Control method and device of motor driving circuit and washing machine

Abstract

The embodiment of the invention provides a control method and device of a motor driving circuit and a washing machine, the method is applied to the washing machine, and the motor driving circuit comprises an inverter circuit connected with a motor of the washing machine and a power factor correction (PFC) circuit connected with the inverter circuit. The control method comprises the step of controlling the bus voltage provided by the PFC circuit to the inverter circuit to be variable. According to the embodiment of the invention, different amplitudes of the bus voltage of the washing machine can be controlled to be matched with different working states of the motor, the power factor of the motor of the washing machine can be improved, and the size of the motor is reduced.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of motor drive technology, and more particularly to a control method and device for a motor drive circuit and a washing machine. Background Art

[0002] With the development of science and technology and the improvement of living standards, manufacturers have higher and higher requirements on the cost and volume of electrical products including household appliances (for example, washing machines). At present, in the motor drive circuit of household appliances with small power motors such as washing machines, power frequency inductors are usually connected in series on the AC side, and the power frequency inductors are installed separately in the home and electrical appliances or integrated with the motor frequency conversion control board, so as to solve the harmonic problem by using series power frequency inductors.

[0003] It should be noted that the above introduction to the background technology is only for the convenience of providing a clear and complete description of the technical solutions of the present application and facilitating the understanding of those skilled in the art. It cannot be considered that the above technical solutions are well known to those skilled in the art simply because they are described in the background technology section of the present application. Summary of the invention

[0004] The inventors have found that in the existing motor drive circuit of the washing machine, the power frequency inductor is large in size and heavy in weight. If it is installed separately, it is time-consuming and labor-intensive. Figure 1 Schematic diagram of the motor drive circuit of a washing machine in the prior art. Figure 1 As shown, the motor drive circuit of the current washing machine is connected in series with an industrial frequency inductor L, which is very large. When integrated into the motor frequency conversion control board, it will seriously affect the miniaturization of the motor control board. The industrial frequency inductor increases with the increase of the capacity of the washing machine, so that the overall volume of the motor and the appliance increases accordingly; and, the bus voltage of the current washing machine remains unchanged in each working state, which may cause the problem of the bus voltage being too high or too low in different working states.

[0005] In order to solve at least one of the above problems or other similar problems, the embodiments of the present application provide a control method and device for a motor drive circuit and a washing machine, so as to control the different amplitudes of the bus voltage of the washing machine to match the different working states of the motor, and can improve the power factor of the washing machine motor and reduce the size of the motor.

[0006] According to a first aspect of an embodiment of the present application, a control method for a motor drive circuit is provided, the method being applied to a washing machine, the motor drive circuit comprising an inverter circuit connected to a motor of the washing machine and a power factor correction (PFC) circuit connected to the inverter circuit, the control method comprising: controlling a bus voltage provided by the PFC circuit to the inverter circuit to be variable.

[0007] In some embodiments, controlling the bus voltage provided by the PFC circuit to the inverter circuit to be variable includes: increasing the bus voltage provided by the PFC circuit to the inverter circuit.

[0008] In some embodiments, controlling the bus voltage value provided by the PFC circuit to the inverter circuit to be variable includes: obtaining a target speed value of the motor; determining the working state of the motor according to the target speed value; setting a bus voltage target value based on the working state; and controlling the PFC circuit so that the bus voltage provided by the PFC circuit to the inverter circuit changes with the bus voltage target value.

[0009] In some embodiments, before controlling the PFC circuit so that the bus voltage provided by the PFC circuit to the inverter circuit changes with the bus voltage target value, controlling the bus voltage value provided by the PFC circuit to the inverter circuit to be variable further includes: collecting a current bus voltage value provided by the PFC circuit to the inverter circuit; collecting a first output current sampling value of the PFC circuit; and collecting a second output current sampling value of the inverter circuit.

[0010] In some embodiments, controlling the PFC circuit so that the bus voltage provided by the PFC circuit to the inverter circuit changes with the bus voltage target value includes: controlling the switching semiconductor device in the PFC circuit according to the current bus voltage value, the first output current sampling value, and the second output current sampling value so that the current bus voltage value is the same as the bus voltage target value; collecting the first output current sampling value of the PFC circuit includes: collecting the first output current sampling value of the PFC circuit through a first current sampling detection resistor in the PFC circuit; collecting the second output current sampling value of the inverter circuit includes: collecting the second output current sampling value of the inverter circuit through multiple second current sampling detection resistors in the inverter circuit.

[0011] In some embodiments, increasing the bus voltage provided by the PFC circuit to the inverter circuit includes: acquiring a target speed value of the motor; determining the working state of the motor according to the target speed value; setting a bus voltage target value based on the working state; collecting a current bus voltage value provided by the PFC circuit to the inverter circuit; collecting a first output current sampling value of the PFC circuit; collecting a second output current sampling value of the inverter circuit; and according to the current bus voltage value, the first output current sampling value and the second output current sampling value control the switching semiconductor device in the PFC circuit, so that the bus voltage provided by the PFC circuit to the inverter circuit increases with the bus voltage target value.

[0012] According to a second aspect of an embodiment of the present application, a control device for a motor drive circuit is provided, the control device for the motor drive circuit comprising: a motor drive circuit comprising an inverter circuit connected to a motor of a washing machine and a power factor correction (PFC) circuit connected to the inverter circuit; and a controller connected to the motor drive circuit for controlling a variable bus voltage provided by the PFC circuit to the inverter circuit.

[0013] In some embodiments, the PFC circuit includes: an inductor, a diode, a switching semiconductor device and a first current sampling detection resistor; the controller includes: a boost module, which is used to control the bus voltage provided by the PFC circuit to the inverter circuit to increase; an acquisition module, which is used to acquire a target speed value of the motor; a determination module, which is used to determine the working state of the motor according to the target speed value; a setting module, which is used to set the bus voltage target value based on the working state; a first acquisition module, which is used to acquire the current bus voltage value provided by the PFC circuit to the inverter circuit; a second acquisition module, which is used to acquire the first output current sampling value of the PFC circuit through the first current sampling detection resistor in the PFC circuit; and a third acquisition module, which is used to acquire the second output current sampling value of the inverter circuit through multiple second current sampling detection resistors in the inverter circuit, and the boost module controls the switching semiconductor device in the PFC circuit according to the current bus voltage value, the first output current sampling value and the second output current sampling value, so that the bus voltage provided by the PFC circuit to the inverter circuit increases with the bus voltage target value.

[0014] In some embodiments, the PFC circuit further includes a capacitor, a positive electrode of the capacitor is connected to the output end of the PFC circuit, a negative electrode of the capacitor is connected to the output end of the switching semiconductor device and one end of the first current sampling detection resistor, and the motor drive circuit further includes: a rectifier circuit, a positive electrode of the rectifier circuit is connected to the input end of the PFC circuit, and a negative electrode of the rectifier circuit is connected to the controller to connect alternating current to the PFC circuit.

[0015] According to a third aspect of an embodiment of the present application, a washing machine is provided, comprising the control device of the motor drive circuit according to the second aspect.

[0016] One of the beneficial effects of the embodiments of the present application is that: according to the embodiments of the present application, by controlling the bus voltage of the washing machine to be variable, different amplitudes of the bus voltage can be matched with different working states of the motor, and a PFC circuit is applied as a harmonic improvement circuit in the motor drive circuit of the washing machine, which can make the power factor reach more than 95%, thereby effectively reducing the size of the power frequency inductor, improving the power factor of the washing machine motor, and reducing the size of the motor.

[0017] With reference to the following description and accompanying drawings, the specific embodiments of the present application are disclosed in detail, indicating the way in which the principles of the present application can be adopted. It should be understood that the embodiments of the present application are not limited in scope. Within the scope of the spirit and clauses of the appended claims, the embodiments of the present application include many changes, modifications and equivalents. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The included drawings are used to provide a further understanding of the embodiments of the present application, which constitute a part of the specification, are used to illustrate the implementation methods of the present application, and together with the text description, explain the principles of the present application. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0019] Figure 1 A schematic diagram of a motor drive circuit of a washing machine in the prior art;

[0020] Figure 2 is a schematic diagram of a control device for a motor drive circuit according to an embodiment of the first aspect of the present application;

[0021] Figure 3 is a circuit diagram of a control device of a circuit driving circuit of an embodiment of the first aspect of the present application;

[0022] Figure 4 is a schematic diagram of a controller according to an embodiment of the first aspect of the present application;

[0023] Figure 5 is a schematic diagram of a control method for a motor drive circuit according to an embodiment of the third aspect of the present application;

[0024] Figure 6 is a schematic diagram of controlling a variable bus voltage in an embodiment of the third aspect of the present application;

[0025] Figure 7 This is a flow chart of controlling bus voltage boosting according to an embodiment of the third aspect of the present application. DETAILED DESCRIPTION

[0026] With reference to the accompanying drawings, the above and other features of the present application will become apparent through the following description. In the description and the accompanying drawings, specific embodiments of the present application are specifically disclosed, which show some embodiments in which the principles of the present application can be adopted. It should be understood that the present application is not limited to the described embodiments. On the contrary, the present application includes all modifications, variations and equivalents falling within the scope of the attached claims.

[0027] In the embodiments of the present application, the terms "first", "second", etc. are used to distinguish different elements in terms of title, but do not indicate the spatial arrangement or temporal order of these elements, etc., and these elements should not be limited by these terms. The term "and / or" includes any one and all combinations of one or more of the associated listed terms. The terms "comprising", "including", "having", etc. refer to the presence of the stated features, elements, components or components, but do not exclude the presence or addition of one or more other features, elements, components or components.

[0028] In the embodiments of the present application, the singular forms "a", "the", etc. include plural forms and should be broadly understood as "a kind" or "a type" rather than being limited to the meaning of "one"; in addition, the term "said" should be understood to include both singular and plural forms, unless the context clearly indicates otherwise. In addition, the term "according to" should be understood as "at least in part according to...", and the term "based on" should be understood as "at least in part based on...", unless the context clearly indicates otherwise.

[0029] The implementation of the embodiments of the present application will be described below with reference to the accompanying drawings.

[0030] Embodiments of the first aspect

[0031] An embodiment of a first aspect of the present application provides a control device for a motor drive circuit, which is applied to a washing machine to control different amplitudes of a bus voltage of the washing machine to match different working states of the motor.

[0032] Figure 2 is a schematic diagram of a control device for a motor drive circuit according to an embodiment of the first aspect of the present application; Figure 3 It is a circuit diagram of a control device of a circuit driving circuit of an embodiment of the first aspect of the present application. Figure 4 It is a schematic diagram of a controller of an embodiment of the first aspect of the present application.

[0033] like Figure 2 and Figure 3 As shown, the control device 2 of the motor drive circuit of the washing machine includes: a motor drive circuit 20 and a controller 30, wherein the motor drive circuit 20 may include a power factor correction (PFC) circuit 201 and an inverter circuit 202, the PFC circuit 201 is connected to the inverter circuit 202, and the inverter circuit 202 is connected to the motor M of the washing machine; the controller 30 is connected to the motor drive circuit 20, and is used to control the bus voltage provided by the PFC circuit 201 to the inverter circuit 202 to be variable.

[0034] According to the above embodiment, the bus voltage provided by the PFC circuit 201 to the inverter circuit 202 is variable through the controller 30, so that different amplitudes of the bus voltage can match different working states of the motor, so that the washing machine is always in the best power consumption in each working state, and the PFC circuit is applied as a harmonic improvement circuit in the motor drive circuit of the washing machine, so that the power factor can reach more than 95%, thereby effectively reducing the size of the power frequency inductor, improving the power factor of the washing machine motor, and reducing the size of the motor.

[0035] In an existing washing machine, when the washing machine is in different working states, the bus voltage provided by the PFC circuit 201 to the inverter circuit 202 is at the same voltage value, which may cause the bus voltage to be too high or too low in different working states, thereby causing problems such as overload operation or high power consumption of the washing machine.

[0036] In an embodiment of the present application, for example, when the washing machine is in a washing state, the bus voltage provided by the PFC circuit 201 to the inverter circuit 202 is V1, and when the washing machine is in a dehydration state, since a higher speed of the motor is required, the bus voltage can be controlled to change from V1 to V2, wherein V2>V1, so that the washing machine can also be in a stable operation in the dehydration state without causing an overload problem; and when the washing machine is in a single drainage state, the required power may be minimal, and at this time the bus voltage can be controlled to change from V1 (or V2) to V3, wherein V3<V1, so that the washing machine can be in a low power consumption state, thereby saving energy.

[0037] In the embodiment of the present application, the above only exemplifies the case where the bus voltage is increased or decreased. In addition to the above, controlling the bus voltage provided by the PFC circuit 201 to the inverter circuit 202 may include increasing, decreasing or maintaining the original voltage value.

[0038] In the embodiment of the present application, since the bus voltage of the washing machine is provided, the washing machine is most likely to be damaged when it is overloaded, and therefore, the control capability of bus voltage boost is more important. That is, in the present application, controlling the bus voltage provided by the PFC circuit 201 to the inverter circuit 202 to be variable more importantly needs to include increasing the bus voltage provided by the PFC circuit 201 to the inverter circuit 202.

[0039] In the following, the bus voltage provided by the PFC circuit 201 to the inverter circuit 202 is controlled to be variable by controlling the increase of the bus voltage.

[0040] In the embodiments of the present application, Figure 3 and Figure 4As shown, the PFC circuit 201 may include: an inductor 2011, a diode 2012, a switch semiconductor device 2013 and a first current sampling detection resistor 2014; the controller 30 may include a boost module 301, an acquisition module 302, a determination module 303, a setting module 304, a first acquisition module 305, a second acquisition module 306 and a third acquisition module 307, wherein the boost module 301 is used to control the bus voltage provided by the PFC circuit 201 to the inverter circuit 202 to increase, and the acquisition module 302 is used to obtain the target speed value S of the motor M. T1 The determination module 303 is used to determine the target speed value S T1 Determine the working state of the motor M, and the setting module 304 is used to set the bus voltage target value V based on the working state T1 The first acquisition module 305 is used to acquire the current bus voltage value V provided by the PFC circuit 201 to the inverter circuit 202 C1 The second acquisition module 306 is used to acquire the first output current sampling value S1 of the PFC circuit 201 through the first current sampling detection resistor 2014 in the PFC circuit 201, and the third acquisition module 307 is used to acquire the second output current sampling value S2 of the inverter circuit 202 through multiple second current sampling detection resistors 2021 in the inverter circuit 202.

[0041] In the embodiment of the present application, the boost module 301 is based on the current bus voltage value V C1 The first output current sampling value S1 and the second output current sampling value S2 control the PFC circuit 201 so that the bus voltage provided by the PFC circuit 201 to the inverter circuit 202 changes with the bus voltage target value V T1 Increase.

[0042] For example, when the washing machine needs to change from the rinsing state to the dehydration state, the acquisition module 302 of the controller 30 obtains the target speed value S that the motor needs to reach from the instruction issued by the main board of the washing machine. T1 Then the determination module 303 of the controller 30 determines the target speed value S T1 To determine the working state that the motor needs to enter (for example, to enter the dehydration working state), the setting module 304 of the controller 30 then sets the bus voltage target value V based on the working state that the motor needs to enter. T1 (For example, the bus voltage target value V is set according to the dehydration state T1 ), the bus voltage target value V T1 For example, the data may be buffered in a buffer (not shown) of the controller 30 .

[0043] For example, the first acquisition module 305 of the controller 30 acquires the bus voltage value V of the current working state of the washing machine. C1(For example, the current bus voltage value V of the washing machine in the rinsing state C1 ), the second acquisition module 306 of the controller 30 acquires the first output current sampling value S1 of the PFC circuit 201 (for example, current sampling is performed through the first current sampling detection resistor 2014 in the PFC circuit 201), and the third acquisition module 307 of the controller 30 acquires the second output current sampling value S2 of the inverter circuit 202 (for example, current sampling is performed through multiple second current sampling detection resistors 2021 in the inverter circuit 202).

[0044] For example, the boost module 301 of the controller 30 obtains the bus voltage target value V from the buffer. T1 , and then according to the current bus voltage value V collected by the first collection module 305 C1 , the first output current sampling value S1 collected by the second acquisition module 306 and the second output current sampling value S2 collected by the third acquisition module 307 to control the PFC circuit 201 (for example, control the switch semiconductor device 2013 in the PFC circuit 201) to change the current bus voltage value V C1 The voltage is increased to the bus voltage target value V T1 .

[0045] Therefore, the controller 30 can control the switching semiconductor device 2013 in the PFC circuit 201 through the sampling results, and increase the bus voltage provided by the PFC circuit 201 to the inverter circuit 202, thereby improving the high-speed weak magnetic capability of the motor, and since the current becomes smaller, the size of the motor driven by the inverter circuit 202 can be reduced, thereby reducing the design material cost of the overall motor.

[0046] In the embodiments of the present application, Figure 3 As shown, the controller 30 may be a microcontroller unit (MCU), and the inverter circuit 202 may include, for example, a plurality of second current sampling detection resistors 2021 and an intelligent power module (IPM) 2022, for example, Figure 3 As shown, the number of the plurality of second current sampling detection resistors 402 is three, and the plurality of second current sampling detection resistors 402 are connected in parallel, so that the three second current sampling detection resistors 2021 can respectively detect the three-phase current of the IPM 2022, for example.

[0047] Hereinafter, the circuit connection of the control device 2 of the circuit driving circuit will be described in detail.

[0048] In the embodiments of the present application, Figure 3As shown, the output terminal I1 of the inverter circuit 202 is connected to the motor M of the washing machine, the first terminal T1 of the IPM 2022 is the input terminal I2 of the inverter circuit 202, the driving terminal D1 of the IPM 2022 is the output terminal I1 of the inverter circuit 202, one end of the plurality of second current sampling detection resistors 2021 is connected to the second end T2 of the IPM 2022, the other end of the plurality of second current sampling detection resistors 2021 is connected to the output terminal 2013-2 of the switching semiconductor device 2013 and is connected in series with one end of the first current sampling detection resistor 2014; the output terminal C1 of the PFC circuit 201 is connected to the input terminal I2 of the inverter circuit 202, that is, the output terminal C1 of the PFC circuit 201 is connected to the IPM The first end T1 of the controller 30 is connected to the first end T2 of the PFC circuit 2022, one end of the inductor 2011 in the PFC circuit 201 is connected to the input end C2 of the PFC circuit 201, the other end of the inductor 2011 is connected to the positive electrode of the diode 2012 and the input end 2013-1 of the switching semiconductor device 2013, the negative electrode of the diode 2012 and the output end 2013-2 of the switching semiconductor device 2013 are connected to the output end C1 of the PFC circuit 201, and one end of the first current sampling detection resistor 2014 is connected to the output end 2013-2 of the switching semiconductor device 2013; the input port of the controller 30 is respectively connected to the other end of the first current sampling detection resistor 2014, the other end of the plurality of second current sampling detection resistors 2021, and the output end C1 of the PFC circuit 201, and the output port of the controller 30 is respectively connected to the control port 2013-3 of the switching semiconductor device 2013 and the control port of the IPM 2022.

[0049] In the embodiments of the present application, Figure 3 As shown, the PFC circuit 201 may further include a capacitor 2015 , the positive electrode of the capacitor 2015 is connected to the output terminal C1 of the PFC circuit 201 , and the negative electrode of the capacitor 2015 is connected to the output terminal 2013 - 2 of the switching semiconductor device 2013 and one end of the first current sampling detection resistor 2014 .

[0050] Therefore, capacitor 2015 can be used to store energy. While increasing the bus voltage, the capacitance of the bus voltage capacitor can be reduced through capacitor 2015 in the PFC circuit 201, thereby further improving the high-speed weak magnetic capability of the motor.

[0051] In the embodiments of the present application, Figure 2 and Figure 3As shown, the motor drive circuit 20 may further include: a rectifier circuit 203, wherein the positive electrode of the rectifier circuit 203 is connected to the input terminal C2 of the PFC circuit 201, the negative electrode of the rectifier circuit 203 is connected to the controller 30, and the rectifier circuit 203 is used to connect the AC power to the PFC circuit 201. Specifically, the rectifier circuit 203 may include a power module 2031 and a bridge rectifier diode (rectifier bridge) 2032, wherein the AC voltage input terminal of the bridge rectifier diode 2032 is connected to the AC voltage output terminal of the power module 2031, the positive electrode of the bridge rectifier diode 2032 is connected to the input terminal C2 of the PFC circuit 201, and the positive electrode of the bridge rectifier diode 2032 is connected to the other end of the first current sampling detection resistor 2014 and the controller 30.

[0052] In the embodiment of the present application, the PFC circuit 201 is an active PFC circuit to further achieve the effects of small size and high power factor.

[0053] In the embodiment of the present application, the PFC circuit 201 is a boost type PFC circuit.

[0054] In the embodiment of the present application, the first current sampling detection resistor 2014 may be a shunt resistor.

[0055] In the embodiment of the present application, in addition to sampling the current and / or voltage of the above three ports, the controller 30 can also perform AC zero-crossing sampling on the rectifier circuit 203. In this way, the controller 30 can control the switching semiconductor device 2013 in the PFC circuit 201 through the four sampling results to increase the bus voltage.

[0056] In the embodiment of the present application, the switch semiconductor device 2013 may be an insulated gate bipolar transistor (IGBT) or a metal oxide semiconductor field effect transistor (MOS). Figure 3 In FIG. 1 , the case where the switching semiconductor device 2013 is an IGBT is illustrated as an example.

[0057] In the case where the switching semiconductor device 2013 is an IGBT or a MOS, the control port 2013 - 3 is a gate of the IGBT or the MOS.

[0058] like Figure 3 As shown, when the switching semiconductor device 2013 is an insulated gate bipolar transistor (IGBT), the collector C of the IGBT is the input terminal 2013 - 1 of the switching semiconductor device 2013 , and the emitter E of the IGBT is the output terminal 2013 - 2 of the switching semiconductor device 2013 .

[0059] When the switching semiconductor device 2013 is a metal oxide semiconductor field effect transistor (MOS) (not shown), the source S of the MOS is the input terminal 2013 - 1 of the switching semiconductor device 2013 , and the drain D of the MOS is the output terminal 2013 - 2 of the switching semiconductor device 2013 .

[0060] It is worth noting that the above Figure 3 The embodiments of the present invention are merely schematically described, but the present invention is not limited thereto. Figure 3 The components or elements shown in the figure are only examples; for example, the connection or position of these components or elements may be adjusted, and / or some components or elements may be omitted, and / or additional components or elements may be added. Figure 3 Components or elements not shown.

[0061] The above embodiments or implementations are only exemplary descriptions of the embodiments of the present invention, but the present invention is not limited thereto, and appropriate modifications can be made on the basis of the above embodiments or implementations. For example, the above embodiments or implementations can be used alone, or one or more of the above embodiments or implementations can be combined.

[0062] In the embodiment of the present application, the control device 2 of the motor drive circuit can be applied to the motor of the washing machine as well as other low-power motors, including motors with a power of less than 1000 watts at a speed of 20,000 rpm and motors with a power of more than 10 watts at a speed of 5,000 rpm. Electrical products with such low-power motors may also include, for example, washing machines, dishwashers, dryers, etc.

[0063] It can be seen from the above embodiments that the bus voltage provided by the PFC circuit 201 to the inverter circuit 202 is variable by the controller 30, so that different amplitudes of the bus voltage can match different working states of the motor, so that the washing machine is always in the best power consumption in each working state, and the PFC circuit is applied as a harmonic improvement circuit in the motor drive circuit of the washing machine, so that the power factor can reach more than 95%, thereby effectively reducing the size of the power frequency inductor, improving the power factor of the washing machine motor, and reducing the size of the motor.

[0064] Embodiments of the second aspect

[0065] An embodiment of the second aspect of the present application provides a washing machine, which has a control device 2 for a motor drive circuit as described in the embodiment of the first aspect. Since the main structure of the control device 2 for a motor drive circuit has been described in detail in the embodiment of the first aspect, its content is included here and will not be repeated here.

[0066] In the embodiment of the present application, the control device 2 of the machine drive circuit can be applied to not only the motor of the washing machine, but also other low-power motors, including motors with a power of less than 1000 watts at a speed of 20,000 rpm and motors with a power of more than 10 watts at a speed of 5,000 rpm. Electrical products with such low-power motors may also include, for example, washing machines, dishwashers, dryers, etc.

[0067] According to the washing machine of the embodiment of the present application, the bus voltage provided by the PFC circuit 201 to the inverter circuit 202 is variable through the controller 30, so that different amplitudes of the bus voltage can match different working states of the motor, so that the washing machine is always in the best power consumption in each working state, and the PFC circuit is applied as a harmonic improvement circuit in the motor drive circuit of the washing machine, so that the power factor can reach more than 95%, thereby effectively reducing the size of the power frequency inductor, improving the power factor of the washing machine motor, and reducing the size of the motor.

[0068] Embodiments of the third aspect

[0069] The embodiment of the third aspect of the present application provides a control method for a motor drive circuit. The method is applied to a washing machine to control different amplitudes of the bus voltage of the washing machine to match different working states of the motor. The motor drive circuit in the embodiment of the third aspect is the same as the motor drive circuit 20 in the embodiment of the first aspect. Since the main structure of the motor drive circuit 20 has been described in detail in the embodiment of the first aspect, its content is included here and will not be repeated here.

[0070] Figure 5 It is a schematic diagram of a control method of a motor drive circuit of an embodiment of the third aspect of the present application.

[0071] like Figure 5 As shown, the control method of the motor drive circuit may include:

[0072] 501, controlling the bus voltage provided by the PFC circuit 201 to the inverter circuit 202 to be variable.

[0073] According to the above embodiment, by controlling the bus voltage provided by the PFC circuit 201 to the inverter circuit 202 to be variable, different amplitudes of the bus voltage can be matched with different working states of the motor, so that the washing machine is always in the best power consumption in each working state, and the PFC circuit is applied as a harmonic improvement circuit in the motor drive circuit of the washing machine, so that the power factor can reach more than 95%, thereby effectively reducing the size of the power frequency inductor, improving the power factor of the washing machine motor, and reducing the size of the motor.

[0074] Figure 6Schematic diagram of controlling the variable bus voltage in the embodiment of the third aspect of the present application. Figure 6 As shown, controlling the bus voltage provided by the PFC circuit 201 to the inverter circuit 202 to be variable (501) may include:

[0075] 601, obtain the target speed value S of the motor T1 ;

[0076] For example, the acquisition module 302 of the controller 30 acquires the target speed value S T1 .

[0077] 602, according to the target speed value S T1 Determine the working state of the motor M;

[0078] For example, the determination module 303 of the controller 30 determines the target speed value S T1 Determine whether the working state of the motor M is the washing state or the dehydration state.

[0079] 603, setting the bus voltage target value V based on the working state T1 ;

[0080] For example, the setting module 304 of the controller 30 sets the bus voltage target value V based on the working state. T1 .

[0081] 604, control the PFC circuit 201 so that the bus voltage provided by the PFC circuit 201 to the inverter circuit 202 changes with the bus voltage target value V T1 Change.

[0082] For example, the boost module 301 of the controller 30 makes the bus voltage follow the bus voltage target value V T1 Increase.

[0083] In the embodiment of the present application, controlling the bus voltage provided by the PFC circuit 201 to the inverter circuit 202 to be variable may include: increasing, decreasing or maintaining the bus voltage at the original voltage value. By increasing the bus voltage, the high-speed weak magnetic capability of the motor can be improved, and since the current becomes smaller, the size of the motor driven by the inverter circuit 202 can be reduced, thereby reducing the design material cost of the overall motor.

[0084] In the embodiment of the present application, before 604, controlling the bus voltage provided by the PFC circuit 201 to the inverter circuit 202 to be variable (501) may also include: collecting the current bus voltage value V provided by the PFC circuit 201 to the inverter circuit 202 C1 For example, the first acquisition module 305 of the controller 30 acquires the bus voltage value V of the current working state of the washing machine. C1 (For example, the current bus voltage value V of the washing machine in the rinsing stateC1 ); collecting a first output current sampling value S1 of the PFC circuit 201, for example, the second acquisition module 306 of the controller 30 collects the first output current sampling value S1 of the PFC circuit 201; and collecting a second output current sampling value S2 of the inverter circuit 202, for example, the third acquisition module 307 of the controller 30 collects the second output current sampling value S2 of the inverter circuit 202.

[0085] In the embodiment of the present application, after collecting the current bus voltage value V C1 , after the first output current sampling value S1 and the second output current sampling value S2, the PFC circuit 201 is controlled so that the bus voltage provided by the PFC circuit 201 to the inverter circuit 202 changes with the bus voltage target value V T1 The change (604) may include: according to the current bus voltage value V C1 The first output current sampling value S1 and the second output current sampling value S2 control the switch semiconductor device 2013 in the PFC circuit 201 so that the current bus voltage value V C1 and bus voltage target value V T1 same.

[0086] For example, the boost module 301 of the controller 30 is based on the current bus voltage value V C1 The first output current sampling value S1 and the second output current sampling value S2 control the switch semiconductor device 2013 of the PFC circuit 201, so that the bus voltage (current bus voltage value V C1 ) with the bus voltage target value V T1 Increase.

[0087] In the embodiment of the present application, collecting the first output current sampling value S1 of the PFC circuit 201 may include: collecting the first output current sampling value S1 of the PFC circuit 201 through the first current sampling detection resistor 2014 in the PFC circuit 201; collecting the second output current sampling value S2 of the inverter circuit 202 may include: collecting the second output current sampling value S2 of the inverter circuit 202 through multiple second current sampling detection resistors 2021 in the inverter circuit 202.

[0088] In the following, taking increasing the bus voltage value of a washing machine as an example, the specific process of the control method of the motor drive circuit is explained.

[0089] Figure 7 This is a flow chart of controlling bus voltage boosting according to an embodiment of the third aspect of the present application.

[0090] like Figure 7 As shown, increasing the bus voltage provided by the PFC circuit 201 to the inverter circuit 202 may include:

[0091] 701, obtain the target speed value S of the motor M T1 ;

[0092] For example, the acquisition module 302 of the controller 30 acquires the target speed value S that the motor needs to reach from the instruction issued by the main board of the washing machine. T1 .

[0093] 702, according to the target speed value S T1 Determine the working state of the motor M;

[0094] For example, the determination module 303 of the controller 30 determines the target speed value S T1 To determine the working state that the motor needs to enter (for example, to enter the dehydration working state).

[0095] 703, setting the bus voltage target value V based on the working state T1 ;

[0096] For example, the setting module 304 of the controller 30 sets the bus voltage target value V based on the working state that the motor M needs to enter. T1 (For example, the bus voltage target value V is set according to the dehydration state T1 ), the bus voltage target value V T1 For example, it may be buffered in a buffer of the controller 30 .

[0097] 704, collecting the current bus voltage value V provided by the PFC circuit 201 to the inverter circuit 202 C1 ;

[0098] For example, the first acquisition module 305 of the controller 30 acquires the bus voltage value V of the current working state of the washing machine. C1 (For example, the current bus voltage value V of the washing machine in the rinsing state C1 ).

[0099] 705 , collecting a first output current sampling value S1 of the PFC circuit 201 ;

[0100] For example, the second acquisition module 306 of the controller 30 acquires the first output current sampling value S1 of the PFC circuit 201 (for example, current sampling is performed through the first current sampling detection resistor 2014 in the PFC circuit 201 ).

[0101] 706, collecting a second output current sample value S2 of the inverter circuit 202;

[0102] For example, the third acquisition module 307 of the controller 30 acquires the second output current sampling value S2 of the inverter circuit 202 (for example, current sampling is performed through a plurality of second current sampling detection resistors 2021 in the inverter circuit 202 ).

[0103] 707, according to the current bus voltage value V C1 The first output current sampling value S1 and the second output current sampling value S2 control the switch semiconductor device 2013 in the PFC circuit 201 so that the current bus voltage value V C1 With the bus voltage target value V T1 Increase.

[0104] For example, the boost module 301 of the controller 30 obtains the bus voltage target value V from the buffer. T1 , and then according to the current bus voltage value V collected by the first collection module 305 C1 , the first output current sampling value S1 collected by the second acquisition module 306 and the second output current sampling value S2 collected by the third acquisition module 307 to control the PFC circuit 201 (for example, control the switch semiconductor device 2013 in the PFC circuit 201) to change the current bus voltage value V C1 The voltage is increased to the bus voltage target value V T1 .

[0105] Therefore, the switching semiconductor device 2013 in the PFC circuit 201 can be controlled by the sampling result, and the bus voltage provided by the PFC circuit 201 to the inverter circuit 202 can be increased, thereby improving the high-speed weak magnetic capability of the motor, and since the current becomes smaller, the size of the motor driven by the inverter circuit 202 can be reduced, thereby reducing the design material cost of the overall motor.

[0106] In the embodiment of the present application, the order of the above 705 and 706 can be swapped.

[0107] According to the control method of the motor drive circuit of the embodiment of the present application, by controlling the bus voltage provided by the PFC circuit 201 to the inverter circuit 202 to be variable, different amplitudes of the bus voltage can be matched with different working states of the motor, so that the washing machine is always in the optimal power consumption in each working state, and the PFC circuit is applied as a harmonic improvement circuit in the motor drive circuit of the washing machine, which can make the power factor reach more than 95%, thereby effectively reducing the size of the power frequency inductor, improving the power factor of the washing machine motor, and reducing the size of the motor.

[0108] The present application is described above in conjunction with specific embodiments, but it should be clear to those skilled in the art that these descriptions are exemplary and are not intended to limit the scope of protection of the present application. Those skilled in the art can make various modifications and variations to the present application based on the spirit and principles of the present application, and these modifications and variations are also within the scope of the present application.

[0109] The preferred embodiments of the present application are described above with reference to the accompanying drawings. Many features and advantages of these embodiments are clear from this detailed description, and therefore the appended claims are intended to cover all such features and advantages of these embodiments that fall within their true spirit and scope. In addition, since many modifications and changes are easily conceivable to those skilled in the art, the embodiments of the present application are not intended to be limited to the precise structures and operations illustrated and described, but all suitable modifications and equivalents that fall within their scope may be covered.

Claims

1. A control method for a motor drive circuit, the method being applied to a washing machine, wherein the motor drive circuit comprises an inverter circuit connected to a motor of the washing machine and a power factor correction (PFC) circuit connected to the inverter circuit, wherein: The control method comprises: The bus voltage provided by the PFC circuit to the inverter circuit is controlled to be variable.

2. The control method of the motor drive circuit according to claim 1, characterized in that: Controlling the bus voltage provided by the PFC circuit to the inverter circuit to be variable includes: The bus voltage provided by the PFC circuit to the inverter circuit is increased.

3. The control method of the motor drive circuit according to claim 1, characterized in that: Controlling the bus voltage value provided by the PFC circuit to the inverter circuit to be variable includes: Get the target speed value of the motor; Determining the working state of the motor according to the target speed value; Setting a bus voltage target value based on the operating state; and The PFC circuit is controlled so that a bus voltage provided by the PFC circuit to the inverter circuit changes according to the bus voltage target value.

4. The control method of the motor drive circuit according to claim 3, characterized in that: Before controlling the PFC circuit so that the bus voltage provided by the PFC circuit to the inverter circuit changes with the bus voltage target value, controlling the bus voltage value provided by the PFC circuit to the inverter circuit to be variable further includes: Collecting a current bus voltage value provided by the PFC circuit to the inverter circuit; collecting a first output current sampling value of the PFC circuit; and A second output current sampling value of the inverter circuit is collected.

5. The control method of the motor drive circuit according to claim 4, characterized in that: Controlling the PFC circuit so that the bus voltage provided by the PFC circuit to the inverter circuit changes with the bus voltage target value includes: According to the current bus voltage value, the first output current sampling value and the second output current sampling value, the switching semiconductor device in the PFC circuit is controlled so that the current bus voltage value is the same as the bus voltage target value. Collecting a first output current sampling value of the PFC circuit includes: The first output current sampling value of the PFC circuit is collected through the first current sampling detection resistor in the PFC circuit. Collecting the second output current sampling value of the inverter circuit includes: The second output current sampling value of the inverter circuit is collected through a plurality of second current sampling detection resistors in the inverter circuit.

6. The control method of the motor drive circuit according to claim 2, characterized in that: Increasing the bus voltage provided by the PFC circuit to the inverter circuit comprises: Get the target speed value of the motor; Determining the working state of the motor according to the target speed value; Setting a bus voltage target value based on the working state; Collecting a current bus voltage value provided by the PFC circuit to the inverter circuit; Collecting a first output current sampling value of the PFC circuit; Collecting a second output current sampling value of the inverter circuit; According to the current bus voltage value, the first output current sampling value and the second output current sampling value, the switching semiconductor device in the PFC circuit is controlled so that the bus voltage provided by the PFC circuit to the inverter circuit increases with the bus voltage target value.

7. A control device for a motor drive circuit, which is applied to a washing machine, characterized in that: The control device of the motor drive circuit comprises: A motor drive circuit, comprising an inverter circuit connected to a motor of a washing machine and a power factor correction (PFC) circuit connected to the inverter circuit; and A controller is connected to the motor drive circuit and is used to control the bus voltage provided by the PFC circuit to the inverter circuit to be variable.

8. The control device for the motor drive circuit according to claim 7, characterized in that: The PFC circuit comprises: An inductor, a diode, a switch semiconductor device and a first current sampling detection resistor; The controller comprises: A boost module, used for controlling the bus voltage provided by the PFC circuit to the inverter circuit to increase; An acquisition module, which is used to obtain a target speed value of the motor; A determination module, configured to determine a working state of the motor according to the target speed value; A setting module, used for setting a bus voltage target value based on the working state; A first acquisition module, which is used to acquire a current bus voltage value provided by the PFC circuit to the inverter circuit; a second acquisition module, which is used to acquire a first output current sampling value of the PFC circuit through a first current sampling detection resistor in the PFC circuit; and a third acquisition module, which is used to acquire a second output current sampling value of the inverter circuit through a plurality of second current sampling detection resistors in the inverter circuit; The boost module controls the switching semiconductor device in the PFC circuit according to the current bus voltage value, the first output current sampling value, and the second output current sampling value, so that the bus voltage provided by the PFC circuit to the inverter circuit increases with the bus voltage target value.

9. The control device for the motor drive circuit according to claim 8, characterized in that: The PFC circuit further includes a capacitor, wherein the positive electrode of the capacitor is connected to the output end of the PFC circuit, and the negative electrode of the capacitor is connected to the output end of the switching semiconductor device and one end of the first current sampling detection resistor. The motor drive circuit further includes: A rectifier circuit, wherein the positive electrode of the rectifier circuit is connected to the input end of the PFC circuit, and the negative electrode of the rectifier circuit is connected to the controller, so as to connect alternating current to the PFC circuit.

10. A washing machine, characterized in that: The washing machine comprises the control device of the motor drive circuit according to any one of claims 7 to 9.

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