DC Fan Startup Control Method, Device, Storage Medium and Electronic Equipment

Abstract

The present application relates to the field of motor control technology, and particularly relates to a DC fan startup control method, device and electronic device. The method includes: controlling the speed of the DC fan to decrease to zero to ensure that the DC fan is finally in a stationary state; performing secondary pre-positioning on the motor rotor of the DC fan to accurately position the motor rotor of the DC fan at a target position; controlling the motor rotor to start rotating from the target position through a variable-frequency magnetic field; when the rotation speed of the motor rotor reaches a preset speed, performing position estimation closed-loop control to make the DC fan in a closed-loop operation state, thereby ensuring the stability of the DC fan startup.

Description

Technical Field

[0001] The present application relates to the technical field of motor control, and particularly to a method, device, storage medium and electronic device for controlling the start of a DC fan. Background Art

[0002] In traditional sensorless DC fan starting methods, a three-stage control method is generally adopted, that is, the motor rotor is forcibly pulled to a specific position, and then the rotor is driven to rotate by a variable-frequency magnetic field, and when a certain speed is reached, position estimation closed-loop control is entered. However, if the matching load (fan blade) changes, the motor is very likely to fail to start and enter the closed loop, resulting in a start failure. Or due to excessive starting torque, starting abnormal noise occurs, affecting the reliability of the DC fan starting. Summary of the Invention

[0003] In view of the problem of unreliable DC fan starting, the present application provides a method, device, storage medium and electronic device for controlling the start of a DC fan.

[0004] In a first aspect, the present application provides a method for controlling the start of a DC fan, the method comprising:

[0005] Controlling the speed of the DC fan to decrease to zero;

[0006] Performing secondary pre-positioning on the motor rotor of the DC fan to make the motor rotor of the DC fan in a target position;

[0007] Controlling the motor rotor to start rotating from the target position through a variable-frequency magnetic field;

[0008] When the rotating speed of the motor rotor reaches a preset speed, performing position estimation closed-loop control to make the DC fan in a closed-loop operation state.

[0009] In the above embodiment, first, the speed of the DC fan is controlled to decrease to zero to ensure that the DC fan is finally in a stationary state, so as to ensure that after the motor rotor of the DC fan is subjected to secondary pre-positioning, the motor rotor can accurately be in the target position. Then, the motor rotor is controlled to start rotating from the target position through a variable-frequency magnetic field, and when the rotating speed of the motor rotor reaches the preset speed, position estimation closed-loop control is performed, so that the DC fan is in a closed-loop operation state, thereby ensuring the stability of the DC fan starting.

[0010] According to an embodiment of the present application, optionally, in the above method for controlling the start of a DC fan, the step of performing secondary pre-positioning on the motor rotor of the DC fan to make the motor rotor of the DC fan in a target position includes:

[0011] Apply a first current vector perpendicular to the magnetic field direction of the motor rotor to the DC fan within a first preset time period, so that the motor rotor is in a first position;

[0012] Apply a second current vector perpendicular to the magnetic field direction of the motor rotor to the DC fan within a second preset time period, so that the motor rotor is adjusted from the first position to a target position; wherein, the first current vector is different from the second current vector.

[0013] In the above embodiment, after applying the first current vector perpendicular to the magnetic field direction of the motor rotor to the DC fan for the first time, then apply the second current vector perpendicular to the magnetic field direction of the motor rotor to the DC fan, so that the motor rotor is accurately positioned at the target position. When performing the two-positioning, the applied first current vector and the second current vector are different, so as to ensure the reliability of the motor rotor positioning by applying two forces at different angles.

[0014] According to an embodiment of the present application, optionally, in the above DC fan starting control method, the step of controlling the motor rotor to rotate from the target position by a variable-frequency magnetic field includes:

[0015] Control the electromagnetic torque of the motor rotor to reach a target starting torque through an open-loop control method;

[0016] Wherein, the motor rotor rotates under the action of the target starting torque.

[0017] According to an embodiment of the present application, optionally, in the above DC fan starting control method, before the step of performing position estimation closed-loop control to make the DC fan in a closed-loop operation state, it further includes:

[0018] When the rotation speed of the motor rotor reaches a preset speed, control the electromagnetic torque of the motor rotor to be constant to keep the rotation speed of the motor rotor within a preset range.

[0019] According to an embodiment of the present application, optionally, in the above DC fan starting control method, the step of performing position estimation closed-loop control to make the DC fan in a closed-loop operation state when the rotation speed of the motor rotor reaches a preset speed includes:

[0020] When the rotation speed of the motor rotor reaches a preset speed, detect whether the position of the motor rotor reaches the target position. If so, perform closed-loop control on the DC fan to make the DC fan in a closed-loop operation state.

[0021] According to an embodiment of the present application, optionally, in the above DC fan starting control method, the step of performing closed-loop control on the DC fan includes:

[0022] Obtain the three-phase current of the DC fan;

[0023] Obtain the target speed of the motor rotor according to the three-phase current and the phase-locked loop estimation module;

[0024] Compare the target speed with a preset speed and obtain a speed comparison result;

[0025] Control the outer-loop linear controller to perform closed-loop control on the motor rotor according to the speed comparison result.

[0026] According to an embodiment of the present application, optionally, in the above DC fan starting control method, the step of obtaining the target speed of the motor rotor according to the three-phase current and the phase-locked loop estimation module includes:

[0027] Transform the three-phase current according to the Clark transformation rule to obtain the axis current in the two-phase stationary coordinate system;

[0028] Obtain the axis voltage corresponding to the axis current;

[0029] Transform the axis voltage according to the Park transformation to obtain the voltage value and current value in the rotating coordinate system;

[0030] Obtain the back electromotive force in the rotating coordinate system according to the voltage value and current value in the rotating coordinate system;

[0031] Obtain the difference between the back electromotive force and the preset back electromotive force of the known coordinate in the rotating coordinate system;

[0032] Obtain the speed difference of the motor rotor according to the speed linear controller and the difference;

[0033] Obtain the estimated speed of the motor rotor and add the estimated speed to the speed difference to obtain the target speed.

[0034] In a second aspect, the present application further provides a DC fan starting control device, and the device includes:

[0035] A braking module for controlling the speed of the DC fan to decrease to zero;

[0036] A secondary positioning module for performing secondary pre-positioning on the motor rotor of the DC fan to make the motor rotor of the DC fan in a target position;

[0037] A rotation control module for controlling the motor rotor to start rotating from the target position through a variable-frequency magnetic field;

[0038] A closed-loop control module, configured to perform position estimation closed-loop control when the rotation speed of the motor rotor reaches a preset speed, so that the DC fan is in a closed-loop operation state.

[0039] According to an embodiment of the present application, optionally, in the above DC fan starting control device, the secondary positioning module includes:

[0040] A first positioning unit, configured to apply a first current vector perpendicular to the magnetic field direction of the motor rotor to the DC fan within a first preset time period, so that the motor rotor is in a first position;

[0041] A second positioning unit, configured to apply a second current vector perpendicular to the magnetic field direction of the motor rotor to the DC fan within a second preset time period, so that the motor rotor is adjusted from the first position to a target position; wherein, the first current vector is different from the second current vector.

[0042] According to an embodiment of the present application, optionally, in the above DC fan starting control device, the rotation control module includes:

[0043] An open-loop control unit, configured to control the electromagnetic torque of the motor rotor to reach a target starting torque through an open-loop control method;

[0044] Wherein, the motor rotor rotates under the action of the target starting torque.

[0045] According to an embodiment of the present application, optionally, in the above DC fan starting control device, the device further includes:

[0046] A speed control module, configured to control the electromagnetic torque of the motor rotor to be constant when the rotation speed of the motor rotor reaches a preset speed, so as to keep the rotation speed of the motor rotor within a preset range.

[0047] According to an embodiment of the present application, optionally, in the above DC fan starting control device, the closed-loop control module includes:

[0048] A closed-loop control unit, configured to detect whether the position of the motor rotor reaches a target position when the rotation speed of the motor rotor reaches a preset speed, and if so, perform closed-loop control on the DC fan to make the DC fan in a closed-loop operation state.

[0049] According to an embodiment of the present application, optionally, in the above DC fan starting control device, the closed-loop control unit includes:

[0050] A three-phase current acquisition subunit, configured to obtain a target speed of the motor rotor according to the three-phase current and a phase-locked loop estimation module;

[0051] A comparison subunit, configured to compare the target speed with a preset speed and obtain a speed comparison result;

[0052] A closed-loop control subunit, configured to control an outer-loop linear controller to perform closed-loop control on the motor rotor according to the speed comparison result.

[0053] According to an embodiment of the present application, optionally, in the above direct current fan starting control device, the three-phase current acquisition subunit includes:

[0054] A first transformation subunit, configured to transform the three-phase current according to the Clark transformation rule to obtain the axis current in the two-phase stationary coordinate system;

[0055] An axis voltage acquisition subunit, configured to obtain the axis voltage corresponding to the axis current;

[0056] A second transformation subunit, configured to transform the axis voltage according to the Park transformation to obtain the voltage value and current value in the rotating coordinate system;

[0057] An electromotive force acquisition subunit, configured to obtain the electromotive force in the rotating coordinate system according to the voltage value and current value in the rotating coordinate system;

[0058] A difference acquisition subunit, configured to obtain the difference between the electromotive force and a preset electromotive force of a known coordinate in the rotating coordinate system;

[0059] A speed difference acquisition subunit, configured to obtain the speed difference of the motor rotor according to a speed linear controller and the difference;

[0060] A target speed acquisition subunit, configured to obtain the estimated speed of the motor rotor and add the estimated speed to the speed difference to obtain the target speed.

[0061] In a third aspect, the present application provides a storage medium, and a computer program stored in the storage medium can be executed by one or more processors and can be used to implement the direct current fan starting control method as described above.

[0062] In a fourth aspect, the present application provides an electronic device, including a memory and a processor, where a computer program is stored on the memory, and when the computer program is executed by the processor, the direct current fan starting control method as described above is executed.

[0063] Compared with the prior art, one or more embodiments in the above solution may have the following advantages or beneficial effects:

[0064] A DC fan starting control method, device, storage medium and electronic device provided by the present application, the method comprising: controlling the rotational speed of the DC fan to decrease to zero; performing secondary pre-positioning on the motor rotor of the DC fan to make the motor rotor of the DC fan in a target position; controlling the motor rotor to rotate from the target position through a variable-frequency magnetic field; when the rotational speed of the motor rotor reaches a preset speed, performing position estimation closed-loop control to make the DC fan in a closed-loop operation state. First, controlling the rotational speed of the DC fan to decrease to zero to ensure that the DC fan is finally in a stationary state, so as to ensure that after the secondary pre-positioning of the motor rotor of the DC fan, the motor rotor can accurately be in the target position. Then, controlling the motor rotor to rotate from the target position through a variable-frequency magnetic field, and when the rotational speed of the motor rotor reaches the preset speed, performing position estimation closed-loop control, so that the DC fan is in a closed-loop operation state, thereby ensuring the stability of the start of the DC fan. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] The present application will be described in more detail below based on embodiments with reference to the drawings.

[0066] Figure 1 It is a schematic flowchart of a DC fan starting control method provided in Embodiment 1 of the present application.

[0067] Figure 2 It is a schematic diagram of the connection of a fan drive system provided in Embodiment 1 of the present application.

[0068] Figure 3 It is a schematic block diagram of the structure of a DC fan starting control device provided in Embodiment 4 of the present application.

[0069] Figure 4 It is a connection block diagram of an electronic device provided in Embodiment 6 of the present application.

[0070] In the drawings, the same components are denoted by the same reference numerals, and the drawings are not drawn to actual scale. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0071] The following will combine the drawings and embodiments to detail the implementation manners of the present application, so as to fully understand how the present application uses technical means to solve technical problems and the implementation process of achieving corresponding technical effects and implement accordingly. Each feature in the embodiments of the present application and the embodiments can be combined with each other on the premise of not conflicting, and the formed technical solutions are all within the protection scope of the present application.

[0072] Example 1

[0073] The present invention provides a method for controlling the start of a DC fan. Please refer to Figure 1 , the method includes the following steps:

[0074] Step S110: Control the speed of the DC fan to decrease to zero.

[0075] When controlling the speed of the DC fan to decrease to zero, the energy consumption braking control of the DC fan can be performed by controlling the full opening of the lower bridge of the inverter, and the speed of the DC fan is decreased to zero speed. For example, the inverter module in the schematic connection diagram of the fan drive system as shown in Figure 2 can be used. The inverter module includes a bridge inverter composed of six Insulated Gate Bipolar Transistors (IGBTs), an IGBT drive circuit, and a protection circuit. Its function is to invert the DC voltage (through the switching control of IGBTs) into an AC voltage and supply it to the motor.

[0076] Controlling the speed of the DC fan to decrease to zero mainly serves as a braking function. Executing this step before the secondary pre-positioning operation can ensure that the DC fan can finally be in a stationary state in different states, such as reverse against the wind, forward with the wind, stationary, etc., so as to ensure the accuracy of the subsequent secondary pre-positioning.

[0077] Step S120: Perform secondary pre-positioning on the motor rotor of the DC fan to make the motor rotor of the DC fan in a target position.

[0078] When performing secondary pre-positioning on the motor rotor of the DC fan, the double current vector braking control method can be used. For example, first apply a current vector with a constant amplitude to the motor, and force the motor rotor to be positioned at the position corresponding to this current vector through current closed-loop control, and then apply another current vector with a constant amplitude to force the motor rotor to rotate to the position corresponding to this current vector. After secondary pre-positioning, the motor rotor of the DC fan can be stably and accurately in the target position, thus ensuring that the subsequent operation of the motor rotor can be controlled stably.

[0079] Step S130: Control the motor rotor to start rotating from the target position through a variable frequency magnetic field.

[0080] When controlling the motor rotor to start rotating from the target position through a variable frequency magnetic field, the electromagnetic torque of the motor rotor can be controlled to reach the target starting torque through an open-loop control method; so that the motor rotor rotates under the action of the target starting torque. Among them, the open-loop control method can be any one of various open-loop control methods such as I / F open-loop control, V / F open-loop control, etc., and can be specifically selected according to actual needs, and is not limited here.

[0081] Step S140: When the rotation speed of the motor rotor reaches a preset speed, perform position estimation closed-loop control to make the DC fan operate in a closed-loop state.

[0082] When the rotation speed of the motor rotor reaches the preset speed, the position and rotation speed of the fan rotor can be estimated through position estimation closed-loop control, so as to achieve closed-loop control according to the position and rotation speed of the fan rotor, thereby ensuring that the DC fan enters the closed-loop operation state and realizing the stable start of the DC fan.

[0083] As an implementation manner, before performing the process of making the DC fan operate in a closed-loop state in step S140, when the rotation speed of the motor rotor reaches the preset speed, control the electromagnetic torque of the motor rotor to be constant to keep the rotation speed of the motor rotor within a preset range, so as to keep the rotation speed of the motor rotor running stably.

[0084] In summary, the present application provides a method for controlling the start of a DC fan, including: controlling the rotation speed of the DC fan to decrease to zero; performing secondary pre-positioning on the motor rotor of the DC fan to make the motor rotor of the DC fan in a target position; controlling the motor rotor to start rotating from the target position through a variable-frequency magnetic field; when the rotation speed of the motor rotor reaches the preset speed, perform position estimation closed-loop control to make the DC fan operate in a closed-loop state. First, control the rotation speed of the DC fan to decrease to zero to ensure that the DC fan is finally in a stationary state, so as to ensure that after the motor rotor of the DC fan is subjected to secondary pre-positioning, the motor rotor can accurately be in the target position. Then, control the motor rotor to start rotating from the target position through a variable-frequency magnetic field, and when the rotation speed of the motor rotor reaches the preset speed, perform position estimation closed-loop control, so that the DC fan operates in a closed-loop state, and then ensure the stability of the start of the DC fan.

[0085] Example 2

[0086] On the basis of Embodiment 1, this embodiment illustrates the method in Embodiment 1 through a specific implementation case.

[0087] According to an embodiment of the present application, optionally, step S120 includes the following steps:

[0088] Step S121: Apply a first current vector perpendicular to the magnetic field direction of the motor rotor to the DC fan within a first preset time period, so that the motor rotor is in a first position;

[0089] Step S122: Apply a second current vector perpendicular to the magnetic field direction of the motor rotor to the DC fan within a second preset time period, so that the motor rotor is adjusted from the first position to the target position; wherein, the first current vector is different from the second current vector.

[0090] Since the position of the motor rotor is uncertain after the rotational speed of the DC fan drops to zero, when applying the first current vector perpendicular to the magnetic field direction of the motor rotor to the DC fan, the duration of applying the first current vector can be set as the first preset time period, so that the motor rotor can have enough time to rotate from the uncertain initial position to the first position. Since the motor rotor of the DC fan is a permanent magnet with magnetic pole characteristics (N pole and S pole), a magnetic field (N pole and S pole) will be generated on the motor stator of the DC fan after passing current through the DC fan. According to the principle of attraction between opposite poles and repulsion between like poles, the motor rotor can be attracted to the position corresponding to the current vector. In some cases, there is a problem that the motor rotor cannot accurately reach the preset first position. For example, if the direction of the magnetic field (N pole and S pole) generated by the first applied current vector is just parallel to the (N pole and S pole) position of the motor rotor, the acting force on the motor rotor is 0, and the motor rotor will not rotate. Therefore, the current can be applied a second time at a different angle, and the generated magnetic field will definitely have an attractive force on the motor rotor, thereby pulling the motor rotor to rotate and positioning it at the corresponding position. Therefore, after applying the first current vector perpendicular to the magnetic field direction of the motor rotor to the DC fan for the first time, apply a second current vector perpendicular to the magnetic field direction of the motor rotor to the DC fan so that the motor rotor is accurately positioned at the target position. It can be understood that when performing the two-positioning, the applied first current vector and the second current vector are different, so as to ensure the reliability of the motor rotor positioning by applying acting forces at two different angles.

[0091] Among them, the first preset time period and the second preset time period can be the same or different, and specifically need to be set according to the actual attributes of the DC fan. And the directions of the first current vector and the second current vector are different, but their magnitudes can be the same or different, and specifically need to be set according to actual requirements. For example, after the rotational speed of the DC fan drops to zero, the first current vector perpendicular to the magnetic field direction of the motor rotor can be applied to the DC fan within 1.5 seconds. The direction of the first current vector is 0°, and the current value of the first current vector is Is, so that the motor rotor is in the first position of 0°. Then apply the second current vector perpendicular to the magnetic field direction of the motor rotor to the DC fan within 1.5 seconds. The direction of the second current vector is 90°, and the current value of the second current vector is Is, so that the motor rotor is in the target position of 90°.

[0092] According to an embodiment of the present application, optionally, in the above direct current (DC) fan starting control method, the step of performing position estimation closed-loop control when the rotation speed of the motor rotor reaches a preset speed to make the DC fan in a closed-loop operation state includes the following process:

[0093] When the rotation speed of the motor rotor reaches the preset speed, detect whether the position of the motor rotor reaches the target position. If so, perform closed-loop control on the DC fan to make the DC fan in a closed-loop operation state.

[0094] When performing closed-loop control on the DC fan, it is necessary to determine the duty ratio of the closed-loop start drive signal of the DC fan according to the position and rotation speed of the motor rotor. Therefore, when the duty ratio is determined, it is required that the rotation speed of the motor rotor reaches the preset speed and its position is at the target position, so that the DC fan can be subjected to closed-loop control according to the determined duty ratio to make the DC fan in a closed-loop operation state.

[0095] Example 3

[0096] On the basis of Embodiment 1, this embodiment illustrates the method in Embodiment 1 through specific implementation cases.

[0097] First, perform energy consumption braking control on the DC fan by fully opening the lower bridge of the inverter to reduce the rotation speed of the motor rotor of the DC fan to zero speed. Then, perform secondary predetermination through double current vector braking control, and forcibly pull the motor rotor to a specific position through secondary predetermination. A first current vector perpendicular to the magnetic field direction of the motor rotor can be applied to the DC fan within 1.5 seconds. The direction of the first current vector is 0°, and the current value of the first current vector is Is, so that the motor rotor is in the first position of 0°. Then, a second current vector perpendicular to the magnetic field direction of the motor rotor is applied to the DC fan within 1.5 seconds. The direction of the second current vector is 90°, and the current value of the second current vector is Is, so that the motor rotor is in the target position of 90°.

[0098] Then, control the rotation of the motor rotor starting from the target position through a variable-frequency magnetic field, and enter the position estimation closed-loop control when the rotational speed of the motor rotor reaches a certain speed. For example, through I / F open-loop control, control the motor torque of the DC fan, and perform a rotational speed ramp-up start on the motor rotor until the motor torque reaches the target starting torque, so as to control the motor rotor to quickly rise to the preset rotational speed at a fixed acceleration, such as reaching 300 rpm. When the rotational speed reaches the preset rotational speed, before operating the position estimation closed-loop control on the DC fan, the electromagnetic torque of the motor rotor can be controlled to be constant so that the rotational speed of the motor rotor is within the preset range to ensure that the motor rotor can operate stably at a constant speed. Then, detect whether the position of the motor rotor reaches the set position. If so, start the closed-loop control. As an implementation manner, when performing closed-loop control on the DC fan, first obtain the three-phase current of the DC fan, and then obtain the target rotational speed of the motor rotor according to the three-phase current and the phase-locked loop estimation module. Then compare the target rotational speed with the preset rotational speed and obtain a rotational speed comparison result, and control the outer-loop linear controller to perform closed-loop control on the motor rotor according to the rotational speed comparison result.

[0099] The motor stator part in the DC fan is composed of three-phase windings. When there is current in the loop, sinusoidal phase currents with a mutual electrical angle difference of 120° will be generated in the three-phase windings, and Kirchhoff's current law is satisfied, that is, i a +i b +i c =0, where i a 、i b 、i c represent the current values of the U, V, and W phases of the three-phase windings of the motor stator.

[0100] First, obtain the three-phase current of the DC fan. The current values of any two phases in the DC fan can be obtained through hardware sampling, and then the current value of the third phase is derived based on Kirchhoff's current law. For example, if the current values of the two known phases are i a and i b , then the current value of the third phase can be derived as i c =-(i a -i b ).

[0101] Convert the three-phase current into the first current value in the two-phase stationary coordinate system according to the Clark transformation rule. According to the Clark transformation rule, the current values of the U, V, and W phases of the three-phase windings can be transformed into the first current values of the orthogonal two-phase stationary rotating coordinate system with equal amplitudes, that is, the currents i α 、i β in the α-β coordinate system:

[0102]

[0103] Among them, i α represents the current value corresponding to the α-axis, i β represents the current value corresponding to the β-axis, i a , i b , i c represents three-phase current.

[0104] Through the Park transformation rule, the two-phase current values are transformed into the second current values in the rotating coordinate system. For example, after passing through the Park transformation rule, the currents i d , i q on the DQ axes of the rotating coordinate system are obtained:

[0105]

[0106] Among them, i d represents the current value corresponding to the D-axis in the rotating coordinate system, i q represents, represents the current value corresponding to the Q-axis in the rotating coordinate system, i α represents the current value corresponding to the α-axis, i β represents the current value corresponding to the β-axis.

[0107] The second current values are compared with the preset second current values to obtain a comparison result; the linear controller of the current inner loop outputs the voltage values in the rotating coordinate system according to the comparison result. For example, after comparing the given preset second current values iq* and id* with the i d , i q values obtained by sampling feedback, the PI controller of the current inner loop outputs the voltages u d , u q under the DQ axes of the rotating coordinate system.

[0108] The voltage values u d , u q are processed through Park inverse transformation and SVPWM modulation, and modulation signals are output, and the motor rotor of the DC fan is driven to rotate according to the modulation signals. For example, the switching tubes of the inverter can be controlled to conduct and turn off in an orderly manner, so as to drive the motor rotor to rotate.

[0109] When the rotation of the motor rotor meets the preset conditions, the target speed and target position of the motor rotor can be obtained according to the phase-locked loop position estimation module, the target speed is compared with the preset speed, and a speed comparison result is obtained, and the outer loop linear controller is controlled to perform closed-loop control on the motor rotor according to the comparison result. For example, the calculated voltages u d , u q and currents i d , iq The motor data is input into the PLL position estimation module to estimate the rotational speed ω and position information θ of the motor. Then, the preset rotational speed Wref of the motor rotor of the given DC fan is obtained, and after comparing it with the feedback rotational speed ω, the closed-loop control of the rotational speed can be achieved through the regulation of the outer speed loop PI controller, controlling the stable operation of the motor.

[0110] As an implementation, when obtaining the target rotational speed of the motor rotor according to the three-phase current and the phase-locked loop estimation module, the three-phase current can be transformed according to the Clark transformation rule to obtain the axis current in the two-phase stationary coordinate system, the axis voltage corresponding to the axis current is obtained according to the axis current, the axis voltage is transformed according to the Park transformation to obtain the voltage value and current value in the rotating coordinate system, the back electromotive force in the rotating coordinate system is obtained according to the voltage value and current value in the rotating coordinate system, and the difference between the back electromotive force and the preset back electromotive force of the known coordinate in the rotating coordinate system is obtained; the rotational speed difference of the motor rotor is obtained according to the speed linear controller and the difference; the estimated rotational speed of the motor rotor is obtained, and the estimated rotational speed is added to the rotational speed difference to obtain the target rotational speed.

[0111] The three-phase current i of the motor is obtained through hardware sampling a 、i b 、i c , and then the α-β axis current i in the rotating coordinate system is obtained through Clark coordinate transformation α 、i β .

[0112]

[0113] The α-β axis voltage u is calculated according to the mathematical model of the motor in the rotating coordinate system α 、u β .

[0114]

[0115] The voltage u in the D-Q coordinate system is obtained through Park transformation d 、u q and the current i d 、i q , and then the back electromotive force of the DQ axis is obtained according to the mathematical model of the motor in the D-Q coordinate system:

[0116]

[0117] The given back electromotive force of the d axis Ed* = 0, and the difference is made with the calculated Ed. After passing through the PI controller, the rotational speed difference Δω of the motor is obtained. Then, the rotational speed ωf of the motor is estimated, and the rotational speed is added to the rotational speed difference to obtain the rotational speed ω of the motor rotor = ωf + Δω.

[0118] Integrate the rotational speed ω obtained in the fifth step to obtain the position information θ of the motor rotor.

[0119] Example 4

[0120] Please refer to Figure 3 , this application provides a DC fan starting control device 300, which includes:

[0121] A braking module 310 for controlling the rotational speed of the DC fan to zero;

[0122] A secondary positioning module 320 for performing secondary pre-positioning on the motor rotor of the DC fan to make the motor rotor of the DC fan in a target position;

[0123] A rotation control module 330 for controlling the rotation of the motor rotor starting from the target position through a variable frequency magnetic field;

[0124] A closed-loop control module 340 for performing position estimation closed-loop control when the rotation speed of the motor rotor reaches a preset speed, so that the DC fan is in a closed-loop operation state.

[0125] According to an embodiment of the present application, optionally, in the above DC fan starting control device, the secondary positioning module includes:

[0126] A first positioning unit for applying a first current vector perpendicular to the magnetic field direction of the motor rotor to the DC fan within a first preset time period, so that the motor rotor is in a first position;

[0127] A second positioning unit for applying a second current vector perpendicular to the magnetic field direction of the motor rotor to the DC fan within a second preset time period, so that the motor rotor is adjusted from the first position to the target position; wherein, the first current vector is different from the second current vector.

[0128] According to an embodiment of the present application, optionally, in the above DC fan starting control device, the rotation control module includes:

[0129] An open-loop control unit for controlling the electromagnetic torque of the motor rotor to reach a target starting torque through an open-loop control method;

[0130] Wherein, the motor rotor rotates under the action of the target starting torque.

[0131] According to an embodiment of the present application, optionally, in the above DC fan starting control device, the device further includes:

[0132] A rotational speed control module, configured to control the electromagnetic torque of the motor rotor to be constant when the rotational speed of the motor rotor reaches a preset speed, so as to keep the rotational speed of the motor rotor within a preset range.

[0133] According to an embodiment of the present application, optionally, in the above DC fan starting control device, the closed-loop control module includes:

[0134] A closed-loop control unit, configured to detect whether the position of the motor rotor reaches a target position when the rotational speed of the motor rotor reaches a preset speed. If so, perform closed-loop control on the DC fan to make the DC fan in a closed-loop operating state.

[0135] According to an embodiment of the present application, optionally, in the above DC fan starting control device, the closed-loop control unit includes:

[0136] A three-phase current acquisition sub-unit, configured to obtain the target rotational speed of the motor rotor according to the three-phase current and the phase-locked loop estimation module;

[0137] A comparison sub-unit, configured to compare the target rotational speed with a preset rotational speed and obtain a rotational speed comparison result;

[0138] A closed-loop control sub-unit, configured to control an outer-loop linear controller to perform closed-loop control on the motor rotor according to the rotational speed comparison result.

[0139] According to an embodiment of the present application, optionally, in the above DC fan starting control device, the three-phase current acquisition sub-unit includes:

[0140] A first transformation sub-unit, configured to transform the three-phase current according to the Clark transformation rule to obtain the axis current in the two-phase stationary coordinate system;

[0141] An axis voltage acquisition sub-unit, configured to obtain the axis voltage corresponding to the axis current;

[0142] A second transformation sub-unit, configured to transform the axis voltage according to the Park transformation to obtain the voltage value and current value in the rotating coordinate system;

[0143] An electromotive force acquisition sub-unit, configured to obtain the electromotive force in the rotating coordinate system according to the voltage value and current value in the rotating coordinate system;

[0144] A difference acquisition sub-unit, configured to obtain the difference between the electromotive force and a preset electromotive force of a known coordinate in the rotating coordinate system;

[0145] A rotational speed difference acquisition sub-unit, configured to obtain the rotational speed difference of the motor rotor according to the rotational speed linear controller and the difference;

[0146] A target rotation speed acquisition subunit, configured to acquire an estimated rotation speed of the motor rotor, and add the estimated rotation speed to the rotation speed difference to obtain a target rotation speed.

[0147] In summary, the present application provides a DC fan startup control device, including: a braking module 310, configured to control the rotation speed of the DC fan to zero; a secondary positioning module 320, configured to perform secondary pre-positioning on the motor rotor of the DC fan, so that the motor rotor of the DC fan is in a target position; a rotation control module 330, configured to control the motor rotor to start rotating from the target position through a variable frequency magnetic field; a closed-loop control module 340, configured to perform position estimation closed-loop control when the rotation speed of the motor rotor reaches a preset speed, so that the DC fan is in a closed-loop operation state. First, control the rotation speed of the DC fan to zero to ensure that the DC fan is finally in a stationary state, so as to ensure that after the motor rotor of the DC fan is subjected to secondary pre-positioning, the motor rotor can accurately be in the target position. Then, control the motor rotor to start rotating from the target position through a variable frequency magnetic field, and perform position estimation closed-loop control when the rotation speed of the motor rotor reaches the preset speed, so that the DC fan is in a closed-loop operation state, thereby ensuring the stability of the DC fan startup.

[0148] Example 5

[0149] This embodiment further provides a computer-readable storage medium, such as a flash memory, a hard disk, a multimedia card, a card-type memory (for example, an SD or DX memory, etc.), a random access memory (RAM), a static random access memory (SRAM), a read-only memory (ROM), an electrically erasable programmable read-only memory (EEPROM), a programmable read-only memory (PROM), a magnetic memory, a magnetic disk, an optical disk, a server, an App application mall, etc., on which a computer program is stored, and when the computer program is executed by a processor, the method steps in the above embodiment can be implemented. The specific implementation process of the specific embodiment can refer to Embodiment 1, and this embodiment will not be repeated here.

[0150] Example 6

[0151] The embodiment of the present application provides an electronic device, which can be a mobile phone, a computer, a tablet computer, etc., including a memory and a processor, and a calculator program is stored on the memory, and when the computer program is executed by the processor, the DC fan startup control method described in Embodiment 1 is implemented. It can be understood that, as shown in FIG. 4, the electronic device 400 may further include: a processor 401, a memory 402, a multimedia component 403, an input / output (I / O) interface 404, and a communication component 405.

[0152] Among them, the processor 401 is configured to execute all or part of the steps in the DC fan startup control method in the first embodiment. The memory 402 is used to store various types of data, which may include, for example, instructions of any application program or method in the electronic device, as well as data related to the application program.

[0153] The processor 401 can be implemented by an application specific integrated circuit (ASIC), a digital signal processor (DSP), a digital signal processing device (DSPD), a programmable logic device (PLD), a field programmable gate array (FPGA), a controller, a microcontroller, a microprocessor, or other electronic components, and is used to execute the DC fan startup control method in the first embodiment above.

[0154] The memory 402 can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as a static random access memory (SRAM), an electrically erasable programmable read-only memory (EEPROM), an erasable programmable read-only memory (EPROM), a programmable read-only memory (PROM), a read-only memory (ROM), a magnetic storage device, a flash memory, a magnetic disk, or an optical disc.

[0155] The multimedia component 403 may include a screen and an audio component. The screen may be a touch screen, and the audio component is used to output and / or input audio signals. For example, the audio component may include a microphone for receiving external audio signals. The received audio signals may be further stored in the memory or sent through the communication component. The audio component further includes at least one speaker for outputting audio signals.

[0156] The I / O interface 404 provides an interface between the processor 401 and other interface modules, and the other interface modules may be a keyboard, a mouse, buttons, etc. These buttons may be virtual buttons or physical buttons.

[0157] The communication component 405 is used for the electronic device 400 to communicate with other devices in a wired or wireless manner. Wireless communication, such as Wi-Fi, Bluetooth, Near Field Communication (NFC), 2G, 3G or 4G, or a combination of one or more of them. Accordingly, the communication component 405 may include: a Wi-Fi module, a Bluetooth module, and an NFC module.

[0158] In summary, a DC fan startup control method, device, storage medium and electronic device provided in this application, the method includes: controlling the rotational speed of the DC fan to decrease to zero; performing secondary pre-positioning on the motor rotor of the DC fan to make the motor rotor of the DC fan in a target position; controlling the motor rotor to start rotating from the target position through a variable-frequency magnetic field; when the rotational speed of the motor rotor reaches a preset speed, performing position estimation closed-loop control to make the DC fan in a closed-loop operation state. First, control the rotational speed of the DC fan to decrease to zero to ensure that the DC fan is finally in a stationary state, so as to ensure that after the secondary pre-positioning of the motor rotor of the DC fan, the motor rotor can accurately be in the target position. Then, control the motor rotor to start rotating from the target position through a variable-frequency magnetic field, and when the rotational speed of the motor rotor reaches the preset speed, perform position estimation closed-loop control, so that the DC fan is in a closed-loop operation state, and then ensure the stability of the startup of the DC fan.

[0159] In several embodiments provided in the embodiments of this application, it should be understood that the disclosed systems and methods can also be implemented in other ways. The system and method embodiments described above are only illustrative.

[0160] It should be noted that in this article, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the phrase "including a..." does not exclude the existence of additional identical elements in the process, method, article or device including the element.

[0161] Although the embodiments disclosed in this application are as described above, the content described is only an embodiment adopted for the convenience of understanding this application and is not used to limit this application. Any person skilled in the art within the technical field to which this application pertains may make any modifications and changes in the form of implementation and details without departing from the spirit and scope disclosed in this application. However, the scope of patent protection of this application shall still be subject to the scope defined by the appended claims.

Claims

1. A method for starting and controlling a DC fan, characterized in that, the method includes: controlling the rotational speed of the DC fan to decrease to zero; performing secondary pre-positioning on the motor rotor of the DC fan to make the motor rotor of the DC fan in a target position; controlling the motor rotor to start rotating from the target position through a variable-frequency magnetic field; when the rotational speed of the motor rotor reaches a preset speed, performing position estimation closed-loop control to make the DC fan in a closed-loop operation state; wherein, before the step of performing position estimation closed-loop control to make the DC fan in a closed-loop operation state, it further includes: when the rotational speed of the motor rotor reaches a preset speed, controlling the electromagnetic torque of the motor rotor to be constant to keep the rotational speed of the motor rotor within a preset range; the step of when the rotational speed of the motor rotor reaches a preset speed, performing position estimation closed-loop control to make the DC fan in a closed-loop operation state includes: when the rotational speed of the motor rotor reaches a preset speed, detecting whether the position of the motor rotor reaches the target position, if so, performing closed-loop control on the DC fan to make the DC fan in a closed-loop operation state.

2. The method according to claim 1, characterized in that, the step of performing secondary pre-positioning on the motor rotor of the DC fan to make the motor rotor of the DC fan in a target position includes: applying a first current vector perpendicular to the magnetic field direction of the motor rotor to the DC fan within a first preset time period, so that the motor rotor is in a first position; applying a second current vector perpendicular to the magnetic field direction of the motor rotor to the DC fan within a second preset time period, so that the motor rotor is adjusted from the first position to the target position; wherein, the first current vector is different from the second current vector.

3. The method according to claim 1, characterized in that, the step of controlling the motor rotor to start rotating from the target position through a variable-frequency magnetic field includes: controlling the electromagnetic torque of the motor rotor to reach a target starting torque through an open-loop control method; wherein, the motor rotor rotates under the action of the target starting torque.

4. The method according to claim 1, characterized in that, the step of performing closed-loop control on the DC fan includes: acquiring the three-phase current of the DC fan; acquiring the target rotational speed of the motor rotor according to the three-phase current and a phase-locked loop estimation module; comparing the target rotational speed with a preset rotational speed and obtaining a rotational speed comparison result; controlling an outer-loop linear controller to perform closed-loop control on the motor rotor according to the rotational speed comparison result.

5. The method according to claim 4, characterized in that, the step of acquiring the target rotational speed of the motor rotor according to the three-phase current and a phase-locked loop estimation module includes: transforming the three-phase current according to the Clark transformation rule to obtain the axis current in a two-phase stationary coordinate system; acquiring the axis voltage corresponding to the axis current; transforming the axis voltage according to the Park transformation to obtain the voltage value and current value in a rotating coordinate system; Obtain the back electromotive force of the rotating coordinate system based on the voltage value and current value of the rotating coordinate system; Obtain the difference between the back electromotive force and the preset back electromotive force of the known coordinates in the rotating coordinate system; Obtain the rotational speed difference of the motor rotor according to the rotational speed linear controller and the difference; Obtain the estimated rotational speed of the motor rotor, and add the estimated rotational speed and the rotational speed difference to obtain the target rotational speed.

6. A DC fan starting control device for implementing the DC fan starting control method according to any one of claims 1-5, characterized in that, the device includes: A braking module for controlling the rotational speed of the DC fan to zero; A secondary positioning module for performing secondary pre-positioning on the motor rotor of the DC fan to make the motor rotor of the DC fan in a target position; A rotation control module for controlling the rotation of the motor rotor starting from the target position through a variable frequency magnetic field; A closed-loop control module for performing position estimation closed-loop control when the rotation speed of the motor rotor reaches a preset speed, so that the DC fan is in a closed-loop operation state.

7. A storage medium, characterized in that, The computer program stored in this storage medium, when executed by one or more processors, is used to implement the method according to any one of claims 1-5.

8. An electronic device, characterized in that, It includes a memory and a processor. A computer program is stored on the memory. When the computer program is executed by the processor, it executes the method according to any one of claims 1-5.

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