Deadbeat direct torque control method, device, system and storage medium

Abstract

This specification relates to the field of permanent magnet synchronous motor control technology and provides a deadbeat direct torque control method, device, system, and storage medium. The method includes: obtaining the input voltage and stator current of the permanent magnet synchronous motor in the current control cycle; predicting the stator current of the permanent magnet synchronous motor in the next control cycle based on the input voltage and stator current; determining the electromagnetic torque and reactive torque of the permanent magnet synchronous motor in the next control cycle based on the stator current of the permanent magnet synchronous motor in the next control cycle; determining the control voltage of the permanent magnet synchronous motor in the next control cycle based on the electromagnetic torque, reactive torque, and a set of torque difference equations with the control voltage as an unknown quantity; and driving the permanent magnet synchronous motor based on the control voltage. This specification can achieve rapid electromagnetic torque response in a permanent magnet synchronous motor torque control system.

Description

Technical Field

[0001] This specification relates to the field of permanent magnet synchronous motor control technology, and in particular to a deadbeat direct torque control method, device, system and storage medium. Background Art

[0002] Permanent magnet synchronous motors (PMSMs) use permanent magnets for excitation, eliminating slip rings and brushes that are prone to problems. This simplifies their structure and improves motor reliability. Furthermore, since they require no excitation current and eliminate excitation losses, they increase motor efficiency and power density. Consequently, PMSMs are now widely used in applications such as servo drives and electric vehicle drives.

[0003] Direct torque control (DTC) is currently one of the main control technologies for permanent magnet synchronous motors. However, the calculation process of traditional direct torque control technology for permanent magnet synchronous motors is relatively complex, which affects the electromagnetic torque response speed. Summary of the Invention

[0004] The purpose of the embodiments of this specification is to provide a deadbeat direct torque control method, device, equipment and storage medium to achieve a fast electromagnetic torque response of a permanent magnet synchronous motor torque control system.

[0005] To achieve the above objectives, on the one hand, an embodiment of this specification provides a deadbeat direct torque control method, comprising:

[0006] Obtain the input voltage and stator current of the permanent magnet synchronous motor in the current control cycle;

[0007] Predicting a stator current of the permanent magnet synchronous motor in a next control cycle according to the input voltage and the stator current;

[0008] determining the electromagnetic torque and reactive torque of the permanent magnet synchronous motor in the next control cycle according to the stator current of the permanent magnet synchronous motor in the next control cycle;

[0009] determining a control voltage of the permanent magnet synchronous motor in a next control cycle according to the electromagnetic torque, the reactive torque, and a torque difference equation group with the control voltage as an unknown quantity;

[0010] The permanent magnet synchronous motor is driven according to the control voltage.

[0011] In an embodiment of this specification, obtaining the input voltage and stator current of the permanent magnet synchronous motor in the current control cycle includes:

[0012] Obtain the input voltage and stator current of the permanent magnet synchronous motor in the abc three-phase stationary coordinate system of the current control cycle;

[0013] Convert the input voltage in the abc three-phase stationary coordinate system into the input voltage in the dq two-phase rotating coordinate system;

[0014] Convert any two stator currents in the abc three-phase stationary coordinate system into stator currents in the αβ two-phase stationary coordinate system;

[0015] The stator current in the αβ two-phase stationary coordinate system is transformed into the stator current in the dq two-phase rotating coordinate system.

[0016] In an embodiment of this specification, determining the electromagnetic torque and reactive torque of the permanent magnet synchronous motor in the next control period according to the stator current of the permanent magnet synchronous motor in the next control period includes:

[0017] Predicting the stator current of the permanent magnet synchronous motor in the next control cycle according to the following formula;

[0018]

[0019] Among them, i d (k+1) and i q (k+1) are the d-axis stator current and q-axis stator current of the permanent magnet synchronous motor in the k+1th control cycle in the dq two-phase rotating coordinate system; T s is the control period; L d and L q are the d-axis stator inductance and q-axis stator inductance of the permanent magnet synchronous motor in the dq two-phase rotating coordinate system; u d (k) and u q (k) are the d-axis input voltage and q-axis input voltage of the permanent magnet synchronous motor in the kth control cycle in the dq two-phase rotating coordinate system; R s is the stator winding resistance of the permanent magnet synchronous motor; pm is the permanent magnet flux linkage of the permanent magnet synchronous motor; ω e is the electrical angular velocity of the permanent magnet synchronous motor; i d (k) and i q (k) are the d-axis stator current and q-axis stator current of the permanent magnet synchronous motor in the kth control cycle in the dq two-phase rotating coordinate system.

[0020] In an embodiment of this specification, determining the electromagnetic torque and reactive torque of the permanent magnet synchronous motor in the next control cycle according to the stator current includes:

[0021] Determine the electromagnetic torque and reactive torque of the permanent magnet synchronous motor in the next control cycle according to the following formula;

[0022]

[0023]

[0024] Among them, T e (k+1) and T r (k+1) are the electromagnetic torque and reactive torque of the permanent magnet synchronous motor in the k+1th control cycle, p n is the number of motor pole pairs of the permanent magnet synchronous motor; d (k+1)=L d ·i d (k+1)+ψ pm ψ q (k+1)=L q ·i q (k+1); L d and L q are the d-axis stator inductance and q-axis stator inductance of the permanent magnet synchronous motor in the dq two-phase rotating coordinate system respectively; i d (k+1) and i q (k+1) are the d-axis stator current and q-axis stator current of the permanent magnet synchronous motor in the k+1th control cycle in the dq two-phase rotating coordinate system; ψ pm is the permanent magnet flux linkage of the permanent magnet synchronous motor.

[0025] In an embodiment of this specification, determining the control voltage of the permanent magnet synchronous motor in the next control cycle based on the electromagnetic torque, the reactive torque, and a torque difference equation group with the control voltage as an unknown quantity includes:

[0026] According to the formula Determining a control voltage of the permanent magnet synchronous motor in a next control cycle;

[0027] in, and are the control voltages of the permanent magnet synchronous motor in the k+1th control cycle in the dq two-phase rotating coordinate system;

[0028]

[0029]

[0030]

[0031]

[0032] E=ω e ·ψ q (k+1)-R s ·i d (k+1);

[0033] F=ω e·ψ d (k+1)+R s ·i q (k+1);

[0034] ΔT e =T e (k+1)-T e (k);

[0035] ΔT r =T r (k+1)-T r (k);

[0036] p n is the number of motor pole pairs of the permanent magnet synchronous motor; T s is the control period; L d and L q are the d-axis stator inductance and q-axis stator inductance of the permanent magnet synchronous motor in the dq two-phase rotating coordinate system; ψ d (k+1)=L d ·i d (k+1)+ψ pm ψ q (k+1)=L q ·i q (k+1);i d (k+1) and i q (k+1) are the d-axis stator current and q-axis stator current of the permanent magnet synchronous motor in the k+1th control cycle in the dq two-phase rotating coordinate system; ψ pm is the permanent magnet flux of the permanent magnet synchronous motor; p is the differential operator; R s is the stator winding resistance of the permanent magnet synchronous motor; ω e is the electrical angular velocity of the permanent magnet synchronous motor; ΔT e and ΔT r are the electromagnetic torque deviation and reactive torque deviation of the permanent magnet synchronous motor in the next control cycle in the dq two-phase rotating coordinate system; T e (k) and T e (k+1) are the electromagnetic torques of the permanent magnet synchronous motor in the kth and k+1th control cycles in the dq two-phase rotating coordinate system respectively; T r (k) and T r (k+1) are the reactive torques of the permanent magnet synchronous motor in the kth and k+1th control cycles in the dq two-phase rotating coordinate system respectively.

[0037] In an embodiment of this specification, driving the permanent magnet synchronous motor according to the control voltage includes:

[0038] Convert the control voltage in the dq two-phase rotating coordinate system into the control voltage in the αβ two-phase stationary coordinate system;

[0039] Performing pulse width modulation on the control voltage in the αβ two-phase stationary coordinate system to generate a pulse width modulation signal;

[0040] Inputting the pulse width modulation signal into the inverter to generate a control voltage in the abc three-phase stationary coordinate system;

[0041] The control voltage in the abc three-phase stationary coordinate system is output to the permanent magnet synchronous motor.

[0042] In the embodiments of this specification, the torque difference equations are obtained in advance in the following manner:

[0043] Construct the torque differential equations;

[0044] The torque differential equations are discretized into a torque difference equation with the control voltage as an unknown quantity.

[0045] On the other hand, an embodiment of this specification further provides a motor control device, including a memory, a processor, and a computer program stored in the memory, wherein the computer program executes instructions of the above method when executed by the processor.

[0046] On the other hand, an embodiment of this specification further provides a motor system, the motor system comprising:

[0047] permanent magnet synchronous motors; and,

[0048] The motor control device described above.

[0049] On the other hand, an embodiment of this specification further provides a computer storage medium having a computer program stored thereon, wherein the computer program executes the instructions of the above method when executed by a processor of a motor control device.

[0050] It can be seen from the technical solutions provided in the above embodiments of this specification that after predicting the stator current of the permanent magnet synchronous motor in the next control cycle based on the input voltage and stator current of the permanent magnet synchronous motor in the current control cycle, the embodiments of this specification can determine the electromagnetic torque and reactive torque of the permanent magnet synchronous motor in the next control cycle based on the stator current of the permanent magnet synchronous motor in the next control cycle, and then calculate the control voltage of the permanent magnet synchronous motor in the next control cycle based on the electromagnetic torque, reactive torque and the torque difference equation group with the control voltage as the unknown quantity, so as to drive the permanent magnet synchronous motor, thereby achieving the electromagnetic torque of the permanent magnet synchronous motor to reach the reference value within one control cycle, that is, realizing the beat-free direct torque control of the magnetic synchronous motor; moreover, compared with the traditional beat-free direct torque control technology, the calculation process based on the torque difference equation group in the embodiments of this specification only involves basic four arithmetic operations, and the calculation processing process is simpler, thereby improving the electromagnetic torque response speed of the permanent magnet synchronous motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In order to more clearly illustrate the embodiments of this specification or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments or the description of the prior art. Obviously, the drawings described below are only some of the embodiments described in this specification. For those skilled in the art, other drawings can be obtained based on these drawings without inventive work. In the drawings:

[0052] Figure 1 A flowchart of a deadbeat direct torque control method according to some embodiments of the present specification is shown;

[0053] Figure 2 A schematic diagram of deadbeat direct torque control principle in some embodiments of this specification is shown;

[0054] Figure 3 A schematic diagram showing the relationship between three coordinate systems of a permanent magnet synchronous motor in some embodiments of this specification is shown;

[0055] Figure 4 A flowchart of obtaining the input voltage and stator current of a permanent magnet synchronous motor in a current control cycle in some embodiments of this specification is shown;

[0056] Figure 5 A flow chart showing driving a permanent magnet synchronous motor according to a control voltage in some embodiments of this specification is shown;

[0057] Figure 6 The figure shows a structural block diagram of a motor control device in some embodiments of the present specification.

[0058] [Description of Reference Numerals]

[0059] 602. Motor control equipment;

[0060] 604, processor;

[0061] 606, memory;

[0062] 608, driving mechanism;

[0063] 610, input / output interface;

[0064] 612. Input devices;

[0065] 614. Output device;

[0066] 616. Presentation equipment;

[0067] 618. Graphical User Interface;

[0068] 620, network interface;

[0069] 622, communication link;

[0070] 624. Communication bus. DETAILED DESCRIPTION

[0071] To help those skilled in the art better understand the technical solutions in this specification, the following will provide a clear and complete description of the technical solutions in the embodiments of this specification, in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of this specification, not all of them. All other embodiments derived by those skilled in the art based on the embodiments in this specification without creative effort shall fall within the scope of protection of this specification.

[0072] The embodiments of this specification relate to direct torque control technology for permanent magnet synchronous motors. The basic principle of direct torque control is to consider the motor and inverter as a whole, compare the stator flux estimation value and torque estimation value obtained by the current observer with the corresponding reference values, and obtain the corresponding difference. If the difference between the stator flux or torque and the corresponding reference value exceeds the allowable range, the switching state of the inverter is controlled based on this difference so that the difference can be reduced to within the allowable range as quickly as possible, thereby achieving direct torque control. In traditional direct torque control technology, the torque calculation and the control voltage calculation process based on the difference are relatively complex, which affects its electromagnetic torque response speed.

[0073] In view of this, the embodiments of this specification provide an improved direct torque control technology. First, this specification provides an embodiment of a deadbeat direct torque control method, which can be applied to the motor controller side. Figure 1 As shown, in some embodiments of this specification, the deadbeat direct torque control method may include the following steps:

[0074] S101. Obtain the input voltage and stator current of the permanent magnet synchronous motor in the current control cycle.

[0075] S102: Predicting the stator current of the permanent magnet synchronous motor in the next control cycle according to the input voltage and the stator current.

[0076] S103 . Determine the electromagnetic torque and reactive torque of the permanent magnet synchronous motor in the next control period according to the stator current of the permanent magnet synchronous motor in the next control period.

[0077] S104: Determine the control voltage of the permanent magnet synchronous motor in the next control cycle according to the electromagnetic torque, the reactive torque, and a torque difference equation group with the control voltage as an unknown quantity.

[0078] S105: Drive the permanent magnet synchronous motor according to the control voltage.

[0079] In an embodiment of the present specification, after predicting the stator current of the permanent magnet synchronous motor in the next control cycle based on the input voltage and stator current of the permanent magnet synchronous motor in the current control cycle, the electromagnetic torque and reactive torque of the permanent magnet synchronous motor in the next control cycle can be determined based on the stator current of the permanent magnet synchronous motor in the next control cycle, and then the control voltage of the permanent magnet synchronous motor in the next control cycle is calculated based on the electromagnetic torque, reactive torque and the torque difference equation group with the control voltage as the unknown quantity, so as to drive the permanent magnet synchronous motor, thereby achieving the electromagnetic torque of the permanent magnet synchronous motor to reach the reference value within one control cycle, that is, achieving the zero-beat direct torque control of the magnetic synchronous motor; moreover, compared with the traditional zero-beat direct torque control technology, the calculation process based on the torque difference equation group in the embodiment of the present specification only involves the basic four arithmetic operations (i.e., addition, subtraction, multiplication and division), and the calculation processing process is simpler, thereby improving the electromagnetic torque response speed of the permanent magnet synchronous motor.

[0080] Combine Figure 4 As shown, in some embodiments of this specification, obtaining the input voltage and stator current of the permanent magnet synchronous motor in the current control cycle may include the following steps:

[0081] S1011. Obtain the input voltage and stator current of the permanent magnet synchronous motor in the abc three-phase stationary coordinate system of the current control cycle.

[0082] Combine Figure 2 The deadbeat direct torque control principle shown in the figure is that the output of the voltage source inverter is the input of the permanent magnet synchronous motor. By collecting the output voltage of the voltage source inverter in the current control cycle, the input voltage of the permanent magnet synchronous motor in the abc three-phase stationary coordinate system of the current control cycle can be obtained (see Figure 2 u in a (k),u b (k) and u c (k)). Similarly, by collecting the output current of the voltage source inverter in the current control cycle, the stator current of the permanent magnet synchronous motor in the abc three-phase stationary coordinate system of the current control cycle can be obtained (see Figure 2 i in a (k) and i b (k)).

[0083] In the embodiments of this specification, the abc three-phase stationary coordinate system, the αβ two-phase stationary coordinate system and the dq two-phase rotating coordinate system (i.e., the dq two-phase synchronous rotating coordinate system) are used. Figure 3 As shown, the abc three-phase stationary coordinate system corresponds to the three-phase stator winding of the permanent magnet synchronous motor, and the spatial angle between the three-phase axis system is 120°. The excitation current flows into the three terminals a, b, and c and then flows out of the three-phase stator winding through the three terminals X, Y, and Z. In the αβ two-phase stationary coordinate system, the α-axis is fixed to the a-axis of the abc three-phase stationary coordinate system, and the β-axis is located 90° counterclockwise from the α-axis. In the dq two-phase rotating coordinate system, the d-axis (also called the direct axis) is fixed to the rotor shaft and rotates at the synchronous speed with the rotor shaft; the q-axis (also called the quadrature axis) is located 90° counterclockwise from the d-axis. The angle between the rotor and stator axes is θ.

[0084] S1012: Convert the input voltage in the abc three-phase stationary coordinate system into an input voltage in the dq two-phase rotating coordinate system.

[0085] In some embodiments of this specification, according to Clarke transformation, the transformation relationship between the abc three-phase stationary coordinate system and the αβ two-phase stationary coordinate system is as follows:

[0086]

[0087] Among them, X α and X β are the α-axis component and β-axis component of the voltage parameter X in the αβ two-phase stationary coordinate system; X a 、X b and X c are the a-axis component, b-axis component, and c-axis component of the voltage parameter X in the abc three-phase stationary coordinate system.

[0088] In some embodiments of this specification, according to the Park transformation, the transformation relationship between the αβ two-phase stationary coordinate system and the dq two-phase rotating coordinate system is as follows:

[0089]

[0090] Among them, X d and X q are the d-axis component and d-axis component of the voltage parameter X in the dq two-phase rotating coordinate system, respectively.

[0091] Therefore, the input voltage in the abc three-phase stationary coordinate system can be transformed into the input voltage in the αβ two-phase stationary coordinate system according to Clarke transformation, and then the input voltage in the αβ two-phase stationary coordinate system can be transformed into the input voltage in the dq two-phase rotating coordinate system according to Park transformation (see Figure 2 u in dq (k),u dq (k) is u d (k) and u q (k)).

[0092] S1013 . Convert any two stator currents in the abc three-phase stationary coordinate system into stator currents in the αβ two-phase stationary coordinate system.

[0093] According to Clarke transformation, the stator current of any two items in the abc three-phase stationary coordinate system can be transformed (see Figure 2 i in a (k) and i b (k)) is the stator current in the αβ two-phase stationary coordinate system (see Figure 2 i in α (k) and i β (k)).

[0094] S1014: transform the stator current in the αβ two-phase stationary coordinate system into the stator current in the dq two-phase rotating coordinate system.

[0095] According to Park transformation, the stator current of αβ two-phase stationary coordinate system (see Figure 2 i in α (k) and i β (k)) is transformed into the stator current in the dq two-phase rotating coordinate system (see Figure 2 i in dq (k), i dq (k) is i d (k) and i q (k)). In this way, the input voltage and stator current of the permanent magnet synchronous motor in the current control cycle can be obtained.

[0096] Combine Figure 2 As shown, in the embodiment of this specification, the input voltage and stator current of the permanent magnet synchronous motor in the current control cycle, and the position information provided by the position sensor of the permanent magnet synchronous motor (i.e., the electrical angular velocity ω of the permanent magnet synchronous motor) can be converted into the input voltage and stator current of the permanent magnet synchronous motor in the current control cycle. e) is input to the current observer to predict the stator current of the permanent magnet synchronous motor in the next control cycle. The next control cycle is relative to the current control cycle, that is, the control cycle next to the current control cycle. For example, if the current control cycle is the kth control cycle, then the next control cycle is the k+1th control cycle.

[0097] In some embodiments of this specification, the current observer may predict the stator current of the permanent magnet synchronous motor in the next control cycle according to the following formula:

[0098]

[0099] Among them, i d (k+1) and i q (k+1) are the d-axis stator current and q-axis stator current of the permanent magnet synchronous motor in the k+1th control cycle in the dq two-phase rotating coordinate system. Figure 2 i in dq (k+1) is i d (k+1) and i q (k+1)); T s is the control period; L d and L q are the d-axis stator inductance and q-axis stator inductance of the permanent magnet synchronous motor in the dq two-phase rotating coordinate system; u d (k) and u q (k) are the d-axis input voltage and q-axis input voltage of the permanent magnet synchronous motor in the kth control cycle in the dq two-phase rotating coordinate system; R s is the stator winding resistance of the permanent magnet synchronous motor; pm is the permanent magnet flux linkage of the permanent magnet synchronous motor; ω e is the electrical angular velocity of the permanent magnet synchronous motor; i d (k) and i q (k) are the d-axis stator current and q-axis stator current of the permanent magnet synchronous motor in the k-th control cycle in the dq two-phase rotating coordinate system; · is the multiplication sign.

[0100] The active power P and reactive power Q of the permanent magnet synchronous motor can be expressed as:

[0101]

[0102]

[0103] Among them, p is the differential operator, i d and i q are the d-axis stator current and q-axis stator current in the dq rotating coordinate system respectively; ψ d and ψ qare the d-axis stator flux and q-axis stator flux in the dq rotating coordinate system respectively; ψ d and ψ q Respectively expressed as:

[0104] ψ d =L d ·i d +ψ pm (1)

[0105] ψ q =L q ·i q (2)

[0106] The last term of the above active power and reactive power corresponds to the electromagnetic torque and reactive torque of the permanent magnet synchronous motor, that is, the electromagnetic torque and reactive torque can be expressed as:

[0107]

[0108]

[0109] Among them, p n is the number of motor pole pairs of the permanent magnet synchronous motor. Therefore, the electromagnetic torque and reactive torque of the permanent magnet synchronous motor in the next control cycle can be calculated based on the predicted stator current (including the d-axis stator current and the q-axis stator current) of the permanent magnet synchronous motor in the next control cycle (obviously, the electromagnetic torque and reactive torque of the permanent magnet synchronous motor in the next control cycle are both predicted values ​​or estimated values). That is, the d-axis stator current i predicted in step S102 can be used as the d (k+1) and q-axis stator current i d (k+1) is substituted into formula (1) to formula (4), so that the electromagnetic torque T of the permanent magnet synchronous motor in the next control cycle can be calculated accordingly. e (k+1) and reactive torque T r Specifically, the electromagnetic torque and reactive torque of the permanent magnet synchronous motor in the next control cycle can be determined according to the following formula:

[0110]

[0111]

[0112] Among them, T e (k+1) and T r (k+1) are the electromagnetic torque and reactive torque of the permanent magnet synchronous motor in the k+1th control cycle, ψ d (k+1)=L d ·i d (k+1)+ψ pm ψ q(k+1)=L q ·i q (k+1).

[0113] Combine Figure 2 As shown in the figure, in the deadbeat direct torque control of the permanent magnet synchronous motor, the electromagnetic torque reference value of the permanent magnet synchronous motor can be given in advance. and reactive torque reference In this way, when the electromagnetic torque T of the permanent magnet synchronous motor in the next control cycle (i.e., the k+1th control cycle) is obtained, e (k+1) and reactive torque T r After (k+1), the electromagnetic torque deviation ΔT of the permanent magnet synchronous motor in the next control cycle in the dq two-phase rotating coordinate system can be calculated according to the following formula: e and reactive torque deviation ΔT r .

[0114] ΔT e =T e (k+1)-T e (k)

[0115] ΔT r =T r (k+1)-T r (k)

[0116] In order to calculate the electromagnetic torque deviation ΔT of the permanent magnet synchronous motor in the next control cycle e and reactive torque deviation ΔT r , calculate the control voltage of the permanent magnet synchronous motor in the next control cycle. You can first construct the torque differential equations of the permanent magnet synchronous motor:

[0117]

[0118]

[0119] The stator voltage of the permanent magnet synchronous motor in the dq rotating coordinate system (i.e. u d and u q ) and stator current (i d and i q ) satisfy the following relationship:

[0120] u d =R s i d +pψ d -ω e ψ q (5)

[0121] u q =R s i q+pψ q +ω e ψ d (6)

[0122] Substituting the above formulas (1), (2), (5) and (6) into the above torque differential equations, we can obtain:

[0123]

[0124]

[0125] To facilitate the solution, the above equation can be discretized to obtain the corresponding torque difference equations:

[0126] ΔT e =A′·u d (k)+C′·u q (k)+A′·E′-C′·F′

[0127] ΔT r =H′·u d (k)+N′·u q (k)+H′·E′-N′·F′

[0128] in:

[0129]

[0130]

[0131]

[0132]

[0133] E′=ω e ·ψ q (k)-R s ·i d (k)

[0134] F′=ω e ·ψ d (k)+R s ·i q (k)

[0135] Converting the above torque difference equations into an expression with the control voltage as the unknown quantity, we can obtain:

[0136]

[0137] In this way, the control voltage of the permanent magnet synchronous motor in any control cycle k can be calculated according to the above formula. Accordingly, in some embodiments of the present specification, the control voltage of the permanent magnet synchronous motor in the next control cycle (i.e., the k+1th control cycle) is determined based on the electromagnetic torque, the reactive torque, and the torque difference equation system with the control voltage as an unknown quantity. The above formula becomes:

[0138]

[0139] That is, according to the formula Determine the control voltage of the permanent magnet synchronous motor in the next control cycle.

[0140] in, and are the control voltages of the permanent magnet synchronous motor in the k+1th control cycle in the dq two-phase rotating coordinate system;

[0141]

[0142]

[0143]

[0144]

[0145] E=ω e ·ψ q (k+1)-R s ·i d (k+1);

[0146] F=ω e ·ψ d (k+1)+R s ·i q (k+1);

[0147] ΔT e =T e (k+1)-T e (k);

[0148] ΔT r =T r (k+1)-T r (k);

[0149] It can be seen that formula (7) only involves four basic arithmetic operations, so the calculation process of the deadbeat direct torque control method of the embodiment of this specification is simpler, thereby improving the electromagnetic torque response speed of the permanent magnet synchronous motor.

[0150] Combine Figure 5As shown, in some embodiments of this specification, driving the permanent magnet synchronous motor according to the control voltage may include the following steps:

[0151] S1051 . Convert the control voltage in the dq two-phase rotating coordinate system into the control voltage in the αβ two-phase stationary coordinate system.

[0152] The control voltage of the permanent magnet synchronous motor in the next control cycle calculated using formula (7) is and It is not suitable as the input for subsequent pulse width modulation. Therefore, it is necessary to transform the control voltage in the dq two-phase rotating coordinate system into the control voltage in the αβ two-phase stationary coordinate system.

[0153] In some embodiments of this specification, according to the Park inverse transform, the transformation relationship between the αβ two-phase stationary coordinate system and the dq two-phase rotating coordinate system is as follows:

[0154]

[0155] Therefore, the control voltage in the dq two-phase rotating coordinate system can be transformed into the control voltage in the αβ two-phase stationary coordinate system according to the Park inverse transformation. Figure 2 As shown, the dq two-phase rotation coordinate system can be and The corresponding transformation is the αβ two-phase stationary coordinate system and

[0156] S1052: Perform pulse width modulation on the control voltage in the αβ two-phase stationary coordinate system to generate a pulse width modulation signal.

[0157] In some embodiments of this specification, space vector pulse width modulation (SVPWM) can be used to pulse width modulate the control voltage in the αβ two-phase stationary coordinate system. Of course, this is merely an example. In other embodiments of this specification, in the deadbeat direct torque control scenario of a permanent magnet synchronous motor, any other suitable pulse width modulation can be selected according to actual needs, and this specification does not limit this to any specific embodiment.

[0158] S1053: Input the pulse width modulation signal to the inverter to generate a control voltage in the abc three-phase stationary coordinate system. Figure 2 The voltage source inverter shown.

[0159] A permanent magnet synchronous motor (PMSM) is an AC motor whose stator winding receives three-phase sinusoidal AC input, generating a circular flux vector that rotates at synchronous speed. To precisely control the PMSM, an inverter generates a corresponding spatial voltage control variable to simulate the generation of the circular flux vector. During each switching cycle, the desired spatial voltage vector is synthesized by combining basic voltage vectors.

[0160] S1054: Output the control voltage in the abc three-phase stationary coordinate system to the permanent magnet synchronous motor.

[0161] Although the process flows described above include multiple operations occurring in a particular order, it should be understood that these processes may include more or fewer operations, which may be performed sequentially or in parallel (eg, using parallel processors or a multi-threaded environment).

[0162] The embodiment of this specification also provides a motor control device. Figure 6 As shown, in some embodiments of this specification, the motor control device 602 may include one or more processors 604, such as one or more central processing units (CPUs) or graphics processing units (GPUs), each of which may implement one or more hardware threads. The motor control device 602 may also include any memory 606 for storing any type of information, such as code, settings, data, etc. In one specific embodiment, the memory 606 may contain a computer program executable on the processor 604. When executed by the processor 604, the computer program may execute instructions for the deadbeat direct torque control method described in any of the above embodiments. For example, and without limitation, the memory 606 may include any one or more combinations of the following: any type of RAM, any type of ROM, a flash memory device, a hard disk, an optical disk, etc. More generally, any memory may use any technology to store information. Furthermore, any memory may provide volatile or non-volatile retention of information. Furthermore, any memory may represent a fixed or removable component of the motor control device 602. In one embodiment, when the processor 604 executes the associated instructions stored in any memory or combination of memories, the motor control device 602 can perform any operation of the associated instructions. The motor control device 602 also includes one or more drive mechanisms 608 for interacting with any memory, such as a hard disk drive mechanism, an optical disk drive mechanism, etc.

[0163] The motor control device 602 may also include an input / output interface 610 (I / O) for receiving various inputs (via input devices 612) and for providing various outputs (via output devices 614). A specific output mechanism may include a presentation device 616 and an associated graphical user interface 618 (GUI). In other embodiments, the input / output interface 610 (I / O), input devices 612, and output devices 614 may not be included, and the device may simply be a motor control device in a network. The motor control device 602 may also include one or more network interfaces 620 for exchanging data with other devices via one or more communication links 622. One or more communication buses 624 couple the components described above together.

[0164] The communication link 622 may be implemented in any manner, for example, via a local area network, a wide area network (e.g., the Internet), a point-to-point connection, etc., or any combination thereof. The communication link 622 may include any combination of hardwired links, wireless links, routers, gateway functions, name servers, etc., governed by any protocol or combination of protocols.

[0165] For the convenience of description, the above devices are described as being divided into various units according to their functions. Of course, when implementing this specification, the functions of each unit can be implemented in the same or multiple software and / or hardware.

[0166] Embodiments of this specification also provide a motor system, which may include: a permanent magnet synchronous motor and the aforementioned motor control device. In some embodiments of this specification, the motor system can be applied to any application scenario requiring a permanent magnet synchronous motor to provide power, including, but not limited to, industrial automation, electric vehicles, CNC machine tools, aerospace, and national defense.

[0167] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products of some embodiments of the present specification. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processor to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processor generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0168] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processor to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, the instruction device being implemented in the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0169] These computer program instructions can also be loaded onto a computer or other programmable data processor so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0170] In a typical configuration, a motor control device includes one or more processors (CPUs), input / output interfaces, network interfaces, and memory.

[0171] Memory may include non-permanent storage in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM. Memory is an example of a computer-readable medium.

[0172] Computer-readable media include permanent and non-permanent, removable and non-removable media that can be used to store information using any method or technology. The information can be computer-readable instructions, data structures, program modules, or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassettes, magnetic disk storage or other magnetic storage devices, or any other non-transmission media that can be used to store information that can be accessed by the motor control device. As defined in this specification, computer-readable media does not include transitory media such as modulated data signals and carrier waves.

[0173] Those skilled in the art will appreciate that the embodiments of this specification may be provided as methods, systems, or computer program products. Therefore, the embodiments of this specification may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Furthermore, the embodiments of this specification may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0174] Embodiments of this specification may be described in the general context of computer-executable instructions executed by a computer, such as program modules. Generally, program modules include routines, programs, objects, components, data structures, and the like that perform specific tasks or implement specific abstract data types. Embodiments of this specification may also be practiced in distributed computing environments where tasks are performed by remote processors connected via a communications network. In distributed computing environments, program modules may be located in local and remote computer storage media, including storage devices.

[0175] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between the various embodiments can be referenced across them. Each embodiment focuses on the differences from the other embodiments. In particular, since the system embodiments are generally similar to the method embodiments, their description is relatively simple. For relevant parts, reference can be made to the description of the method embodiments. Throughout this specification, reference to the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the embodiments in this specification. In this specification, the schematic representations of these 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 any one or more embodiments or examples. Furthermore, those skilled in the art may combine and integrate the different embodiments or examples, and features of different embodiments or examples, described in this specification, without conflict.

[0176] The foregoing is merely an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application should all be included within the scope of the claims of the present application.

Claims

1. A deadbeat direct torque control method, characterized in that: include: Obtain the input voltage and stator current of the permanent magnet synchronous motor in the current control cycle; Predicting a stator current of the permanent magnet synchronous motor in a next control cycle according to the input voltage and the stator current; determining the electromagnetic torque and reactive torque of the permanent magnet synchronous motor in the next control cycle according to the stator current of the permanent magnet synchronous motor in the next control cycle; Solving a torque difference equation group with the control voltage as an unknown quantity according to the electromagnetic torque and the reactive torque to obtain a control voltage of the permanent magnet synchronous motor in the next control cycle; The solution process of the torque difference equation group is realized based on four arithmetic operations; The permanent magnet synchronous motor is driven according to the control voltage.

2. The deadbeat direct torque control method according to claim 1, wherein: The obtaining of the input voltage and stator current of the permanent magnet synchronous motor in the current control cycle includes: Obtain the input voltage and stator current of the permanent magnet synchronous motor in the abc three-phase stationary coordinate system of the current control cycle; Convert the input voltage in the abc three-phase stationary coordinate system into the input voltage in the dq two-phase rotating coordinate system; Convert any two stator currents in the abc three-phase stationary coordinate system into stator currents in the αβ two-phase stationary coordinate system; The stator current in the αβ two-phase stationary coordinate system is transformed into the stator current in the dq two-phase rotating coordinate system.

3. The deadbeat direct torque control method according to claim 1, wherein: The step of determining the electromagnetic torque and reactive torque of the permanent magnet synchronous motor in the next control cycle according to the stator current of the permanent magnet synchronous motor in the next control cycle includes: Predicting the stator current of the permanent magnet synchronous motor in the next control cycle according to the following formula; Among them, i d (k+1) and i q (k+1) are the d-axis stator current and q-axis stator current of the permanent magnet synchronous motor in the k+1th control cycle in the dq two-phase rotating coordinate system; T s is the control period; L d and L q are the d-axis stator inductance and q-axis stator inductance of the permanent magnet synchronous motor in the dq two-phase rotating coordinate system; u d (k) and u q (k) are the d-axis input voltage and q-axis input voltage of the permanent magnet synchronous motor in the kth control cycle in the dq two-phase rotating coordinate system; R s is the stator winding resistance of the permanent magnet synchronous motor; pm is the permanent magnet flux linkage of the permanent magnet synchronous motor; ω e is the electrical angular velocity of the permanent magnet synchronous motor; i d (k) and i q (k) are the d-axis stator current and q-axis stator current of the permanent magnet synchronous motor in the kth control cycle in the dq two-phase rotating coordinate system.

4. The deadbeat direct torque control method according to claim 1, wherein: The determining of the electromagnetic torque and reactive torque of the permanent magnet synchronous motor in the next control cycle according to the stator current includes: Determine the electromagnetic torque and reactive torque of the permanent magnet synchronous motor in the next control cycle according to the following formula; Among them, T e (k+1) and T r (k+1) are the electromagnetic torque and reactive torque of the permanent magnet synchronous motor in the k+1th control cycle, p n is the number of motor pole pairs of the permanent magnet synchronous motor; d (k+1)=L d ·i d (k+1)+ψ pm ψ q (k+1)=L q ·i q (k+1); L d and L q are the d-axis stator inductance and q-axis stator inductance of the permanent magnet synchronous motor in the dq two-phase rotating coordinate system respectively; i d (k+1) and i q (k+1) are the d-axis stator current and q-axis stator current of the permanent magnet synchronous motor in the k+1th control cycle in the dq two-phase rotating coordinate system; ψ pm is the permanent magnet flux linkage of the permanent magnet synchronous motor.

5. The deadbeat direct torque control method according to claim 1, wherein: The step of determining the control voltage of the permanent magnet synchronous motor in the next control cycle according to the electromagnetic torque, the reactive torque, and a torque difference equation group with the control voltage as an unknown quantity includes: According to the formula Determining a control voltage of the permanent magnet synchronous motor in a next control cycle; in, and are the control voltages of the permanent magnet synchronous motor in the k+1th control cycle in the dq two-phase rotating coordinate system; E=ω e ·ψ q (k+1)-R s ·i d (k+1); F=ω e ·ψ d (k+1)+R s ·i q (k+1); ΔT e =T e (k+1)-T e (k); ΔT r =T r (k+1)-T r (k); p n is the number of motor pole pairs of the permanent magnet synchronous motor; T s is the control period; L d and L q are the d-axis stator inductance and q-axis stator inductance of the permanent magnet synchronous motor in the dq two-phase rotating coordinate system; ψ d (k+1)=L d ·i d (k+1)+ψ pm ψ q (k+1)=L q ·i q (k+1);i d (k+1) and i q (k+1) are the d-axis stator current and q-axis stator current of the permanent magnet synchronous motor in the k+1th control cycle in the dq two-phase rotating coordinate system; ψ pm is the permanent magnet flux of the permanent magnet synchronous motor; p is the differential operator; R s is the stator winding resistance of the permanent magnet synchronous motor; ω e is the electrical angular velocity of the permanent magnet synchronous motor; ΔT e and ΔT r are the electromagnetic torque deviation and reactive torque deviation of the permanent magnet synchronous motor in the next control cycle in the dq two-phase rotating coordinate system; T e (k) and T e (k+1) are the electromagnetic torques of the permanent magnet synchronous motor in the kth and k+1th control cycles in the dq two-phase rotating coordinate system respectively; T r (k) and T r (k+1) are the reactive torques of the permanent magnet synchronous motor in the kth and k+1th control cycles in the dq two-phase rotating coordinate system respectively.

6. The deadbeat direct torque control method according to claim 1, wherein: The step of driving the permanent magnet synchronous motor according to the control voltage includes: Convert the control voltage in the dq two-phase rotating coordinate system into the control voltage in the αβ two-phase stationary coordinate system; Performing pulse width modulation on the control voltage in the αβ two-phase stationary coordinate system to generate a pulse width modulation signal; Inputting the pulse width modulation signal into the inverter to generate a control voltage in the abc three-phase stationary coordinate system; The control voltage in the abc three-phase stationary coordinate system is output to the permanent magnet synchronous motor.

7. The deadbeat direct torque control method according to claim 1, wherein: The torque difference equations are obtained in advance in the following way: Construct the torque differential equations; The torque differential equations are discretized into a torque difference equation with the control voltage as an unknown quantity.

8. A motor control device comprising a memory, a processor, and a computer program stored in the memory, wherein: When the computer program is executed by the processor, the computer program executes the instructions of the method according to any one of claims 1 to 7.

9. A motor system, characterized in that: The motor system comprises: permanent magnet synchronous motors; and, The motor control device according to claim 8.

10. A computer storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor of a motor control device, the computer program executes instructions of the method according to any one of claims 1 to 7.

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