Motor rotating speed control method, controller and air conditioner outdoor unit

Abstract

The invention discloses a motor rotating speed control method, a controller and an air conditioner outdoor unit, and the motor rotating speed control method comprises the steps: carrying out the judgment according to an environment temperature value and a first preset value, when the environment temperature value reaches the first preset value, controlling to execute a resistance identification program, and obtaining a resistance value of a stator of a motor through the resistance identification program; according to the resistance value and a preset corresponding relation between resistance and temperature, calculating to obtain a motor temperature value, and performing proportional integral differential control on the rotating speed of the motor according to the motor temperature value to achieve the purpose of closed-loop control on the rotating speed of the motor, so that the motor temperature can be controlled within a safe range; and the high-rotating-speed operation reliability of the motor in a complex environment can be realized.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioning equipment, and in particular to a motor speed control method, a controller and an air conditioning outdoor unit. Background Art

[0002] The motor current frequency limiting technology is a method of protecting the motor. It prevents the motor from overloading and damage by limiting the motor current, thereby extending the motor's service life and improving the motor's efficiency and stability. In practical applications, the motor current frequency limiting technology is usually implemented through a motor controller.

[0003] In the motor controller, usually only one current limit value is set. However, the operating environment of the air-conditioning outdoor unit is related to factors such as the installation conditions and local climate. Setting only one current limit value cannot meet the efficient and stable operation of the air-conditioning outdoor unit under all working conditions and complex environments. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a motor speed control method, which can realize closed-loop control of the motor speed and achieve high speed operation reliability of the motor in complex environments.

[0005] The present invention also provides a controller, an air conditioner outdoor unit and a computer-readable storage medium applicable to the above-mentioned controller.

[0006] According to the first aspect of the present invention, the motor speed control method includes: obtaining an ambient temperature value; when the ambient temperature value reaches a first preset value, controlling the execution of a resistance identification program to obtain the resistance value of the stator of the motor; calculating the motor temperature value based on the resistance value and a preset resistance-temperature correspondence; and performing proportional-integral-differential control on the speed of the motor based on the motor temperature value.

[0007] The motor speed control method according to the embodiment of the present invention has at least the following beneficial effects:

[0008] The motor speed control method makes a judgment based on the ambient temperature value and a first preset value. When the ambient temperature value reaches the first preset value, the control executes a resistance identification program, and uses the resistance identification program to obtain the resistance value of the stator of the motor. Then, according to the resistance value and the preset resistance-temperature correspondence, the motor temperature value is calculated. The motor speed is controlled by proportional-integral-differential according to the motor temperature value, so as to achieve the purpose of closed-loop control of the motor speed, thereby controlling the motor temperature within a safe range and realizing the high-speed operation reliability of the motor in a complex environment.

[0009] According to some embodiments of the present invention, the controlling executing a resistance identification procedure to obtain a resistance value of a stator of the motor includes:

[0010] Sampling the stator current signal of the motor and obtaining the coordinate system current through coordinate transformation;

[0011] The resistance value is determined according to the coordinate system current.

[0012] According to some embodiments of the present invention, determining the resistance value according to the coordinate system current includes:

[0013] Obtaining a resistance estimate value based on the coordinate system current and motor parameter model;

[0014] The resistance estimation value is judged online, and when the resistance estimation value reaches a second preset value, the corresponding resistance estimation is output as the resistance value.

[0015] According to some embodiments of the present invention, the resistance identification program is preset with an identification completion mark, and the determining the resistance value according to the coordinate system current further includes:

[0016] When the resistance estimation value reaches a second preset value, outputting the identification completion mark, and ending the resistance identification procedure according to the identification completion mark;

[0017] Otherwise, the control execution resistance identification procedure is repeatedly executed until the resistance value is obtained.

[0018] According to some embodiments of the present invention, calculating the motor temperature value according to the resistance value and a preset corresponding relationship between resistance and temperature includes:

[0019] Calibrate the corresponding relationship between the resistance and the temperature, and fit the relationship curve between the resistance and the temperature by interpolation;

[0020] The motor temperature value is obtained by looking up the table according to the resistance value and the relationship curve.

[0021] According to some embodiments of the present invention, performing proportional-integral-differential control on the rotation speed of the motor according to the motor temperature value includes:

[0022] According to the proportional-integral-derivative control, the motor is controlled to run at a maximum speed.

[0023] According to some embodiments of the present invention, the motor speed control method further includes:

[0024] When the ambient temperature value does not reach the first preset value, the motor is controlled to operate with current control parameters.

[0025] According to the controller of the second aspect embodiment of the present invention, it includes a memory, a processor and a computer program stored in the memory and executable on the processor, and when the processor executes the computer program, it implements the motor speed control method as described in the first aspect embodiment.

[0026] An air-conditioning outdoor unit according to an embodiment of the third aspect of the present invention comprises a fan and the controller described in the embodiment of the second aspect, wherein the fan comprises the motor.

[0027] According to a computer-readable storage medium of an embodiment of the fourth aspect of the present invention, computer-executable instructions are stored, and the computer-executable instructions are used to execute the motor speed control method as described in the embodiment of the first aspect.

[0028] Other features and advantages of the present invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a flow chart of a motor speed control method according to an embodiment of the present invention;

[0030] Figure 2 is a structural diagram of FOC according to an embodiment of the present invention;

[0031] Figure 3 It is a flowchart of controlling and executing a resistance identification program to obtain a stator resistance value according to an embodiment of the present invention;

[0032] Figure 4 is a schematic diagram of a process for determining a resistance value according to a coordinate system current according to an embodiment of the present invention;

[0033] Figure 5 is a schematic diagram of a flow chart of determining a resistance value according to a coordinate system current according to another embodiment of the present invention;

[0034] Figure 6 is a flow chart of a motor speed control method according to another embodiment of the present invention;

[0035] Figure 7 It is a schematic diagram of a flow chart of calculating the temperature value of a motor according to a resistance value and a preset corresponding relationship between resistance and temperature according to an embodiment of the present invention;

[0036] Figure 8 is a schematic diagram of PID control according to an embodiment of the present invention;

[0037] Fig. 9 It is a flow chart of a motor speed control method applicable to an air conditioner outdoor unit according to an embodiment of the present invention;

[0038] Fig.10 It is a structural schematic diagram of an air conditioner outdoor unit according to an embodiment of the present invention.

[0039] Reference numerals:

[0040] 100, controller; 200, fan; DETAILED DESCRIPTION

[0041] In order to more clearly understand the above-mentioned purpose, features and advantages of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0042] In the description of the present invention, examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0043] In the description of the present invention, the various steps described in the method implementation can be performed in different orders and / or in parallel. In addition, the method implementation may include additional steps and / or omit the steps shown. The scope of the present disclosure is not limited in this respect.

[0044] In the description of the present invention, if there is a description of first and second, it is only for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0045] In the description of the present invention, it should be noted that the terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention in combination with the specific content of the technical solution.

[0046] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described below are part of the embodiments of the present invention, not all of the embodiments. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited by the specific embodiments disclosed below.

[0047] At present, in order to protect the air-conditioning motor, the current of the motor is limited to prevent the motor from overloading and damage, that is, a current limit value is set, thereby extending the service life of the motor and improving the efficiency and stability of the motor. The means of limiting the motor current is the motor controller. The working principle of the motor controller is to control the speed and direction of the motor by a given current, and to change the speed of the motor by controlling the intensity of the current. The larger the current, the faster the speed. In addition, the motor controller can also control the direction of the motor by changing the direction of the current. If the direction of the current is reversed, the direction of the motor will also be reversed. However, since the use environment of the air conditioner is related to factors such as installation conditions and climate, setting only a current limit value cannot meet the efficient and stable operation of the air conditioner under all working conditions and complex environments. In order to solve the above problems, an embodiment of the present invention proposes a motor speed control method. The main idea of ​​this method is: based on the numerical value of the current ambient temperature, determine whether to output current to obtain a motor current signal, determine the resistance value of the motor stator based on the current, and then determine the temperature value of the motor based on the resistance value of the motor stator. Finally, use the motor temperature value to implement PID closed-loop control of the motor speed. Refer to the following Figures 1 to 9 The motor speed control method according to an embodiment of the present invention is introduced, and the method includes the following steps S100 to S400:

[0048] Step S100: Obtain the ambient temperature value.

[0049] In this step, the ambient temperature value refers to the temperature value of the environment in which the air conditioner is located. Taking the air conditioner outdoor unit acting on the air conditioner as an example, the air conditioner outdoor unit is usually installed outdoors. At this time, a sensor for measuring the ambient temperature can be used to measure the outdoor ambient temperature value. It should be noted that the sensor for measuring the ambient temperature can be an outdoor ambient temperature sensor carried by the air conditioner outdoor unit itself, or it can be a thermometer carried by a person independent of the air conditioner outdoor unit, and no specific limitation is made here. It should also be noted that although the present embodiment takes the air conditioner outdoor unit as an example, this method can not only be used for the motor speed control of the fan of the air conditioner outdoor unit, but can also act on the motor speed control of the air conditioner indoor unit, etc., and this cannot be used as a limitation on the scope of protection of the present application.

[0050] Step S200: When the ambient temperature reaches a first preset value, a resistance identification program is executed to obtain the resistance value of the stator of the motor.

[0051] After the ambient temperature value is obtained in the above step S100, the ambient temperature value can be used to determine whether the air-conditioning motor needs to execute the subsequent motor speed control scheme of the present application. The present embodiment uses the size relationship between the ambient temperature value and the first preset value to make a judgment. The first preset value set here is a threshold value for determining whether the ambient temperature value reaches a preset condition. This preset condition is used to characterize whether the working condition of the air-conditioning outdoor unit is bad. Therefore, the first preset value can be a lower preset temperature value, such as minus 5 degrees, or a higher preset temperature value, such as 36 degrees. Then, between minus 5 degrees and 36 degrees is a working condition suitable for the air-conditioning motor. The first preset value can be set manually, and the present embodiment does not limit its value.

[0052] When the ambient temperature value measured in the above step S100 reaches the preset first preset value, for example, when the current ambient temperature reaches -5 degrees or lower, the resistance identification program can be controlled to be executed, or when the ambient temperature reaches 36 degrees or higher, the resistance identification program can be controlled to be executed. When the ambient temperature value does not reach the first preset value, for example, the outdoor temperature is 25 degrees, the air conditioner outdoor unit is in a relatively good working condition, and the motor control can be operated according to the preset program, for example, according to the current control parameters of the motor.

[0053] The resistance identification program is a program used to obtain the resistance value of the motor stator according to the ambient temperature value. In this field, there are currently two main methods for identifying stator resistance, one is the offline identification method, and the other is the online identification method. The commonly used method for offline identification of stator resistance is the DC volt-ampere method. Taking the motor with star connection as an example, its implementation method is to connect any two phases with low-voltage DC when the motor is stationary, measure the voltage at both ends of the winding and the current flowing through the winding, and calculate the resistance of the winding by measuring the voltage and current. The existing stator resistance offline identification method can only measure the stator resistance of the motor at room temperature, and cannot measure the stator resistance of the motor when the motor is running normally, and cannot measure the stator resistance of the motor when it changes with factors such as load and time. Online identification of stator resistance can track the instantaneous value of stator resistance changing with factors such as motor load and running time in real time, and use the identified stator resistance value to adjust the stator resistance parameters in the control algorithm in real time, thereby improving the motor control performance. There are many online identification methods, including the least squares method, the model reference adaptive method, and the Kalman filter method. For example, when the motor is in a steady state, the motor stator current is and the stator voltage us are obtained; the motor stator current is is oriented to the d-axis on the synchronously rotating dq coordinate system, and the d-axis stator current component id is calculated, or the stator current is oriented to the q-axis on the synchronously rotating dq coordinate system, and the q-axis stator current component iq is calculated; the phase-locking angle θ is calculated. iand synchronous rotation speed ω s ; According to the calculated phase-locking angle θ i , calculate the d-axis component ud and q-axis component uq of the stator voltage us; obtain the given value Ψs_ref of the flux control loop as the amplitude |Ψs| of the motor stator flux Ψs, and calculate the d-axis component Ψsd or the q-axis component Ψsq of the stator flux Ψs; finally calculate the stator resistance value R s .

[0054] In some embodiments of the present application, the resistance identification program uses the motor stator resistance identification module as a carrier, and the motor stator resistance identification module can be integrated in FOC (Field-Oriented Control) control. FOC control is also called vector control, which is one of the best methods for efficient control of brushless DC motors (BLDC) and permanent magnet synchronous motors (PMSM). FOC aims to precisely control the size and direction of the magnetic field to make the motor's motion torque smooth, low noise, high efficiency, and high-speed dynamic response. The structure of FOC is shown in the figure. Figure 2 As shown, the specific structure and principle will not be described in detail here.

[0055] Reference Figure 3 In some embodiments of the present application, the control in step S200 executes a resistance identification procedure to obtain the resistance value of the stator of the motor, including steps S210 and S220:

[0056] Step S210: sampling the stator current signal of the motor, and obtaining the coordinate system current through coordinate transformation.

[0057] Step S220: determining the resistance value according to the coordinate system current.

[0058] First, input the set current into the motor. After the current is input, the motor generates a current signal and the controller collects the stator current signal of the motor. Then, the coordinate system current corresponding to the stator current signal is obtained through coordinate transformation. Finally, based on the corresponding relationship between the coordinate system current and the resistance value, the stator resistance value is determined.

[0059] In step S210 to step S220, the method is based on the stator current signal of the motor obtained by injecting current, and the stator current signal is integrated into the existing resistance identification program, without adding additional hardware equipment and cost. Figure 4 In some embodiments of the present application, the above step S220 of determining the resistance value according to the coordinate system current specifically includes the following steps S221 and S222:

[0060] Step S221, obtaining a resistance estimation value according to the coordinate system current and the motor parameter model.

[0061] Step S222: judging the estimated resistance value online, and when the estimated resistance value reaches a second preset value, outputting the corresponding estimated resistance value as the resistance value.

[0062] In step S221, the motor parameter model is an estimation model that uses the coordinate system current as input to run a built-in current-resistance estimation program and outputs a resistance estimation value. For the current-resistance estimation program, a common current-resistance estimation algorithm in the art can be used to calculate the resistance estimation value, which is not limited here.

[0063] In step S222, because the selected current-resistance estimation program is usually an iterative calculation, in order to meet the iterative end condition, the resistance identification program is ended when and only when the resistance estimation value meets the second preset value, and the output resistance estimation value is used as the stator resistance value of the motor. The specific value of the second preset value is not limited here.

[0064] Reference Figure 5 In some embodiments of the present application, when the resistance identification procedure of step S200 is preset with an identification completion mark, the resistance value is determined according to the coordinate system current, and the following process steps S230 and S240 are also included:

[0065] Step S230: When the estimated resistance value reaches the second preset value, an identification completion mark is output, and the resistance identification procedure is terminated according to the identification completion mark.

[0066] Step S240 , otherwise, repeatedly execute the control execution resistance identification procedure until the resistance value is obtained.

[0067] In the resistance identification program, a recognition completion mark is first preset, which is equivalent to the condition for the end of iteration. If the resistance estimation value output by the resistance identification program in a certain iteration reaches the second preset value, it is proved that the iteration end condition is met, and a recognition completion mark is output at this time, and then the resistance identification program is ended by the recognition completion mark. If the resistance estimation value output by a certain iteration does not reach the second preset value, the iteration continues until the resistance estimation value output by the next iteration reaches the second preset value, and the recognition completion mark is output.

[0068] Reference Figure 6 In some embodiments of the present application, the method further includes the following step S500:

[0069] Step S500: When the ambient temperature value does not reach the first preset value, the motor is controlled to run with the current control parameters.

[0070] In step S500, if the ambient temperature value does not reach the first preset value, it proves that the air conditioner outdoor unit is in a good working condition. For example, if the current ambient temperature value is 25 degrees, there is no need to perform additional control (current limiting) on ​​the speed of the motor of the outdoor unit, and the motor can be controlled to run with the current control parameters.

[0071] Step S300: Calculate the motor temperature value according to the resistance value and the preset corresponding relationship between resistance and temperature.

[0072] After the stator resistance value of the motor is determined in step S200, the temperature value of the motor is further determined based on the stator resistance value. Generally speaking, if the stator resistance value of the motor is different, the temperature of the motor will also be different, and there is a corresponding relationship between the stator resistance value and the motor temperature value.

[0073] In some embodiments of the present application, the relative relationship between the resistance value of the stator and the temperature value of the motor can be obtained by statistical methods, such as: setting up multiple groups of experiments, in each group of experiments, injecting current into the motor, measuring the resistance value of the motor stator and the temperature of the motor when it is at the current resistance value, recording the relationship between the two, and finally forming a corresponding relationship between resistance and temperature.

[0074] Reference Figure 7 In some embodiments of the present application, the motor temperature value is calculated according to the resistance value and the preset corresponding relationship between resistance and temperature in step S300, which specifically includes the following steps S310 and S320:

[0075] Step S310, calibrate the corresponding relationship between resistance and temperature, and fit the relationship curve between resistance and temperature by interpolation.

[0076] The interpolation and fitting method is to determine the parameters of a certain type of known function or seek an approximate function through some discrete data obtained by experiments and measurements, so that the obtained approximate function has a higher fitting accuracy with the known data. If this approximate function (curve or surface) is required to pass through all known data points, then this type of problem is called an interpolation problem. A batch of measured data has been given. Due to the influence of some external factors such as the measurement method and experimental environment, random interference and errors will inevitably occur. According to the general trend of data distribution, the accidental errors in the observed data are eliminated. Fitting is also called data smoothing (or data smoothing) problem. In this step, interpolation and fitting can be achieved through interp1 (one-dimensional interpolation), intero2 (two-dimensional interpolation), interp3 (three-dimensional interpolation) and fitting functions.

[0077] Step S320: Obtain the motor temperature value by looking up the table according to the resistance value and the relationship curve.

[0078] The method calibrates the relationship between the stator resistance and the temperature through steps S310 and S320, and then fits the stator resistance-temperature curve through interpolation. The stator resistance-temperature relationship curve will be stored in the controller, and the controller can be used to retrieve the calculated temperature at any time when needed.

[0079] Step S400: Perform proportional-integral-differential control on the motor speed according to the motor temperature value.

[0080] Proportional-integral-derivative control (PID) is one of the earliest developed control strategies. It is widely used in industrial process control due to its simple algorithm, good robustness and high reliability. Figure 8 As shown, P, I, and D represent the three control strategies of Propotional, Integral, and Differential, respectively. In this embodiment, a discrete PID control algorithm can be used to control the speed of the motor, so as to adjust the speed of the fan of the air conditioner outdoor unit, for example:

[0081] According to the motor temperature value, the temperature difference between the air conditioner outlet pipe and the water inlet pipe is used as a parameter. The temperature difference is compared with the set target value in real time to obtain the system error e and the system error change rate ec as the input variables of the fuzzy controller. The proportional parameter fine-tuning value ΔK in the PID controller parameters is adjusted through the fuzzy algorithm output variable. p And the integral parameter fine-tuning value ΔK i ; Using the basic PI parameter K p0 , K i0 And the proportional parameter fine-tuning value ΔK p , integral parameter fine-tuning value ΔK i Calculate the proportional parameter K in the PI regulator parameters p and the integration parameter K i ; Adopting adaptive fuzzy PID algorithm to output the output duty cycle of the PWM circuit to obtain the control current; the control current controls the frequency converter to achieve the control of the speed of the fan motor.

[0082] This step S400 is to implement closed-loop control of the motor temperature. According to the motor temperature value obtained in the above step S300, the motor temperature value is used as a control target to put the motor in a safe operating state.

[0083] In some embodiments of the present application, step S400 includes the following step 410:

[0084] Step S410: Control the motor to run at the highest speed according to proportional-integral-derivative control.

[0085] Control the motor to run at the highest speed to adapt to harsh working conditions.

[0086] At present, the prior art generally uses two calibration schemes for setting the motor current limit value: 1. Calibrate the motor current limit value under the worst conditions; 2. Calibrate the motor current limit value under normal conditions.

[0087] There are certain defects in both of the above two motor current limit calibration methods. If the current limit calibration method of scheme 1 is adopted, although it can ensure the stable operation of the motor in the worst environment, it will also limit the operating efficiency and the maximum speed that can be achieved in the normal environment of the motor, and limit the high speed output capacity of the motor under complex conditions; the calibration method of scheme 2 will sacrifice the steady-state operation performance of the motor under bad working conditions, and even cause damage to the motor under extreme conditions.

[0088] The solution of the above steps S100 to S400 provided in this embodiment first uses current injection to obtain the stator current signal of the motor, extracts the stator resistance value of the motor according to the motor parameter model, and then inquires and obtains the current temperature of the motor rotor according to the identified stator resistance value, and finally implements PID closed-loop control of the motor speed according to the rotor temperature. Through the above control strategy, the motor temperature can be controlled within a safe range, and the motor can be reliably operated at high speed in various complex environments.

[0089] Reference Fig. 9 An embodiment of the present application provides a motor speed control method applicable to an air conditioner outdoor unit, such as Fig.10 The air conditioner outdoor unit includes a controller and a fan, the fan includes a motor, and the method includes the following process:

[0090] First, the outdoor ambient temperature sensor provided as standard on the air conditioner outdoor unit is used to detect the operating environment of the motor of the fan in the air conditioner outdoor unit to obtain the ambient temperature value.

[0091] Secondly, determine whether the ambient temperature value is between the preset A value and B value, where the A value is minus 5 degrees and the B value is 36 degrees. When the ambient temperature value is between the A value and the B value, the motor current limit value is controlled according to the default configuration parameters.

[0092] When the ambient temperature is less than value A or greater than value B, the resistance identification program is run to obtain the motor stator resistance value. First, the current is injected, the stator current signal of the motor is sampled, and the coordinate system current is obtained through coordinate transformation. Then, the resistance value of the motor stator resistance is judged online according to the motor parameter model to obtain the motor stator resistance value.

[0093] Then, the stator resistance value is looked up in a table to obtain the corresponding temperature value of the motor rotor.

[0094] Finally, when the air-conditioning system requires the motor of the air-conditioning outdoor unit to output at the highest speed, the motor temperature value is used as the control target, and PID closed-loop control is implemented on the speed to control the motor temperature within the safety limit.

[0095] The method of this embodiment uses current injection into the motor of the fan to obtain the stator current signal of the motor, extract the stator resistance value of the motor according to the motor parameter model, and then query the current temperature of the motor rotor according to the identified stator resistance value, and finally implement PID closed-loop control of the motor speed according to the rotor temperature. Through the above control strategy, the motor temperature can be controlled within a safe range, and the motor can be reliably operated at high speed in various complex environments.

[0096] In addition, an embodiment of the present invention further provides a controller, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the motor speed control method as described in the above embodiment is implemented.

[0097] Take the control processor and memory in the controller as an example that can be connected through a bus. The memory, as a non-transient computer-readable storage medium, can be used to store non-transient software programs and non-transient computer executable programs. In addition, the memory may include a high-speed random access memory, and may also include a non-transient memory, such as at least one disk memory, a flash memory device, or other non-transient solid-state storage device. In some embodiments, the memory may optionally include a memory remotely arranged relative to the control processor, and these remote memories may be connected to the controller via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0098] The non-transient software program and instructions required to implement the motor speed control method of the above embodiment are stored in the memory. When executed by the processor, the motor speed control method of the above embodiment is executed, for example, the above described Figure 1 Steps S100 to S400 of the method, Figure 3 Step S210 and step S220, Figure 4 Step S221 and step S222 in Figure 5 Step S230 and step S240, Figure 6 Steps S100 to S500 in Figure 7 Step S310 and step S320 in .

[0099] An embodiment of the present application further provides an air conditioner outdoor unit, that is, an air conditioner outdoor unit, referring to Fig.10The structure of the air conditioner outdoor unit includes a fan 200 and a controller 100. The fan 200 includes a motor. The controller 100 is used to perform the above Figure 1 Steps S100 to S400 of the method, Figure 3 Step S210 and step S220, Figure 4 Step S221 and step S222 in Figure 5 Step S230 and step S240, Figure 6 Steps S100 to S500 in Figure 7 Step S310 and step S320 in .

[0100] The device embodiments described above are merely illustrative, and the units described as separate components may or may not be physically separated, that is, they may be located in one place or distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0101] In addition, the motor speed control method of the embodiment of the present invention is specifically applicable to controlling the fan motor of the air conditioner outdoor unit. The motor speed control method includes the controller of the above embodiment, and the controller executes the control method of the motor speed control method of the above embodiment.

[0102] In addition, an embodiment of the present invention further provides a computer-readable storage medium, which stores computer-executable instructions, and the computer-executable instructions are used to execute the above-mentioned control method, for example, being executed by a processor, so that the above-mentioned one or more processors can execute the control method in the above-mentioned method embodiment, for example, executing the above-mentioned Figure 1 Steps S100 to S400 of the method, Figure 3 Step S210 and step S220, Figure 4 Step S221 and step S222 in Figure 5 Step S230 and step S240, Figure 6 Steps S100 to S500 in Figure 7 Step S310 and step S320 in .

[0103] The device embodiments described above are merely illustrative, and the units described as separate components may or may not be physically separated, that is, they may be located in one place or distributed on multiple network nodes. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0104] It will be appreciated by those skilled in the art that all or some of the steps and systems in the disclosed method above may be implemented as software, firmware, hardware and appropriate combinations thereof. Some physical components or all physical components may be implemented as software executed by a processor, such as a central processing unit, a digital signal processor or a microprocessor, or may be implemented as hardware, or may be implemented as an integrated circuit, such as an application specific integrated circuit. Such software may be distributed on a computer-readable medium, which may include a computer-readable storage medium (or a non-transitory medium) and a communication medium (or a temporary medium). As known to those skilled in the art, the term computer-readable storage medium includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules or other data). Computer-readable storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tapes, disk storage or other magnetic storage devices, or any other medium that may be used to store desired information and may be accessed by a computer. Furthermore, it is well known to those skilled in the art that communication media typically embodies computer readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transport mechanism, and may include any information delivery media.

[0105] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in the relevant technical field without departing from the purpose of the present invention.

Claims

1. A motor speed control method, characterized in that: include: Get the ambient temperature value; When the ambient temperature reaches a first preset value, controlling execution of a resistance identification program to obtain a resistance value of the stator of the motor; Calculating the motor temperature value according to the resistance value and the preset corresponding relationship between resistance and temperature; The rotation speed of the motor is controlled by proportional-integral-differential method according to the temperature value of the motor.

2. The motor speed control method according to claim 1, characterized in that: The control executes a resistance identification procedure to obtain the resistance value of the stator of the motor, including: Sampling the stator current signal of the motor and obtaining the coordinate system current through coordinate transformation; The resistance value is determined according to the coordinate system current.

3. The motor speed control method according to claim 2, characterized in that: The determining the resistance value according to the coordinate system current includes: Obtaining a resistance estimate value based on the coordinate system current and motor parameter model; The resistance estimation value is judged online, and when the resistance estimation value reaches a second preset value, the corresponding resistance estimation is output as the resistance value.

4. The motor speed control method according to claim 3, characterized in that: The resistance identification program is preset with an identification completion mark, and the determining of the resistance value according to the coordinate system current further includes: When the resistance estimation value reaches a second preset value, outputting the identification completion mark, and ending the resistance identification procedure according to the identification completion mark; Otherwise, the control execution resistance identification procedure is repeatedly executed until the resistance value is obtained.

5. The motor speed control method according to claim 1, characterized in that: The step of calculating the motor temperature value according to the resistance value and a preset corresponding relationship between resistance and temperature includes: Calibrate the corresponding relationship between the resistance and the temperature, and fit the relationship curve between the resistance and the temperature by interpolation; The motor temperature value is obtained by looking up the table according to the resistance value and the relationship curve.

6. The motor speed control method according to claim 1, characterized in that: The proportional-integral-differential control of the rotation speed of the motor according to the motor temperature value comprises: According to the proportional-integral-derivative control, the motor is controlled to run at a maximum speed.

7. The motor speed control method according to claim 1, characterized in that: The motor speed control method further includes: When the ambient temperature value does not reach the first preset value, the motor is controlled to operate with current control parameters.

8. A controller, characterized in that The method comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor implements the motor speed control method according to any one of claims 1 to 7 when executing the computer program.

9. An air conditioner outdoor unit, characterized in that: The invention comprises a fan and the controller as claimed in claim 8, wherein the fan comprises the motor.

10. A computer-readable storage medium, characterized in that Computer executable instructions are stored, and the computer executable instructions are used to execute the motor speed control method as described in any one of claims 1 to 7.

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