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

Abstract

The present invention discloses a drive control circuit, a drive control method, a circuit board and an air conditioner. The drive control circuit includes a first drive circuit, a switch component, a second drive circuit, a first power supply circuit and a second power supply circuit. By setting the switch component, the connection mode of the three-phase windings can be switched according to different operating frequencies of the motor, thereby improving the operating efficiency of the motor. By setting the first power supply circuit and the second power supply circuit, different power supply voltages can be provided for the first drive circuit and the second drive circuit respectively. The first drive circuit and the second drive circuit then provide corresponding drive voltages to the three-phase windings when the three-phase windings are in different connection states, so that suitable drive voltages can be obtained when the three-phase windings are in different connection states, so as to achieve efficient operation of the motor in different connection modes.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioners, and more particularly, to a drive control circuit, a drive control method, a circuit board, an air conditioner and a storage medium. Background Art

[0002] Most of the variable-frequency compressors of existing variable-frequency air conditioners use permanent magnet motors as drive motors. Affected by the operating requirements of variable-frequency air conditioners, the three-phase windings of permanent magnet motors usually need to be switched between star connection and delta connection. When in different connection modes, the operating frequencies of the motors are different, and thus the drive voltages required for the three-phase windings are also different. However, the DC bus voltage cannot simultaneously meet the drive voltage requirements of the motor when operating in different connection modes, and it is impossible to achieve efficient operation of the motor in different connection modes. Summary of the Invention

[0003] The present invention aims to at least solve one of the technical problems existing in the prior art. To this end, embodiments of the present invention provide a drive control circuit, a drive control method, a circuit board, an air conditioner and a storage medium, which can achieve efficient operation of the motor in different connection modes.

[0004] In a first aspect, an embodiment of the present invention provides a drive control circuit for driving an open-winding motor having three-phase windings. One end of each phase of the winding forms a first three-phase outgoing line group, and the other end of each phase of the winding forms a second three-phase outgoing line group. The drive control circuit includes:

[0005] A switch assembly including a first switch group and a second switch group. The first switch group is connected to the first three-phase outgoing line group, and the second switch group is respectively connected to the first three-phase outgoing line group and the second three-phase outgoing line group. When the first switch group is closed and the second switch group is open, the three-phase windings are switched to star connection. When the first switch group is open and the second switch group is closed, the three-phase windings are switched to delta connection;

[0006] A first drive circuit connected to the second three-phase outgoing line group for providing a first drive voltage to the three-phase windings in a star connection state or a delta state;

[0007] A second drive circuit connected to the first three-phase outgoing line group for providing a third drive voltage to the three-phase windings in a delta connection state;

[0008] A first power supply circuit connected to the first drive circuit for providing a first power supply voltage to the first drive circuit;

[0009] A second power supply circuit connected to the second drive circuit for providing a second power supply voltage to the second drive circuit.

[0010] The drive control circuit provided by the embodiment of the present invention has at least the following beneficial effects: By setting the switch component, the connection mode of the three-phase windings can be switched according to different operating frequencies of the motor, improving the operating efficiency of the motor; By setting the first power supply circuit and the second power supply circuit, different power supply voltages can be provided for the first drive circuit and the second drive circuit respectively. The first drive circuit and the second drive circuit then provide corresponding drive voltages to the three-phase windings when the three-phase windings are in different connection states, so that suitable drive voltages can be obtained when the three-phase windings are in different connection states, so as to achieve efficient operation of the motor in different connection modes.

[0011] In some embodiments of the present invention, the first power supply circuit includes a buck circuit.

[0012] In the above technical solution, the first power supply circuit includes a buck circuit, which can provide a lower power supply voltage for the first drive circuit.

[0013] In some embodiments of the present invention, the second power supply circuit includes a boost circuit.

[0014] In the above technical solution, the second power supply circuit includes a boost circuit, which can provide a higher power supply voltage for the second drive circuit.

[0015] In some embodiments of the present invention, the first power supply circuit and the second power supply circuit are grounded and arranged on a common bus.

[0016] In the above technical solution, the first power supply circuit and the second power supply circuit are grounded and arranged on a common bus, which is beneficial to improving the working stability.

[0017] In some embodiments of the present invention, both the first switch group and the second switch group are disconnected, and the three-phase windings are switched to an open winding connection; the first drive circuit is further configured to provide a fourth drive voltage to the three-phase windings in the open winding connection state, and the second drive circuit is further configured to provide a fifth drive voltage to the three-phase windings in the open winding connection state.

[0018] In the above technical solution, when both the first switch group and the second switch group are disconnected, the three-phase windings are switched to an open winding connection. The first drive circuit also provides a fourth drive voltage to the three-phase windings, and the second drive circuit also provides a fifth drive voltage to the three-phase windings, so that suitable drive voltages can be obtained when the three-phase windings are in the open winding connection state, so as to achieve efficient operation of the motor in different connection modes.

[0019] In some embodiments of the present invention, during the process of switching the three-phase windings between the star connection and the delta connection, the second drive circuit provides a sixth drive voltage to the three-phase windings, and the sixth drive voltage is used to keep the motor running during the switching process of the connection state of the three-phase windings.

[0020] In the above technical solution, the switch assembly is generally mechanical, and the action of closing or opening it requires a certain period of time to complete. When using the existing solution to switch the connection method, the permanent magnet motor needs to be shut down briefly, thus affecting the normal operation of the compressor. Therefore, when switching the connection method of the three-phase windings, the second drive circuit can provide a sixth drive voltage to the three-phase windings during the switching process of the connection state of the three-phase windings to simulate the voltage environment in which the first switch group and the second switch group are located during the switching process. Therefore, when switching the connection method, even if the first switch group or the second switch group changes the opening and closing state, the motor still operates normally, and the non-stop switching of the connection method of the motor's three-phase windings can be realized without affecting the normal operation of the compressor.

[0021] In some embodiments of the present invention, the sixth drive voltage is the neutral point voltage when the three-phase windings are in the star connection state, or the three-phase voltage when the three-phase windings are in the delta connection state.

[0022] In the above technical solution, the sixth drive voltage being the neutral point voltage when the three-phase windings are in the star connection state can simulate the voltage environment when the three-phase windings are in the star connection; the sixth drive voltage being the three-phase voltage when the three-phase windings are in the delta connection state can simulate the voltage environment when the three-phase windings are in the delta connection.

[0023] In some embodiments of the present invention, during the process of switching the three-phase windings between the delta connection and the open winding connection, the second drive circuit also provides a seventh drive voltage to the three-phase windings, and the seventh drive voltage is used to keep the motor running during the switching process of the connection state of the three-phase windings.

[0024] In the above technical solution, the second drive circuit also provides a seventh drive voltage to the three-phase windings, which can simulate the voltage environment in which the second switch group is located during the process of switching the three-phase windings between the delta connection and the open winding connection. Therefore, when switching between the delta connection and the open winding connection, even if the second switch group changes the opening and closing state, the motor still operates normally, and the non-stop switching of the connection method of the motor's three-phase windings can be realized without affecting the normal operation of the compressor.

[0025] In some embodiments of the present invention, the seventh driving voltage is the three-phase voltage when the three-phase windings are in the delta connection state.

[0026] In the above technical solution, the seventh driving voltage is the three-phase voltage when the three-phase windings are in the delta connection state, which can simulate the voltage environment when the three-phase windings are in the delta connection.

[0027] In some embodiments of the present invention, the first switch group includes a first switch and a second switch, the first three-phase outgoing line group includes a first pin, a second pin, and a third pin, the first switch is respectively connected to the first pin and the second pin, and the second switch is respectively connected to the second pin and the third pin.

[0028] In the above technical solution, the first switch group includes a first switch and a second switch. When the first switch and the second switch are both closed and the second switch is in the open state, at this time, the first pin, the second pin, and the third pin are connected to each other, so that the three-phase windings are in the star connection state.

[0029] In some embodiments of the present invention, the first switch group includes a first switch, a second switch, and a third switch, the first three-phase outgoing line group includes a first pin, a second pin, and a third pin, one ends of the first switch, the second switch, and the third switch are connected to each other, and the other ends of the first switch, the second switch, and the third switch are respectively connected to the first pin, the second pin, and the third pin.

[0030] In the above technical solution, the first switch group includes a first switch, a second switch, and a third switch. When the first switch, the second switch, and the third switch are all closed and the second switch group is in the open state, at this time, the first pin, the second pin, and the third pin are connected to each other, so that the three-phase windings are in the star connection state.

[0031] In some embodiments of the present invention, the second switch group includes a third switch, a fourth switch, and a fifth switch, the three-phase windings include a first-phase winding, a second-phase winding, and a third-phase winding, the first-phase winding includes a first pin and a sixth pin, the second-phase winding includes a second pin and a fifth pin, the third-phase winding includes a third pin and a fourth pin, the first three-phase outgoing line group includes a first pin, a second pin, and a third pin, the second three-phase outgoing line group includes a fourth pin, a fifth pin, and a sixth pin, the third switch is respectively connected to the second pin and the sixth pin, the fourth switch is respectively connected to the third pin and the fifth pin, and the fifth switch is respectively connected to the first pin and the fourth pin.

[0032] In the above technical solution, the second switch group includes a third switch, a fourth switch, and a fifth switch. When the third switch, the fourth switch, and the fifth switch are closed simultaneously, and the first switch group is in an open state, at this time, the second pin and the sixth pin are connected to each other, the third pin and the fifth pin are connected to each other, and the first pin and the fourth pin are connected to each other, so that the three-phase windings are connected in a triangle.

[0033] In some embodiments of the present invention, the buck circuit is a buck chopper circuit. The buck chopper circuit includes a first switch tube, a first freewheeling element, a first inductor, a first capacitor, and a first diode. The drain of the first switch tube, the source of the first switch tube, and the first inductor are connected in series in sequence and then connected to the first drive circuit. The source of the first switch tube, the first freewheeling element, and the reference ground are connected in series in sequence. The source of the first switch tube, the first inductor, the first capacitor, and the reference ground are connected in series in sequence. The first diode is anti-parallel connected across the first switch tube.

[0034] In the above technical solution, when the second switch tube is controlled to be turned off, when the first switch tube is turned on, the power supply for power supply charges the first inductor and simultaneously charges the first capacitor to provide electrical energy for the first drive circuit. When the first switch tube is turned off, the first inductor discharges through the second diode, and the current of the first inductor decreases linearly. The electrical energy output to the first drive circuit is maintained by the first capacitor. Therefore, the voltage output to the first drive circuit is lower than the voltage provided by the power supply for power supply, achieving a buck effect.

[0035] In some embodiments of the present invention, the boost circuit is a boost chopper circuit or a totem pole circuit.

[0036] In some embodiments of the present invention, the boost chopper circuit includes a second freewheeling element, a fourth switch tube, a second inductor, a second capacitor, and a fourth diode. The second inductor and the second freewheeling element are connected in series in sequence and then connected to the second drive circuit. The second inductor, the drain of the fourth switch tube, the source of the fourth switch tube, and the reference ground are connected in series in sequence. The second freewheeling element, the second capacitor, and the reference ground are connected in series in sequence. The fourth diode is anti-parallel connected across the fourth switch tube.

[0037] In the above technical solution, when the third switch tube is controlled to be turned off, when the fourth switch tube is turned on, the power supply for power supply charges the second inductor. When the fourth switch tube is turned off, the second power supply component charges the second capacitor. Therefore, the electrical energy finally output to the second drive circuit is provided by the second capacitor and the second inductor simultaneously. Therefore, the voltage output to the second drive circuit is higher than the voltage provided by the power supply for power supply, achieving a boost effect.

[0038] In some embodiments of the present invention, the first power supply circuit further includes a first power supply group, and the first power supply group is connected to the buck circuit.

[0039] In the above technical solution, by providing the first power supply group, an input voltage can be provided for the buck circuit.

[0040] In some embodiments of the present invention, the second power supply circuit further includes a second power supply group, and the second power supply group is connected to the boost circuit.

[0041] In the above technical solution, by providing the second power supply group, an input voltage can be provided for the boost circuit.

[0042] In some embodiments of the present invention, both the first drive circuit and the second drive circuit include a first bridge arm, a second bridge arm, and a third bridge arm connected in parallel with each other. The first bridge arm, the second bridge arm, and the third bridge arm each include two fifth switching tubes connected in series, and a fifth diode is anti-parallel connected to the fifth switching tube.

[0043] In the above technical solution, the first bridge arm, the second bridge arm, and the third bridge arm form a three-phase bridge structure. By controlling the on-off states of the six fifth switching tubes, the first drive circuit and the second drive circuit can respectively output a first drive voltage and a third drive voltage.

[0044] In a second aspect, an embodiment of the present invention further provides a drive control method, which is applied to a drive control circuit. The drive control circuit is used to drive an open-winding motor with three-phase windings. One end of each phase of the windings forms a first three-phase outgoing line group, and the other end of each phase of the windings forms a second three-phase outgoing line group. The drive control circuit includes:

[0045] A switch assembly, including a first switch group and a second switch group. The first switch group is connected to the first three-phase outgoing line group, and the second switch group is respectively connected to the first three-phase outgoing line group and the second three-phase outgoing line group. When the first switch group is closed and the second switch group is open, the three-phase windings are switched to star connection. When the first switch group is open and the second switch group is closed, the three-phase windings are switched to delta connection;

[0046] A first drive circuit, connected to the second three-phase outgoing line group;

[0047] A second drive circuit, connected to the first three-phase outgoing line group;

[0048] A first power supply circuit, connected to the first drive circuit;

[0049] A second power supply circuit, connected to the second drive circuit;

[0050] The drive control method includes:

[0051] Controlling the opening and closing of the switch assembly to switch the three-phase windings from a first connection state to a second connection state;

[0052] Control the first driving circuit and the second driving circuit to start or stop working, so that the first driving circuit or the second driving circuit provides a driving voltage to the three-phase windings in the corresponding connection state.

[0053] The driving control method provided by the embodiments of the present invention has at least the following beneficial effects: By controlling the opening and closing of the switching component to switch the three-phase windings from the first connection state to the second connection state, it is possible to realize switching the connection mode of the three-phase windings according to different operating frequencies of the motor, improving the operating efficiency of the motor; By controlling the first driving circuit and the second driving circuit to start or stop working, so that the first driving circuit or the second driving circuit provides a driving voltage to the three-phase windings in the corresponding connection state, it is possible to obtain a suitable driving voltage when the three-phase windings are in different connection states, so as to realize the efficient operation of the motor in different connection modes.

[0054] In some embodiments of the present invention, the first connection state is a delta connection, the second connection state is a star connection, and the control of the first driving circuit and the second driving circuit to start or stop working, so that the first driving circuit or the second driving circuit provides a driving voltage to the three-phase windings in the corresponding connection state, includes:

[0055] Control the first driving circuit to start working and control the second driving circuit to stop working, so that the first driving circuit provides a first driving voltage to the three-phase windings in the star connection state.

[0056] In the above technical solution, when the three-phase windings are switched from a delta connection to a star connection, the first driving circuit provides a first driving voltage to the three-phase windings, and the second driving circuit stops working, so that a suitable driving voltage can be obtained when the three-phase windings are in a star connection.

[0057] In some embodiments of the present invention, the first connection state is a star connection, the second connection state is a delta connection, and the control of the first driving circuit and the second driving circuit to start or stop working, so that the first driving circuit or the second driving circuit provides a driving voltage to the three-phase windings in the corresponding connection state, includes:

[0058] Control the first driving circuit to start working and control the second driving circuit to stop working, so that the first driving circuit provides a second driving voltage to the three-phase windings in the delta connection state;

[0059] Or,

[0060] Control the first driving circuit to stop working, and control the second driving circuit to start working, so that the second driving circuit provides a third driving voltage to the three-phase windings in the delta connection state.

[0061] In the above technical solution, when the three-phase windings are switched from the star connection to the delta connection, the second driving circuit provides a third driving voltage to the three-phase windings, and the first driving circuit stops working, so that a suitable driving voltage can be obtained when the three-phase windings are in the delta connection. In addition, the first driving circuit can also provide a second driving voltage to the three-phase windings, and the three-phase windings can also be in the delta connection.

[0062] In some embodiments of the present invention, both the first switch group and the second switch group are disconnected, the three-phase windings are switched to the open winding connection, the first connection state is the delta connection, the second connection state is the open winding connection, and controlling the first driving circuit and the second driving circuit to start or stop working so that the first driving circuit or the second driving circuit provides a driving voltage to the three-phase windings in the corresponding connection state includes:

[0063] Control the first driving circuit to start working, and control the second driving circuit to start working, so that the first driving circuit provides a fourth driving voltage to the three-phase windings in the open winding connection state, and the second driving circuit provides a fifth driving voltage to the three-phase windings in the open winding connection state.

[0064] In the above technical solution, when the three-phase windings are switched from the delta connection to the open winding connection, the first driving circuit provides a fourth driving voltage to the three-phase windings, and the second driving circuit provides a fifth driving voltage to the three-phase windings, so that a suitable driving voltage can be obtained when the three-phase windings are in the open winding connection.

[0065] In some embodiments of the present invention, both the first switch group and the second switch group are disconnected, the three-phase windings are switched to the open winding connection, the first connection state is the open winding connection, the second connection state is the delta connection, and controlling the first driving circuit and the second driving circuit to start or stop working so that the first driving circuit or the second driving circuit provides a driving voltage to the three-phase windings in the corresponding connection state includes:

[0066] Control the first driving circuit to start working, and control the second driving circuit to stop working, so that the first driving circuit provides a second driving voltage to the three-phase windings in the delta connection state;

[0067] Or,

[0068] Control the first drive circuit to stop working and control the second drive circuit to start working, so that the second drive circuit provides a third drive voltage to the three-phase windings in the delta connection state.

[0069] In the above technical solution, when the three-phase windings are switched from the open winding connection to the delta connection, the second drive circuit provides a third drive voltage to the three-phase windings, and the first drive circuit stops working, so that a suitable drive voltage can be obtained when the three-phase windings are in the delta connection. In addition, the first drive circuit can also provide a second drive voltage to the three-phase windings, and the three-phase windings can also be in the delta connection.

[0070] In some embodiments of the present invention, the drive control method further includes:

[0071] Control the second drive circuit to provide a sixth drive voltage to the three-phase windings during the switching process of the connection state of the three-phase windings.

[0072] In the above technical solution, control the second drive circuit to provide a sixth drive voltage to the three-phase windings during the switching process of the connection state of the three-phase windings to simulate the voltage environment in which the first switch group and the second switch group are located during the switching process. Therefore, when switching the connection method, even if the first switch group or the second switch group changes the on-off state, the motor still operates normally, and the non-stop switching of the connection method of the three-phase windings of the motor can be realized without affecting the normal operation of the compressor.

[0073] In some embodiments of the present invention, the first connection state is a star connection, the second connection state is a delta connection, and controlling the second drive circuit to provide a sixth drive voltage to the three-phase windings during the switching process of the connection state of the three-phase windings includes:

[0074] The three-phase windings maintain the star connection, and control the second drive circuit to output the neutral point voltage of the three-phase windings in the star connection state;

[0075] Control the first switch group to disconnect, and the second drive circuit outputs the neutral point voltage of the three-phase windings in the star connection state for a first time threshold;

[0076] Control the second drive circuit to output the three-phase voltages of the three-phase windings in the delta connection state;

[0077] Control the second switch group to close, and the second drive circuit outputs the three-phase voltages of the three-phase windings in the delta connection state for a second time threshold;

[0078] Control the first drive circuit to output a second drive voltage and control the second drive circuit to stop working.

[0079] In the above technical solution, first control the second drive circuit to simulate the neutral point voltage when the three-phase windings are in the star connection state. Even if the first switch group is disconnected, the motor can still operate in the star connection state. Then control the second drive circuit to simulate the three-phase voltages when the three-phase windings are in the delta connection state. That is, during the closing process of the second switch group, the motor can already operate in the delta connection state first, so as to achieve seamless switching.

[0080] In some embodiments of the present invention, the first connection state is the delta connection, the second connection state is the star connection, and controlling the second drive circuit to provide a sixth drive voltage to the three-phase windings during the switching process of the connection state of the three-phase windings includes:

[0081] Controlling the first drive circuit to output a second drive voltage to keep the three-phase windings in the delta connection, and controlling the second drive circuit to output the three-phase voltages when the three-phase windings are in the delta connection state;

[0082] Controlling the second switch group to disconnect, and the second drive circuit outputs the three-phase voltages when the three-phase windings are in the delta connection state for a second time threshold;

[0083] Controlling the second drive circuit to output the neutral point voltage when the three-phase windings are in the star connection state;

[0084] Controlling the first switch group to close, and the second drive circuit outputs the neutral point voltage when the three-phase windings are in the star connection state for a first time threshold;

[0085] Controlling the first drive circuit to output a first drive voltage and controlling the second drive circuit to stop working.

[0086] In the above technical solution, first control the second drive circuit to simulate the three-phase voltages when the three-phase windings are in the delta connection state. Even if the second switch group is disconnected, the motor can still operate in the delta connection state. Then control the second drive circuit to simulate the neutral point voltage when the three-phase windings are in the star connection state. That is, during the closing process of the first switch group, the motor can already operate in the star connection state first, so as to achieve seamless switching.

[0087] In some embodiments of the present invention, both the first switch group and the second switch group are disconnected, and the three-phase windings are switched to the open winding connection. The drive control method further includes:

[0088] Controlling the second drive circuit to provide a seventh drive voltage to the three-phase windings during the switching process of the connection state of the three-phase windings.

[0089] In the above technical solution, the second driving circuit also provides a seventh driving voltage for the three-phase windings during the switching process of the connection state of the three-phase windings, which can simulate the voltage environment of the second switch group during the switching process between the delta connection and the open winding connection of the three-phase windings. Therefore, when switching between the delta connection and the open winding connection, even if the second switch group changes its on-off state, the motor still operates normally, and the non-stop switching of the connection mode of the three-phase windings of the motor can be realized without affecting the normal operation of the compressor.

[0090] In some embodiments of the present invention, the first connection state is a delta connection, the second connection state is an open winding connection, and controlling the second driving circuit to provide a seventh driving voltage for the three-phase windings during the switching process of the connection state of the three-phase windings includes:

[0091] The three-phase windings maintain the delta connection, and control the second driving circuit to output the three-phase voltages of the three-phase windings in the delta connection state;

[0092] Control the second switch group to disconnect, and the second driving circuit outputs the three-phase voltages of the three-phase windings in the delta connection state for a second time threshold;

[0093] Control the first driving circuit to output a fourth driving voltage, and control the second driving circuit to output a fifth driving voltage.

[0094] In the above technical solution, first control the second driving circuit to simulate the three-phase voltages of the three-phase windings in the delta connection state. Even if the second switch group is disconnected, the three-phase windings can still operate in the delta connection state, thus realizing non-stop switching.

[0095] In some embodiments of the present invention, the first connection state is an open winding connection, the second connection state is a delta connection, and controlling the second driving circuit to provide a seventh driving voltage for the three-phase windings during the switching process of the connection state of the three-phase windings includes:

[0096] The three-phase windings maintain the open winding connection, and control the second driving circuit to output the three-phase voltages of the three-phase windings in the delta connection state;

[0097] Control the second switch group to close, and the second driving circuit outputs the three-phase voltages of the three-phase windings in the delta connection state for a second time threshold;

[0098] Control the second driving circuit to stop working, the first driving circuit to output a second driving voltage, or control the first driving circuit to stop working, and the second driving circuit to output a third driving voltage.

[0099] In the above technical solution, first control the second drive circuit to simulate the three-phase voltage when the three-phase windings are in a delta connection state, that is, during the closing process of the second switch group, the three-phase windings can already operate in a delta connection state first, so as to achieve seamless switching.

[0100] In some embodiments of the present invention, the first connection state is a star connection, the second connection state is a delta connection, and the controlling the second drive circuit to provide a sixth drive voltage to the three-phase windings during the switching process of the connection state of the three-phase windings includes:

[0101] Keep the three-phase windings in the star connection, and control the second drive circuit to output the neutral point voltage of the three-phase windings in the star connection state;

[0102] Control the first switch group to disconnect, and the second drive circuit outputs the neutral point voltage of the three-phase windings in the star connection state for a first time threshold;

[0103] Control the second drive circuit to output a third drive voltage, and the first drive circuit to output the three-phase voltage of the three-phase windings in the delta connection state;

[0104] Control the second switch group to close, and the second drive circuit outputs the third drive voltage, and the first drive circuit outputs the three-phase voltage of the three-phase windings in the delta connection state for a second time threshold;

[0105] Control the first drive circuit to stop working.

[0106] In the above technical solution, first control the second drive circuit to simulate the neutral point voltage of the three-phase windings in the star connection state, so that even if the first switch group is disconnected, the motor can still operate in the star connection state; then control the first drive circuit to simulate the three-phase voltage of the three-phase windings in the delta connection state, and the second drive circuit outputs the third drive voltage, that is, during the closing process of the second switch group, the motor can already operate in the delta connection state first, so as to achieve seamless switching, and after the switching is completed, the second drive circuit provides the third drive voltage to the three-phase windings in the delta connection, which can achieve the efficient operation of the motor.

[0107] In some embodiments of the present invention, the first connection state is a delta connection, the second connection state is a star connection, and the controlling the second drive circuit to provide a sixth drive voltage to the three-phase windings during the switching process of the connection state of the three-phase windings includes:

[0108] Control the second driving circuit to output a third driving voltage to keep the three-phase windings in the delta connection, and control the first driving circuit to output the three-phase voltages of the three-phase windings in the delta connection state;

[0109] Control the second switch group to disconnect, and the first driving circuit outputs the three-phase voltages of the three-phase windings in the delta connection state for a second time threshold;

[0110] Control the first driving circuit to output a first driving voltage and the second driving circuit to output the neutral point voltage of the three-phase windings in the star connection state;

[0111] Control the first switch group to close, and the first driving circuit outputs the first driving voltage and the second driving circuit outputs the neutral point voltage of the three-phase windings in the star connection state for a first time threshold;

[0112] Control the second driving circuit to stop working.

[0113] In the above technical solution, first control the first driving circuit to simulate the three-phase voltages of the three-phase windings in the delta connection state. Even if the second switch group is disconnected, the motor can still operate in the delta connection state; then control the second driving circuit to simulate the neutral point voltage of the three-phase windings in the star connection state. That is, during the closing process of the first switch group, the motor can already operate in the star connection state first, so as to achieve seamless switching. And after the switching is completed, the first driving circuit provides the first driving voltage to the three-phase windings in the delta connection, which can achieve the efficient operation of the motor.

[0114] In some embodiments of the present invention, the controlling the opening and closing of the switch assembly to switch the three-phase windings from the first connection state to the second connection state includes at least one of the following:

[0115] According to the operating frequency of the motor being lower than the first frequency threshold, control the opening and closing of the switch assembly to switch the three-phase windings from the delta connection to the star connection;

[0116] According to the operating frequency of the motor being higher than the first frequency threshold and lower than the second frequency threshold, control the opening and closing of the switch assembly to switch the three-phase windings from the star connection or the open winding connection to the delta connection;

[0117] According to the operating frequency of the motor being higher than the second frequency threshold, control the opening and closing of the switch assembly to switch the three-phase windings from the delta connection to the open winding connection;

[0118] Wherein, the first frequency threshold is less than the second frequency threshold.

[0119] In the above technical solution, by judging the operating frequency of the motor and switching the three-phase windings to the corresponding connection states according to the high or low operating frequency of the motor, the motor can operate in a connection mode adapted to the operating frequency, thereby improving the operating efficiency of the motor.

[0120] In some embodiments of the present invention, controlling the opening and closing of the switch assembly to switch the three-phase windings from the first connection state to the second connection state includes at least one of the following:

[0121] According to the operating frequency of the motor being lower than the third frequency threshold, controlling the opening and closing of the switch assembly to switch the three-phase windings from delta connection to star connection;

[0122] According to the operating frequency of the motor being higher than the fourth frequency threshold and lower than the fifth frequency threshold, controlling the opening and closing of the switch assembly to switch the three-phase windings from star connection or open winding connection to delta connection;

[0123] According to the operating frequency of the motor being higher than the sixth frequency threshold, controlling the opening and closing of the switch assembly to switch the three-phase windings from delta connection to open winding connection;

[0124] Wherein, the third frequency threshold, the fourth frequency threshold, the fifth frequency threshold, and the sixth frequency threshold increase in sequence.

[0125] In the above technical solution, through the third frequency threshold, the fourth frequency threshold, the fifth frequency threshold, and the sixth frequency threshold that increase in sequence, when judging the operating frequency of the motor, the third frequency threshold and the fourth frequency threshold can form a hysteresis interval, and the fifth frequency threshold and the sixth frequency threshold can form a hysteresis interval, thereby avoiding the phenomenon of frequent switching of the connection state of the motor and ensuring the stability of the motor operation.

[0126] In a third aspect, an embodiment of the present invention further provides a circuit board, including the drive control circuit described in the first aspect.

[0127] Therefore, by setting the switch assembly, the above circuit board can realize switching the connection mode of the three-phase windings according to different operating frequencies of the motor, thereby improving the operating efficiency of the motor; by setting the first power supply circuit and the second power supply circuit, different power supply voltages can be provided for the first drive circuit and the second drive circuit respectively, and the first drive circuit and the second drive circuit then provide corresponding drive voltages to the three-phase windings when the three-phase windings are in different connection states, so that suitable drive voltages can be obtained when the three-phase windings are in different connection states, so as to realize the efficient operation of the motor in different connection modes.

[0128] In a fourth aspect, an embodiment of the present invention further provides an air conditioner, including the circuit board described in the third aspect.

[0129] Or,

[0130] 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 drive control method described in the second aspect.

[0131] Therefore, by providing the switch assembly, the above air conditioner can switch the connection mode of the three-phase windings according to different operating frequencies of the motor, improving the operating efficiency of the motor; by providing the first power supply circuit and the second power supply circuit, different power supply voltages can be provided for the first drive circuit and the second drive circuit respectively. The first drive circuit and the second drive circuit then provide corresponding drive voltages to the three-phase windings when the three-phase windings are in different connection states, so that suitable drive voltages can be obtained when the three-phase windings are in different connection states, to achieve efficient operation of the motor in different connection modes.

[0132] In a fifth aspect, an embodiment of the present invention further provides a computer-readable storage medium storing computer-executable instructions for causing a computer to execute the drive control method described in the second aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0133] The above and / or additional aspects and advantages of the present invention will become apparent and be readily understood from the following description of the embodiments in conjunction with the accompanying drawings, where:

[0134] Figure 1 is a circuit schematic diagram of a drive control circuit provided by an embodiment of the present invention;

[0135] Figure 2 is a circuit schematic diagram of a drive control circuit provided by another embodiment of the present invention;

[0136] Figure 3 is a circuit schematic diagram of a drive control circuit provided by another embodiment of the present invention;

[0137] Figure 4 is a circuit schematic diagram of a first power supply circuit provided by an embodiment of the present invention;

[0138] Figure 5 is a circuit schematic diagram of a second power supply circuit provided by an embodiment of the present invention;

[0139] Figure 6 is a signal waveform diagram of the drive control circuit provided by an embodiment of the present invention for controlling the three-phase windings to switch from star connection to delta connection;

[0140] Figure 7 The signal waveform diagram for the drive control circuit provided by another embodiment of the present invention to control the three-phase windings to switch from star connection to delta connection;

[0141] Figure 8 The signal waveform diagram for the drive control circuit provided by an embodiment of the present invention to control the three-phase windings to switch from delta connection to open winding connection;

[0142] Figure 9 The schematic structural diagram of the first drive circuit provided by an embodiment of the present invention;

[0143] Figure 10 The schematic structural diagram of the second drive circuit provided by an embodiment of the present invention;

[0144] Figure 11 The flowchart of the drive control method provided by an embodiment of the present invention;

[0145] Figure 12 The flowchart of the supplementary steps of the drive control method provided by another embodiment of the present invention;

[0146] Figure 13 The flowchart for controlling the second drive circuit to provide the sixth drive voltage to the three-phase windings during the switching process of the connection state of the three-phase windings provided by an embodiment of the present invention;

[0147] Figure 15 The flowchart of the supplementary steps of the drive control method provided by an embodiment of the present invention;

[0148] Figure 14 The flowchart for controlling the second drive circuit to provide the sixth drive voltage to the three-phase windings during the switching process of the connection state of the three-phase windings provided by another embodiment of the present invention;

[0149] Figure 16 The flowchart for controlling the second drive circuit to provide the sixth drive voltage to the three-phase windings during the switching process of the connection state of the three-phase windings provided by another embodiment of the present invention;

[0150] Figure 17 The flowchart for controlling the second drive circuit to provide the sixth drive voltage to the three-phase windings during the switching process of the connection state of the three-phase windings provided by another embodiment of the present invention;

[0151] Figure 18 The flowchart for controlling the second drive circuit to provide the sixth drive voltage to the three-phase windings during the switching process of the connection state of the three-phase windings provided by another embodiment of the present invention;

[0152] Figure 19Flowchart for controlling a second drive circuit to provide a sixth drive voltage to a three-phase winding during a switching process of a three-phase winding connection state according to another embodiment of the present invention;

[0153] Figure 20 Schematic diagram for switching the connection mode of a three-phase winding according to the operating frequency of a motor according to an embodiment of the present invention;

[0154] Figure 21 Schematic diagram for switching the connection mode of a three-phase winding according to the operating frequency of a motor according to another embodiment of the present invention;

[0155] Figure 22 Brief schematic diagram of the structure of a circuit board according to an embodiment of the present invention;

[0156] Figure 23 Brief schematic diagram of the structure of an air conditioner according to an embodiment of the present invention;

[0157] Figure 24 Brief schematic diagram of the structure of an air conditioner according to another embodiment of the present invention. Detailed implementation manners

[0158] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings, wherein 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 drawings are exemplary only for explaining the present invention and should not be construed as limiting the present invention.

[0159] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by terms such as up, down, front, back, left, right, etc. is based on the orientation or positional relationship shown in the drawings, and is only for facilitating the description of the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present invention.

[0160] In the description of the present invention, the meaning of "at least two" is one or more, the meaning of "a plurality" is at least 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 should not be construed 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.

[0161] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above terms in the present invention in combination with the specific content of the technical solution.

[0162] Most of the variable - frequency compressors of existing variable - frequency air conditioners use permanent - magnet motors as drive motors. Affected by the operating requirements of variable - frequency air conditioners, the three - phase windings of permanent - magnet motors usually need to be switched between star connection and delta connection. When in different connection modes, the operating frequencies of the motors are different, and thus the drive voltages required for the three - phase windings are also different. However, the DC bus voltage cannot simultaneously meet the drive - voltage requirements of the motor when operating in different connection modes, and it is impossible to achieve efficient operation of the motor in different connection modes.

[0163] Based on this, the embodiments of the present invention provide a drive control circuit, a drive control method, a circuit board, an air conditioner, and a storage medium, which can achieve efficient operation of the motor in different connection modes.

[0164] The following further elaborates on the embodiments of the present invention with reference to the accompanying drawings.

[0165] Refer to Figure 1 , an embodiment of the present invention provides a drive control circuit for driving an open - winding motor with three - phase windings 100. One end of each phase winding forms a first three - phase output group 101, and the other end of each phase winding forms a second three - phase output group 102. The drive control circuit includes a first drive circuit 110, a switch component 120, a second drive circuit 130, a first power - supply circuit, and a second power - supply circuit. The switch component 120 includes a first switch group 121 and a second switch group 122. The first switch group 121 is connected to the first three - phase output group 101, and the second switch group 122 is respectively connected to the first three - phase output group 101 and the second three - phase output group 102. When the first switch group 121 is closed and the second switch group 122 is open, the three - phase windings 100 are switched to star connection. When the first switch group 121 is open and the second switch group 122 is closed, the three - phase windings 100 are switched to delta connection. When both the first switch group 121 and the second switch group 122 are open, the three - phase windings 100 are switched to open - winding connection. The first drive circuit 110 is connected to the second three - phase output group 102 and is used to provide a first drive voltage to the three - phase windings 100 in star - connection state, or a second drive voltage to the three - phase windings 100 in delta - connection state, or a fourth drive voltage to the three - phase windings 100 in open - winding connection state. The second drive circuit 130 is connected to the first three - phase output group 101 and is used to provide a third drive voltage to the three - phase windings 100 in delta - connection state, or a fifth drive voltage to the three - phase windings 100 in open - winding connection state. The first power - supply circuit is connected to the first drive circuit 110 and is used to provide a first power - supply voltage to the first drive circuit 110. The second power - supply circuit is connected to the second drive circuit 130 and is used to provide a second power - supply voltage to the second drive circuit 130.

[0166] In one embodiment, the first switch group 121 includes a first switch K1 and a second switch K2, and the three-phase winding 100 includes a three-phase winding. The leads of the first-phase winding, the second-phase winding, and the third-phase winding are led out of the motor. The two ends of the first-phase winding are respectively led out as a first lead M1 and a sixth lead M6, the two ends of the second-phase winding are respectively led out as a second lead M2 and a fifth lead M5, and the two ends of the third-phase winding are respectively led out as a third lead M3 and a fourth lead M4. Based on this, the first three-phase lead-out group 101 includes the first lead M1, the second lead M2, and the third lead M3. The first switch K1 is respectively connected to the first lead M1 and the second lead M2, and the second switch K2 is respectively connected to the second lead M2 and the third lead M3. The second switch group 122 includes a fourth switch K4, a fifth switch K5, and a sixth switch K6. The first three-phase lead-out group 101 includes the first lead M1, the second lead M2, and the third lead M3, and the second three-phase lead-out group 102 includes the fourth lead M4, the fifth lead M5, and the sixth lead M6. The fourth switch K4 is respectively connected to the second lead M2 and the sixth lead M6, the fifth switch K5 is respectively connected to the third lead M3 and the fifth lead M5, and the sixth switch K6 is respectively connected to the first lead M1 and the fourth lead M4.

[0167] Wherein, when the first switch K1 and the second switch K2 are closed simultaneously and the second switch group 122 is in an open state, at this time, the first lead M1, the second lead M2, and the third lead M3 are connected to each other, so that the three-phase winding 100 is in a star connection state. When the fourth switch K4, the fifth switch K5, and the sixth switch K6 are closed simultaneously and the first switch group 121 is in an open state, at this time, the second lead M2 and the sixth lead M6 are connected to each other, the third lead M3 and the fifth lead M5 are connected to each other, and the first lead M1 and the fourth lead M4 are connected to each other, so that the three-phase winding 100 is in a triangular connection. When the first switch K1, the second switch K2, the fourth switch K4, the fifth switch K5, and the sixth switch K6 are all open, the first lead M1, the second lead M2, the third lead M3, the fourth lead M4, the fifth lead M5, and the sixth lead M6 are powered separately, so that the three-phase winding 100 is in an open-winding connection.

[0168] Referring to Figure 2 , in one embodiment, the first switch group 121 may also include a first switch K1, a second switch K2, and a third switch K3. One ends of the first switch K1, the second switch K2, and the third switch K3 are connected to each other, and the other ends of the first switch K1, the second switch K2, and the third switch K3 are respectively connected to the first lead M1, the second lead M2, and the third lead M3. When the first switch K1, the second switch K2, and the third switch K3 are closed simultaneously and the second switch group 122 is in an open state, at this time, the first lead M1, the second lead M2, and the third lead M3 are connected to each other, and the three-phase winding 100 can also be in a star connection state.

[0169] In one embodiment, the first switch K1, the second switch K2, the third switch K3, the fourth switch K4, the fifth switch K5, and the sixth switch K6 can all be selected from electromagnetic relays, solid-state relays, contactors, or electronic switches, thus having the advantages of stable switching and low cost. In one embodiment, the first switch K1, the second switch K2, the third switch K3, the fourth switch K4, the fifth switch K5, and the sixth switch K6 are all single-pole single-throw relays. It should be added that if an electronic switch is selected, its on-resistance does not exceed 1 ohm.

[0170] Among them, when the three-phase winding 100 is in a star connection state, the motor generally operates at a low frequency, and the first driving circuit 110 provides a relatively low first driving voltage to the three-phase winding 100; when the three-phase winding 100 is in a delta connection state, the motor generally operates at an intermediate frequency, and the third driving voltage provided by the second driving circuit 130 to the three-phase winding 100 is higher than the first driving voltage; when the three-phase winding 100 is in an open winding connection state, the motor generally operates at a high frequency, and at this time, the first driving circuit 110 and the second driving circuit 130 supply power to the three-phase winding 100 simultaneously. It can be understood that the above low-frequency operation, intermediate-frequency operation, and high-frequency operation are based on relative judgments among the three connection methods, and no specific operating frequency is restricted.

[0171] In one embodiment, the buck circuit and the boost circuit are grounded and share a common bus, which is beneficial to improving the working stability. Among them, the first power supply circuit includes a buck circuit 150, the second power supply circuit includes a boost circuit 160, and the first power supply circuit and the second power supply circuit may further include a power supply component 140. The power supply component 140 is respectively connected to the buck circuit 150 and the boost circuit 160. By setting the power supply component 140, an input voltage can be provided for the buck circuit 150 and the boost circuit 160. When the three-phase winding 100 is switched to the star connection, the buck circuit 150 provides a first power supply voltage for the first driving circuit 110; when the three-phase winding 100 is switched to the delta connection, the boost circuit 160 provides a second power supply voltage for the second driving circuit 130. Therefore, with the input voltage provided by the power supply component 140 remaining unchanged, the buck circuit 150 performs a buck conversion on the power supply voltage to obtain the first power supply voltage, and the boost circuit 160 performs a boost conversion on the power supply voltage to obtain the second power supply voltage.

[0172] Among them, the number of the power supply components 140 can be one, which supplies power to the buck circuit 150 and the boost circuit 160 simultaneously. Refer to Figure 3, in one embodiment, the power supply component 140 includes a first power supply group 141 and a second power supply group 142. The first power supply circuit includes the first power supply group 141 and a buck circuit 150. The first power supply group 141 is connected to the buck circuit 150. The second power supply circuit includes the second power supply group 142 and a boost circuit 160. The second power supply group 142 is connected to the boost circuit 160. By providing the first power supply group 141 and the second power supply group 142, the buck circuit 150 and the boost circuit 160 can be powered respectively, which is beneficial to improving flexibility.

[0173] It can be understood that the above-mentioned buck circuit 150 and boost circuit 160 can be provided simultaneously or alternatively.

[0174] Refer to Figure 4 , in one embodiment, the buck circuit 150 is a buck chopper circuit. The buck circuit includes a first switching transistor Q1, a second switching transistor Q2, a first inductor L1, a first capacitor C1, a first diode D1, and a second diode D2. The positive electrode of the power supply component 140, the drain of the first switching transistor Q1, the source of the first switching transistor Q1, and the first inductor L1 are connected in series in sequence and then connected to the first driving circuit 110. The source of the first switching transistor Q1, the drain of the second switching transistor Q2, and the negative electrode of the power supply component 140 are connected in series in sequence. The source of the first switching transistor Q1, the first inductor L1, the first capacitor C1, and the negative electrode (reference ground) of the power supply component 140 are connected in series in sequence. The negative electrode of the power supply component 140 is connected to the first driving circuit 110. The first diode D1 is anti-parallel connected to the first switching transistor Q1, and the second diode D2 is anti-parallel connected to the second switching transistor Q2. Among them, the second switching transistor Q2 serves as a first freewheeling element. The first freewheeling element can also remove the second switching transistor Q2 and be separately provided as the second diode D2.

[0175] When the buck circuit 150 works, control the second switching transistor Q2 to turn off. When the first switching transistor Q1 is turned on, the power supply component 140 charges the first inductor L1 and simultaneously charges the first capacitor C1 to provide electrical energy for the first driving circuit 110. When the first switching transistor Q1 is turned off, the first inductor L1 discharges through the second diode D2, and the current of the first inductor L1 decreases linearly. The electrical energy output to the first driving circuit 110 is maintained by the first capacitor C1. Therefore, the voltage output to the first driving circuit 110 is lower than the voltage provided by the power supply component 140, achieving a buck effect.

[0176] Refer to Figure 5, in one embodiment, the boost circuit 160 is a boost chopper circuit. The boost circuit includes a third switching transistor Q3, a fourth switching transistor Q4, a second inductor L2, a second capacitor C2, a third diode D3, and a fourth diode D4. The positive electrode of the power supply assembly 140, the second inductor L2, the source electrode of the third switching transistor Q3, and the drain electrode of the first switching transistor Q1 are connected in series in sequence and then connected to the second drive circuit 130. The second inductor L2, the drain electrode of the fourth switching transistor Q4, the source electrode of the fourth switching transistor Q4, and the negative electrode (reference ground) of the power supply assembly 140 are connected in series in sequence. The drain electrode of the third switching transistor Q3, the second capacitor C2, and the negative electrode of the power supply assembly 140 are connected in series in sequence. The negative electrode of the power supply assembly 140 is connected to the second drive circuit 130. The third diode D3 is anti-parallelly connected across the third switching transistor Q3, and the fourth diode D4 is anti-parallelly connected across the fourth switching transistor Q4. Among them, the third switching transistor Q3 serves as the second freewheeling element. The second freewheeling element can also remove the third switching transistor Q3 and be separately set as the third diode D3. In addition, the boost circuit 160 can also be a totem pole circuit.

[0177] When the boost circuit operates, the third switching transistor Q3 is controlled to be turned off. When the fourth switching transistor Q4 is turned on, the power supply assembly 140 charges the second inductor L2; when the fourth switching transistor Q4 is turned off, the power supply assembly 140 charges the second capacitor C2; therefore, the electric energy finally output to the second drive circuit 130 is provided by both the second capacitor C2 and the second inductor L2, so the voltage output to the second drive circuit 130 is higher than the voltage provided by the power supply assembly 140, achieving the boost effect.

[0178] Based on the above buck circuit 150, when the three-phase winding 100 switches to the open winding connection, the first drive circuit 110 and the second drive circuit 130 supply power to the three-phase winding 100 simultaneously. Since the first drive voltage is obtained after bucking, the efficiency of the three-phase winding 100 will be reduced. Therefore, when the three-phase winding 100 switches to the open winding connection, the first switching transistor Q1 can be controlled to be continuously turned on and the second switching transistor Q2 can be controlled to be continuously turned off. At this time, the first inductor L1 and the first capacitor C1 form an LC filter circuit. In this state, the voltage output by the first drive circuit 110 is the fourth drive voltage, so that the bucking effect of the buck circuit 150 almost disappears, improving the voltage utilization efficiency of the power supply assembly 140 and making the three-phase winding 100 operate more efficiently in the open winding connection state.

[0179] Therefore, by setting the switch component 120, the connection mode of the three-phase winding 100 can be switched according to different operating frequencies of the motor, improving the operating efficiency of the motor. By setting the first power supply circuit and the second power supply circuit, different power supply voltages can be provided for the first drive circuit 110 and the second drive circuit 130 respectively. The first drive circuit 110 and the second drive circuit 130 then provide corresponding drive voltages to the three-phase winding 100 when the three-phase winding 100 is in different connection states, so that the three-phase winding 100 can obtain suitable drive voltages in different connection states, so as to realize the efficient operation of the motor in different connection modes.

[0180] In addition, the switch component 120 is generally mechanical, and the action of closing or disconnecting it takes a certain amount of time to complete. When using the existing scheme to switch the connection mode, the permanent magnet motor needs to be stopped briefly, thus affecting the normal operation of the compressor. Therefore, the second drive circuit 130 provides a sixth drive voltage to the three-phase winding during the switching process of the connection state of the three-phase winding 100. The sixth drive voltage is used to keep the motor running during the switching process of the connection state of the three-phase winding 100. In this embodiment, the motor keeps running during the switching process of the connection state of the three-phase winding 100, which means that the motor runs with power rather than by inertia. By setting the second drive circuit 130 in the embodiment of the present invention, when the three-phase winding 100 is switched from star connection to delta connection, it first enters a transition state. Refer to Figure 6, when the three-phase winding 100 is in star connection, the first drive circuit 110 provides a first drive voltage, the second drive circuit 130 is shut down, the first switch group 121 is closed, and the second switch group 122 is opened. Then, it enters a transition state. In the transition state, in the first stage, the states of the first switch group 121 and the second switch group 122 are controlled to remain unchanged, and the second drive circuit 130 outputs the neutral point voltage of the star connection. In this stage, the motor still operates in the star connection state; in the second stage, the first switch group 121 is controlled to open, the state of the second switch group 122 remains unchanged, and the second drive circuit 130 outputs the neutral point voltage of the star connection and lasts for a first time threshold. In this stage, since the second drive circuit 130 outputs the neutral point voltage of the star connection, the motor can still operate in the star connection state even if the first switch group 121 is opened. In addition, since it takes a certain time for the first switch group 121 to change from closed to open, the first time threshold needs to be maintained. The first time threshold can be the action duration of the first switch group 121; in the third stage, the first switch group 121 completes the opening action, the state of the second switch group 122 is controlled to remain unchanged, and the second drive circuit 130 outputs the three-phase voltage of the delta connection. In this stage, since the first switch group 121 and the second switch group 122 do not act, the second drive circuit 130 changes from outputting the neutral point voltage of the star connection to outputting the three-phase voltage of the delta connection (which is the second drive voltage at this time). In this stage, the motor is still in the normal power supply state and can thus maintain operation; in the fourth stage, the state of the first switch group 121 is controlled to remain unchanged, the second switch group 122 is closed, and the second drive circuit 130 outputs the three-phase voltage of the delta connection and lasts for a second time threshold. Since the second drive circuit 130 outputs the three-phase voltage of the delta connection, during the closing process of the second switch group 122, the three-phase winding 100 is already equivalent to being in the delta connection state, that is, the motor can maintain operation. Since it takes a certain time for the second switch group 122 to change from open to closed, the second time threshold needs to be maintained. The second time threshold can be the action duration of the second switch group 122. Finally, the second switch group 122 completes the closing action, the first drive circuit 110 is controlled to output the second drive voltage, the second drive circuit 130 is controlled to shut down, and the three-phase winding 100 completes the switching from star connection to delta connection. In summary, through the second drive circuit 130, a transition state can be added when the three-phase winding 100 switches from star connection to delta connection, thus achieving a non-stop switching.

[0181] In addition, referring to Figure 7, in one embodiment, the three-phase winding 100 is in a star connection and the first driving circuit 110 provides a first driving voltage. When it needs to be switched to a delta connection, the sixth driving voltage can also be provided by the first driving circuit 110 and the second driving circuit 130 respectively, that is, the following switching method is adopted: in the first stage, the second driving circuit 130 outputs the neutral point voltage of the star connection and continuously outputs it. In the third stage, the second driving circuit 130 is changed to output the third driving voltage, and then the first driving circuit 110 outputs the three-phase voltage of the delta connection (which is the third driving voltage at this time). After the final switching is completed, the first driving circuit 110 is shut down and the second driving circuit 130 keeps supplying power to the three-phase winding 100 of the delta connection, and the purpose of non-stop switching can also be achieved. The advantage of this switching method is that finally the second driving circuit 130 supplies power to the three-phase winding 100 of the delta connection, and cooperating with the second power supply circuit 160 can achieve the efficient operation of the motor.

[0182] Refer to Figure 6, the principle of switching the three-phase winding 100 from delta connection to star connection is similar to the above process. When the three-phase winding 100 is in delta connection, the second driving voltage can also be provided by the first driving circuit 110, the first switch group 121 is disconnected, and the second switch group 122 is closed. Then, it enters the transition state. In the transition state, in the fourth stage, the states of the first switch group 121 and the second switch group 122 are controlled to remain unchanged, and the second driving circuit 130 outputs the three-phase voltage of delta connection (which is the second driving voltage at this time). In this stage, the motor still operates in delta connection state; in the third stage, the state of the first switch group 121 is controlled to remain unchanged, the second switch group 122 is disconnected, and the second driving circuit 130 outputs the three-phase voltage of delta connection and lasts for the second time threshold. In this stage, since the second driving circuit 130 outputs the three-phase voltage of delta connection, the motor can still operate in delta connection state even if the second switch group 122 is disconnected. In addition, since it takes a certain time for the second switch group 122 to change from closed to open, the second time threshold needs to be lasted. The second time threshold can be the action duration of the second switch group 122; in the second stage, the second switch group 122 completes the disconnection action, the state of the first switch group 121 is controlled to remain unchanged, and the second driving circuit 130 outputs the neutral point voltage of star connection. In this stage, since the first switch group 121 and the second switch group 122 do not act, the second driving circuit 130 changes from outputting the three-phase voltage of delta connection to outputting the neutral point voltage of star connection. In this stage, the motor is still in the normal power supply state and can thus keep running; in the first stage, the first switch group 121 is controlled to close, the state of the second switch group 122 remains unchanged, and the second driving circuit 130 outputs the neutral point voltage of star connection and lasts for the first time threshold. Since the second driving circuit 130 outputs the neutral point voltage of star connection, during the process of closing the first switch group 121, the three-phase winding 100 is already equivalent to being in star connection state, that is, the motor can keep running. Since it takes a certain time for the first switch group 121 to change from open to closed, the first time threshold needs to be lasted. The first time threshold can be the action duration of the first switch group 121. Finally, the first switch group 121 completes the closing action, the second driving circuit 130 is controlled to shut down, the first driving circuit keeps outputting the first driving voltage, and the three-phase winding 100 completes the switching from delta connection to star connection. In summary, through the second driving circuit 130, a transition state can be added when the three-phase winding 100 switches from delta connection to star connection, so as to achieve seamless switching.

[0183] In addition, referring to Figure 7, in one embodiment, the three-phase winding 100 is in a delta connection and the third driving voltage is provided by the second driving circuit 130. When it needs to be switched to a star connection, the first driving circuit 110 and the second driving circuit 130 can also respectively provide the sixth driving voltage, that is, the following switching method is adopted: in the IV stage, the first driving circuit 110 first outputs the three-phase voltage of the delta connection (which is the third driving voltage at this time) and continuously outputs it. In the II stage, the second driving circuit 130 then outputs the neutral point voltage of the star connection, and the first driving circuit 110 is changed to output the first driving voltage. After the final switching is completed, the second driving circuit 130 is shut down, and the first driving circuit 110 keeps supplying power to the three-phase winding 100 of the star connection, and the purpose of non-stop switching can also be achieved. The advantage of this switching method is that finally the first driving circuit 110 supplies power to the three-phase winding 100 of the star connection, and cooperating with the first power supply circuit 150 can achieve the efficient operation of the motor.

[0184] It should be added that the sixth driving voltage is the neutral point voltage when the three-phase winding 100 is in a star connection state, or the three-phase voltage when the three-phase winding 100 is in a delta connection state, which can make the transition of the three-phase winding 100 during the star connection and delta connection switching smoother and more stable. Those skilled in the art can understand that the sixth driving voltage can also be set to other voltage values during the switching process.

[0185] In addition, referring to Figure 8, in the embodiment of the present invention, by providing the second driving circuit 130, when the three-phase winding 100 switches from the delta connection to the open winding connection, it first enters a transition state. When the three-phase winding 100 is in the delta connection, the first driving circuit 110 provides the second driving voltage, the second driving circuit 130 is shut down, the first switch group 121 is disconnected, and the second switch group 122 is closed. Then, it enters the transition state. Among them, in the transition state, in the Vth stage, the states of the first switch group 121 and the second switch group 122 are controlled to remain unchanged, and the second driving circuit 130 outputs the three-phase voltage of the delta connection (which is the second driving voltage at this time). In this stage, the motor still operates in the delta connection state; in the VIth stage, the state of the first switch group 121 is controlled to remain unchanged, the second switch group 122 is disconnected, and the second driving circuit 130 outputs the three-phase voltage of the delta connection and lasts for the second time threshold. In this stage, since the second driving circuit 130 outputs the three-phase voltage of the delta connection, the motor can still operate in the delta connection state even if the second switch group 122 is disconnected. In addition, since it takes a certain time for the second switch group 122 to change from closed to open, the second time threshold needs to be lasted. The second time threshold can be the action duration of the second switch group 122. Finally, the second switch group 122 completes the disconnection action, the first driving circuit 110 outputs the fourth driving voltage, the second driving circuit 130 outputs the fifth driving voltage, and the three-phase winding 100 completes the switching from the delta connection to the open winding connection. In summary, through the second driving circuit 130, a transition state can be added when the three-phase winding 100 switches from the delta connection to the open winding connection, so as to achieve seamless switching.

[0186] In addition, in an embodiment, when the three-phase winding 100 is in the delta connection, the third driving voltage can also be provided by the second driving circuit 130, the first driving circuit 110 is shut down, the first switch group 121 is disconnected, and the second switch group 122 is closed. The switching principle is similar to that of the above embodiment and will not be elaborated here.

[0187] The principle of the three-phase winding 100 switching from the open winding connection to the delta connection is similar to the above process. When the three-phase winding 100 is in the open winding connection, the first drive circuit 110 provides the fourth drive voltage, the second drive circuit 130 provides the fifth drive voltage, the first switch group 121 is disconnected, and the second switch group 122 is disconnected. Then, it enters the transition state. In the transition state, in the VI stage, the states of the first switch group 121 and the second switch group 122 are controlled to remain unchanged, and the second drive circuit 130 outputs the three-phase voltage of the delta connection (which is the second drive voltage at this time). In this stage, the motor still operates in the open winding connection state; in the V stage, the state of the first switch group 121 is controlled to remain unchanged, the second switch group 122 is closed, and the second drive circuit 130 outputs the three-phase voltage of the delta connection and lasts for the second time threshold. In this stage, since the second drive circuit 130 outputs the three-phase voltage of the delta connection, during the closing process of the second switch group 122, the three-phase winding 100 is already equivalent to being in the delta connection state, that is, the motor can keep running. Since it takes a certain time for the second switch group 122 to change from disconnected to closed, the second time threshold needs to be lasted. The second time threshold can be the action duration of the second switch group 122. Finally, the second switch group 122 completes the closing action, the second drive circuit 130 is controlled to shut down, the first drive circuit 110 provides the second drive voltage, and the three-phase winding 100 completes the switching from the open winding connection to the delta connection. In summary, through the second drive circuit 130, a transition state can be added when the three-phase winding 100 switches from the open winding connection to the delta connection, so as to achieve seamless switching.

[0188] In addition, in an embodiment, after the three-phase winding 100 switches from the open winding connection to the delta connection, the second drive circuit 130 can also provide the third drive voltage, and the first drive circuit 110 is controlled to shut down to make the motor operate efficiently.

[0189] It should be added that the seventh drive voltage is the three-phase voltage when the three-phase winding 100 is in the delta connection state, which can make the transition of the three-phase winding 100 during the switching between the delta connection and the open winding connection smoother and more stable. Those skilled in the art can understand that the seventh drive voltage can also be set to other voltage values during the switching process.

[0190] In summary, when switching the connection mode of the three-phase winding 100, the second driving circuit 130 can provide a sixth driving voltage for the three-phase winding 100 during the switching process between the star connection and the delta connection of the three-phase winding 100, or provide a seventh driving voltage during the switching process between the delta connection and the open winding connection, so as to simulate the voltage environment in which the first switch group 121 and the second switch group 122 are located during the switching process. Therefore, when switching the connection mode, even if the opening and closing states of the first switch group 121 or the second switch group 122 change, the motor still operates normally, and the non-stop switching of the connection mode of the three-phase winding 100 of the motor can be realized without affecting the normal operation of the compressor.

[0191] Referring to Figure 9 , Figure 10 , in an embodiment, both the first driving circuit 110 and the second driving circuit 130 include a first bridge arm 910, a second bridge arm 920, and a third bridge arm 930 that are connected in parallel with each other. The first bridge arm 910, the second bridge arm 920, and the third bridge arm 930 each include two fifth switching tubes Q5 connected in series, and a fifth diode D5 is anti-parallelly connected to the fifth switching tube Q5. The fifth switching tube Q5 can be Figure 9 the MOS tube shown in Figure 10 , or the IGBT tube shown in Figure 1, correspondingly, the three output terminals A1, B1, and C1 of the first drive circuit 110 are respectively connected to the sixth pin M6, the fifth pin M5, and the fourth pin M4 of the three-phase winding 100, and the three output terminals A2, B2, and C2 of the second drive circuit 130 are respectively connected to the first pin M1, the second pin M2, and the third pin M3 of the three-phase winding 100. Exemplarily, SPWM can be used as the drive signal for driving the first drive circuit 110, which can effectively reduce the harmonic components of the output voltage and output current, improve the output waveform, and enable the first drive circuit 110 to output a sinusoidal AC signal, that is, a first drive voltage can be provided to the three-phase winding 100 (the same applies to the second drive circuit 130). When using SPWM as the drive signal for driving the first drive circuit 110, when the three-phase winding 100 is in a star connection, the neutral point voltage is zero voltage. Correspondingly, the three output terminals A2, B2, and C2 of the second drive circuit 130 can be adjusted to a PWM output with a 50% duty cycle, which can provide the neutral point voltage for the star connection of the three-phase winding 100. In addition, the second drive circuit 130 outputs a triangular three-phase voltage, that is, the output terminal A2 of the second drive circuit 130 outputs the same voltage as the output terminal C1 of the first drive circuit 110, the output terminal B2 of the second drive circuit 130 outputs the same voltage as the output terminal A1 of the first drive circuit 110, and the output terminal C2 of the second drive circuit 130 outputs the same voltage as the output terminal B1 of the first drive circuit 110 (the same applies to the first drive 110). Those skilled in the art can understand that the first drive voltage, the second drive voltage, the third drive voltage, the fourth drive voltage, and the fifth drive voltage can be adjusted according to the connection state of the three-phase winding.

[0192] In one embodiment, the power supply assembly 140 includes an AC power supply 143 and a rectification assembly 144 for converting the AC power supply 143 into a DC output. The AC power supply 143 is connected to the rectification assembly 144, and the rectification assembly 144 is respectively connected to the buck circuit 150 and the boost circuit 160. By setting the rectification assembly 144, the AC power supply 143 can be converted into a DC output to adapt to the input signal requirements of the buck circuit 150 and the boost circuit 160. It can be understood that the above-mentioned first power supply group 141 and second power supply group 142 can each include an AC power supply 143 and a rectification assembly 144 for converting the AC power supply 143 into a DC output.

[0193] In one embodiment, the control of the above-mentioned first drive circuit 110, switch assembly 120, second drive circuit 130, buck circuit 150, and boost circuit 160 can be implemented by a controller, such as a microcontroller.

[0194] In addition, referring to Figure 11 , an embodiment of the present invention also provides a drive control method, which is applied to Figure 1 ,Figure 2 Or Figure 3 the drive control circuit in Figure 3 , the drive control method includes but is not limited to the following steps:

[0195] Step 1101: Control the opening and closing of the switch component to switch the three-phase winding from the first connection state to the second connection state;

[0196] Step 1102: Control the first drive circuit and the second drive circuit to start or stop working, so that the first drive circuit or the second drive circuit provides a drive voltage to the three-phase winding in the corresponding connection state.

[0197] Exemplarily, the first drive circuit is powered by a buck circuit, and the second drive circuit is powered by a boost circuit. Therefore, the drive voltage output by the first drive circuit is lower than the drive voltage output by the second drive circuit. The first drive voltage and the third drive voltage have been explained in the embodiments of the above drive control circuit and will not be elaborated here.

[0198] Wherein, the first connection state and the second connection state have at least the following possible combinations:

[0199] One combination is that the first connection state is a delta connection and the second connection state is a star connection. In this case, in the above step 1102, controlling the first drive circuit and the second drive circuit to start or stop working so that the first drive circuit or the second drive circuit provides a drive voltage to the three-phase winding in the corresponding connection state specifically includes the following steps:

[0200] Control the first drive circuit to start working and control the second drive circuit to stop working, so that the first drive circuit provides the first drive voltage to the three-phase winding in the star connection state.

[0201] When the three-phase winding is switched from a delta connection to a star connection, the first drive circuit provides the first drive voltage to the three-phase winding, and the second drive circuit stops working. Since the motor generally operates at a low frequency when the three-phase winding is in a star connection, the first drive circuit provides the first drive voltage to the three-phase winding, so that a suitable drive voltage can be obtained when the three-phase winding is in a star connection.

[0202] Another combination is that the first connection state is a star connection and the second connection state is a delta connection. In this case, in the above step 1102, controlling the first drive circuit and the second drive circuit to start or stop working so that the first drive circuit or the second drive circuit provides a drive voltage to the three-phase winding in the corresponding connection state includes:

[0203] Control the first drive circuit to start working and control the second drive circuit to stop working, so that the first drive circuit provides the second drive voltage to the three-phase winding in the delta connection state;

[0204] Or,

[0205] Control the first drive circuit to stop working and control the second drive circuit to start working, so that the second drive circuit provides a third drive voltage to the three-phase windings in the delta connection state.

[0206] When the three-phase windings are switched from the star connection to the delta connection, the second drive circuit provides the third drive voltage to the three-phase windings, and the first drive circuit stops working. Since the operating frequency of the motor is generally higher under the same conditions when the three-phase windings are in the delta connection than in the star connection, the second drive circuit provides the third drive voltage to the three-phase windings, so that the three-phase windings can obtain a suitable drive voltage when in the delta connection. In addition, the first drive circuit can also provide the second drive voltage to the three-phase windings, and the three-phase windings can also be in the delta connection.

[0207] Another combination is that the first connection state is the delta connection and the second connection state is the open winding connection. In this case, in step 1102 above, controlling the first drive circuit and the second drive circuit to start or stop working so that the first drive circuit or the second drive circuit provides a drive voltage to the three-phase windings in the corresponding connection state includes:

[0208] Control the first drive circuit to start working and control the second drive circuit to start working, so that the first drive circuit provides a fourth drive voltage to the three-phase windings in the open winding connection state and the second drive circuit provides a fifth drive voltage to the three-phase windings in the open winding connection state.

[0209] When the three-phase windings are switched from the delta connection to the open winding connection, since the operating frequency of the motor is generally higher under the same conditions when the three-phase windings are in the open winding connection than in the delta connection, the first drive circuit provides the fourth drive voltage to the three-phase windings and the second drive circuit provides the fifth drive voltage to the three-phase windings, so that the three-phase windings can obtain a suitable drive voltage when in the open winding connection.

[0210] On this basis, in an embodiment, since the power supply of the first drive circuit is supplied by a buck circuit, when the three-phase windings are in the open winding connection state, the buck function of the buck circuit can be controlled to stop, and the original power supply voltage, that is, the fourth drive voltage, is output to the first drive circuit, which is beneficial to improving the operating efficiency of the motor.

[0211] Another combination is that the first connection state is the open winding connection and the second connection state is the delta connection. In this case, in step 1102 above, controlling the first drive circuit and the second drive circuit to start or stop working so that the first drive circuit or the second drive circuit provides a drive voltage to the three-phase windings in the corresponding connection state includes:

[0212] Control the first drive circuit to start working and control the second drive circuit to stop working, so that the first drive circuit provides a second drive voltage to the three-phase windings in the delta connection state;

[0213] Or,

[0214] Control the first drive circuit to stop working and control the second drive circuit to start working, so that the second drive circuit provides a third drive voltage to the three-phase windings in the delta connection state.

[0215] When the three-phase windings are switched from the open-winding connection to the open-delta connection, since when the three-phase windings are in the delta connection, under the same conditions, the operating frequency of the motor is generally lower than that in the open-winding connection. Therefore, the second drive circuit provides a third drive voltage to the three-phase windings and the first drive circuit stops working, so that a suitable drive voltage can be obtained when the three-phase windings are in the delta connection. Additionally, the first drive circuit can also provide a second drive voltage to the three-phase windings, and the three-phase windings can also be in the delta connection.

[0216] By controlling the opening and closing of the switch component to switch the three-phase windings from the first connection state to the second connection state, it is possible to switch the connection mode of the three-phase windings according to different operating frequencies of the motor, improving the operating efficiency of the motor; by controlling the first drive circuit and the second drive circuit to start or stop working, so that the first drive circuit or the second drive circuit provides a drive voltage to the three-phase windings in the corresponding connection state, a suitable drive voltage can be obtained when the three-phase windings are in different connection states, so as to achieve efficient operation of the motor in different connection modes.

[0217] Referring to Figure 12 , an embodiment of the present invention further provides a drive control method. Based on the drive control method in the above embodiment, the following steps are further included:

[0218] Step 1201: Control the second drive circuit to provide a sixth drive voltage to the three-phase windings during the switching process of the connection state of the three-phase windings.

[0219] The switch component is generally mechanical, and its closing or opening action requires a certain period of time to complete. When using the existing solution to switch the connection mode, the permanent magnet motor needs to be briefly stopped, thus affecting the normal operation of the compressor. Therefore, when switching the connection mode of the three-phase windings, the second drive circuit is controlled to provide a sixth drive voltage to the three-phase windings during the switching process of the connection state of the three-phase windings, so as to simulate the voltage environment in which the first switch group and the second switch group are located during the switching process. Therefore, when switching the connection mode, even if the opening and closing states of the first switch group or the second switch group change, the motor still operates normally, and the non-stop switching of the connection mode of the three-phase windings of the motor can be realized without affecting the normal operation of the compressor.

[0220] Refer to Figure 6 、 Figure 13 When the first connection state is star connection and the second connection state is delta connection, in step 1201 above, controlling the second drive circuit to provide a sixth drive voltage to the three-phase windings during the switching process of the connection state of the three-phase windings specifically includes the following steps:

[0221] Step 1301: The three-phase windings remain in star connection, and the second drive circuit is controlled to output the neutral point voltage when the three-phase windings are in star connection state;

[0222] Step 1302: Control the first switch group to open, and the second drive circuit outputs the neutral point voltage when the three-phase windings are in star connection state for a first time threshold;

[0223] Step 1303: Control the second drive circuit to output the three-phase voltage when the three-phase windings are in delta connection state;

[0224] Step 1304: Control the second switch group to close, and the second drive circuit outputs the three-phase voltage when the three-phase windings are in delta connection state for a second time threshold;

[0225] Step 1305: Control the first drive circuit to output the second drive voltage and control the second drive circuit to stop working.

[0226] Specifically, in step 1301, the motor is still operating in the star connection state; in step 1302, the second drive circuit is controlled to simulate the neutral point voltage of the three-phase windings in the star connection state. Even if the first switch group is disconnected, the motor can still operate in the star connection state. The first time threshold can be the operation duration of the first switch group; in step 1303, the motor is in the normal power supply state, so it can keep running; in step 1304, the second drive circuit is controlled to simulate the three-phase voltages of the three-phase windings in the delta connection state. That is, during the closing process of the second switch group, the motor can already operate in the delta connection state first. The second time threshold is the operation duration of the second switch group. In step 1305, the first drive circuit is controlled to output the second drive voltage, and the second drive circuit is controlled to stop working. It can be seen that through the above steps 1301 to 1305, the non-stop switching of the motor can be achieved. After the switching is completed, the second drive circuit stops working, and the first drive circuit supplies power to the electronic windings.

[0227] Refer to Figure 6 、 Figure 14 , when the first connection state is the delta connection and the second connection state is the star connection, in the above step 1201, the second drive circuit is controlled to provide the sixth drive voltage to the three-phase windings during the switching process of the three-phase winding connection states, which specifically includes the following steps:

[0228] Step 1401: Control the first drive circuit to output the second drive voltage to keep the three-phase windings in the delta connection, and control the second drive circuit to output the three-phase voltages of the three-phase windings in the delta connection state;

[0229] Step 1402: Control the second switch group to disconnect, and the second drive circuit outputs the three-phase voltages of the three-phase windings in the delta connection state for the second time threshold;

[0230] Step 1403: Control the second drive circuit to output the neutral point voltage of the three-phase windings in the star connection state;

[0231] Step 1404: Control the first switch group to close, and the second drive circuit outputs the neutral point voltage of the three-phase windings in the star connection state for the first time threshold;

[0232] Step 1405: Control the first drive circuit to output the first drive voltage, and control the second drive circuit to stop working.

[0233] Specifically, in step 1401, the motor is still operating in the delta connection state; in step 1402, the second drive circuit is controlled to simulate the three-phase voltage when the three-phase windings are in the delta connection state. Even if the second switch group is disconnected, the motor can still operate in the delta connection state, where the second time threshold can be the operation duration of the second switch group; in step 1403, the motor is in the normal power supply state and can thus maintain operation; in step 1404, the second drive circuit is controlled to simulate the neutral point voltage when the three-phase windings are in the star connection state, that is, during the closing process of the first switch group, the motor can already operate in the star connection state first, where the first time threshold is the operation duration of the first switch group. In step 1305, the first drive circuit is controlled to output the first drive voltage, and the second drive circuit is controlled to stop working. It can be seen that through the above steps 1401 to 1405, the non-stop switching of the motor can be achieved. After the switching is completed, the second drive circuit stops working, and the first drive circuit supplies power to the electronic windings.

[0234] The neutral point voltage when the three-phase windings are in the star connection state or the three-phase voltage when the three-phase windings are in the delta connection state have been explained in the above embodiments of the drive control circuit and will not be elaborated here.

[0235] Refer to Figure 15 , when the three-phase windings are switched between the delta connection and the open winding connection, the above drive control method may further include the following steps:

[0236] Step 1501: Control the second drive circuit to provide the seventh drive voltage to the three-phase windings during the switching process of the connection state of the three-phase windings.

[0237] Refer to Figure 8 , Figure 16 , when the first connection state is the delta connection and the second connection state is the open winding connection, in the above step 1501, controlling the second drive circuit to provide the seventh drive voltage to the three-phase windings during the switching process of the connection state of the three-phase windings specifically includes the following steps:

[0238] Step 1601: The three-phase windings remain in the delta connection, and the second drive circuit is controlled to output the three-phase voltage when the three-phase windings are in the delta connection state;

[0239] Step 1602: Control the second switch group to disconnect, and the second drive circuit outputs the three-phase voltage when the three-phase windings are in the delta connection state for a duration of the second time threshold;

[0240] Step 1603: Control the first drive circuit to output the fourth drive voltage and control the second drive circuit to output the fifth drive voltage.

[0241] Specifically, in step 1601, the motor is still operating in the delta connection state. The second drive voltage can be output by the first drive circuit, or the third drive voltage can be output by the third drive circuit. In step 1602, the second drive circuit is controlled to simulate the three-phase voltage in the delta connection state of the three-phase windings. Even if the second switch group is disconnected, the motor can still operate in the delta connection state. The second time threshold can be the operation duration of the second switch group. In step 1603, the first drive circuit is controlled to output the fourth drive voltage, and the second drive circuit is controlled to output the fifth drive voltage. It can be seen that through the above steps 1601 and 1603, the non-stop switching of the motor can be achieved. After the switching is completed, the first drive circuit and the second drive circuit jointly supply power to the electronic windings.

[0242] Refer to Figure 8 、 Figure 17 , when the first connection state is the open winding connection and the second connection state is the delta connection, in the above step 1501, the second drive circuit is controlled to provide the seventh drive voltage to the three-phase windings during the switching process of the connection state of the three-phase windings, which specifically includes the following steps:

[0243] Step 1701: The three-phase windings remain in the open winding connection, and the second drive circuit is controlled to output the three-phase voltage in the delta connection state of the three-phase windings.

[0244] Step 1702: Control the second switch group to close, and the second drive circuit outputs the three-phase voltage in the delta connection state of the three-phase windings for the second time threshold.

[0245] Step 1703: Control the second drive circuit to stop working and the first drive circuit to output the second drive voltage, or control the first drive circuit to stop working and the second drive circuit to output the third drive voltage.

[0246] Specifically, in step 1701, the motor is still operating in the open winding connection state. In step 1702, the second drive circuit is controlled to simulate the three-phase voltage in the delta connection state of the three-phase windings, that is, during the closing process of the second switch group, the three-phase windings can already operate in the delta connection state first. The second time threshold can be the operation duration of the second switch group. In step 1703, control the second drive circuit to stop working and the first drive circuit to output the second drive voltage, or control the first drive circuit to stop working and the second drive circuit to output the third drive voltage. It can be seen that through the above steps 1701 and 1703, the non-stop switching of the motor can be achieved. After the switching is completed, the second drive circuit stops working, and the first drive circuit supplies power to the electronic windings; or the first drive circuit stops working, and the second drive circuit supplies power to the electronic windings.

[0247] In addition, refer to Figure 18, in one embodiment, when the first connection state is a star connection and the second connection state is a delta connection, in the above step 1201, controlling the second drive circuit to provide a sixth drive voltage to the three-phase windings during the switching process of the three-phase winding connection state may also include the following steps:

[0248] Step 1801: The three-phase windings remain in a star connection, and control the second drive circuit to output the neutral point voltage when the three-phase windings are in a star connection state;

[0249] Step 1802: Control the first switch group to open, and the second drive circuit outputs the neutral point voltage when the three-phase windings are in a star connection state, lasting for a first time threshold;

[0250] Step 1803: Control the second drive circuit to output a third drive voltage, and the first drive circuit outputs the three-phase voltages when the three-phase windings are in a delta connection state;

[0251] Step 1804: Control the second switch group to close, and the second drive circuit outputs a third drive voltage, and the first drive circuit outputs the three-phase voltages when the three-phase windings are in a delta connection state, lasting for a second time threshold;

[0252] Step 1805: Control the first drive circuit to stop working.

[0253] Specifically, in step 1801, the motor is still operating in a star connection state; in step 1802, control the second drive circuit to simulate the neutral point voltage when the three-phase windings are in a star connection state. Even if the first switch group is opened, the motor can still operate in a star connection state, where the first time threshold can be the action duration of the first switch group; in step 1803, the motor is in a normal power supply state, so it can keep running; in step 1804, control the second drive circuit to output a third drive voltage, and control the first drive circuit to simulate the three-phase voltages when the three-phase windings are in a delta connection state. That is, during the closing process of the second switch group, the motor can already operate in a delta connection state first. Among them, the second time threshold is the action duration of the second switch group. It can be seen that through the above steps 1801 to 1805, the non-stop switching of the motor can be realized, and after the switching is completed, the second drive circuit provides a third drive voltage to the three-phase windings in a delta connection, which can achieve the efficient operation of the motor.

[0254] In addition, referring to Figure 19 , in one embodiment, when the first connection state is a delta connection and the second connection state is a star connection, in the above step 1201, controlling the second drive circuit to provide a sixth drive voltage to the three-phase windings during the switching process of the three-phase winding connection state may also include the following steps:

[0255] Step 1901: Control the second drive circuit to output a third drive voltage to keep the three-phase windings in a delta connection, and control the first drive circuit to output three-phase voltages when the three-phase windings are in a delta connection state;

[0256] Step 1902: Control the second switch group to disconnect, and the first drive circuit outputs three-phase voltages when the three-phase windings are in a delta connection state, for a second time threshold;

[0257] Step 1903: Control the first drive circuit to output a first drive voltage, and the second drive circuit to output a neutral point voltage when the three-phase windings are in a star connection state;

[0258] Step 1904: Control the first switch group to close, and the first drive circuit outputs a first drive voltage, and the second drive circuit outputs a neutral point voltage when the three-phase windings are in a star connection state, for a first time threshold;

[0259] Step 1905: Control the second drive circuit to stop working.

[0260] Specifically, in step 1901, the motor is still operating in a delta connection state; in step 1902, control the first drive circuit to simulate the three-phase voltages when the three-phase windings are in a delta connection state. Even if the second switch group is disconnected, the motor can still operate in a delta connection state, where the second time threshold can be the action duration of the second switch group; in step 1903, the motor is in a normal power supply state and can thus keep running; in step 1904, control the first drive circuit to output a first drive voltage, and control the second drive circuit to simulate the neutral point voltage when the three-phase windings are in a star connection state. That is, during the closing process of the first switch group, the motor can already operate in a star connection state first, where the first time threshold is the action duration of the first switch group. It can be seen that through the above steps 1901 to 1905, the non-stop switching of the motor can be achieved. And after the switching is completed, the first drive circuit provides a first drive voltage to the three-phase windings in a star connection, which can achieve the efficient operation of the motor.

[0261] In an embodiment, referring to Figure 20 , the connection mode of the three-phase windings can be switched according to the operating frequency of the motor. Specifically, it can include one or a combination of the following judgment methods:

[0262] According to the operating frequency of the motor being lower than the first frequency threshold, control the opening and closing of the switch assembly to switch the three-phase windings from a delta connection to a star connection;

[0263] According to the operating frequency of the motor being higher than the first frequency threshold and lower than the second frequency threshold, control the opening and closing of the switch assembly to switch the three-phase windings from a star connection or an open winding connection to a delta connection;

[0264] When the operating frequency of the motor is higher than the second frequency threshold, control the opening and closing of the switch assembly to switch the three-phase winding from a delta connection to an open winding connection.

[0265] Wherein, the first frequency threshold is less than the second frequency threshold.

[0266] By judging the operating frequency of the motor and switching the three-phase winding to the corresponding connection state according to the high or low operating frequency of the motor, the motor can operate in a connection mode adapted to the operating frequency, improving the operating efficiency of the motor. It can be understood that the above-mentioned second frequency threshold is greater than the first frequency threshold, and the first frequency threshold and the second frequency threshold can be determined according to the actual operating conditions of the motor, which are not limited herein.

[0267] In one embodiment, referring to Figure 21 , to switch the connection mode of the three-phase winding according to the operating frequency of the motor, the third frequency threshold, the fourth frequency threshold, the fifth frequency threshold and the sixth frequency threshold that increase in sequence can be set. Specifically, it can include one or a combination of the following judgment methods:

[0268] When the operating frequency of the motor is lower than the third frequency threshold, control the opening and closing of the switch assembly to switch the three-phase winding from a delta connection to a star connection;

[0269] When the operating frequency of the motor is higher than the fourth frequency threshold and lower than the fifth frequency threshold, control the opening and closing of the switch assembly to switch the three-phase winding from a star connection or an open winding connection to a delta connection;

[0270] When the operating frequency of the motor is higher than the sixth frequency threshold, control the opening and closing of the switch assembly to switch the three-phase winding from a delta connection to an open winding connection;

[0271] When judging the operating frequency of the motor, the third frequency threshold and the fourth frequency threshold can form a hysteresis interval, and the fifth frequency threshold and the sixth frequency threshold can form a hysteresis interval, so as to avoid the phenomenon of frequent switching of the connection state of the motor and ensure the stability of the motor operation. The third frequency threshold, the fourth frequency threshold, the fifth frequency threshold and the sixth frequency threshold can be determined according to the actual operating conditions of the motor, which are not limited herein.

[0272] It should be added that the method in the above embodiment is only schematically applied to the Figure 1 , Figure 2 or Figure 3 shown drive control circuit, and can also be applied to other similar circuits.

[0273] Referring to Figure 22 , Figure 22An embodiment of the present invention provides a circuit board, which includes the drive control circuit in any of the above embodiments. Therefore, by setting the switch component, the circuit board can switch the connection mode of the three-phase windings according to different operating frequencies of the motor, improving the operating efficiency of the motor; by setting the first power supply circuit and the second power supply circuit, different power supply voltages can be provided for the first drive circuit and the second drive circuit respectively. The first drive circuit and the second drive circuit then provide corresponding drive voltages to the three-phase windings when the three-phase windings are in different connection states, so that suitable drive voltages can be obtained when the three-phase windings are in different connection states, so as to achieve efficient operation of the motor in different connection modes.

[0274] Refer to Figure 23 An embodiment of the present invention also provides an air conditioner, which includes the circuit board and the compressor in the above embodiments. The compressor is driven by a permanent magnet motor, and the above circuit board is used to control the operation mode of the permanent magnet motor. By setting the switch component, the air conditioner can switch the connection mode of the three-phase windings according to different operating frequencies of the motor, improving the operating efficiency of the motor; by setting the first power supply circuit and the second power supply circuit, different power supply voltages can be provided for the first drive circuit and the second drive circuit respectively. The first drive circuit and the second drive circuit then provide corresponding drive voltages to the three-phase windings when the three-phase windings are in different connection states, so that suitable drive voltages can be obtained when the three-phase windings are in different connection states, so as to achieve efficient operation of the motor in different connection modes.

[0275] Refer to Figure 24 , Figure 24 It is a schematic diagram of the air conditioner provided by an embodiment of the present invention. The air conditioner according to the embodiment of the present invention includes one or more processors 2401 and a memory 2402. Figure 24 Taking one processor 2401 and one memory 2402 as an example in

[0276] The processor 2401 and the memory 2402 can be connected through a bus or other means. Figure 24 Taking the connection through the bus as an example in

[0277] The memory 2402, 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 2402 may include a high-speed random access memory 2402, and may also include a non-transitory memory 2402, such as at least one magnetic disk storage device, a flash memory component, or other non-transitory solid-state storage devices. In some embodiments, the memory 2402 may optionally include a memory 2402 that is remotely disposed relative to the processor 2401, and these remote memories 2402 can be connected to the operation control device through a network. Examples of the above network include but are not limited to the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0278] Those skilled in the art can understand that Figure 24 the device structure shown in does not constitute a limitation on the air conditioner, and may include more or fewer components than shown in the figure, or combine some components, or have different component arrangements.

[0279] The non-transitory software programs and instructions required to implement the drive control method applied to the air conditioner in the above embodiments are stored in the memory 2402. When executed by the processor 2401, the drive control method applied to the air conditioner in the above embodiments is executed. For example, the Figure 11 method steps 1101 to 1102 described above, Figure 12 the method step 1201 in, Figure 13 the method steps 1301 to 1305 in, Figure 14 the method steps 1401 to 1405 in, Figure 15 the method step 1501 in, Figure 16 the method steps 1601 to 1603 in, Figure 17 the method steps 1701 to 1703 in, Figure 18 the method steps 1801 to 1805 in, Figure 19 the method steps 1901 to 1905 in.

[0280] 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 may be 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.

[0281] In addition, an embodiment of the present invention also provides a computer-readable storage medium. The computer-readable storage medium stores computer-executable instructions, and the computer-executable instructions are executed by one or more processors 2401. For example, by Figure 24executed by one of the processors 2401, which can cause the above one or more processors 2401 to execute the drive control method in the above method embodiments. For example, execute the Figure 11 method steps 1101 to 1102 in Figure 12 method step 1201 in Figure 13 method steps 1301 to 1305 in Figure 14 method steps 1401 to 1405 in Figure 15 method step 1501 in Figure 16 method steps 1601 to 1603 in Figure 17 method steps 1701 to 1703 in Figure 18 method steps 1801 to 1805 in Figure 19 method steps 1901 to 1905 in

[0282] 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 disc (DVD), or other optical disc storage, magnetic cartridges, tapes, 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 contains 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.

[0283] The above has specifically described the preferred embodiments of the present invention, but the present invention is not limited to the above embodiments. Those skilled in the art can also make various equivalent deformations or substitutions without departing from the spirit of the present invention, and these equivalent deformations or substitutions are all included within the scope defined by the claims of the present invention.

Claims

1. A drive control circuit for driving an open-winding motor having three-phase windings, one end of each winding forming a first three-phase output group, and the other end of each winding forming a second three-phase output group, characterized in that, The drive control circuit includes: A switch component, including a first switch group and a second switch group. The first switch group is connected to the first three-phase output line group, and the second switch group is respectively connected to the first three-phase output line group and the second three-phase output line group. When the first switch group is closed and the second switch group is open, the three-phase windings are switched to star connection; when the first switch group is open and the second switch group is closed, the three-phase windings are switched to delta connection; when both the first switch group and the second switch group are open, the three-phase windings are switched to open winding connection. A first drive circuit, connected to the second three-phase output line group, for providing a first drive voltage to the three-phase windings in star connection state or providing a second drive voltage to the three-phase windings in delta connection state. A second drive circuit, connected to the first three-phase output line group, for providing a third drive voltage to the three-phase windings in delta connection state. A first power supply circuit, connected to the first drive circuit, for providing a first power supply voltage to the first drive circuit. A second power supply circuit, connected to the second drive circuit, for providing a second power supply voltage to the second drive circuit. The first power supply circuit includes a buck circuit or the second power supply circuit includes a boost circuit. During the process of the three-phase windings switching between star connection and delta connection, the second drive circuit provides a sixth drive voltage to the three-phase windings. The sixth drive voltage is used to keep the motor running during the switching process of the three-phase winding connection states. The sixth drive voltage is the neutral point voltage of the three-phase windings in star connection state or the three-phase voltage of the three-phase windings in delta connection state. Or, During the process of the three-phase windings switching between delta connection and open winding connection, the second drive circuit also provides a seventh drive voltage to the three-phase windings. The seventh drive voltage is used to keep the motor running during the switching process of the three-phase winding connection states. The seventh drive voltage is the three-phase voltage of the three-phase windings in delta connection state.

2. The drive control circuit according to claim 1, wherein: The first power supply circuit and the second power supply circuit are grounded and set on a common bus.

3. The drive control circuit according to claim 1, characterized in that: The first drive circuit is also used to provide a fourth drive voltage to the three-phase windings in open winding connection state, and the second drive circuit is also used to provide a fifth drive voltage to the three-phase windings in open winding connection state.

4. The drive control circuit according to claim 1, characterized in that: The first switch group includes a first switch and a second switch. The first three-phase output line group includes a first pin, a second pin, and a third pin. The first switch is respectively connected to the first pin and the second pin, and the second switch is respectively connected to the second pin and the third pin.

5. The drive control circuit according to claim 1, characterized in that: The first switch group includes a first switch, a second switch, and a third switch. The first three-phase output line group includes a first pin, a second pin, and a third pin. One ends of the first switch, the second switch, and the third switch are connected to each other, and the other ends of the first switch, the second switch, and the third switch are respectively connected to the first pin, the second pin, and the third pin.

6. The drive control circuit according to claim 1, wherein: The second switch group includes a fourth switch, a fifth switch, and a sixth switch. The three-phase winding includes a first-phase winding, a second-phase winding, and a third-phase winding. The first-phase winding includes a first pin and a sixth pin. The second-phase winding includes a second pin and a fifth pin. The third-phase winding includes a third pin and a fourth pin. The first three-phase output line group includes the first pin, the second pin, and the third pin. The second three-phase output line group includes the fourth pin, the fifth pin, and the sixth pin. The fourth switch is respectively connected to the second pin and the sixth pin. The fifth switch is respectively connected to the third pin and the fifth pin. The sixth switch is respectively connected to the first pin and the fourth pin.

7. The drive control circuit according to claim 1, wherein: The buck circuit is a buck chopper circuit. The buck chopper circuit includes a first switch tube, a first freewheeling element, a first inductor, a first capacitor, and a first diode. The drain of the first switch tube, the source of the first switch tube, and the first inductor are connected in series and then connected to the first drive circuit. The source of the first switch tube, the first freewheeling element, and the reference ground are connected in series. The source of the first switch tube, the first inductor, the first capacitor, and the reference ground are connected in series. The first diode is anti-parallelly connected across the first switch tube.

8. The drive control circuit according to claim 1, wherein: The boost circuit is a boost chopper circuit or a totem pole circuit.

9. The drive control circuit according to claim 8, wherein: The boost chopper circuit includes a second freewheeling element, a fourth switch tube, a second inductor, a second capacitor, and a fourth diode. The second inductor and the second freewheeling element are connected in series and then connected to the second drive circuit. The second inductor, the drain of the fourth switch tube, the source of the fourth switch tube, and the reference ground are connected in series. The second freewheeling element, the second capacitor, and the reference ground are connected in series. The fourth diode is anti-parallelly connected across the fourth switch tube.

10. The drive control circuit according to claim 1, wherein: The first power supply circuit further includes a first power supply group, and the first power supply group is connected to the buck circuit.

11. The drive control circuit according to claim 1, wherein: The second power supply circuit further includes a second power supply group, and the second power supply group is connected to the boost circuit.

12. The drive control circuit according to claim 1, wherein: Both the first drive circuit and the second drive circuit include a first bridge arm, a second bridge arm, and a third bridge arm connected in parallel with each other. The first bridge arm, the second bridge arm, and the third bridge arm each include two fifth switch tubes connected in series, and a fifth diode is anti-parallelly connected across the fifth switch tube.

13. A drive control method is applied to a drive control circuit, and the drive control circuit is used to drive an open-winding motor with three-phase windings. One end of each winding forms a first three-phase output line group, and the other end of each winding forms a second three-phase output line group. It is characterized in that, The drive control circuit includes: The switch assembly includes a first switch group and a second switch group. The first switch group is connected to the first three-phase output line group, and the second switch group is respectively connected to the first three-phase output line group and the second three-phase output line group. When the first switch group is closed and the second switch group is open, the three-phase windings are switched to star connection. When the first switch group is open and the second switch group is closed, the three-phase windings are switched to delta connection. When both the first switch group and the second switch group are open, the three-phase windings are switched to open winding connection; The first drive circuit is connected to the second three-phase output line group; The second drive circuit is connected to the first three-phase output line group; The first power supply circuit is connected to the first drive circuit; The second power supply circuit is connected to the second drive circuit; During the process of the three-phase windings switching between star connection and delta connection, the second drive circuit provides a sixth drive voltage for the three-phase windings. The sixth drive voltage is used to keep the motor running during the switching process of the connection state of the three-phase windings. The sixth drive voltage is the neutral point voltage when the three-phase windings are in star connection state, or the three-phase voltage when the three-phase windings are in delta connection state; Or, During the process of the three-phase windings switching between delta connection and open winding connection, the second drive circuit also provides a seventh drive voltage for the three-phase windings. The seventh drive voltage is used to keep the motor running during the switching process of the connection state of the three-phase windings. The seventh drive voltage is the three-phase voltage when the three-phase windings are in delta connection state; The drive control method includes: Controlling the opening and closing of the switch assembly to switch the three-phase windings from a first connection state to a second connection state; Controlling the first drive circuit and the second drive circuit to start or stop working, so that the first drive circuit or the second drive circuit provides a drive voltage for the three-phase windings in the corresponding connection state.

14. The drive control method according to claim 13, characterized in that, When the first connection state is delta connection and the second connection state is star connection, controlling the first drive circuit and the second drive circuit to start or stop working, so that the first drive circuit or the second drive circuit provides a drive voltage for the three-phase windings in the corresponding connection state includes: Controlling the first drive circuit to start working and controlling the second drive circuit to stop working, so that the first drive circuit provides a first drive voltage for the three-phase windings in star connection state.

15. The drive control method according to claim 13, characterized in that When the first connection state is star connection and the second connection state is delta connection, controlling the first drive circuit and the second drive circuit to start or stop working, so that the first drive circuit or the second drive circuit provides a drive voltage for the three-phase windings in the corresponding connection state includes: Controlling the first drive circuit to start working and controlling the second drive circuit to stop working, so that the first drive circuit provides a second drive voltage for the three-phase windings in delta connection state; Or, Control the first drive circuit to stop working and control the second drive circuit to start working, so that the second drive circuit provides a third drive voltage to the three-phase windings in the delta connection state.

16. The drive control method according to claim 13, characterized in that, The first connection state is delta connection, and the second connection state is open winding connection. Controlling the first drive circuit and the second drive circuit to start or stop working, so that the first drive circuit or the second drive circuit provides a drive voltage to the three-phase windings in the corresponding connection state, includes: Control the first drive circuit to start working and control the second drive circuit to start working, so that the first drive circuit provides a fourth drive voltage to the three-phase windings in the open winding connection state and the second drive circuit provides a fifth drive voltage to the three-phase windings in the open winding connection state.

17. The drive control method according to claim 13, characterized in that The first connection state is open winding connection, and the second connection state is delta connection. Controlling the first drive circuit and the second drive circuit to start or stop working, so that the first drive circuit or the second drive circuit provides a drive voltage to the three-phase windings in the corresponding connection state, includes: Control the first drive circuit to start working and control the second drive circuit to stop working, so that the first drive circuit provides a second drive voltage to the three-phase windings in the delta connection state; Or, Control the first drive circuit to stop working and control the second drive circuit to start working, so that the second drive circuit provides a third drive voltage to the three-phase windings in the delta connection state.

18. The drive control method according to claim 13, wherein It further includes: Control the second drive circuit to provide a sixth drive voltage to the three-phase windings during the switching process of the three-phase winding connection state.

19. The drive control method according to claim 18, wherein, The first connection state is star connection, and the second connection state is delta connection. Controlling the second drive circuit to provide a sixth drive voltage to the three-phase windings during the switching process of the three-phase winding connection state, includes: Keep the three-phase windings in the star connection, and control the second drive circuit to output the neutral point voltage of the three-phase windings in the star connection state; Control the first switch group to disconnect, and the second drive circuit outputs the neutral point voltage of the three-phase windings in the star connection state for a first time threshold; Control the second drive circuit to output the three-phase voltages of the three-phase windings in the delta connection state; Control the second switch group to close, and the second drive circuit outputs the three-phase voltages of the three-phase windings in the delta connection state for a second time threshold; Control the first drive circuit to output a second drive voltage and control the second drive circuit to stop working.

20. The drive control method according to claim 18, characterized in that, The first connection state is delta connection, and the second connection state is star connection. Controlling the second drive circuit to provide a sixth drive voltage to the three-phase windings during the switching process of the three-phase winding connection state, includes: Control the first driving circuit to output a second driving voltage to keep the three-phase windings in the delta connection, and control the second driving circuit to output the three-phase voltages of the three-phase windings in the delta connection state; Control the second switch group to disconnect, and the second driving circuit outputs the three-phase voltages of the three-phase windings in the delta connection state for a second time threshold; Control the second driving circuit to output the neutral point voltage of the three-phase windings in the star connection state; Control the first switch group to close, and the second driving circuit outputs the neutral point voltage of the three-phase windings in the star connection state for a first time threshold; Control the first driving circuit to output a first driving voltage and control the second driving circuit to stop working.

21. The drive control method according to claim 13, wherein The driving control method further includes: Control the second driving circuit to provide a seventh driving voltage to the three-phase windings during the switching process of the connection state of the three-phase windings.

22. The drive control method according to claim 20, wherein The first connection state is the delta connection, and the second connection state is the open winding connection. Controlling the second driving circuit to provide a seventh driving voltage to the three-phase windings during the switching process of the connection state of the three-phase windings includes: Keep the three-phase windings in the delta connection, and control the second driving circuit to output the three-phase voltages of the three-phase windings in the delta connection state; Control the second switch group to disconnect, and the second driving circuit outputs the three-phase voltages of the three-phase windings in the delta connection state for a second time threshold; Control the first driving circuit to output a fourth driving voltage and control the second driving circuit to output a fifth driving voltage.

23. The drive control method according to claim 20, characterized in that, The first connection state is the open winding connection, and the second connection state is the delta connection. Controlling the second driving circuit to provide a seventh driving voltage to the three-phase windings during the switching process of the connection state of the three-phase windings includes: Keep the three-phase windings in the open winding connection, and control the second driving circuit to output the three-phase voltages of the three-phase windings in the delta connection state; Control the second switch group to close, and the second driving circuit outputs the three-phase voltages of the three-phase windings in the delta connection state for a second time threshold; Control the second driving circuit to stop working and the first driving circuit to output a second driving voltage, or control the first driving circuit to stop working and the second driving circuit to output a third driving voltage.

24. The drive control method according to claim 18, wherein The first connection state is the star connection, and the second connection state is the delta connection. Controlling the second driving circuit to provide a sixth driving voltage to the three-phase windings during the switching process of the connection state of the three-phase windings includes: Keep the three-phase windings in the star connection, and control the second driving circuit to output the neutral point voltage of the three-phase windings in the star connection state; Control the first switch group to disconnect, and the second driving circuit outputs the neutral point voltage of the three-phase windings in the star connection state for a first time threshold; Control the second drive circuit to output a third drive voltage, and the first drive circuit to output three-phase voltages when the three-phase windings are in the delta connection state; Control the second switch group to close, the second drive circuit to output the third drive voltage, and the first drive circuit to output three-phase voltages when the three-phase windings are in the delta connection state, for a second time threshold; Control the first drive circuit to stop working.

25. The drive control method according to claim 18, wherein The first connection state is delta connection, the second connection state is star connection. The control of the second drive circuit to provide a sixth drive voltage to the three-phase windings during the switching process of the connection state of the three-phase windings includes: Control the second drive circuit to output a third drive voltage to keep the three-phase windings in the delta connection, and control the first drive circuit to output three-phase voltages when the three-phase windings are in the delta connection state; Control the second switch group to open, the first drive circuit to output three-phase voltages when the three-phase windings are in the delta connection state, for a second time threshold; Control the first drive circuit to output a first drive voltage, and the second drive circuit to output the neutral point voltage when the three-phase windings are in the star connection state; Control the first switch group to close, the first drive circuit to output the first drive voltage, and the second drive circuit to output the neutral point voltage when the three-phase windings are in the star connection state, for a first time threshold; Control the second drive circuit to stop working.

26. The drive control method according to any one of claims 13 to 25, characterized in that The control of the opening and closing of the switch assembly to switch the three-phase windings from the first connection state to the second connection state includes at least one of the following: According to the operating frequency of the motor being lower than a first frequency threshold, control the opening and closing of the switch assembly to switch the three-phase windings from delta connection to star connection; According to the operating frequency of the motor being higher than the first frequency threshold and lower than a second frequency threshold, control the opening and closing of the switch assembly to switch the three-phase windings from star connection or open winding connection to delta connection; According to the operating frequency of the motor being higher than the second frequency threshold, control the opening and closing of the switch assembly to switch the three-phase windings from delta connection to open winding connection; Wherein, the first frequency threshold is less than the second frequency threshold.

27. The drive control method according to any one of claims 13 to 25, characterized in that, The control of the opening and closing of the switch assembly to switch the three-phase windings from the first connection state to the second connection state includes at least one of the following: According to the operating frequency of the motor being lower than a third frequency threshold, control the opening and closing of the switch assembly to switch the three-phase windings from delta connection to star connection; According to the operating frequency of the motor being higher than a fourth frequency threshold and lower than a fifth frequency threshold, control the opening and closing of the switch assembly to switch the three-phase windings from star connection or open winding connection to delta connection; According to the operating frequency of the motor being higher than a sixth frequency threshold, control the opening and closing of the switch assembly to switch the three-phase windings from delta connection to open winding connection; Among them, the third frequency threshold, the fourth frequency threshold, the fifth frequency threshold, and the sixth frequency threshold increase in sequence.

28. A circuit board, characterized in that: It includes the drive control circuit as described in any one of claims 1 to 12.

29. An air conditioner, characterized in that: It includes the circuit board as described in claim 28; Or, It includes 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 when the instructions are executed by the at least one processor, the at least one processor is enabled to execute the drive control method as described in any one of claims 13 to 27.

30. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer-executable instructions for causing a computer to execute the drive control method as described in any one of claims 13 to 27.

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