Control method and system of interior permanent magnet motor, household appliance and storage medium

Abstract

The application discloses a control method and system of an embedded permanent magnet motor, household electrical appliances and a computer readable storage medium. The control method of the embedded permanent magnet motor comprises the following steps: obtaining a first-phase current and a second-phase current of the embedded permanent magnet motor respectively, obtaining a third-phase current of the embedded permanent magnet motor based on the first-phase current and the second-phase current, obtaining a current vector of the embedded permanent magnet motor, and obtaining a voltage vector of the embedded permanent magnet motor; obtaining a position estimation value of a rotor of the embedded permanent magnet motor based on the current vector and the voltage vector by using a sliding mode observation model; and compensating a torque of the embedded permanent magnet motor by using the position estimation value. In this way, the embedded permanent magnet motor can realize constant torque and constant speed output, the hardware structure of a current sampling module of the embedded permanent magnet motor can be simplified, and cost can be saved.

Description

Technical Field

[0001] This application relates to the field of motor technology, and in particular to a control method and system for an embedded permanent magnet motor, household appliances, and computer-readable storage media. Background Technology

[0002] Currently, the mainstream motors in blenders and other home appliances on the market are cascade motors. Cascade motors have low torque output at low speeds, which cannot meet the speed requirements of some cooking functions, and they also have large speed fluctuations and high noise. Summary of the Invention

[0003] The main technical problem addressed in this application is how to achieve constant torque and constant speed output of an embedded permanent magnet motor, while simplifying the hardware structure of its current sampling module and saving costs.

[0004] To address the aforementioned technical problems, this application provides a control method for an embedded permanent magnet motor. This control method includes: acquiring the first-phase current and the second-phase current of the embedded permanent magnet motor, and acquiring the third-phase current of the embedded permanent magnet motor based on the first-phase current and the second-phase current to obtain the current vector and voltage vector of the embedded permanent magnet motor; using a sliding mode observation model to obtain the position estimate of the rotor of the embedded permanent magnet motor based on the current vector and the voltage vector; and using the position estimate to compensate for the torque of the embedded permanent magnet motor.

[0005] To address the aforementioned technical problems, another technical solution adopted in this application is: providing a control system for an embedded permanent magnet motor. This control system includes: a detection module, used to acquire the first-phase current and the second-phase current of the embedded permanent magnet motor, and based on the first-phase current and the second-phase current, acquire the third-phase current of the embedded permanent magnet motor to obtain the current vector of the embedded permanent magnet motor, and acquire the voltage vector of the embedded permanent magnet motor; a position estimation module, connected to the detection module, used to acquire the position estimate of the embedded permanent magnet motor based on the current vector and the voltage vector using a sliding mode observation model; and a control module, connected to both the position estimation module and the embedded permanent magnet motor, used to compensate for the torque of the embedded permanent magnet motor using the position estimate.

[0006] To solve the above-mentioned technical problems, another technical solution adopted in this application is to provide a household appliance. This household appliance includes an embedded permanent magnet motor and a control system connected to the embedded permanent magnet motor, wherein the control system is the control system of the aforementioned embedded permanent magnet motor.

[0007] To address the aforementioned technical problems, another technical solution adopted in this application is to provide a computer-readable storage medium. This computer-readable storage medium stores program instructions that can be executed to implement the aforementioned control method for the embedded permanent magnet motor.

[0008] The beneficial effects of the embodiments of this application are as follows: The control method for the embedded permanent magnet motor of this application includes: acquiring the first phase current and the second phase current of the embedded permanent magnet motor respectively, and acquiring the third phase current of the embedded permanent magnet motor based on the first phase current and the second phase current to obtain the current vector of the embedded permanent magnet motor, and acquiring the voltage vector of the embedded permanent magnet motor; using a sliding mode observation model to obtain the position estimate of the rotor of the embedded permanent magnet motor based on the current vector and the voltage vector; and using the position estimate to compensate for the torque of the embedded permanent magnet motor. In this way, this application can estimate the position of the rotor of the embedded permanent magnet motor using a sliding mode observation model, and use the position estimate to compensate for the torque of the embedded permanent magnet motor, which can achieve constant torque and constant speed output of the embedded permanent magnet motor and reduce noise; and this application only needs to collect the first phase current and the second phase current of the embedded permanent magnet motor to obtain the current vector of the embedded permanent magnet motor, thus simplifying the hardware structure of its current sampling module and saving costs. Attached Figure Description

[0009] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0010] Figure 1 This is a flowchart illustrating an embodiment of the control method for an embedded permanent magnet motor according to this application;

[0011] Figure 2 yes Figure 1 A schematic diagram illustrating the specific steps of step S11 in the control method of the embedded permanent magnet motor in the embodiment;

[0012] Figure 3 This is a schematic diagram of the circuit structure of the embedded permanent magnet motor and its inverter circuit of this application;

[0013] Figure 4 yes Figure 2 A timing diagram of two-phase current sampling in the embodiment;

[0014] Figure 5 yes Figure 1 A schematic diagram of the motor model of the embedded permanent magnet motor in the embodiment;

[0015] Figure 6 yes Figure 1 A schematic diagram of the sliding mode observation model of the embedded permanent magnet motor in the embodiment;

[0016] Figure 7 yes Figure 1 A schematic diagram of the specific steps in step S12 of the control method for the embedded permanent magnet motor in the embodiment;

[0017] Figure 8 yes Figure 7 A flowchart illustrating the specific steps of step S72 in the embodiment;

[0018] Figure 9 yes Figure 1 A schematic diagram illustrating the specific steps of step S13 in the control method of the embedded permanent magnet motor in the embodiment;

[0019] Figure 10 This is a flowchart illustrating an embodiment of the control method for an embedded permanent magnet motor according to this application;

[0020] Figure 11 This is a schematic diagram of the structure of an embodiment of the control system of the embedded permanent magnet motor of this application;

[0021] Figure 12 This is a schematic diagram of the workflow of an embodiment of the control system of the embedded permanent magnet motor of this application;

[0022] Figure 13 This is a schematic diagram of the structure of one embodiment of the household appliance of this application;

[0023] Figure 14 This is a schematic diagram of the structure of an embodiment of the computer-readable storage medium of this application. Detailed Implementation

[0024] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be particularly noted that the following embodiments are for illustrative purposes only and do not limit the scope of the application. Similarly, the following embodiments are only some, not all, embodiments of the present application, and all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of the present application.

[0025] This application first proposes a control method for an embedded permanent magnet motor, such as... Figure 1 As shown, Figure 1 This is a flowchart illustrating an embodiment of the control method for an embedded permanent magnet motor according to this application. The control method for the embedded permanent magnet motor in this embodiment specifically includes the following steps:

[0026] Step S11: Obtain the first phase current and the second phase current of the embedded permanent magnet motor respectively, and obtain the third phase current of the embedded permanent magnet motor based on the first phase current and the second phase current, so as to obtain the current vector of the embedded permanent magnet motor and the voltage vector of the embedded permanent magnet motor.

[0027] Specifically, this embodiment can be achieved through, as follows: Figure 2 The method described above implements step S11. Specifically, the method of this embodiment includes steps S21 to S23.

[0028] Step S21: Obtain the first phase current through the first resistor and the second phase current through the second resistor.

[0029] In an application scenario, such as Figure 3 As shown, in this embodiment, a first resistor R1 can be connected in series on the lower bridge arm connected to the u-phase winding in the inverter circuit (not shown in the figure) of the embedded permanent magnet motor 31, and a second resistor R2 can be connected in series on the lower bridge arm connected to the v-phase winding; the current on the lower bridge arm connected to the u-phase winding can be sampled through the first resistor R1 to obtain the first phase current i of the embedded permanent magnet motor 31. a The current on the lower bridge arm connected to the v-phase winding can be sampled through the second resistor R2 to obtain the second phase current i of the embedded permanent magnet motor 31. b .

[0030] It should be noted that when sampling the two-phase current of the embedded permanent magnet motor 31, the sampling timing is when the lower bridge arm connected by the three-phase windings is simultaneously turned on.

[0031] In the above application scenarios, the current sampling timing is as follows: Figure 4 As shown, when the lower bridge arm connected by the three-phase windings u, v, and w is simultaneously turned on, the current corresponding to the u-phase winding is sampled through the first resistor R1 to obtain the first-phase current i. a The current corresponding to phase v winding is sampled through the second resistor R2 to obtain the second phase current i. b .

[0032] In other embodiments, the current of any two other phases of the embedded permanent magnet motor can also be collected through two resistors.

[0033] Step S22: Calculate the third phase current using the first phase current and the second phase current to obtain the current vector.

[0034] When the lower bridge arm connected by the three-phase windings u, v, and w is simultaneously turned on, the first phase current i a Second phase current i b and the third phase current i c Conditions are met: i a +i b +i c=0. Therefore, based on this condition, the first phase current i can be used... a Second phase current i b Obtain the third phase current i c The obtained current vector i s Satisfy: i s =(i a i b i c ).

[0035] Furthermore, this embodiment can also estimate the current reference, maximum sampling current, and minimum sampling current based on the sampling resistor, operational amplifier amplification factor, and ADC reference voltage of the chip.

[0036] Step S23: Obtain the voltage vector of the embedded permanent magnet motor based on the current vector.

[0037] Specifically, the voltage vector can be obtained by taking the voltage of each phase based on the current of each phase in the current vector, the equivalent resistance of the winding corresponding to each phase current, and the equivalent inductance.

[0038] Step S12: Use the sliding mode observation model to obtain the position estimate of the embedded permanent magnet motor based on the current vector and voltage vector.

[0039] The motor model of the embedded permanent magnet motor in the two-phase stationary αβ coordinate system (which can be transformed into the three-phase stationary abc coordinate system (corresponding to the three-phase current vectors mentioned above) is as follows: Figure 5 As shown, v s R is the input voltage of the embedded permanent magnet motor, L is the equivalent resistance of the embedded permanent magnet motor windings, and e is the equivalent inductance of the embedded permanent magnet motor. s This is the back electromotive force of the embedded permanent magnet motor. The embedded permanent magnet motor model satisfies the following formula:

[0040]

[0041] Solve for the current vector i s :

[0042]

[0043] In the number domain, the above expression can be represented as:

[0044]

[0045] Where s = α, β.

[0046] Solve for the current vector i s (n+1):

[0047]

[0048] Among them, T s This represents the motor torque.

[0049] A sliding mode observation model is established to estimate the induced electromotive force, rotational speed (angular velocity), and position of the embedded permanent magnet motor. The structure of the sliding mode observation model in this embodiment is as follows: Figure 6 As shown, the current observation model in the sliding mode observation model is:

[0050]

[0051] Among them, i * s is the estimated value of the current vector in the current observation model, and z is the correction factor.

[0052] Specifically, this embodiment can be achieved through, as follows: Figure 7 The method shown implements the above step S12. The method in this embodiment includes steps S71 to S74.

[0053] Step S71: Calculate the estimated value of the current vector corresponding to the initial values ​​of the voltage vector, the back electromotive force vector, and the correction factor based on the sliding mode observation model.

[0054] In such Figure 6 In the sliding mode observation model shown, the actual motor system and the current observation model have the same input voltage v. s In the current observation model, the back electromotive force e * s With the back electromotive force es (initial value) of the actual motor system being the same, the estimated value of the current vector i is obtained using the current observation model. * s .

[0055] Among them, the estimated value of the current vector i * s satisfy:

[0056]

[0057] Step S72: Match the estimated value of the current vector with the current vector, and adjust the correction factor according to the matching result to obtain the estimated value of the correction factor.

[0058] Using the estimated value i of the current vector * s Matching the current vector i of the actual motor system s .

[0059] Optionally, this embodiment can be achieved through, as follows: Figure 8 The method described above implements step S72. The method of this embodiment includes steps S81 to S84.

[0060] Step S81: Calculate the current difference between the current vector estimate and the current vector.

[0061] Calculate the estimated value of the current vector i * s With respect to the current vector i of the actual motor system s Current difference (i) * s -i s ).

[0062] Step S82: In response to the current difference being less than the difference threshold, calculate the product of the output value and the first preset parameter to obtain an estimated value of the correction factor.

[0063] The first preset parameter is the ratio of the second preset parameter k to the difference threshold ME, k / ME.

[0064] In response to the current difference (i * s -i s ()( Figure 6 If E is less than the difference threshold ME, then the current difference (i) is calculated. * s -i s The product of (k*(i) and the first preset parameter k / ME) * s -i s ) / ME) is the estimated value of the correction factor z.

[0065] Step S83: In response to the current difference being greater than or equal to the current threshold and greater than zero, the second preset parameter is inverted to obtain an estimated value of the correction factor.

[0066] In response to the current difference (i * s- i s If the difference threshold ME is greater than or equal to the difference value, and is greater than zero, then (-k) is obtained as the estimated value of the correction factor z.

[0067] Step S84: In response to the current difference being greater than or equal to the current threshold and less than or equal to zero, obtain the estimated value of the second preset parameter as the correction factor.

[0068] In response to the current difference (i * s -i s If the difference threshold ME is greater than or equal to the difference value, and less than or equal to zero, then the second preset constant k is obtained as the estimated value of the correction factor z.

[0069] In other embodiments, the sign function can also be obtained for the current difference (i).* s -i s The output value of Sign(i) * s -i s And obtain the estimated value of the correction factor z according to the following formula:

[0070] z(n) = kSign(i * s (n)-i s (n))

[0071] Where z(n) is the value of z in the nth period.

[0072] Step S73: Calculate the estimated value of the back electromotive force corresponding to the estimated values ​​of the current vector, voltage vector and correction factor based on the sliding mode observation model.

[0073] The current vector and voltage vector of the actual motor system are consistent with the current observation model. The back electromotive force e is estimated by filtering with a correction factor z. * s The estimated value of the back electromotive force e for each period * s The data is updated and fed back to the current observation model.

[0074] The estimated value of back electromotive force e * s z(n) can be obtained by low-pass filtering z(n) and satisfies the following equation:

[0075]

[0076] Among them, f c This refers to the load duration rate.

[0077] Step S74: Use the estimated value of the back electromotive force to obtain the estimated value of the position of the embedded permanent magnet motor rotor.

[0078] The position of the rotor of an embedded permanent magnet motor is the same as the angle of the rotor of an embedded permanent magnet motor.

[0079] The estimated value of back electromotive force e can be used. * s The vector components e of (n) α and e β Estimate the rotor angle θ * (n). Specifically, the estimated value of the back electromotive force e * s (n) and the estimated angle θ * satisfy:

[0080]

[0081] Step S13: Compensate for the torque of the embedded permanent magnet motor using the position estimate.

[0082] Optionally, this embodiment can be achieved through, as follows: Figure 9 The method shown implements step S13 above.

[0083] Step S91: Obtain the sum of multiple angular velocity differences of the embedded permanent magnet motor, where the angular velocity difference is the difference between the angular velocities of adjacent cycles.

[0084] The sum of multiple angular velocity differences ω * satisfy:

[0085]

[0086] Where K is an adjustable parameter.

[0087] Step S92: Calculate the estimated angular velocity of the embedded permanent magnet motor based on the sum of multiple angular velocity differences, and perform low-pass filtering on the estimated angular velocity.

[0088] Estimate of angular velocity ω * Perform low-pass filtering to obtain the intermediate value ω * filtered.

[0089] Step S93: Calculate the position compensation based on the filtered angular velocity estimate and position estimate.

[0090] Angular velocity estimate ω * With position (angle) estimate θ * Satisfy: θ * =ω * t.

[0091] Therefore, the intermediate value ω of the low-pass filter can be used. * The filtered value is used to obtain the compensation amount θ of the rotor position. * offset (n).

[0092] Step S94: Use the compensation amount to compensate for the position of the rotor of the embedded permanent magnet motor in order to compensate for the torque of the embedded permanent magnet motor.

[0093] Therefore, the position of the rotor of the compensated embedded permanent magnet motor satisfies:

[0094] θ * comp (n)=θ * (n)+θ * offset (n)

[0095] Because the position (angle) compensation uses a filtering function, phase compensation is required before the embedded permanent magnet motor is powered on, based on the estimated angular velocity and position values.

[0096] Unlike existing technologies, this embodiment can use a sliding mode observation model to estimate the position of the embedded permanent magnet motor rotor and use the position estimate to compensate for the torque of the embedded permanent magnet motor, thereby achieving constant torque and constant speed output of the embedded permanent magnet motor and reducing noise. Furthermore, this embodiment only needs to collect the first phase current and the second phase current of the embedded permanent magnet motor to obtain the current vector of the embedded permanent magnet motor, thus simplifying the hardware structure of its current sampling module and saving costs.

[0097] Currently, household appliances such as blenders on the market can only achieve high-speed blending functions and cannot achieve low-speed, high-torque output. To address this, this application establishes a maximum torque per ampere (MTPA) curve through the following embodiments, and controls the torque output of the embedded permanent magnet motor based on the MTPA curve, thereby achieving low-speed, high-torque output of the embedded permanent magnet motor.

[0098] like Figure 10 As shown, Figure 10 This is a flowchart illustrating an embodiment of the control method for an embedded permanent magnet motor according to this application. The control method for the embedded permanent magnet motor in this embodiment specifically includes the following steps:

[0099] Step S101: Establish the MTPA curves between the torque, direct-axis current and quadrature-axis current of the embedded permanent magnet motor.

[0100] Specifically, this embodiment calculates the permanent magnet flux linkage of the embedded permanent magnet motor rotor based on the experimentally measured no-load back electromotive force e0 and rotational speed (angular velocity) ω2 of the embedded permanent magnet motor. Control power transistor output quadrature axis current i q and direct-axis current i d The quadrature axis inductance L of the embedded permanent magnet motor was measured. q With cross-axis current i q and direct-axis inductance L d With direct-axis current i d Experimental data on the corresponding relationship; torque T based on satisfying the MTPA condition. s With cross-axis current i q The relationship is determined by the given quadrature-axis current i. q This yields several equally spaced torque values, and is calculated according to the i-th condition that satisfies MTPA. d -i q The relationship is used to obtain the direct-axis current i under the corresponding torque. q Based on the obtained torque values ​​at several equal intervals from zero to maximum torque, the torque T is determined.s With cross-axis current i q Direct-axis current i d The MTPA curve of the relationship.

[0101] Among them, T that satisfies the MTPA condition s -i q as follows:

[0102]

[0103] Where p is a constant.

[0104] i that meets the MTPA criteria d -i q The relationship is as follows:

[0105]

[0106] quadrature axis current i q satisfy:

[0107]

[0108] As can be seen from the above analysis, setting different i q It will correspond to different T s -i q L q i d L d Relational data, and by T e -i q With T e -i d The data was fitted to MTPA curves.

[0109] Step S102: Obtain the given torque of the embedded permanent magnet motor, and obtain the direct-axis current and quadrature-axis current corresponding to the given torque based on the MTPA curve, so as to control the current and torque output of the embedded permanent magnet motor.

[0110] Based on the MTPA curve, the current and torque output of the embedded permanent magnet motor are controlled. Steps S103 to S105 are executed during the operation of the embedded permanent magnet motor to achieve torque compensation of the embedded permanent magnet motor.

[0111] Step S103: Obtain the first phase current and the second phase current of the embedded permanent magnet motor respectively, and obtain the third phase current of the embedded permanent magnet motor based on the first phase current and the second phase current, so as to obtain the current vector of the embedded permanent magnet motor and the voltage vector of the embedded permanent magnet motor.

[0112] Step S104: Use the sliding mode observation model to obtain the position estimate of the embedded permanent magnet motor based on the current vector and voltage vector.

[0113] Step S105: Compensate for the torque of the embedded permanent magnet motor using the position estimate.

[0114] Steps S104 to S106 are similar to steps S11 to S13 above, and will not be repeated here.

[0115] Unlike existing technologies, this embodiment can use a sliding mode observation model to estimate the position of the embedded permanent magnet motor rotor and use the position estimate to compensate for the torque of the embedded permanent magnet motor, thereby achieving constant torque and constant speed output of the embedded permanent magnet motor and reducing noise. Furthermore, this embodiment only needs to collect the first phase current and the second phase current of the embedded permanent magnet motor to obtain the current vector of the embedded permanent magnet motor, thus simplifying the hardware structure of its current sampling module and saving costs.

[0116] Furthermore, this embodiment controls the current and torque output of the embedded permanent magnet motor based on the MTPA curve, which can achieve low-speed, high-torque output and expand the functions of home appliances.

[0117] This application further proposes a control system for an embedded permanent magnet motor, such as Figure 11 As shown, Figure 11 This is a schematic diagram of a control system for an embedded permanent magnet motor according to an embodiment of this application. The control system 100 for the embedded permanent magnet motor in this embodiment includes: a detection module 110, a position estimation module 120, and a control module 130. The detection module 110 is used to acquire the first-phase current and the second-phase current of the embedded permanent magnet motor 31, and based on the first-phase current and the second-phase current, acquire the third-phase current of the embedded permanent magnet motor 31 to obtain the current vector of the embedded permanent magnet motor 31, and acquire the voltage vector of the embedded permanent magnet motor 31. The position estimation module 120 is connected to the detection module 110, and is used to acquire the position estimate of the embedded permanent magnet motor 31 based on the current vector and the voltage vector using a sliding mode observation model. The control module 130 is connected to both the position estimation module 120 and the embedded permanent magnet motor 31, and is used to compensate for the torque of the embedded permanent magnet motor 31 using the position estimate.

[0118] The detection module 110 includes a dual-resistance detection submodule (not shown) and a calculation module (not shown); the dual-resistance detection submodule includes, for example: Figure 3 As shown in the diagram, the first resistor R1 and the second resistor R2 can be connected in series on the lower bridge arm connected to the u-phase winding in the inverter circuit of the embedded permanent magnet motor 31, and the second resistor R2 can be connected in series on the lower bridge arm connected to the v-phase winding. The first phase current i of the embedded permanent magnet motor 31 can be sampled through the first resistor R1.a The current on the lower bridge arm connected to the v-phase winding can be sampled through the second resistor R2 to obtain the second phase current i of the embedded permanent magnet motor 31. b .

[0119] This embodiment can use the calculation module to calculate the first phase current i a Second phase current i b Obtain the third phase current i c The current vector is obtained by [the process]. When the lower bridge arm connected by the three-phase windings u, v, and w is simultaneously turned on, the first-phase current i a Second phase current i b and the third phase current i c Condition i a +i b +i c =0. Therefore, based on this condition, the first phase current i can be used... a Second phase current i b Obtain the third phase current i c The obtained current vector i s Satisfy: i s =(i a i b i c ).

[0120] Furthermore, the calculation module further obtains the voltage vector of the embedded permanent magnet motor based on the current vector.

[0121] The position estimation module 120 includes a sliding mode observation model (not shown in the figure). The sliding mode observation model is used to obtain the position estimate of the embedded permanent magnet motor 31 based on the current vector and voltage vector output by the calculation module. Specifically, in this embodiment, a sliding mode observation model can be established first, and the estimated value of the current vector corresponding to the initial values ​​of the voltage vector, the back electromotive force vector, and the initial value of the correction factor can be calculated based on the sliding mode observation model. Then, the estimated value of the current vector is matched with the current vector, and the correction factor is adjusted according to the matching result to obtain the estimated value of the correction factor. Then, the estimated value of the back electromotive force corresponding to the estimated values ​​of the current vector, the voltage vector, and the correction factor can be calculated based on the sliding mode observation model. Finally, the estimated value of the back electromotive force is used to obtain the position estimate of the rotor of the embedded permanent magnet motor 31.

[0122] This embodiment can compensate for the position of the rotor of the embedded permanent magnet motor 31 based on the position estimate, so as to compensate for the angular velocity and torque of the embedded permanent magnet motor 31.

[0123] Unlike existing technologies, this embodiment can use a sliding mode observation model to estimate the position of the rotor of the embedded permanent magnet motor 31, and use the position estimate to compensate for the torque of the embedded permanent magnet motor 31, thereby achieving constant torque and constant speed output of the embedded permanent magnet motor 31 and reducing noise. Moreover, this embodiment only needs to collect the first phase current and the second phase current of the embedded permanent magnet motor 31 to obtain the current vector of the embedded permanent magnet motor 31. Therefore, it can simplify the hardware structure of its current sampling module and save costs.

[0124] In this embodiment, the control module 130 includes a drive control chip 131, a logic control module 132, and a power control module 133. The drive control chip 131 is connected to the position estimation module 120 and the logic control module 132, respectively. The power control module 133 is connected to the logic control module 132 and the embedded permanent magnet motor 31, respectively.

[0125] The control system 100 of the embedded permanent magnet motor in this embodiment further includes a main control module 140, a communication module 150, and a drive signal power amplification module 160; the communication module 150 is connected to the main control module 140 and the drive control chip 131 respectively; the drive signal power amplification module 160 is connected to the drive control chip 131 and the power control module 133 respectively.

[0126] The main control module 140 is used to output control commands; the communication module 150 is used to transmit the control commands to the drive control chip 131; the drive control chip 131 is used to generate drive signals and logic control signals according to the control commands; the logic control module 132 generates control logic according to the logic control signals; the drive signal power amplification module 160 is used to amplify the drive signals; the power control module 133 generates power control signals from the amplified drive signals according to the control logic to control the embedded permanent magnet motor 31 to work; at the same time, the position estimation module 120 feeds back the position estimation value of the rotor of the embedded permanent magnet motor 31 to the drive control chip 131 so that the control system 100 of the embedded permanent magnet motor forms a closed-loop control of the embedded permanent magnet motor 31.

[0127] The control system 100 of the embedded permanent magnet motor in this embodiment is also used to implement the above-mentioned control method of the embedded permanent magnet motor.

[0128] In an application scenario, such as Figure 12 As shown, Figure 12This is a schematic diagram of the workflow of an embodiment of the control system of the embedded permanent magnet motor of this application. In this embodiment, a low-frequency, low-speed torque is obtained by setting the starting frequency ramp rate of the embedded permanent magnet motor 31; and based on the observed (estimated) values ​​(current / back EMF / angular velocity / position) of the embedded permanent magnet motor 31 and its real-time speed (angular velocity), the output torque limited by the external characteristics of the embedded permanent magnet motor 31 is obtained; the limited output torque is used as the torque input of the MTPA curve, and the corresponding quadrature and direct-axis current is obtained at this torque; based on the rotor position of the embedded permanent magnet motor 31, i.e., the rotor magnetic field orientation, the deviation between the given and feedback quadrature and direct-axis currents can output the quadrature and direct-axis voltage components through a separate PI regulator; after PARK / CLARK coordinate inverse transformation and space vector pulse width modulation (SVPWM), an insulated gate bipolar transistor (IGBT) is obtained. The six voltage space vectors output by the Transistor (IGBT) enable the embedded permanent magnet motor 31 to operate according to the given torque under the control of the IGBT. At the same time, through the feedback of the phase current and rotor position of the embedded permanent magnet motor 31, the current and torque closed-loop vector control of the embedded permanent magnet motor 31 is finally formed.

[0129] This application further proposes a household appliance, such as Figure 13 As shown, Figure 13 This is a schematic diagram of the structure of a household appliance according to an embodiment of the present application. The household appliance of this embodiment (not shown) includes an embedded permanent magnet motor 31 and a control system (not shown) connected to the embedded permanent magnet motor 31; the control system controls the embedded permanent magnet motor 31 to work.

[0130] The embedded permanent magnet motor 31 and its control system, as well as the control method of the control system in this embodiment, can be referred to in the above embodiments, and will not be repeated here.

[0131] This embodiment uses a sliding mode observation model to estimate the position of the rotor of the embedded permanent magnet motor 31, and uses the estimated position value to compensate for the torque of the embedded permanent magnet motor 31, achieving constant torque and constant speed output of the embedded permanent magnet motor 31 and reducing noise. Furthermore, this embodiment only needs to collect the first-phase current and the second-phase current of the embedded permanent magnet motor 31 to obtain the current vector, thus simplifying the hardware structure of its current sampling module and saving costs.

[0132] The household appliance in this embodiment is a high-speed blender, which further includes: a cup body 701, a cup lid 702, a machine body shell 703, an electrode drive board 704, a power board 705, a reactor 706, and a base 707; wherein, the cup body 701 is disposed inside the machine body shell 703; the cup lid 702 and the base 707 are respectively disposed at both ends of the machine body shell 703; the electrode drive board 704, the power board 705, and the reactor 706 are respectively disposed inside the machine body shell 703.

[0133] In other embodiments, the household appliance may also be a blender, a cooking machine, etc.

[0134] This application further proposes a computer-readable storage medium, such as Figure 14 As shown, the computer-readable storage medium 80 in this embodiment is used to store the program instructions 810 of the above embodiments. The program instructions 810 can be executed according to the methods of the above method embodiments. The program instructions 810 have been described in detail in the above method embodiments, and will not be repeated here.

[0135] In this embodiment, the computer-readable storage medium 80 may be, but is not limited to, a USB flash drive, SD card, PD optical drive, portable hard drive, large-capacity floppy drive, flash memory, multimedia memory card, server, etc.

[0136] Unlike existing technologies, this application presents a control method for an embedded permanent magnet motor. This method includes: acquiring the first-phase current and second-phase current of the embedded permanent magnet motor, and acquiring the third-phase current based on the first and second-phase currents to obtain the current vector and voltage vector of the embedded permanent magnet motor; using a sliding mode observation model to obtain an estimated position of the embedded permanent magnet motor rotor based on the current and voltage vectors; and using the estimated position to compensate for the torque of the embedded permanent magnet motor. In this way, this application can estimate the position of the embedded permanent magnet motor rotor using a sliding mode observation model and compensate for the torque of the embedded permanent magnet motor using the estimated position, achieving constant torque and constant speed output and reducing noise. Furthermore, this application only needs to acquire the first and second-phase currents of the embedded permanent magnet motor to obtain its current vector, thus simplifying the hardware structure of its current sampling module and saving costs.

[0137] Furthermore, this application adopts an IGBT three-bridge discrete power device, IGBT driver and main control chip structure in terms of hardware, combined with control algorithm, which can achieve small size and low cost.

[0138] Furthermore, the MTPA curve of the embedded permanent magnet motor of this application can achieve low-speed high-torque output and improve the salient pole effect of the embedded permanent magnet motor (which is essentially to generate reluctance torque by using the demagnetizing effect of the direct-axis current), and make it easier to obtain the position and angular velocity of the embedded permanent magnet motor rotor.

[0139] Furthermore, this application can achieve wide-frequency, high-torque output by injecting high-frequency current, which can expand the blending and cooking functions of home appliances.

[0140] Furthermore, if the aforementioned functions are implemented as software functions and sold or used as independent products, they can be stored in a mobile terminal-readable storage medium. That is, this application also provides a storage device storing program data, which can be executed to implement the methods of the above embodiments. This storage device can be, for example, a USB flash drive, an optical disc, or a server. In other words, this application can be embodied in the form of a software product, which includes several instructions to cause a smart terminal to execute all or part of the steps of the methods described in the various embodiments.

[0141] In the description of this application, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0142] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0143] Any process or method described in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing a particular logical function or process, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the function involved, as will be understood by those skilled in the art to which embodiments of this application pertain.

[0144] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (which may be a personal computer, server, network device, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include: an electrical connection having one or more wires (electronic device), a portable computer disk drive (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Furthermore, the computer-readable medium can even be paper or other suitable media on which the program can be printed, because the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in a computer memory. The above descriptions are merely embodiments of this application and do not limit the scope of this patent application. Any equivalent structural or procedural modifications made based on the content of this specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of this application.

Claims

1. A control method for an embedded permanent magnet motor, characterized in that, The first phase winding of the embedded permanent magnet motor is connected to a first resistor, and the second phase winding of the embedded permanent magnet motor is connected to a second resistor. The control method includes: The first phase current is obtained through the first resistor, and the second phase current is obtained through the second resistor; wherein, the first phase current and the second phase current are sampled when the lower bridge arm of the three-phase winding connection is simultaneously turned on. The third phase current is calculated using the first phase current and the second phase current to obtain the current vector of the embedded permanent magnet motor; The voltage vector of the embedded permanent magnet motor is obtained based on the current vector; The position estimate of the embedded permanent magnet motor rotor is obtained based on the current vector and the voltage vector using a sliding mode observation model; Establish the MTPA curves between the torque, direct-axis current, and quadrature-axis current of the embedded permanent magnet motor; The given torque of the embedded permanent magnet motor is obtained, and the direct-axis current and quadrature-axis current corresponding to the given torque are obtained based on the MTPA curve, so as to control the current and torque output of the embedded permanent magnet motor. Compensating for the torque of the embedded permanent magnet motor using the position estimate includes: The sum of multiple angular velocity differences of the embedded permanent magnet motor is obtained, wherein the angular velocity difference is the difference between the angular velocities of adjacent cycles; The estimated angular velocity of the embedded permanent magnet motor is calculated based on the sum of the multiple angular velocity differences, and the estimated angular velocity is then low-pass filtered. The position compensation amount is calculated based on the filtered angular velocity estimate and the position estimate; The position of the rotor of the embedded permanent magnet motor is compensated using the compensation amount, so as to compensate the torque of the embedded permanent magnet motor. Phase compensation is performed on the embedded permanent magnet motor before it is powered on, based on the estimated angular velocity and the estimated position.

2. The control method according to claim 1, characterized in that, The method of obtaining the position estimate of the embedded permanent magnet motor rotor based on the current vector and the voltage vector using the sliding mode observation model includes: Based on the sliding mode observation model, calculate the estimated value of the current vector corresponding to the initial values ​​of the voltage vector, the back electromotive force vector, and the initial value of the correction factor; The estimated value of the current vector is matched with the current vector, and the correction factor is adjusted according to the matching result to obtain the estimated value of the correction factor; Based on the sliding mode observation model, the estimated value of the back electromotive force corresponding to the estimated values ​​of the current vector, the voltage vector, and the correction factor is calculated; The estimated position of the embedded permanent magnet motor rotor is obtained using the estimated value of the back electromotive force.

3. The control method according to claim 2, characterized in that, The step of matching the estimated value of the current vector with the current vector and adjusting the correction factor based on the matching result to obtain the estimated value of the correction factor includes: Calculate the current difference between the current vector estimate and the current vector; In response to the current difference being less than the difference threshold, the product of the current difference and the first preset parameter is calculated to obtain an estimated value of the correction factor. In response to the current difference being greater than or equal to the difference threshold and being greater than zero, the second preset parameter is inverted to obtain an estimated value of the correction factor, wherein the first preset parameter is the ratio of the second preset parameter to the difference threshold; In response to the current difference being greater than or equal to the difference threshold and less than or equal to zero, the second preset parameter is obtained as an estimated value of the correction factor.

4. A control system for an embedded permanent magnet motor, characterized in that, The first phase winding of the embedded permanent magnet motor is connected to a first resistor, and the second phase winding of the embedded permanent magnet motor is connected to a second resistor. The control system includes: The detection module is used to obtain the first phase current through the first resistor and the second phase current through the second resistor; calculate the third phase current using the first phase current and the second phase current to obtain the current vector of the embedded permanent magnet motor; wherein, the first phase current and the second phase current are sampled when the lower bridge arm connected by the three-phase winding is simultaneously turned on; and the voltage vector of the embedded permanent magnet motor is obtained based on the current vector. A position estimation module, connected to the detection module, is used to obtain the position estimate of the embedded permanent magnet motor based on the current vector and the voltage vector using a sliding mode observation model; A control module, connected to both the position estimation module and the embedded permanent magnet motor, is used to acquire a given torque of the embedded permanent magnet motor and, based on the MTPA curve, acquire the direct-axis current and quadrature-axis current corresponding to the given torque to control the current and torque output of the embedded permanent magnet motor; and to compensate the torque of the embedded permanent magnet motor using the position estimate, including: acquiring the sum of multiple angular velocity differences of the embedded permanent magnet motor, wherein the angular velocity difference is the difference between the angular velocities of adjacent cycles; calculating an estimated angular velocity value of the embedded permanent magnet motor based on the sum of the multiple angular velocity differences, and performing low-pass filtering on the estimated angular velocity value; calculating a position compensation amount based on the filtered estimated angular velocity value and the position estimate; compensating the position of the rotor of the embedded permanent magnet motor using the compensation amount to compensate the torque of the embedded permanent magnet motor; and performing phase compensation on the embedded permanent magnet motor before energizing based on the estimated angular velocity value and the estimated position value.

5. A household appliance, characterized in that, The home appliance includes an embedded permanent magnet motor and a control system connected to the embedded permanent magnet motor, wherein the control system is the control system of the embedded permanent magnet motor as described in claim 4.

6. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores program instructions that can be executed to implement the control method for the embedded permanent magnet motor according to any one of claims 1-3.

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