PFC circuit further includes a bridge circuit, the bridge circuit includes a first bridge arm unit and a second bridge arm unit, the first bridge arm unit includes a first rectifying component and a second rectifying component connected in series in the same direction, the second bridge arm unit includes a third rectifying component and a fourth rectifying component connected in series in the same direction, and the first capacitor is connected to the output end of the bridge circuit and is in parallel with the first bridge arm unit;

[0039] Controlling the totem pole PFC circuit to enter the low-frequency switching state includes:

[0040] In the positive half cycle of the AC input, continuously turn on the fourth rectifying component, continuously turn off the second rectifying component and the third rectifying component, and turn on the first rectifying component during the period when current flows through the first rectifying component;

[0041] During the negative half - cycle of the AC input, the third rectifying component is continuously turned on, the first rectifying component and the fourth rectifying component are continuously turned off, and the second rectifying component is turned on during the period when current flows through the second rectifying component.

[0042] According to some embodiments of the second aspect of the present application, the driving method further includes:

[0043] According to the load of the open - winding motor, control the totem - pole PFC circuit to enter the high - frequency switching state, and control the buck - switching circuit to perform filtered output.

[0044] According to some embodiments of the second aspect of the present application, the totem - pole PFC circuit further includes a bridge circuit. The bridge circuit includes a first bridge - arm unit and a second bridge - arm unit. The first bridge - arm unit includes a first rectifying component and a second rectifying component connected in series in the same direction. The second bridge - arm unit includes a third rectifying component and a fourth rectifying component connected in series in the same direction. The first capacitor is connected to the output end of the bridge circuit and is in parallel with the first bridge - arm unit;

[0045] The control of the totem - pole PFC circuit to enter the high - frequency switching state includes:

[0046] During the positive half - cycle of the AC input, the first rectifying component is switched on and off at high frequency, the fourth rectifying component is continuously turned on, and the second rectifying component and the third rectifying component are continuously turned off;

[0047] During the negative half - cycle of the AC input, the second rectifying component is switched on and off at high frequency, the third rectifying component is continuously turned on, and the first rectifying component and the fourth rectifying component are continuously turned off.

[0048] According to some embodiments of the second aspect of the present application, the buck - switching circuit includes a buck - chopper circuit. The buck - chopper circuit includes a fifth switching device, a sixth free - wheeling device, a second inductor, and a second capacitor. The output end of the totem - pole PFC circuit, the fifth switching device, the sixth free - wheeling device, and the reference ground are connected in sequence. The connection point between the fifth switching device and the sixth free - wheeling device, the second inductor, the second capacitor, and the reference ground are connected in sequence. The connection point between the second inductor and the second capacitor is connected to the first power module;

[0049] The control of the buck - switching circuit to perform buck output includes:

[0050] Control the fifth switching device to be switched on and off at high frequency;

[0051] In the on - state of the fifth switching device, control the sixth free - wheeling device to be turned off. In the off - state of the fifth switching device, control the sixth free - wheeling device to be turned on or off.

[0052] According to some embodiments of the second aspect of the present application, the driving method further includes:

[0053] Controlling the totem-pole PFC circuit to enter a high-frequency switching state according to the load of the open-winding motor, and controlling the buck switching circuit to perform filtering output;

[0054] The controlling the buck switching circuit to perform filtering output includes:

[0055] Controlling the fifth switching device to conduct continuously and controlling the sixth freewheeling device to turn off continuously.

[0056] According to some embodiments of the second aspect of the present application, the buck switching circuit further includes a short-circuit switch, and the short-circuit switch is connected in parallel with the buck chopper circuit;

[0057] The driving method further includes: controlling the totem-pole PFC circuit to enter a high-frequency switching state according to the load of the open-winding motor, and controlling the short-circuit switch to close.

[0058] According to some embodiments of the second aspect of the present application, the motor drive control circuit further includes a second switch group, the second switch group is respectively connected to the first three-phase lead-out wire group and the second three-phase lead-out wire group, the first switch group is opened, the second switch group is closed, and the three-phase winding is switched to a delta connection;

[0059] The driving method further includes:

[0060] Controlling the first switch group to open and the second switch group to close according to the load of the open-winding motor so that the three-phase winding is switched to a delta connection, controlling the totem-pole PFC circuit to enter a high-frequency switching state, and controlling the buck switching circuit to perform filtering output.

[0061] According to some embodiments of the second aspect of the present application, if the load of the open-winding motor is the operating power parameter of the open-winding motor, the driving method includes:

[0062] Controlling the totem-pole PFC circuit, the buck switching circuit, the first switch group and the second switch group to reach at least one of the following states according to the operating power parameter of the open-winding motor:

[0063] When the operating power parameter of the open-winding motor is less than the first operating power parameter, controlling the first switch group to close and the second switch group to open so that the stator winding is switched to a star connection, and controlling the totem-pole PFC circuit to enter a diode rectification state and controlling the buck switching circuit to perform buck output;

[0064] The operating power parameter of the open-winding motor is greater than the first operating power parameter and less than the second power operating parameter. Control the first switch group to close and the second switch group to open to switch the stator winding into a star connection, and control the totem-pole PFC circuit to enter the low-frequency switching state, and control the buck switch circuit to perform buck output;

[0065] The operating power parameter of the open-winding motor is greater than the second operating power parameter and less than the third power operating parameter. Control the first switch group to close and the second switch group to open to switch the stator winding into a star connection, and control the totem-pole PFC circuit to enter the high-frequency switching state, and control the buck switch circuit to perform filtering output;

[0066] The operating power parameter of the open-winding motor is greater than the third operating power parameter and less than the fourth power operating parameter. Control the first switch group to open and the second switch group to close to switch the stator winding into a delta connection, and control the totem-pole PFC circuit to enter the high-frequency switching state, and control the buck switch circuit to perform filtering output;

[0067] The operating power parameter of the open-winding motor is greater than the fourth power operating parameter. Control the first switch group to open and the second switch group to open to switch the stator winding into an open-winding connection, and control the totem-pole PFC circuit to enter the high-frequency switching state, and control the buck switch circuit to perform filtering output.

[0068] The circuit board according to the third aspect embodiment of the present application includes the motor drive control circuit according to any one of the first aspect embodiments.

[0069] The circuit board according to the third aspect embodiment of the present application has at least the following beneficial effects: By carrying the above-mentioned motor drive control circuit on the circuit board, it is convenient to install the circuit board on the device to apply the functions of the above-mentioned motor drive control circuit. That is, on the basis of the open-winding motor, by controlling the switching of the first switch group, the switching of the working state of the totem PFC circuit, and the switching of the working state of the buck switch circuit, different driving methods can be realized corresponding to various loads of the open-winding motor. For example, when the open-winding motor operates at low frequency, by closing the first switch group, the connection mode of the three-phase windings is switched to a star connection, and at the same time, the totem-pole PFC circuit is controlled to work in the diode rectification state or the low-frequency switching state, and the buck switch circuit is controlled to work in the buck output state. In this way, the access loss of the second power module can be avoided, and at the same time, the first power module can also obtain a lower supply voltage, thereby reducing the inverter conversion loss in the first power module, so that the open-winding motor can obtain a higher energy efficiency ratio under the low-frequency operation state and meet the energy-saving requirements.

[0070] An air conditioner according to an embodiment of the fourth aspect of the present application, a circuit board as described in the third aspect;

[0071] Or,

[0072] including at least one processor and a memory communicatively connected to the at least one processor; the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to execute the driving method as described in any one of the second aspect.

[0073] The air conditioner according to an embodiment of the fourth aspect of the present application has at least the following beneficial effects: Installing a circuit board integrated with a motor drive control circuit or executing the corresponding driving method in the air conditioner can apply the functions of the above-mentioned motor drive control circuit. Therefore, on the basis that the motor of the air conditioner is an open-winding motor, by controlling the switching of the first switch group, the switching of the operating state of the totem PFC circuit, and the switching of the operating state of the buck switch circuit, different driving methods can be realized corresponding to various loads of the open-winding motor. For example, when the open-winding motor operates at a low frequency, the connection mode of the three-phase windings is switched to star connection by closing the first switch group, and at the same time, the totem-pole PFC circuit is controlled to operate in the diode rectification state or the low-frequency switching state, and the buck switch circuit is controlled to operate in the buck output state. In this way, the access loss of the second power module can be avoided, and the first power module can also obtain a lower supply voltage, thereby reducing the inverter conversion loss in the first power module, so that the open-winding motor can obtain a higher energy efficiency ratio under the low-frequency operation state and meet the energy-saving requirements.

[0074] A computer-readable storage medium according to an embodiment of the fifth aspect of the present application, the computer-readable storage medium stores computer-executable instructions, and the computer-executable instructions are used to cause a computer to execute the driving method as described in any one of the embodiments of the second aspect.

[0075] Additional aspects and advantages of the present application will be given in part in the following description, become apparent in part from the following description, or be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0076] The above and / or additional aspects and advantages of the present application will become apparent and be readily understood from the description of the embodiments in conjunction with the following drawings, wherein:

[0077] Figure 1 is a circuit diagram of a motor drive control circuit provided by an embodiment of the present application;

[0078] Figure 2The equivalent circuit diagram of the motor drive control circuit when the totem-pole PFC circuit is in the diode rectification state, the buck switch circuit is in the buck output state, and the stator windings are in the star connection state provided by an embodiment of the present application;

[0079] Figure 3 The equivalent circuit diagram of the motor drive control circuit when the totem-pole PFC circuit is in the low-frequency switching state, the buck switch circuit is in the buck output state, and the stator windings are in the star connection state provided by an embodiment of the present application;

[0080] Figure 4 The equivalent circuit diagram of the motor drive control circuit when the totem-pole PFC circuit is in the high-frequency switching state, the buck switch circuit is in the constant-voltage output state, and the stator windings are in the star connection state provided by an embodiment of the present application;

[0081] Figure 5 The equivalent circuit diagram of the motor drive control circuit when the totem-pole PFC circuit is in the high-frequency switching state, the buck switch circuit is in the constant-voltage output state, and the stator windings are in the delta connection state provided by an embodiment of the present application;

[0082] Figure 6 The equivalent circuit diagram of the motor drive control circuit when the totem-pole PFC circuit is in the high-frequency switching state, the buck switch circuit is in the constant-voltage output state, and the stator windings are in the open-winding connection state provided by an embodiment of the present application;

[0083] Figure 7 Provided by an embodiment of the present application corresponding to Figure 2 and Figure 3 The waveform diagram of the working state;

[0084] Figure 8 Provided by an embodiment of the present application corresponding to Figures 4 to 6 The waveform diagram of the working state;

[0085] Figure 9 The circuit diagram of the motor drive control circuit provided by another embodiment of the present application;

[0086] Figure 10 The structural diagram of the control device provided by an embodiment of the present application;

[0087] Figure 11 The flowchart of the driving method provided by an embodiment of the present application;

[0088] Figure 12 The flowchart of the driving method provided by another embodiment of the present application;

[0089] Figure 13 The flowchart of the driving method provided by another embodiment of the present application;

[0090] Figure 14 Flow chart of the driving method provided for another embodiment of the present application;

[0091] Figure 15 Flow chart of the driving method provided for another embodiment of the present application;

[0092] Figure 16 Flow chart of the driving method provided for another embodiment of the present application;

[0093] Figure 17 Flow chart of the driving method provided for another embodiment of the present application;

[0094] Figure 18 Working state diagram corresponding to the motor drive control circuit under different operating power parameters provided for an embodiment of the present application. Detailed implementation manners

[0095] The embodiments of the present application will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary only for explaining the present application and should not be construed as limiting the present application.

[0096] In the description of the present application, the meaning of several is one or more, the meaning of a plurality is more than two, and understandings such as greater than, less than, exceeding, etc. do not include the present number, and understandings such as above, below, within, etc. include the present number. If there is a description of first and second, it is only for the purpose of distinguishing technical features and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or implicitly indicating the sequence relationship of the indicated technical features.

[0097] In the description of the present application, unless otherwise clearly defined, words such as setting, installing, connecting, etc. should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above words in the present application in combination with the specific content of the technical solution.

[0098] The motor drive control circuit realizes variable frequency control in the equipment by providing a variable voltage. In order to meet the high-frequency working requirements of the variable frequency equipment, some variable frequency motors adopt an open-winding motor structure, which can achieve very high torque and power in high-power drive occasions, such as variable frequency air conditioners. However, although the use of open-winding motors can ensure high-frequency operation, the operating efficiency of open-winding motors at low frequencies is not ideal. This is particularly obvious under extremely low-frequency working conditions, because both inverters of the open-winding motor have conduction losses and switching losses, and the low-frequency output of the drive control circuit of the open-winding motor often has only one voltage value, which corresponds to a low-frequency working state with optimal operating efficiency. When the equipment enters a lower frequency working state, the motor drive control circuit can only drive the motor through this voltage value. At this time, the operating efficiency of the equipment is reduced, and the energy loss in the circuit is increased, which obviously cannot meet people's growing energy-saving needs.

[0099] Based on this, the present application proposes a motor drive control circuit, a drive method, a circuit board, an air conditioner and a computer-readable storage medium. When the equipment is operating in a low-frequency state, a lower power supply voltage is obtained by cooperating with a step-down switching circuit in different working states of a totem pole PFC circuit, thereby matching different working states of an open-winding motor. Under the premise of ensuring high-frequency operation of the open-winding motor, the low-frequency operation efficiency of the open-winding motor is improved.

[0100] It is well known to those skilled in the art that an open-winding motor has three windings with a total of six terminals. The three windings include a first phase winding, a second phase winding and a third phase winding, forming a three-phase power supply. Each winding includes two terminals, i.e., a first pin and a sixth pin are respectively led out from both ends of the first phase winding, a second pin and a fifth pin are respectively led out from both ends of the second phase winding, and a third pin and a fourth pin are respectively led out from both ends of the third phase winding. In this way, the first pin, the second pin and the third pin constitute the three-phase lead-out wire on one side of the open-winding motor, and the fourth pin, the fifth pin and the sixth pin constitute the three-phase lead-out wire on the other side of the open-winding motor. The open-winding motor can be driven by connecting the three-phase lead-out wires on both sides of the open-winding motor through two inverter modules.

[0101] The embodiments of the present application are further described below in conjunction with the accompanying drawings.

[0102] Reference Figure 1 , Figure 1 1 is a circuit diagram of a motor drive control circuit provided in a first aspect of an embodiment of the present application, the motor drive control circuit is used to drive an open-winding motor having a three-phase winding 100, one end of each phase winding constitutes a first three-phase lead wire group 110, and the other end of each phase winding constitutes a second three-phase lead wire group 120, and the motor drive control circuit includes:

[0103] The first power module PM1 is connected to the first three-phase lead-out wire group 110;

[0104] The second power module PM2 is connected to the second three-phase lead-out wire group 120;

[0105] The first switch group KY1 is connected to the second three-phase lead-out wire group 120 and is used to switch the three-phase winding 100 between star connection and open winding connection;

[0106] The controller is respectively connected to the first power module PM1, the second power module PM2 and the first switch group KY1;

[0107] The totem-pole PFC circuit 200 (Totem-pole PFC), the controller is connected to the totem-pole PFC circuit 200 to control the totem-pole PFC circuit 200 to reach at least one of the following states:

[0108] Diode rectification state, low-frequency switching state and high-frequency switching state;

[0109] The buck switching circuit 300, the totem-pole PFC circuit 200, the buck switching circuit 300 and the three-phase winding 100 are connected in sequence, and the controller is connected to the buck switching circuit 300 to control the output voltage of the buck switching circuit 300.

[0110] In an embodiment, the working state of the totem-pole PFC circuit 200 is switched by the controller to enter the diode rectification state, the low-frequency switching state or the high-frequency switching state; wherein, the diode rectification state of the totem-pole PFC circuit 200 is applicable to small current output, because at this time the circuit loss is equal to the conduction loss brought by the diode, and the diode conduction loss is not high under small current, which is applicable to the extremely low frequency output of the open winding motor; however, under large current, the voltage drop of the diode increases, the conduction loss increases accordingly, and the operation efficiency of the circuit decreases. Therefore, when the open winding motor increases the working frequency and the totem-pole PFC circuit 200 needs to output a larger current, the diode rectification state is no longer applicable. At this time, the totem-pole PFC circuit 200 is switched to the low-frequency switching state to obtain a higher output voltage. In the low-frequency switching state, some or all of the diodes in the totem-pole PFC circuit 200 are replaced by switching devices. Because the conduction loss of the switching device is lower than that of the diode, a lower conduction voltage drop can be obtained, and the operation efficiency of the open winding motor is improved; when the open winding motor enters high-frequency operation, the totem-pole PFC circuit 200 needs to output a high voltage, and the low-frequency switching state is no longer applicable. At this time, the totem-pole PFC circuit 200 is switched to the high-frequency switching state, and the duty cycle of the switching device is increased to obtain a higher voltage and current to adapt to the operation efficiency under high-frequency output. As for the specific circuit structure of the totem-pole PFC circuit 200 and how to enter the corresponding working state, it will be described in detail in the following embodiments.

[0111] Although the totem-pole PFC circuit 200 can adjust the output voltage, the PFC circuit does not have a buck function. In practical applications, in order to ensure that the open-winding motor with a high back-electromotive force coefficient can smoothly enter the high frequency, the totem-pole PFC circuit 200 is equipped with boost components such as inductors. However, this results in an unsatisfactory efficiency at medium frequencies. Therefore, a buck switch circuit 300 needs to be combined to obtain a lower voltage output to meet the energy-saving requirements for the low-frequency operation of the motor. In this embodiment, the buck switch circuit 300 is connected to the output terminal of the totem-pole PFC circuit 200. After the output voltage of the totem-pole PFC circuit 200 in the diode rectification state or the low-frequency switching state is processed by the buck switch circuit 300, it becomes a lower voltage to meet the low-frequency operation requirements of the device.

[0112] It can be understood that the buck switch circuit 300 can be a buck circuit composed of discrete components or an integrated packaged voltage conversion chip; the buck switch circuit 300 can output different driving voltages in different operating modes. For example, if the buck switch circuit 300 is a buck circuit, by controlling the opening and closing of the switch tube in the buck circuit through a controller, the buck circuit can operate in the buck mode or the LC filtering mode. Another example is that if the buck switch circuit 300 is a voltage conversion chip, the controller is connected to the enable terminal of the chip to control the enable signal, and the voltage conversion chip can output different levels of voltage values.

[0113] The first power module PM1 and the second power module PM2 are connected to the three-phase winding 100 to achieve inverter conversion, providing a driving voltage for the motor and also constituting the connection structure of the open-winding motor; the first power module PM1 and the second power module PM2 can be a module circuit composed of discrete devices in terms of selection. For example, the first power module PM1 and the second power module PM2 are a three-phase bridge inverter circuit composed of six switching devices. At this time, the switching devices can be IGBT devices, MOSFETs made of Si material, MOSFETs made of SiO material, or MOSFETs made of GaN material. The first power module PM1 and the second power module PM2 can also be an integrated packaged intelligent power module, such as an IPM module (Intelligent Power Module), which can also achieve the function of inverter conversion.

[0114] Refer to Figure 1, the first switch group KY1 is connected to the first three-phase lead-out wire 110. The controller controls the first switch group KY1 to close, and the three-phase winding 100 is switched to a star connection. The controller controls the first switch group KY1 to open, and the three-phase winding 10 is switched to an open winding connection. In the low and medium frequency operating state of the motor, the operating efficiency of the star connection is better than that of the open winding connection. Therefore, by adding the first switch group KY1, the connection method of the three-phase winding 100 is switched to adapt to the low frequency operation of the motor. There are various implementation manners of the first switch group KY1. Specifically, in one embodiment, the first switch group KY1 includes a first switch and a second switch. The second three-phase lead-out wire group 120 includes a first pin M1, a second pin M2, and a third pin M3. The first three-phase lead-out wire group 110 includes a fourth pin M4, a fifth pin M5, and a sixth pin M6. The first switch is respectively connected to the first pin M1 and the second pin M2, and the second switch is respectively connected to the second pin M2 and the third pin M3. When the first switch and the second switch are closed simultaneously, the first pin M1, the second pin M2, and the third pin M3 are connected to each other, so that the three-phase winding 100 is in a star connection state, as Figure 2 , 3 , 4 and 6 show. Since the second power module PM2 is not connected to the drive circuit of the motor in the star connection state, the loss brought by the second power module PM2 can be ignored. Cooperating with the totem pole PFC circuit 200 and the buck switch circuit 300, the operating efficiency of the motor at low frequencies can be greatly improved. When the star-connected three-phase winding 100 needs to enter the high frequency operating state, the first switch group KY1 is disconnected to switch back to the open winding state to adapt to the high frequency operation of the motor.

[0115] It can be understood that the two switches of the first switch group KY1 can be discrete components or integrated on a single component. For example, the first switch and the second switch are respectively an electromagnetic relay, a contactor, a solid state relay, or an electronic switch with a conduction resistance not exceeding 1 ohm. Another example is that the first switch and the second switch are integrated on a rotary switch. Rotating the rotary switch can simultaneously close and open the first switch and the second switch. There are many implementation manners of the first switch group KY1, and different switch forms have different switching times. Different switch forms can be selected according to the response requirements of the motor drive control circuit, which will not be elaborated here one by one.

[0116] Referring to Figure 1, in one embodiment, the totem-pole PFC circuit 200 includes a first inductor L1, a first capacitor C1, and a bridge circuit. The AC input terminal, the first inductor L1, the bridge circuit, and the first capacitor C1 are connected in sequence, and the controller is connected to the bridge circuit. In this embodiment, the totem-pole PFC circuit 200 is a boost rectifier circuit. One end of the AC input terminal (such as mains input, including two connection ports) is connected to the first inductor L1 to achieve voltage boost, and then the DC voltage is output after rectification by the bridge circuit. Finally, the first capacitor C1 is used to achieve the power factor correction (PFC) of the circuit. The characteristic that the current on the first capacitor C1 leads the voltage is used to compensate for the characteristic that the current on the first inductor L1 lags the voltage, so that the characteristic of the bridge circuit is close to resistive, thereby improving the rectification efficiency.

[0117] In one embodiment, the bridge circuit includes a first bridge arm unit and a second bridge arm unit. The first bridge arm unit includes a first rectifying component T1 and a second rectifying component T2 connected in series in the same direction. The second bridge arm unit includes a third rectifying component T3 and a fourth rectifying component T4 connected in series in the same direction. The first capacitor C1 is connected to the output terminal of the bridge circuit and is in parallel with the first bridge arm unit. The first rectifying component T1, the second rectifying component T2, the third rectifying component T3, and the fourth rectifying component T4 are respectively connected to the controller.

[0118] The bridge circuit in this embodiment is used to achieve the rectification function. In terms of the circuit structure, the first rectifying component T1, the second rectifying component T2, the third rectifying component T3, and the fourth rectifying component T4 are all connected in the same direction in the bridge circuit to form a rectifier bridge. The first rectifying component T1, the second rectifying component T2, the third rectifying component T3, and the fourth rectifying component T4 can be adjusted according to the requirements of the circuit in terms of selection. For example, if the first rectifying component T1, the second rectifying component T2, the third rectifying component T3, and the fourth rectifying component T4 are all MOSFETs, then in the first bridge arm unit, the source of the first rectifying component T1 is connected to the drain of the second rectifying component T2. In the second bridge arm unit, the source of the third rectifying component T3 is connected to the drain of the fourth rectifying component T4. The drain of the first rectifying component T1 is connected to the drain of the third rectifying component T3. The source of the second rectifying component T2 is connected to the source of the fourth rectifying component T4. The AC input terminal is respectively connected to the source of the first rectifying component T1 and the source of the third rectifying component T3. The drain of the first rectifying component T1 is the positive output terminal of the bridge circuit, and the source of the second rectifying component T2 is the negative output terminal of the bridge circuit. The above circuit structure is only exemplary, and the actual circuit can be adjusted accordingly according to the control requirements.

[0119] In fact, in order to achieve the diode rectification state, low-frequency switching state, and high-frequency switching state, there are certain requirements for the selection of the first rectifying component T1, the second rectifying component T2, the third rectifying component T3, and the fourth rectifying component T4. In one implementation, the first rectifying component T1, the second rectifying component T2, the third rectifying component T3, and the fourth rectifying component T4 are semiconductor switching devices. The first rectifying component T1, the second rectifying component T2, the third rectifying component T3, and the fourth rectifying component T4 are all provided with anti-parallel diodes. The anti-parallel diode can be a separate diode element or a parasitic diode. In this implementation, the first rectifying component T1, the second rectifying component T2, the third rectifying component T3, and the fourth rectifying component T4 are respectively connected to the enable terminal of the controller, thereby switching the working state of the totem-pole PFC circuit 200. For example, if the controller has at least four enable pins and the first rectifying component T1, the second rectifying component T2, the third rectifying component T3, and the fourth rectifying component T4 are all MOSFETs, then the gates of the rectifying components T1 to T4 are respectively connected to the four enable pins of the controller; In another implementation, the first rectifying component T1 and the second rectifying component T2 are semiconductor switching devices, the third rectifying component T3 and the fourth rectifying component T4 are diodes, and only the first rectifying component T1 and the second rectifying component T2 are provided with anti-parallel diodes. In this implementation, the two enable pins of the controller are respectively connected to the gates of the first rectifying component T1 and the second rectifying component T2 to achieve on-off control, while the third rectifying component T3 and the fourth rectifying component T4 are ordinary diodes and do not require control, and the switching of the working state of the totem-pole PFC circuit 200 can also be achieved.

[0120] Taking the first rectifying component T1, the second rectifying component T2, the third rectifying component T3, and the fourth rectifying component T4 as all MOSFETs as an example, several working states of the totem-pole PFC circuit 200 are described as follows:

[0121] Diode rectification state: Refer to Figure 2 and Figure 7 , the controller controls the first rectifying component T1, the second rectifying component T2, the third rectifying component T3, and the fourth rectifying component T4 to be in a continuously off state. At this time, the current can only pass forward through the anti-parallel diode, and the totem-pole PFC circuit 200 is equivalent to a bridgeless boost PFC circuit; Since the loss of the alternating current passing through the bridge circuit only comes from the conduction loss of the diode, and the conduction loss of the diode is related to the current, the diode rectification state is suitable for small current situations;

[0122] Low-frequency switching state: Refer to Figure 3 and Figure 7, also known as the synchronous rectification state. Compared with the diode rectification state, when the current in the circuit increases, the on-voltage drop of the diode also increases. Therefore, a MOSFET with low on-loss is used to reduce the impact brought by the on-loss of the diode. Specifically, in the positive half-cycle of the alternating current, the second rectifying component T2 and the third rectifying component T3 are continuously turned off, the fourth rectifying component T4 is continuously turned on, and the first rectifying component T1 is turned on during the period when current flows through its anti-parallel diode. In the negative half-cycle of the alternating current, the first rectifying component T1 and the fourth rectifying component T4 are continuously turned off, the third rectifying component T3 is continuously turned on, and the second rectifying component T2 is turned on during the period when current flows through its anti-parallel diode. Since the on-voltage drop of the MOSFET is very low, the rectification loss at the output end can be reduced, thereby improving the conversion efficiency, which is applicable to the situation of low voltage and large current;

[0123] High-frequency switching state: Refer to Figure 4 and Figure 8 , in the positive half-cycle of the alternating current, the controller controls the first rectifying component T1 to switch on and off at a high frequency while the fourth rectifying component T4 is continuously turned on, and the second rectifying component T2 and the third rectifying component T3 are continuously turned off. In the negative half-cycle of the alternating current, the controller controls the second rectifying component T2 to switch on and off at a high frequency while the third rectifying component T3 is continuously turned on, and the first rectifying component T1 and the fourth rectifying component T4 are continuously turned off. By controlling the duty cycle of the high-frequency on-off, a large voltage and large current output can be obtained at the output end of the totem-pole PFC circuit 200, which is suitable for the high-frequency working state of the motor.

[0124] In one embodiment, the buck switching circuit 300 includes a buck chopper circuit. The buck chopper circuit includes a fifth switching device Q5, a sixth freewheeling device Q6, a second inductor L2, and a second capacitor C2. The output end of the PFC circuit, the fifth switching device Q5, the sixth freewheeling device Q6, and the reference ground are connected in sequence. The connection point between the fifth switching device Q5 and the sixth freewheeling device Q6, the second inductor L2, the second capacitor C2, and the reference ground are connected in sequence. The connection point between the second inductor L2 and the second capacitor C2 is connected to the first power module PM1.

[0125] In this embodiment, the buck chopper circuit is a buck circuit. The fifth switching device Q5 is used for on-off control, and the sixth freewheeling device Q6, as a freewheeling device, cooperates with the second inductor L2 and the second capacitor C2 to form a chopper output. In terms of selection, both the fifth switching device Q5 and the sixth freewheeling device Q6 can be power switching transistors and are connected to the enable terminal of the controller. In this case, the buck chopper circuit has the following two working modes under the control of the controller:

[0126] One is the mode of buck output. Refer to Figure 2 and Figure 3, the controller controls the fifth switching device Q5 to turn off and on periodically. The sixth freewheeling device Q6 turns off when the fifth switching device Q5 is on, and turns off or on when the fifth switching device Q5 is off. The controller adjusts the bucking amplitude by controlling the duty cycle of the fifth switching device Q5; a lower voltage can be obtained in the bucking output state, which is suitable for cooperating with the diode rectification state and the low-frequency switching state of the totem-pole PFC circuit 200;

[0127] Another is the filtering output mode. Refer to Figures 4 to 6 , the controller controls the fifth switching device Q5 to conduct continuously, and the sixth freewheeling device Q6 to turn off continuously. At this time, the bucking chopper circuit is equivalent to an LC filter circuit, and the voltage drop can be ignored, which is suitable for cooperating with the high-frequency switching state of the totem-pole PFC circuit 200.

[0128] As can be seen from the above two working modes, the sixth freewheeling device Q6 can be replaced by a diode. In this case, since the diode is uncontrollable, the sixth freewheeling device Q6 does not need to be connected to the controller.

[0129] In one embodiment, the fifth switching device Q5 is provided with an anti-parallel diode. In this embodiment, by adding an anti-parallel diode, the fifth switching device Q5 can be prevented from being damaged by reverse breakdown. Of course, the fifth switching device Q5 may also not have an anti-parallel diode, which does not affect the function to be achieved by the fifth switching device Q5.

[0130] In one embodiment, refer to Figure 1 , the bucking switch circuit 300 further includes a shorting switch KY3, and the shorting switch KY3 is connected in parallel with the bucking chopper circuit. After the shorting switch KY3 is closed, the bucking chopper circuit can be short-circuited, which is equivalent to the bucking chopper circuit not working. The output of the totem-pole PFC circuit 200 is directly input to the first power module PM1. Since the output of the totem-pole PFC circuit 200 is not bucked, the situation where the shorting switch KY3 is closed is suitable for the high-frequency working state of the motor, which is equivalent to the bucking switch circuit 300 working in the direct output mode.

[0131] In the above embodiment, the switching between the star connection and the open-winding connection is realized by the opening and closing of the first switch group KY1. However, there is still a certain gap between the optimal operating frequencies corresponding to the star connection and the open-winding connection. At this time, this embodiment introduces a delta connection to adapt to the medium-high frequency operation of the motor. Based on this, the following winding switching structure can be adopted:

[0132] Refer to Figure 1, in one embodiment, it further includes a second switch group KY2. The second switch group KY2 is respectively connected to the first three-phase lead-out wire group 110 and the second three-phase lead-out wire group 120. When the first switch group KY1 is open and the second switch group KY2 is closed, the three-phase winding 100 is switched to a delta connection. In this embodiment, the second switch group KY2 is added to realize the switching of the delta connection of the three-phase winding 100. Specifically, in one embodiment, the second switch group KY2 includes a third switch, a fourth switch, and a fifth switch. The third switch is respectively connected to the second pin M2 and the sixth pin M6, the fourth switch is respectively connected to the third pin M3 and the fifth pin M5, and the fifth switch is respectively connected to the first pin M1 and the fourth pin M4. When the third switch, the fourth switch, and the fifth switch are closed simultaneously, and the first switch group KY1 is in the off state, at this time, the second pin M2 and the sixth pin M6 are connected to each other, the third pin M3 and the fifth pin M5 are connected to each other, and the first pin M1 and the fourth pin M4 are connected to each other, so that the three-phase winding 100 is in a delta connection, as Figure 5 and Figure 6 shown. The delta connection allows the motor with the three-phase winding 100 to operate at a higher voltage compared to the star connection and is suitable for higher operating frequencies. Since the second switch KY2 is added, the opening and closing of the first switch KY1 are also related to the opening and closing state of the second switch KY2. Therefore, the switching of the connection mode of the three-phase winding 100 is carried out as follows:

[0133] When the first switch group KY1 is closed and the second switch group KY2 is open, the three-phase winding 100 is switched to a star connection;

[0134] When the first switch group KY1 is open and the second switch group KY2 is closed, the three-phase winding 100 is switched to a delta connection;

[0135] When the first switch group KY1 is open and the second switch group KY2 is open, the three-phase winding 100 is switched to an open winding connection.

[0136] It can be understood that the second switch group KY2 is also a switch. When selecting the type, it can refer to the selection of the first switch group KY1. According to the response requirements of the motor drive control circuit, different switch forms can be selected to meet the switching requirements of the connection mode of the three-phase winding 100.

[0137] In one embodiment, the second power module PM2 is connected to the output end of the buck switch circuit 300 or the output end of the totem-pole PFC circuit 200. One implementation of this embodiment is that the power supply of the second power module PM2 comes from the output of the totem-pole PFC circuit 200. Refer to Figure 1, then the second power module PM2 continuously receives high-voltage drive, which is not conducive to the medium and low-frequency operation of the motor. Therefore, this connection method needs to be combined with the above-mentioned first switch group KY1, or a combination of the first switch group KY1 and the second switch group KY2, so as to short-circuit the second power module PM2 during medium and low-frequency operation; Another implementation manner of this embodiment is that the power supply of the second power module PM2 comes from the output of the buck switch circuit 300. Refer to Figure 9 , then both the first power module PM1 and the second power module PM2 receive the same voltage value, which can enable the open-winding connected motor to operate at low, medium, and high frequencies. If the above-mentioned first switch group KY1 and the second switch group KY2 are combined, then it is possible to realize that the second power module PM2 is connected only in the high-frequency working state of the motor. At this time, the buck switch circuit 300 performs filtering output, and the second power module PM2 can still obtain high-voltage drive to adapt to the high-frequency working state of the motor.

[0138] It should be noted that in the above embodiments based on the switching connection method of open-winding connection, the second power module PM2 is specifically used for open-winding connection and is suitable for high-frequency operation, while the first power module PM1 can be suitable for low, medium, and high-frequency operation. Therefore, in terms of component selection, the second power module PM2 can select devices that are only targeted at high-voltage drive, obtaining higher operating efficiency and saving component costs at the same time.

[0139] Refer to Figure 10 , Figure 10 is a schematic diagram of the control device 1000 provided by an embodiment of the present application. In the motor drive control circuit of the first aspect of the above embodiment, the control device 1000 can be provided, or the control device 1000 can be set based on the motor drive control circuit of another circuit structure. Specifically, the control device 1000 is connected to the totem pole PFC circuit and the buck switch circuit to realize the control of the totem pole PFC circuit and the buck switch circuit. It can be understood that the control device 1000 includes a control processor 1001 and a memory 1002. Figure 10 In

[0140] , an example of one control processor 1001 and one memory 1002 is given. Figure 10 In

[0141] The memory 1002, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs and non-transitory computer-executable programs. In addition, the memory 1002 may include a high-speed random access memory 1002, and may also include non-transitory memories 1002, such as at least one disk memory 1002, flash memory devices, or other non-transitory solid-state memory 1002 components. In some embodiments, the memory 1002 may optionally include memories 1002 that are remotely provided with respect to the control processor 1001, and these remote memories 1002 can be connected to the control device 1000 through a network. Examples of the above-mentioned network include but are not limited to the Internet, intranet, local area network, mobile communication network, and combinations thereof.

[0142] Those skilled in the art can understand that Figure 10 the device structure shown in

[0143] does not constitute a limitation on the control device 1000, and may include more or fewer components than shown in the figure, or combine certain components, or have different component arrangements. Figure 1 In the motor drive control circuit shown in

[0144] Based on a motor drive control circuit, various embodiments of the drive method according to the second aspect of the embodiments of the present application are proposed.

[0145] Referring to Figure 11 , Figure 11 is a flowchart of the drive method provided by the second aspect of an embodiment of the present application, where the drive method is used to drive an open-winding motor having three-phase windings 100. One end of each phase winding forms a first three-phase lead-out wire group 110, and the other end of each phase winding forms a second three-phase lead-out wire group 120. It is characterized in that the motor drive control circuit includes:

[0146] A first power module PM1, connected to the first three-phase lead-out wire group 110;

[0147] A second power module PM2, connected to the second three-phase lead-out wire group 120;

[0148] A first switch group KY1, connected to the second three-phase lead-out wire group 120, for switching the three-phase windings 100 between star connection and open-winding connection;

[0149] A totem-pole PFC circuit 200, for achieving at least one of the following states:

[0150] Diode rectification state, low-frequency switching state, and high-frequency switching state;

[0151] The buck switching circuit 300, the totem-pole PFC circuit 200, the buck switching circuit 300 and the three-phase winding 100 are connected in sequence.

[0152] The driving method includes:

[0153] S1100, according to the load of the open-winding motor, control the first switch group KY1 to close so that the three-phase winding 100 is switched to star connection, control the totem-pole PFC circuit 200 to enter the diode rectification state or the low-frequency switching state, and control the buck switching circuit 300 to perform buck output.

[0154] Refer to Figure 12 The driving method further includes:

[0155] S1200, according to the load of the open-winding motor, control the totem-pole PFC circuit 200 to enter the high-frequency switching state, and control the buck switching circuit 300 to perform filtering output.

[0156] The object to which the above driving method is applied is based on the motor drive control circuit of the second aspect of the embodiments of the present application. Since the circuit structure of the motor drive control circuit of the first aspect of the embodiments of the present application has been described in detail, in order to avoid repeated description, the following takes the motor drive control circuit of the first aspect of the embodiments of the present application as an example to describe the driving method in detail. It can be understood that this does not limit that the driving method of the second aspect of the embodiments of the present application can only be applied to the motor drive control circuit of the first aspect.

[0157] Taking the first rectifying component T1, the second rectifying component T2, the third rectifying component T3 and the fourth rectifying component T4 as MOSFETs as an example for illustration, the first rectifying component T1, the second rectifying component T2, the third rectifying component T3 and the fourth rectifying component T4 are all attached with anti-parallel diodes. Among them, refer to Figure 13 In step S1100, controlling the totem-pole PFC circuit 200 to enter the diode rectification state includes:

[0158] S1300, continuously turn off the first rectifying component T1, the second rectifying component T2, the third rectifying component T3 and the fourth rectifying component T4.

[0159] Since the first rectifying component T1, the second rectifying component T2, the third rectifying component T3 and the fourth rectifying component T4 are all attached with anti-parallel diodes, when the first rectifying component T1, the second rectifying component T2, the third rectifying component T3 and the fourth rectifying component T4 are all turned off, the circuit is equivalent to a bridge circuit composed of four diodes. At this time, the totem-pole PFC circuit 200 enters the diode rectification state and only performs rectification output through the diodes.

[0160] Refer to Figure 14, in step S1100, controlling the totem-pole PFC circuit 200 to enter the low-frequency switching state, including:

[0161] S1410, during the positive half-cycle of the AC input, continuously conducting the fourth rectifying component T4, continuously turning off the second rectifying component T2 and the third rectifying component T3, and conducting the first rectifying component T1 during the period when current flows through the first rectifying component T1;

[0162] S1420, during the negative half-cycle of the AC input, continuously conducting the third rectifying component T3, continuously turning off the first rectifying component T1 and the fourth rectifying component T4, and conducting the second rectifying component T2 during the period when current flows through the second rectifying component T2.

[0163] Since the first rectifying component T1, the second rectifying component T2, the third rectifying component T3, and the fourth rectifying component T4 are only switched on and off once within an AC cycle, it belongs to the low-frequency switching state. This operating state is also called the synchronous rectification state, which uses the lower on-state loss of the MOSFET to replace the on-state loss of the diode, so as to adapt to the situation of slightly larger current.

[0164] Refer to Figure 15 , in step S1200, controlling the totem-pole PFC circuit 200 to enter the high-frequency switching state, including:

[0165] S1510, during the positive half-cycle of the AC input, high-frequency switching the first rectifying component T1, continuously conducting the fourth rectifying component T4, continuously turning off the second rectifying component T2 and the third rectifying component T3;

[0166] S1520, during the negative half-cycle of the AC input, high-frequency switching the second rectifying component T2, continuously conducting the third rectifying component T3, continuously turning off the first rectifying component T1 and the fourth rectifying component T4.

[0167] The first rectifying component T1 and the fourth rectifying component T4 form a current path during the positive half-cycle. By high-frequency switching the first rectifying component T1, a chopped output is formed. The second rectifying component T2 and the third rectifying component T3 form a current path during the negative half-cycle. By high-frequency switching the second rectifying component T2, a chopped output is formed, thereby improving the voltage and current output of the totem-pole PFC circuit and adapting to the situation of high-frequency operation of the motor.

[0168] Taking the buck switching circuit 300 including the fifth switching device Q5, the sixth freewheeling device Q6, the second inductor L2, and the second capacitor C2 as an example, buck output and filtering output can be realized. Refer to Figure 16 , in step S1100, controlling the buck switching circuit 300 to perform buck output, including:

[0169] S1610, control the fifth switching device Q5 to open and close at high frequency;

[0170] S1620, when the fifth switching device Q5 is in the conducting state, control the sixth freewheeling device Q6 to turn off, and when the fifth switching device Q5 is in the off state, control the sixth freewheeling device Q6 to conduct or turn off.

[0171] Since the fifth switching device Q5 opens and closes at high frequency, the buck switching circuit 300 is equivalent to a buck circuit, realizing buck output. Among them, the sixth freewheeling device Q6 plays a freewheeling role in the buck circuit. Therefore, the sixth freewheeling device Q6 can be a controllable switch tube or an uncontrollable diode.

[0172] Refer to Figure 17 , in step S1200, control the buck switching circuit 300 to perform filtering output, including:

[0173] S1710, control the fifth switching device Q5 to conduct continuously and control the sixth freewheeling device Q6 to turn off continuously.

[0174] At this time, the buck switching circuit 300 is equivalent to an LC filter circuit. The output of the totem-pole PFC circuit 200 is directly input to the first power module PM1 after LC filtering. Therefore, it is applicable to the situation where the motor operates at high frequency.

[0175] According to the short-circuit switch KY3 involved in the first aspect embodiment of the present application, by closing the short-circuit switch KY3, the buck chopper circuit can be directly short-circuited, which is equivalent to the buck switching circuit 300 entering the direct output mode. This mode is similar to the filtering output mode of the buck switching circuit 300, both of which output the output of the totem-pole PFC circuit 200 to the first power module PM1 without buck processing. Therefore, the content mentioned below about the buck switching circuit 300 performing filtering output can actually be directly applied to the direct output mode, and will not be repeated below.

[0176] In the motor drive control circuit of the first aspect embodiment of the present application, in order to realize the switching of the connection mode of the three-phase winding 100, a first switch group KY1 and a second switch group KY2 are provided. Based on this structure, refer to Figure 18 , according to the operating power parameters of the open-winding motor, control the totem-pole PFC circuit 200, the buck switching circuit 300, the first switch group KY1, and the second switch group KY2 to reach at least one of the following states:

[0177] When the operating power parameter of the open-winding motor is less than the first operating power parameter, control the first switch group KY1 to close and the second switch group KY2 to open to switch the three-phase winding 100 into a star connection, and control the totem-pole PFC circuit 200 to enter the diode rectification state and control the buck switching circuit 300 to perform buck output;

[0178] The operating power parameter of the open-winding motor is greater than the first operating power parameter and less than the second power operating parameter. Control the first switch group KY1 to close and the second switch group KY2 to open so that the three-phase winding 100 is switched to a star connection, and control the totem pole PFC circuit 200 to enter the low-frequency switching state, and control the buck switch circuit 300 to perform buck output;

[0179] The operating power parameter of the open-winding motor is greater than the second operating power parameter and less than the third power operating parameter. Control the first switch group KY1 to close and the second switch group KY2 to open so that the three-phase winding 100 is switched to a star connection, and control the totem pole PFC circuit 200 to enter the high-frequency switching state, and control the buck switch circuit 300 to perform filtering output;

[0180] The operating power parameter of the open-winding motor is greater than the third operating power parameter and less than the fourth power operating parameter. Control the first switch group KY1 to open and the second switch group KY2 to close so that the three-phase winding 100 is switched to a delta connection, and control the totem pole PFC circuit 200 to enter the high-frequency switching state, and control the buck switch circuit 300 to perform filtering output;

[0181] The operating power parameter of the open-winding motor is greater than the fourth power operating parameter. The first switch group KY1 is opened and the second switch group KY2 is opened so that the three-phase winding 100 is switched to an open-winding connection, and control the totem pole PFC circuit 200 to enter the high-frequency switching state, and control the buck switch circuit 300 to perform filtering output.

[0182] The parameters corresponding to the first operating power parameter, the second operating power parameter, the third operating power parameter, and the fourth operating power parameter are related to the operating conditions of the motor. For example, this parameter can be the current of the motor, the operating frequency of the motor, or the operating power of the motor. It can be understood that under the same operating conditions of the open-winding motor, the current of the motor, the operating frequency of the motor, and the operating power of the motor are positively correlated. In one embodiment, the parameter values corresponding to the first operating power parameter, the second operating power parameter, the third operating power parameter, and the fourth operating power parameter can be set to increase in sequence, as Figure 18 shown.

[0183] A third aspect of an embodiment of the present application provides a circuit board, including the motor drive control circuit of the first aspect of the embodiment. By carrying the motor drive control circuit of the first aspect in the form of a circuit board, it can be conveniently installed in a variable-frequency motor to achieve drive control. Based on the open-winding motor, by controlling the switching of the first switch group KY1, the switching of the operating state of the totem PFC circuit 200, and the switching of the operating state of the buck switch circuit 300, different drive modes can be realized corresponding to various loads of the open-winding motor. For example, when the open-winding motor operates at a low frequency, by closing the first switch group KY1, the connection mode of the three-phase windings is switched to a star connection, and at the same time, the totem-pole PFC circuit 200 is controlled to operate in a diode rectification state or a low-frequency switching state, and the buck switch circuit 300 is controlled to operate in a buck output state. In this way, the access loss of the second power module PM2 can be avoided, and at the same time, the first power module PM1 can also obtain a lower supply voltage, thereby reducing the inverter conversion loss in the first power module PM1, enabling the open-winding motor to obtain a higher energy efficiency ratio under the low-frequency operation state and meeting the energy-saving requirements.

[0184] A fourth aspect of an embodiment of the present application provides an air conditioner, including the circuit board of the third aspect above. Installing the circuit board of the second aspect above in the air conditioner to drive the compressor of the air conditioner to work and achieve the variable-frequency control of the air conditioner. Therefore, based on the fact that the motor of the air conditioner is an open-winding motor, by controlling the switching of the first switch group KY1, the switching of the operating state of the totem PFC circuit 200, and the switching of the operating state of the buck switch circuit 300, different drive modes can be realized corresponding to various loads of the open-winding motor. For example, when the open-winding motor operates at a low frequency, by closing the first switch group KY1, the connection mode of the three-phase windings is switched to a star connection, and at the same time, the totem-pole PFC circuit 200 is controlled to operate in a diode rectification state or a low-frequency switching state, and the buck switch circuit 300 is controlled to operate in a buck output state. In this way, the access loss of the second power module PM2 can be avoided, and at the same time, the first power module PM1 can also obtain a lower supply voltage, thereby reducing the inverter conversion loss in the first power module PM1, enabling the open-winding motor to obtain a higher energy efficiency ratio under the low-frequency operation state and meeting the energy-saving requirements.

[0185] Since the air conditioner in this embodiment has the control device 1000 in any of the above embodiments, the air conditioner in this embodiment has the hardware structure of the control device 1000 in the above embodiments, and can enable the control processor 1001 in the control device 1000 to call the control program of the air conditioner stored in the memory 1002 to implement the drive method of the second aspect of the embodiment of the present application.

[0186] In addition, an embodiment of the present application further provides a computer-readable storage medium storing computer-executable instructions, which are executed by one or more control processors 1001, for example, by Figure 10 one of the control processors 1001 therein, enabling the one or more control processors 1001 to execute the refrigeration method of the refrigeration device in the above method embodiment. For example, execute the Figure 11 method step S1100 in Figure 12 method step S1200 in Figure 13 method step S1300 in Figure 14 method steps S1410 to S1420 in Figure 15 method steps S1510 to S1520 in Figure 16 method steps S1610 to S1620 in Figure 17 and method step S1710 in

[0187] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separated, that is, they may be located in one place or distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0188] Those of ordinary skill in the art can understand that all or some of the steps and systems in the methods disclosed above can be implemented as software, firmware, hardware, and their appropriate combinations. Some physical components or all physical components can be implemented as software executed by a processor, such as a central processing unit, a digital signal processor, or a microprocessor, or implemented as hardware, or implemented as an integrated circuit, such as an application-specific integrated circuit. Such software can be distributed on a computer-readable medium, which can include a computer storage medium (or non-transitory medium) and a communication medium (or transitory medium). As is well known to those of ordinary skill in the art, the term computer storage medium includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information, such as computer-readable instructions, data structures, program modules, or other data. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disk (DVD) or other optical disk storage, magnetic cassette, tape, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store the desired information and can be accessed by a computer. In addition, as is well known to those of ordinary skill in the art, a communication medium typically includes computer-readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transmission mechanism, and can include any information delivery medium.

[0189] The above is a specific description of the preferred embodiment of the present application. However, the present application is not limited to the above embodiments. Those skilled in the art can make various equivalent deformations or substitutions without departing from the spirit of the present application, and these equivalent deformations or substitutions are all included within the scope defined by the claims of the present application.

Claims

1. A motor drive control circuit for driving an open-winding motor having three-phase windings, one end of each winding forming a first three-phase lead-out wire group, and the other end of each winding forming a second three-phase lead-out wire group, characterized in that, The motor drive control circuit includes: A first power module, connected to the first three-phase lead-out wire group; A second power module, connected to the second three-phase lead-out wire group; A first switch group, connected to the second three-phase lead-out wire group, for switching the three-phase winding between star connection and open winding connection; A controller, respectively connected to the first power module, the second power module and the first switch group; A totem pole PFC circuit, the controller is connected to the totem pole PFC circuit to control the totem pole PFC circuit to reach at least one of the following states: Diode rectification state, low-frequency switching state and high-frequency switching state; A buck switch circuit, the totem pole PFC circuit, the buck switch circuit and the three-phase winding are connected in sequence, and the controller is connected to the buck switch circuit to control the output voltage of the buck switch circuit; A second switch group, the second switch group is respectively connected to the first three-phase lead-out wire group and the second three-phase lead-out wire group, the first switch group is opened, the second switch group is closed, and the three-phase winding is switched to delta connection; The controller is used to control the totem pole PFC circuit, the buck switch circuit, the first switch group and the second switch group to reach at least one of the following states according to the operating power parameters of the open winding motor: When the operating power parameter of the open winding motor is less than the first operating power parameter, control the first switch group to close and the second switch group to open so that the stator winding of the open winding motor is switched to star connection, and control the totem pole PFC circuit to enter the diode rectification state, and control the buck switch circuit to perform buck output; When the operating power parameter of the open winding motor is greater than the first operating power parameter and less than the second operating power parameter, control the first switch group to close and the second switch group to open so that the stator winding of the open winding motor is switched to star connection, and control the totem pole PFC circuit to enter the low-frequency switching state, and control the buck switch circuit to perform buck output; When the operating power parameter of the open winding motor is greater than the second operating power parameter and less than the third operating power parameter, control the first switch group to close and the second switch group to open so that the stator winding of the open winding motor is switched to star connection, and control the totem pole PFC circuit to enter the high-frequency switching state, and control the buck switch circuit to perform filtering output; When the operating power parameter of the open winding motor is greater than the third operating power parameter and less than the fourth power operating parameter, control the first switch group to open and the second switch group to close so that the stator winding of the open winding motor is switched to delta connection, and control the totem pole PFC circuit to enter the high-frequency switching state, and control the buck switch circuit to perform filtering output; The operating power parameter of the open-winding motor is greater than the fourth power operating parameter. Control the first switch group to disconnect and the second switch group to disconnect so that the stator winding of the open-winding motor is switched to an open-winding connection, and control the totem-pole PFC circuit to enter the high-frequency switching state, and control the buck switch circuit to perform filtering output.

2. The motor drive control circuit according to claim 1, characterized in that The totem-pole PFC circuit further includes a first inductor, a first capacitor, and a bridge circuit. The AC input terminal, the first inductor, the bridge circuit, and the first capacitor are connected in sequence, and the controller is connected to the bridge circuit.

3. The motor drive control circuit according to claim 2, wherein The bridge circuit includes a first bridge arm unit and a second bridge arm unit. The first bridge arm unit includes a first rectifying component and a second rectifying component connected in series in the same direction. The second bridge arm unit includes a third rectifying component and a fourth rectifying component connected in series in the same direction. The first capacitor is connected to the output terminal of the bridge circuit and is in parallel with the first bridge arm unit. The first rectifying component, the second rectifying component, the third rectifying component, and the fourth rectifying component are respectively connected to the controller.

4. The motor drive control circuit according to claim 3, wherein The first rectifying component, the second rectifying component, the third rectifying component, and the fourth rectifying component are semiconductor switch devices, and reverse-parallel diodes are provided for the first rectifying component, the second rectifying component, the third rectifying component, and the fourth rectifying component.

5. The motor drive control circuit according to claim 1, wherein, The buck switch circuit includes a buck chopper circuit. The buck chopper circuit includes a fifth switching device, a sixth freewheeling device, a second inductor, and a second capacitor. The output terminal of the totem-pole PFC circuit, the fifth switching device, the sixth freewheeling device, and the reference ground are connected in sequence. The connection point between the fifth switching device and the sixth freewheeling device, the second inductor, the second capacitor, and the reference ground are connected in sequence. The connection point between the second inductor and the second capacitor is connected to the first power module.

6. The motor drive control circuit according to claim 5, characterized in that, The buck switch circuit further includes a short-circuit switch, and the short-circuit switch is in parallel with the buck chopper circuit.

7. A driving method for driving an open-winding motor having a three-phase winding, one end of each phase of the winding forming a first three-phase lead-out wire group, and the other end of each phase of the winding forming a second three-phase lead-out wire group, characterized in that, The motor drive control circuit includes: A first power module, connected to the first three-phase lead-out wire group; A second power module, connected to the second three-phase lead-out wire group; A first switch group, connected to the second three-phase lead-out wire group, for switching the three-phase winding between a star connection and an open-winding connection; A totem-pole PFC circuit, for achieving at least one of the following states: Diode rectification state, low-frequency switching state, and high-frequency switching state; A buck switch circuit, the totem-pole PFC circuit, the buck switch circuit, and the three-phase winding are connected in sequence; A second switch group, the second switch group is respectively connected to the first three-phase lead-out wire group and the second three-phase lead-out wire group. When the first switch group is open and the second switch group is closed, the three-phase winding is switched to a delta connection; The driving method includes: According to the operating power parameter of the open-winding motor, control the totem-pole PFC circuit, the buck switch circuit, the first switch group, and the second switch group to achieve at least one of the following states: The operating power parameter of the open-winding motor is less than the first operating power parameter. Control the first switch group to close and the second switch group to open so that the stator winding of the open-winding motor is switched to a star connection, and control the totem-pole PFC circuit to enter the diode rectification state, and control the buck switch circuit to perform buck output; The operating power parameter of the open-winding motor is greater than the first operating power parameter and less than the second operating power parameter. Control the first switch group to close and the second switch group to open so that the stator winding of the open-winding motor is switched to a star connection, and control the totem-pole PFC circuit to enter the low-frequency switching state, and control the buck switch circuit to perform buck output; The operating power parameter of the open-winding motor is greater than the second operating power parameter and less than the third operating power parameter. Control the first switch group to close and the second switch group to open so that the stator winding of the open-winding motor is switched to a star connection, and control the totem-pole PFC circuit to enter the high-frequency switching state, and control the buck switch circuit to perform filtering output; The operating power parameter of the open-winding motor is greater than the third operating power parameter and less than the fourth power operating parameter. Control the first switch group to open and the second switch group to close so that the stator winding of the open-winding motor is switched to a delta connection, and control the totem-pole PFC circuit to enter the high-frequency switching state, and control the buck switch circuit to perform filtering output; The operating power parameter of the open-winding motor is greater than the fourth power operating parameter. Control the first switch group to open and the second switch group to open so that the stator winding of the open-winding motor is switched to an open-winding connection, and control the totem-pole PFC circuit to enter the high-frequency switching state, and control the buck switch circuit to perform filtering output.

8. The driving method according to claim 7, wherein The totem-pole PFC circuit includes a first inductor, a first capacitor and a bridge circuit. The first inductor, the bridge circuit and the first capacitor are connected in sequence. The bridge circuit includes a first bridge arm unit and a second bridge arm unit. The first bridge arm unit includes a first rectifying component and a second rectifying component connected in series in the same direction. The second bridge arm unit includes a third rectifying component and a fourth rectifying component connected in series in the same direction. The first capacitor is connected to the output end of the bridge circuit and is in parallel with the first bridge arm unit; The control for the totem-pole PFC circuit to enter the diode rectification state includes: Continuously turn off the first rectifying component, the second rectifying component, the third rectifying component and the fourth rectifying component.

9. The driving method according to claim 7, characterized in that, The totem-pole PFC circuit includes a first inductor, a first capacitor and a bridge circuit. The first inductor, the bridge circuit and the first capacitor are connected in sequence. The bridge circuit includes a first bridge arm unit and a second bridge arm unit. The first bridge arm unit includes a first rectifying component and a second rectifying component connected in series in the same direction. The second bridge arm unit includes a third rectifying component and a fourth rectifying component connected in series in the same direction. The first capacitor is connected to the output end of the bridge circuit and is in parallel with the first bridge arm unit; The control for the totem-pole PFC circuit to enter the low-frequency switching state includes: During the positive half - cycle of the AC input, the fourth rectifying component is continuously turned on, the second rectifying component and the third rectifying component are continuously turned off, and the first rectifying component is turned on during the time period when current flows through the first rectifying component; During the negative half - cycle of the AC input, the third rectifying component is continuously turned on, the first rectifying component and the fourth rectifying component are continuously turned off, and the second rectifying component is turned on during the time period when current flows through the second rectifying component.

10. The driving method according to claim 7, characterized in that, The driving method further includes: According to the load of the open - winding motor, controlling the totem - pole PFC circuit to enter the high - frequency switching state and controlling the buck - switching circuit to perform filtering output.

11. The driving method according to claim 10, wherein The totem - pole PFC circuit includes a first inductor, a first capacitor, and a bridge circuit. The first inductor, the bridge circuit, and the first capacitor are connected in sequence. The bridge circuit includes a first bridge - arm unit and a second bridge - arm unit. The first bridge - arm unit includes a first rectifying component and a second rectifying component connected in series in the same direction. The second bridge - arm unit includes a third rectifying component and a fourth rectifying component connected in series in the same direction. The first capacitor is connected to the output terminal of the bridge circuit and is in parallel with the first bridge - arm unit; The controlling the totem - pole PFC circuit to enter the high - frequency switching state includes: During the positive half - cycle of the AC input, the first rectifying component is switched on and off at high frequency, the fourth rectifying component is continuously turned on, and the second rectifying component and the third rectifying component are continuously turned off; During the negative half - cycle of the AC input, the second rectifying component is switched on and off at high frequency, the third rectifying component is continuously turned on, and the first rectifying component and the fourth rectifying component are continuously turned off.

12. The driving method according to claim 7, characterized in that The buck - switching circuit includes a buck - chopper circuit. The buck - chopper circuit includes a fifth switching device, a sixth free - wheeling device, a second inductor, and a second capacitor. The output terminal of the totem - pole PFC circuit, the fifth switching device, the sixth free - wheeling device, and the reference ground are connected in sequence. The connection point between the fifth switching device and the sixth free - wheeling device, the second inductor, the second capacitor, and the reference ground are connected in sequence. The connection point between the second inductor and the second capacitor is connected to the first power module; The controlling the buck - switching circuit to perform buck output includes: Controlling the fifth switching device to be switched on and off at high frequency; In the on - state of the fifth switching device, controlling the sixth free - wheeling device to be turned off. In the off - state of the fifth switching device, controlling the sixth free - wheeling device to be turned on or off.

13. The driving method according to claim 12, characterized in that, The driving method further includes: According to the load of the open - winding motor, controlling the totem - pole PFC circuit to enter the high - frequency switching state and controlling the buck - switching circuit to perform filtering output; The controlling the buck - switching circuit to perform filtering output includes: Controlling the fifth switching device to be continuously turned on and controlling the sixth free - wheeling device to be continuously turned off.

14. The driving method according to claim 12, characterized in that, The buck - switching circuit further includes a short - circuit switch, and the short - circuit switch is in parallel with the buck - chopper circuit; The driving method further includes: According to the load of the open - winding motor, controlling the totem - pole PFC circuit to enter the high - frequency switching state and controlling the short - circuit switch to be closed.

15. Circuit board, characterized in that, including the motor drive control circuit according to any one of claims 1 to 6.

16. Air conditioner, characterized in that, including the circuit board according to claim 15; or including at least one processor and a memory for communicatively connecting with the at least one processor; the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to execute the driving method according to any one of claims 7 to 14.

17. A computer-readable storage medium, characterized in that, the computer-readable storage medium stores computer-executable instructions for causing a computer to execute the driving method according to any one of claims 7 to 14.

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