Constant air volume control method and device of fan, air conditioning equipment and medium

Abstract

The invention discloses a constant air volume control method and device of a fan, air conditioning equipment and a medium. The method comprises the steps that the current target air volume and the current actual rotating speed of the fan are obtained; the current target air volume and the current actual rotating speed are input into a pre-established relation model to obtain target characteristic values of characteristic parameters of the draught fan, and the relation model represents the mapping relation between the rotating speed of the draught fan and the characteristic parameters under different target air volumes; obtaining a current characteristic value of the characteristic parameters of the fan, and determining a three-phase control voltage for the fan according to the current characteristic value and the target characteristic value; and outputting the three-phase control voltage to the fan so as to adjust the characteristic parameters of the fan. According to the invention, the technical problem of low constant air volume control precision in the prior art is solved.

Description

Technical Field

[0001] This invention belongs to the field of home appliance technology, and particularly relates to a constant air volume control method, device, air conditioning equipment and medium for a fan. Background Technology

[0002] For ducted air conditioning equipment, if a long exhaust duct is required for air intake, the increased static pressure caused by the long duct will affect the actual air volume. At the same rotational speed, a short exhaust duct will produce a larger air volume at the outlet, while a long exhaust duct will produce a smaller air volume. However, the actual length of the exhaust duct installed by the user is entirely limited by the installation environment, resulting in poor consistency. Therefore, a constant air volume control mode is needed to achieve a constant air volume output at the equipment outlet under different duct lengths installed by the user.

[0003] In related technologies, the constant air volume control mode requires real-time estimation of the actual air volume. The estimated actual air volume participates in the constant air volume control to achieve constant air volume output. The error in estimating the actual air volume will affect the constant air volume control result, resulting in low accuracy of constant air volume control. Summary of the Invention

[0004] This invention provides a constant air volume control method, device, air conditioning equipment, and medium for a fan, in order to solve the technical problem of low accuracy in constant air volume control in related technologies.

[0005] In a first aspect, the present invention provides a constant airflow control method for a fan, comprising: acquiring a current target airflow and the current actual rotational speed of the fan; inputting the current target airflow and the current actual rotational speed into a pre-established relational model to obtain target characteristic values ​​of fan characteristic parameters, wherein the relational model characterizes the mapping relationship between fan rotational speed and characteristic parameters under different target airflows; acquiring the current characteristic values ​​of the fan characteristic parameters, and determining a three-phase control voltage for the fan based on the current characteristic values ​​and the target characteristic values; and outputting the three-phase control voltage to the fan to adjust the fan characteristic parameters.

[0006] In conjunction with the first aspect, in some embodiments, determining the three-phase control voltage for the wind turbine based on the current characteristic value and the target characteristic value includes: performing a difference calculation on the current characteristic value and the target characteristic value to obtain a characteristic difference; performing a preset adjustment step based on the characteristic difference to obtain a current amplitude, wherein the preset adjustment step includes at least one PID adjustment; determining a quadrature-axis current setpoint and a direct-axis current setpoint based on the current amplitude; and performing current control based on the quadrature-axis current setpoint and the direct-axis current setpoint to obtain the three-phase control voltage.

[0007] In conjunction with the first aspect, in some embodiments, the step of performing a preset adjustment step based on the characteristic difference to obtain the current amplitude includes: performing a PID adjustment on the characteristic difference through a first PID controller to obtain the current amplitude, or performing a PID adjustment on the characteristic difference and adjusting a preset proportional coefficient through the first PID controller to obtain the current amplitude.

[0008] In conjunction with the first aspect, in some embodiments, the step of performing a preset adjustment step based on the characteristic difference to obtain the current amplitude includes: performing a first PID adjustment on the characteristic difference using a second PID controller to obtain a target speed; performing a difference calculation between the current actual speed and the target speed to obtain a speed difference; and performing a second PID adjustment on the speed difference using a third PID controller to obtain the current amplitude.

[0009] In conjunction with the first aspect, in some embodiments, determining the quadrature-axis current setpoint and the direct-axis current setpoint based on the current amplitude includes: limiting the current amplitude based on a predetermined threshold value to obtain a limited current amplitude; and transforming the limited current amplitude to obtain the quadrature-axis current setpoint and the direct-axis current setpoint.

[0010] In conjunction with the first aspect, in some embodiments, obtaining the current target air volume and the current actual rotation speed of the fan includes: obtaining an air volume setting instruction; setting a target air volume according to the air volume setting instruction to obtain the current target air volume; and if the current target air volume is greater than zero, periodically sampling the current actual rotation speed of the fan according to a preset constant air volume control cycle.

[0011] In conjunction with the first aspect, in some embodiments, the periodic sampling of the current actual speed of the fan includes: periodically sampling the actual value of the three-phase current of the fan according to a preset constant air volume control cycle; after each sampling of the actual value of the three-phase current of the fan, performing a coordinate transformation on the currently sampled actual value of the three-phase current to obtain the actual value of the two-phase current in a two-phase static coordinate system; and estimating the rotor angle and speed of the fan based on the actual value of the two-phase current in the two-phase static coordinate system and the given value of the two-phase voltage to obtain the current actual speed of the fan.

[0012] In conjunction with the first aspect, in some embodiments, obtaining the current characteristic value of the wind turbine characteristic parameter includes: after each sampling of the actual value of the three-phase current of the wind turbine, performing coordinate transformation and filtering on the current sampled actual value of the three-phase current to obtain the actual value of the quadrature-axis current and the actual value of the direct-axis current in a two-phase rotating coordinate system; and determining the current characteristic value of the wind turbine characteristic parameter based on the actual value of the quadrature-axis current and the actual value of the direct-axis current in the two-phase rotating coordinate system.

[0013] In a second aspect of the invention, a constant airflow control device for a fan is provided, comprising: an airflow and rotational speed acquisition unit for acquiring a current target airflow and the current actual rotational speed of the fan; a feature acquisition unit for inputting the current target airflow and the current actual rotational speed into a pre-established relational model to obtain target feature values ​​of fan feature parameters, wherein the relational model characterizes the mapping relationship between fan rotational speed and feature parameters under different target airflows; a voltage determination unit for acquiring the current feature values ​​of the fan feature parameters and determining a three-phase control voltage for the fan based on the current feature values ​​and the target feature values; and a parameter adjustment unit for outputting the three-phase control voltage to the fan to adjust the fan feature parameters.

[0014] In a third aspect of the invention, an air conditioning device is provided, having a fan, the air conditioning device further comprising: a processor; and a memory for storing processor-executable instructions, wherein the processor is configured to execute the instructions to implement the constant airflow control method of the fan described above.

[0015] In a fourth aspect of the invention, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the constant airflow control method for the fan described above.

[0016] According to one or more technical solutions provided in the embodiments of the present invention, at least the following technical effects or advantages are achieved:

[0017] By inputting the current target airflow and the current actual rotational speed into a pre-established relational model, target characteristic values ​​of the fan's characteristic parameters are obtained. The current characteristic values ​​of these parameters are then acquired, and the three-phase control voltage for the fan is determined based on the current and target characteristic values. This three-phase control voltage is then output to the fan to adjust its characteristic parameters. The relational model used in this technical solution characterizes the mapping relationship between fan rotational speed and characteristic parameters under different target airflows. It eliminates the need for separate estimation of the actual airflow, meaning the estimated airflow is not involved in the constant airflow control of the fan. Therefore, the constant airflow control accuracy is higher. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 A flowchart of a constant air volume control method for a fan provided in some embodiments of the present invention is shown;

[0020] Figure 2 A control block diagram of a constant air volume control method for a fan provided in some embodiments of the present invention is shown;

[0021] Figure 3 A control block diagram of a constant air volume control method for a fan provided in some embodiments of the present invention is shown;

[0022] Figure 4A It shows Figure 2 The control logic of the constant air volume control method for medium-sized fans;

[0023] Figure 4B It shows Figure 3 The control logic of the constant air volume control method for medium-sized fans;

[0024] Figure 5 A schematic diagram of a curve model in some embodiments of the present invention is shown;

[0025] Figure 6 A schematic diagram of a surface model in some embodiments of the present invention is shown;

[0026] Figure 7 The diagram shows a schematic of the structure of a constant air volume control device for a fan provided in some embodiments of the present invention;

[0027] Figure 8 A schematic diagram of the structure of an air conditioning device provided in some embodiments of the present invention is shown. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0029] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this invention.

[0030] This invention provides a constant airflow control method for a fan, which can be applied to air conditioning equipment with a fan to achieve a constant airflow output from the air outlet of the air conditioning equipment, such as an air purifier, air conditioner, heater, or fresh air system. Figure 1 As shown, the constant air volume control method for a fan provided by the present invention includes the following steps S101 to S104.

[0031] S101: Obtain the current target air volume and the current actual speed of the fan.

[0032] In some implementations, after receiving a command to activate the constant airflow control mode, the current target airflow and the current actual fan speed are periodically acquired according to a preset constant airflow control cycle. For example... Figure 2 and Figure 3 As shown, in some other embodiments, an air volume setting command is obtained; a target air volume is set according to the air volume setting command to obtain the current target air volume; it is determined whether the current target air volume is greater than zero; if the current target air volume is greater than zero, the current actual speed of the fan is periodically sampled according to a preset constant air volume control cycle.

[0033] like Figure 4A and Figure 4B As shown, the fan includes a variable frequency drive circuit and a permanent magnet synchronous motor. In some embodiments, the current actual speed of the fan is periodically sampled according to a preset constant air volume control cycle. This may include: periodically sampling the actual value of the three-phase current of the fan (reference) according to a preset constant air volume control cycle. Figure 4A , Figure 4B As shown, the actual three-phase current value is collected from the output terminal of the variable frequency drive circuit to the permanent magnet synchronous motor. a i b i c After sampling the actual three-phase current of the fan, a coordinate transformation is performed on the current sampled actual three-phase current to obtain the actual two-phase current in a two-phase static coordinate system (the actual two-phase current is referenced). Figure 4A , Figure 4B The i shownα i β It can be understood that this coordinate transformation is from a three-phase static coordinate system to a two-phase static coordinate system; based on the actual values ​​of the two-phase currents and the given values ​​of the two-phase voltages in the two-phase static coordinate system (the given values ​​of the two-phase voltages are referenced...), Figure 4A , Figure 4B u shown α u β To estimate the rotor angle and speed of the fan, the current actual speed of the fan is obtained (current actual speed reference). Figure 4A , Figure 4B The ω shown also provides the rotor angle required for transformation from a three-phase static coordinate system to a two-phase static coordinate system.

[0034] In some implementations, the airflow setting command can originate from a host computer. The airflow setting command generated by the user's airflow setting operation on the host computer is sent to the controller of the air conditioning equipment where the fan is located, such as an MCU.

[0035] (Microcontroller Unit) The MCU responds to the received airflow setting command and sets the target airflow for constant airflow control. The host computer can be a remote control, wired controller, or mobile terminal used to control the air conditioning equipment.

[0036] The set current target airflow is any airflow value within the constant airflow adjustment range configured for the air conditioning equipment. In some implementations, the constant airflow adjustment range is a continuous airflow interval that can be steplessly adjusted by the user, for example, the constant airflow adjustment range can be 1000~1600m³ / h. 3 / h, then the current target airflow is 1000~1600m³ / h. 3 Any airflow value within the range of / h, for example: the current target airflow can be 1000m³ / h. 3 / h、1001m 3 / h、1341m 3 / h or 1600m 3 / h, etc. In other implementations, the constant air volume adjustment range is limited to a variety of preset candidate air volume values, for example: the constant air volume adjustment range is only 1000m. 3 / h、1100m 3 / h, 1200m 3 / h, 1300m 3 / h, 1400m 3 / h, 1500m 3 / h, 1600m 3 / h.

[0037] After setting the target air volume, the current actual speed of the fan is sampled every T1 time interval, where T1 time is the preset constant air control cycle. After each sampling of the current speed of the fan, the following steps S102 to S104 are triggered.

[0038] S102: Input the current target air volume and the current actual speed into the pre-established relational model to obtain the target characteristic values ​​of the fan characteristic parameters. The relational model represents the mapping relationship between the fan speed and the characteristic parameters under different target air volumes.

[0039] It is understandable that the characteristic parameters of the wind turbine in the relational model can be any of the following: total power of the wind turbine, total current of the negative bus, torque, magnitude of the sum of dq-axis current vectors, actual q-axis current (when id=0 control), square of the magnitude of the sum of dq-axis current vectors, square of the magnitude of the sum of dq-axis voltage vectors, magnitude of the sum of dq-axis voltage vectors, etc.

[0040] In some implementations, the pre-established relational model is a set of multiple curve models that correspond one-to-one with a variety of preset candidate air volume values, such as... Figure 5 As shown, each curve model represents the mapping relationship between fan speed and fan characteristic parameters under a given candidate airflow value. Multiple fan speed values ​​and multiple characteristic values ​​of fan characteristic parameters are obtained for each candidate airflow value, and a curve model for that candidate airflow value is established based on these values. It can be understood that the multiple fan speed values ​​and multiple characteristic values ​​of fan characteristic parameters for that candidate airflow value are obtained by adjusting the static pressure in the duct and the fan speed of the air conditioning prototype in a laboratory environment.

[0041] In other implementations, the pre-established relational model is a surface model established for a continuous air volume range. This surface model represents the mapping relationship between the target air volume, fan speed and fan characteristic parameters within the continuous air volume range.

[0042] Understandably, the surface model is built based on pre-determined full-volume 3D mapping data. This full-volume 3D mapping data includes mappings between airflow, fan speed, and fan characteristic parameters within the constant airflow adjustment range. Specifically, the full-volume 3D mapping data represents mappings for multiple airflow values ​​within the constant airflow adjustment range. Each airflow value's mapping data includes multiple data points. Each mapping data point for that airflow value represents a mapping between that airflow value and a fan speed value and a characteristic value of a fan characteristic parameter. These airflow values ​​are uniformly distributed within the constant airflow adjustment range at preset intervals. For example, if the preset interval is 100 m³ / h, the airflow values ​​in the full-volume 3D mapping data would be 100 m³ / h, 200 m³ / h, 300 m³ / h, 400 m³ / h, 500 m³ / h, and so on.

[0043] In some implementations, the full three-dimensional mapping data for the constant air volume adjustment range can be referenced in Table 1 below:

[0044] Table 1.

[0045]

[0046] Surface modeling is performed based on the full 3D mapping data. The model function of the resulting surface model is m = F(n, Q). (See reference...) Figure 6 As shown. It should be noted that, Figure 6 This is only for displaying the model style of the curved surface; the coordinate values ​​of the XYZ axes should be based on actual measurements. Figure 6 The coordinate values ​​of the XYZ axes are not limited. The surface model can be a three-dimensional surface built using MATLAB, with the fan characteristic parameters as the Z-axis, the target air volume as the x-axis, and the fan speed as the y-axis.

[0047] In some implementations, the model function of the surface model can be a cubic equation in two variables that characterizes the relationship between the target air volume, the characteristic parameters of the fan, and the fan speed within the constant air volume adjustment range. The surface model is the trajectory of the solution of the cubic equation in two variables.

[0048] The model functions of the pre-established surface model are written into the controller of the air conditioning equipment, such as the memory of the MCU chip, to complete the algorithm pre-made for the constant air volume control mode, so that the air conditioning equipment can call it when it runs.

[0049] In some implementations, the surface model is established in advance through the following steps: establishing N curve models corresponding to N discrete candidate air volume values, each curve model representing the relationship between the fan speed and fan characteristic parameters under that candidate air volume value, where N is an integer greater than 1; obtaining full three-dimensional mapping data based on the N curve models, where each mapping data in the full three-dimensional mapping data is a mapping of fan speed, air volume, and fan characteristic parameters; and performing surface modeling based on the full three-dimensional mapping data to obtain the surface model.

[0050] like Figure 5 As shown, it can be used for 800m 3 / h, 1000m 3 / h, 1200m 3 / h, 1400m 3 / h, 1600m 3 / h, 1800m 3 / h、2000m 3 / h、2200m 3 / h, 2400m 3 For each of the various discrete candidate air volume values, a corresponding curve model is established. Each curve model is a continuous curve that characterizes the relationship between the fan speed and the fan characteristic parameters under that candidate air volume value.

[0051] In some implementations, establishing N curve models corresponding to N candidate air volume values ​​may include: for each of the N discrete candidate air volume values, obtaining multiple speed values ​​of the fan speed and multiple characteristic values ​​of the fan characteristic parameters under that candidate air volume value, and establishing a curve model for that candidate air volume value based on the multiple speed values ​​of the fan speed and the multiple characteristic values ​​of the fan characteristic parameters under that current target air volume.

[0052] It is understandable that, for each candidate air volume value, the multiple speed values ​​of the fan and the multiple characteristic values ​​of the fan characteristic parameters are obtained by adjusting the static pressure in the air duct and the fan speed of the air conditioning prototype in a laboratory environment.

[0053] Understandably, in a laboratory environment, for each candidate airflow value, the static pressure within the duct and the fan speed of the air conditioning prototype are adjusted to obtain multiple speed values ​​and multiple characteristic values ​​for that candidate airflow value. Specifically, the static pressure within the air conditioning prototype's duct is sequentially adjusted to multiple different static pressure values ​​across the entire air pressure range. These different static pressure values ​​can be evenly spaced; for example, the static pressure within the duct is sequentially increased from 0 Pa to 20 Pa, 40 Pa, 60 Pa, 80 Pa, and so on, until the maximum static pressure value. For each adjusted static pressure value, the fan speed of the air conditioning prototype is then adjusted to ensure that the actual airflow at the air outlet is constant at that candidate airflow value. The parameter values ​​of the fan's characteristic parameters and the fan speed are then collected. It should be noted that when the static pressure within the duct is at a certain value, only one speed point can ensure that the airflow at the air outlet is at that candidate airflow value. This process is continued sequentially to obtain multiple speed values ​​and multiple characteristic values ​​corresponding one-to-one with various static pressure values ​​for that candidate airflow value. Other candidate airflow values ​​and multiple speed values ​​and multiple characteristic values ​​can also be obtained by testing in the above manner. Based on this, the curve model of each candidate airflow value can be obtained by curve fitting of each speed value and each characteristic value obtained in the entire air pressure range (0 Pa to maximum static pressure value) under that candidate airflow value.

[0054] S103: Obtain the current characteristic value of the wind turbine's characteristic parameters, and determine the three-phase control voltage for the wind turbine based on the current characteristic value and the target characteristic value.

[0055] In some implementations, obtaining the current characteristic value of the fan characteristic parameters may include: during the periodic sampling of the actual value of the three-phase current of the fan according to a preset constant air volume control cycle, after each sampling of the actual value of the three-phase current of the fan, performing two coordinate transformations and filtering processes on the current sampled actual value of the three-phase current to obtain the actual value of the quadrature-axis current and the actual value of the direct-axis current in a two-phase rotating coordinate system; and determining the current characteristic value of the fan characteristic parameters based on the actual value of the quadrature-axis current and the actual value of the direct-axis current in the two-phase rotating coordinate system, wherein the current characteristic value is the actual characteristic value of the fan characteristic parameters at the current moment.

[0056] like Figure 4A and Figure 4B As shown, it can be understood that the actual three-phase current value of the current sampling is subjected to two coordinate transformations, including: first, the actual three-phase current value is detected by the detection circuit (the actual three-phase current value is referenced). Figure 4A , Figure 4B The i shown a i b i cThe detected actual values ​​of the three-phase current are transformed from the three-phase static coordinate system to the two-phase static coordinate system to obtain the actual values ​​of the two-phase current in the two-phase static coordinate system (the actual values ​​of the two-phase current are referenced). Figure 4A , Figure 4B The i shown α i β Then, the actual values ​​of the two-phase currents are transformed from the two-phase static coordinate system to the two-phase rotating coordinate system to obtain the actual values ​​of the cross-axis currents in the two-phase rotating coordinate system (refer to...). Figure 4A , Figure 4B The i shown q ) and actual value of direct-axis current (reference) Figure 4A , Figure 4B The i shown d ).

[0057] Taking the motor torque as an example of a fan characteristic parameter, the above-mentioned determination of the current characteristic value of the fan characteristic parameter based on the actual values ​​of the quadrature-axis current and the direct-axis current in a two-phase rotating coordinate system may include: taking the actual value of the quadrature-axis current i q and the actual value of the direct-axis current i d The current motor torque of the fan is calculated based on the motor current and motor parameters using the following formula: T'=1.5P(Ke+(Ld-Lq)*i d )i q Ld and Lq are the stator d-axis inductances and q-axis inductances of the fan, respectively, and Ke is the stator winding flux linkage.

[0058] It should be noted that, as can be seen from the process of obtaining the current characteristic value of the wind turbine characteristic parameters in step S103, obtaining the current characteristic value of the wind turbine characteristic parameters and obtaining the current actual speed of the wind turbine can be carried out simultaneously. That is, the process of detecting the actual value of the three-phase current and converting the actual value of the three-phase current into the actual value of the two-phase current in the two-phase static coordinate system can be shared.

[0059] like Figure 2 and Figure 3 As shown, in some embodiments, determining the three-phase control voltage for the wind turbine based on the current characteristic value and the target characteristic value may include: performing a difference calculation on the current characteristic value and the target characteristic value to obtain a characteristic difference; performing a preset adjustment step based on the characteristic difference to obtain a current amplitude, wherein the preset adjustment step includes at least one PID adjustment; determining the quadrature-axis current setpoint and the direct-axis current setpoint based on the current amplitude; and performing current control based on the quadrature-axis current setpoint and the direct-axis current setpoint to obtain the three-phase control voltage.

[0060] It is understandable that the obtained current amplitude i s This refers to the direct-axis current setpoint i d* and quadrature axis current given value i q * The vector magnitude, that is

[0061] It is understandable that the preset adjustment steps can be one PID adjustment, two PID adjustments, or one PID adjustment plus one adjustment based on the proportional coefficient. Therefore, there are multiple implementation methods for executing the preset adjustment steps based on the characteristic difference, which are described below:

[0062] In some implementations, such as Figure 3 and Figure 4B As shown, the first PID adjustment of the characteristic difference is performed by the second PID controller to obtain the target speed; the difference between the current actual speed and the target speed is calculated to obtain the speed difference; the second PID adjustment of the speed difference is performed by the third PID controller to obtain the current amplitude.

[0063] In other implementations, such as Figure 2 As shown, the characteristic difference is adjusted once by a first PID controller to obtain the current amplitude. In some other embodiments, such as... Figure 2 and Figure 4A As shown, the current amplitude is obtained by adjusting the characteristic difference through a PID controller and the proportional coefficient k. Compared with the first method, the two methods of obtaining the current amplitude described above eliminate a speed control loop, thus resulting in faster control speed.

[0064] It should be noted that in any of the above embodiments, each PID adjustment does not necessarily involve all three types of adjustment: proportional (P), integral (I), and derivative (D). Instead, the adjustment is selected according to actual needs. It can be designed to perform only I adjustment, or only P and I adjustment, or all three types of adjustment: P, I, and D adjustment.

[0065] In some implementations, determining the quadrature-axis current setpoint and the direct-axis current setpoint based on the current amplitude may include: limiting the current amplitude based on a predetermined threshold to obtain a limited current amplitude; and converting the limited current amplitude to obtain the quadrature-axis current setpoint and the direct-axis current setpoint. Limiting the current amplitude using a predetermined threshold can implement a protection circuit. In other implementations, the process of limiting the current amplitude may be omitted.

[0066] It is understandable that, such as Figure 4A and Figure 4BAs shown, the MTPA (Maximum Torque Per Ampere) current control strategy can be used to convert the current amplitude (or the current amplitude after limiting) into a quadrature-axis current setpoint i. q * and direct-axis current given value i d * Other control strategies are also used to calculate the quadrature-axis current setpoint i from the current amplitude. q * and direct-axis current given value i d * For example: i d =0 current control strategy.

[0067] In some implementations, based on the quadrature axis current given value i q * and direct-axis current given value i d * Current control to obtain three-phase control voltage can include controlling the output three-phase control voltage of the frequency converter drive circuit through FOC (Field Oriented Control, also known as vector control) current closed-loop control or other current control methods.

[0068] It is understandable that, such as Figure 4A and Figure 4B As shown, taking FOC current closed-loop control as an example, when the quadrature axis current setpoint i q * The actual value of the sampled cross-axis current i q After performing difference calculations to obtain the quadrature-axis current difference, a PI controller is applied to the quadrature-axis current difference to obtain the quadrature-axis voltage setpoint. Similarly, the direct-axis current setpoint i is... d * Compared with the actual value of the sampled direct-axis current i d After performing difference calculations to obtain the direct-axis current difference, a PI control is applied to the direct-axis current difference to obtain the direct-axis voltage setpoint. Next, a coordinate transformation is performed on the quadrature-axis voltage setpoint and the direct-axis voltage setpoint to obtain the two-phase voltage setpoints in a two-phase static coordinate system (e.g., ...). Figure 4A , Figure 4B u shown α u β Next, the two-phase voltage setpoint u in the two-phase static coordinate system is... α u β Space vector modulation (SVM) is used to generate pulse width modulation signals to control the switching of the frequency converter drive circuit, thereby generating the required three-phase control voltage.

[0069] S104: Outputs three-phase control voltage to the fan to adjust the fan's characteristic parameters.

[0070] By outputting three-phase control voltage to the fan, the actual value of the fan's characteristic parameters is adjusted. After multiple adjustments to the actual characteristic value of the fan's characteristic parameters, the actual characteristic value of the fan's characteristic parameters can be made equal to or substantially equal to the target characteristic value. When the actual characteristic value is equal to or substantially equal to the target characteristic value, it indicates that the fan has achieved a stable constant air volume output.

[0071] Taking motor torque as an example of a characteristic parameter of a fan, in some implementations, before obtaining the current target air volume and the current actual speed, the following steps S01 to S07 may also be included:

[0072] Step S01: Has an activation command for the constant air volume mode been received from the host computer? If not, proceed to step S02; if yes, proceed to step S03.

[0073] Step S02: Control the fan to enter constant speed mode and run at the constant speed set by the host computer;

[0074] Step S03: Determine if the current target airflow set by the host computer is ≥0. If yes, proceed to step S04:

[0075] Step S04: Run at a constant speed for a fixed duration;

[0076] Step S05: Determine whether the actual duration of operation at a constant speed has reached the fixed duration. If so, proceed to step S06.

[0077] Step S06: Execute the second stage of constant air volume control;

[0078] Step S07: Has the execution time of the second stage ended? If so, proceed to step S08. In step S08, the current target air volume and the current actual speed can be periodically obtained according to the preset constant air volume control cycle.

[0079] In some implementations, after each acquisition of the current target airflow and the current actual rotational speed, steps S09 to S015 are continued:

[0080] Step S09: Based on the pre-established relational model, obtain the current target air volume and the target motor torque at the current actual speed;

[0081] Step S010: Obtain the current actual motor torque of the fan and filter it;

[0082] Step S011: Calculate the torque difference between the actual motor torque after filtering and the target motor torque;

[0083] Step S012: After PI regulation of the torque difference, the amplitude is limited to output the target speed;

[0084] Step S013: Calculate the speed difference between the target speed and the current actual speed;

[0085] Step S014: PI-adjust the speed difference to adjust the output current amplitude;

[0086] Step S015: Input the current amplitude into the MTPA algorithm to obtain the quadrature-axis current setpoint i. q * and direct-axis current given value i d * According to the quadrature axis current given value i q * and direct-axis current given value i d * FOC current loop closed-loop control is performed, and the two-phase voltage setpoints in the two-phase static coordinate system are output. The two-phase voltage setpoints are converted into pulse width modulation signals through space vector modulation to control the switching of the frequency converter drive circuit, so that the frequency converter drive circuit controlling the fan outputs the corresponding three-phase control voltage, thereby controlling the actual motor torque of the fan.

[0087] In other implementations, after each acquisition of the current target air volume and the current actual rotational speed, steps S09' to S013' are continued:

[0088] Step S09': Based on the pre-established relational model, obtain the current target air volume and the target motor torque at the current actual speed;

[0089] Step S010': Obtain the current motor torque and filter it;

[0090] Step S011': Calculate the torque difference between the current motor torque and the target motor torque after filtering;

[0091] Step S012': After PI regulation of the torque difference, the amplitude is limited to output current amplitude;

[0092] Step S013': Input the current amplitude into the MTPA algorithm. Based on the current amplitude input into the MTPA algorithm, obtain the quadrature-axis current setpoint i. q * and direct-axis current given value i d * According to the quadrature axis current given value i q * and direct-axis current given value i d *FOC current loop closed-loop control is performed, and the two-phase voltage setpoints in the two-phase static coordinate system are output. The two-phase voltage setpoints are converted into pulse width modulation signals through space vector modulation to control the switching of the frequency converter drive circuit, so that the frequency converter drive circuit controlling the fan outputs the corresponding three-phase control voltage, thereby controlling the actual motor torque of the fan.

[0093] Based on the same inventive concept, the present invention also provides a constant air volume control device for a fan, such as... Figure 7 As shown, the constant air volume control device includes: an air volume and speed acquisition unit 701, used to acquire the current target air volume and the current actual speed of the fan; a feature acquisition unit 702, used to input the current target air volume and the current actual speed into a pre-established relational model to obtain the target feature values ​​of the fan feature parameters, the relational model representing the mapping relationship between the fan speed and the feature parameters under different target air volumes; a voltage determination unit 703, used to acquire the current feature values ​​of the fan feature parameters and determine the three-phase control voltage for the fan based on the current feature values ​​and the target feature values; and a parameter adjustment unit 704, used to output the three-phase control voltage to the fan to adjust the fan feature parameters.

[0094] In some embodiments, the parameter adjustment unit 704 includes: a calculation subunit for performing a difference calculation between the current feature value and the target feature value to obtain a feature difference value; an adjustment subunit for performing a preset adjustment step based on the feature difference value to obtain a current amplitude value, wherein the preset adjustment step includes at least one PID adjustment; a setpoint subunit for determining a quadrature-axis current setpoint value and a direct-axis current setpoint value based on the current amplitude value; and a control subunit for performing current control based on the quadrature-axis current setpoint value and the direct-axis current setpoint value to obtain the three-phase control voltage.

[0095] In some implementations, the adjustment subunit is used to: perform a PID adjustment on the characteristic difference through a first PID controller to obtain the current amplitude, or perform a PID adjustment on the characteristic difference and an adjustment of a preset proportional coefficient through the first PID controller to obtain the current amplitude.

[0096] In other embodiments, the adjustment subunit is used to: perform a first PID adjustment on the characteristic difference using a second PID controller to obtain a target speed; perform a difference calculation between the current actual speed and the target speed to obtain a speed difference; and perform a second PID adjustment on the speed difference using a third PID controller to obtain the current amplitude.

[0097] In some implementations, the given subunit is used to: limit the current amplitude based on a predetermined threshold value to obtain a limited current amplitude; and transform the limited current amplitude to obtain the quadrature-axis current setpoint and the direct-axis current setpoint.

[0098] In some embodiments, the air volume and speed acquisition unit 701 is used to: acquire an air volume setting instruction; set a target air volume according to the air volume setting instruction to obtain the current target air volume; if the current target air volume is greater than zero, periodically sample the current actual speed of the fan according to a preset constant air volume control cycle.

[0099] In some embodiments, the air volume and speed acquisition unit 701 includes a speed acquisition subunit, used for: periodically sampling the actual value of the three-phase current of the fan according to a preset constant air volume control cycle; after each sampling of the actual value of the three-phase current of the fan, performing a coordinate transformation on the currently sampled actual value of the three-phase current to obtain the actual value of the two-phase current in a two-phase static coordinate system; and estimating the rotor angle and speed of the fan based on the actual value of the two-phase current in the two-phase static coordinate system and the given value of the two-phase voltage to obtain the current actual speed of the fan.

[0100] In some embodiments, the voltage determination unit 703 is configured to: after each sampling of the actual value of the three-phase current of the fan, perform two coordinate transformations and filtering processes on the current sampled actual value of the three-phase current to obtain the actual value of the quadrature-axis current and the actual value of the direct-axis current in a two-phase rotating coordinate system; and determine the current characteristic value of the characteristic parameter of the fan based on the actual value of the quadrature-axis current and the actual value of the direct-axis current in the two-phase rotating coordinate system.

[0101] The specific functions of each functional unit in the above-mentioned device have been described in detail in the constant air volume control method for fans provided in some embodiments of the present invention, and will not be elaborated here.

[0102] Based on the same inventive concept, embodiments of the present invention also provide an air conditioning device, which includes a fan, such as... Figure 8 As shown, the air conditioning device further includes: a processor 802; and a memory 804 for storing executable instructions of the processor 802, wherein the processor 802 is configured to execute the instructions to implement the constant air volume control method for the fan described in any of the above embodiments.

[0103] Among them, Figure 8In this document, a bus architecture (represented by bus 800) is used. Bus 800 may include any number of interconnected buses and bridges, linking various circuits including one or more processors represented by processor 802 and memory represented by memory 804. Bus 800 may also link various other circuits such as peripheral devices, voltage regulators, and power management circuits, which are well known in the art and therefore will not be described further herein. Bus interface 805 provides an interface between bus 800 and receiver 801 and transmitter 803. Receiver 801 and transmitter 803 may be the same element, i.e., a transceiver, providing a unit for communicating with various other devices over a transmission medium. Processor 802 is responsible for managing bus 800 and general processing, while memory 804 can be used to store data used by processor 802 during operation.

[0104] Based on the same inventive concept, the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the constant air volume control method for a fan as described in any of the above embodiments.

[0105] According to one or more embodiments provided by the present invention, the current target air volume and the current actual rotation speed are input into a pre-established relational model to obtain target characteristic values ​​of the fan characteristic parameters. The current characteristic values ​​of the fan characteristic parameters are then obtained, and a three-phase control voltage for the fan is determined based on the current and target characteristic values. The three-phase control voltage is output to the fan to adjust the fan characteristic parameters. The relational model used in the above technical solution characterizes the mapping relationship between fan rotation speed and characteristic parameters under different target air volumes. It eliminates the need to separately estimate the actual air volume, meaning the estimated air volume does not participate in the constant air volume control of the fan. Therefore, the constant air volume control accuracy is higher.

[0106] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 Devices that specify the functions in one or more boxes.

[0107] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including an instruction device, which is implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0108] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0109] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0110] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

[0111] The above description is merely an embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of the claims of the present invention.

Claims

1. A method for controlling the constant air volume of a fan, characterized in that, include: Obtain the current target air volume and the current actual speed of the fan; The current target air volume and the current actual rotation speed are input into a pre-established relational model to obtain the target feature values ​​of the fan characteristic parameters. The relational model represents the mapping relationship between the fan rotation speed and the characteristic parameters under different target air volumes. Obtain the current characteristic value of the wind turbine characteristic parameter, and determine the three-phase control voltage for the wind turbine based on the current characteristic value and the target characteristic value; The three-phase control voltage is output to the fan to adjust the fan's characteristic parameters.

2. The method as described in claim 1, characterized in that, The step of determining the three-phase control voltage for the wind turbine based on the current feature value and the target feature value includes: Perform a difference operation between the current feature value and the target feature value to obtain a feature difference; A preset adjustment step is performed based on the characteristic difference to obtain the current amplitude, wherein the preset adjustment step includes at least one PID adjustment; The quadrature-axis current setpoint and the direct-axis current setpoint are determined based on the current amplitude. Current control is performed based on the quadrature-axis current setpoint and the direct-axis current setpoint to obtain the three-phase control voltage.

3. The method as described in claim 2, characterized in that, The step of performing a preset adjustment step based on the characteristic difference to obtain the current amplitude includes: The characteristic difference is adjusted once by the first PID controller to obtain the current amplitude, or The characteristic difference is adjusted by a first PID controller using PID adjustment and a preset proportional coefficient to obtain the current amplitude.

4. The method as described in claim 2, wherein the step of performing a preset adjustment step based on the characteristic difference to obtain the current amplitude includes: The target speed is obtained by first PID adjustment of the characteristic difference using a second PID controller. The difference between the current actual speed and the target speed is calculated to obtain the speed difference. The speed difference is adjusted a second time by a third PID controller to obtain the current amplitude.

5. The method as described in claim 2, characterized in that, The step of determining the quadrature-axis current setpoint and the direct-axis current setpoint based on the current amplitude includes: The current amplitude is limited based on a predetermined threshold value to obtain a limited current amplitude. The amplitude of the current after the limit is transformed to obtain the quadrature-axis current setpoint and the direct-axis current setpoint.

6. The method according to any one of claims 1-5, characterized in that, The process of obtaining the current target air volume and the current actual rotational speed of the fan includes: Get the airflow setting command; Set the target airflow according to the airflow setting command to obtain the current target airflow; If the current target air volume is greater than zero, the current actual speed of the fan is periodically sampled according to the preset constant air volume control cycle.

7. The method as described in claim 6, characterized in that, The periodic sampling of the current actual rotational speed of the fan includes: According to the preset constant air volume control cycle, the actual value of the three-phase current of the fan is periodically sampled; After each sampling of the actual three-phase current value of the wind turbine, a coordinate transformation is performed on the current sampling of the actual three-phase current value to obtain the actual two-phase current value in the two-phase static coordinate system. The rotor angle and speed of the fan are estimated based on the actual values ​​of the two-phase current and the given values ​​of the two-phase voltage in the two-phase static coordinate system, so as to obtain the current actual speed of the fan.

8. The method as described in claim 7, characterized in that, The step of obtaining the current feature value of the wind turbine feature parameter includes: After each sampling of the actual three-phase current value of the fan, the actual three-phase current value of the current sampling is subjected to two coordinate transformations and filtering processes to obtain the actual cross-axis current value and the actual direct-axis current value in the two-phase rotating coordinate system. Based on the actual values ​​of the quadrature-axis current and the direct-axis current in the two-phase rotating coordinate system, the current characteristic values ​​of the wind turbine characteristic parameters are determined.

9. A constant air volume control device for a fan, characterized in that, include: The air volume and speed acquisition unit is used to acquire the current target air volume and the current actual speed of the fan; The feature acquisition unit is used to input the current target air volume and the current actual rotation speed into a pre-established relational model to obtain the target feature values ​​of the fan feature parameters. The relational model represents the mapping relationship between the fan rotation speed and the feature parameters under different target air volumes. A voltage determination unit is used to acquire the current characteristic value of the wind turbine characteristic parameters, and determine the three-phase control voltage for the wind turbine based on the current characteristic value and the target characteristic value; The parameter adjustment unit is used to output the three-phase control voltage to the fan to adjust the characteristic parameters of the fan.

10. An air conditioning device, characterized in that, The air conditioning device, which includes a fan, further includes: a processor; and a memory for storing executable instructions of the processor, wherein the processor is configured to execute the instructions to implement the constant air volume control method for the fan as described in any one of claims 1 to 8.

11. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the constant air volume control method for the fan as described in any one of claims 1 to 8.

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