A control method and device of a motor driver and a motor driver

Abstract

The present application relates to the technical field of rotating speed control, and particularly relates to a control method and device of a motor driver and the motor driver.The method comprises the following steps: determining a first rotating speed and a second rotating speed; every other preset time, judging whether the estimated rotating speed is less than the first rotating speed, if yes, determining the estimated rotating speed through high-frequency signal injection; if no, if the estimated rotating speed is less than or equal to the second rotating speed, determining a first electric angle and a second electric angle and calculating an angle difference; according to the comparison between the angle difference and 0, executing different schemes: if the angle difference is greater than 0, determining the estimated rotating speed according to the first electric angle; if the angle difference is less than 0, determining the estimated rotating speed through a second sliding mode observer; if the angle difference is equal to 0, determining the estimated rotating speed according to the second electric angle; if the estimated rotating speed is greater than the second rotating speed, determining the estimated rotating speed through a first sliding mode observer.The present application solves the problem of inaccurate estimation result in the switching process.

Description

Technical Field

[0001] This invention relates to the field of speed control technology, and in particular to a control method, device and motor driver for a motor driver. Background Technology

[0002] A motor driver is the core device for controlling the operation of a motor. It controls the speed, direction, and torque of the motor by adjusting voltage, current, and signals. Its core function is to convert electrical energy from the power supply into mechanical energy of the motor and to precisely adjust the motor speed according to control commands.

[0003] Currently, motor drivers operate by using high-frequency injection to calculate the rotor angle and control the motor speed at low speeds, and by using a sliding mode observer to calculate the rotor angle and control the motor speed at medium to high speeds.

[0004] When switching between high-frequency injection and sliding mode observer, the current method only uses a weighted average algorithm with fixed coefficients to obtain a comprehensive rotor angle, and then the rotational speed is obtained based on the comprehensive rotor angle. Since the rotor angles obtained by the two methods both have errors, and the comprehensive rotor angle cannot be controlled, there is a problem of inaccurate estimation results during the switching process. Summary of the Invention

[0005] Therefore, it is necessary to provide a control method, device, and motor driver for the motor driver to address the above-mentioned problems.

[0006] The present invention is implemented as follows: a control method for a motor driver, the control method for the motor driver comprising:

[0007] Determine the first and second rotational speeds based on the target rotational speed;

[0008] At preset intervals, it is determined whether the estimated rotational speed is less than the first rotational speed. If so, the estimated rotational speed is determined by injecting a high-frequency signal.

[0009] If the estimated rotational speed is greater than or equal to the first rotational speed, then determine whether the estimated rotational speed is greater than the second rotational speed. If not, determine the first electrical angle by injecting a high-frequency signal, determine the second electrical angle by using the first sliding mode observer, and calculate the angle difference between the first electrical angle and the second electrical angle.

[0010] Different schemes are implemented based on the comparison between the angle difference and 0: if the angle difference is greater than 0, the estimated rotational speed is determined based on the first electrical angle;

[0011] If the angle difference is less than 0, the estimated rotational speed is determined by the second sliding mode observer;

[0012] If the angle difference is equal to 0, the estimated rotational speed is determined based on the second electrical angle;

[0013] If the estimated rotational speed is greater than the second rotational speed, the estimated rotational speed is determined by the first sliding mode observer.

[0014] In one embodiment, the present invention provides a control device for a motor driver, the control device for the motor driver comprising:

[0015] The rotational speed determination module is used to determine the first rotational speed and the second rotational speed based on the target rotational speed.

[0016] The first control module is used to determine whether the estimated rotational speed is less than the first rotational speed at preset intervals. If so, the estimated rotational speed is determined by injecting a high-frequency signal.

[0017] The difference calculation module is used to determine whether the estimated rotational speed is greater than the second rotational speed if the estimated rotational speed is greater than or equal to the first rotational speed. If not, the first electrical angle is determined by high-frequency signal injection, the second electrical angle is determined by the first sliding mode observer, and the angle difference between the first electrical angle and the second electrical angle is calculated.

[0018] The second control module is used to execute different schemes based on the comparison between the angle difference and 0: if the angle difference is greater than 0, the estimated rotational speed is determined based on the first electrical angle;

[0019] The third control module is used to determine the estimated rotational speed through the second sliding mode observer if the angle difference is less than 0.

[0020] The fourth control module is used to determine the estimated rotational speed based on the second electrical angle if the angle difference is equal to 0.

[0021] The fifth control module is used to determine the estimated speed through the first sliding mode observer if the estimated speed is greater than the second speed.

[0022] In one embodiment, the present invention provides a motor driver, the motor driver comprising: a control module, a power conversion module, and a detection module;

[0023] The control module is used to execute the steps of the control method for the motor driver described above;

[0024] The power conversion module is connected to the control module and is used to control the power of the motor according to the control module.

[0025] The detection module is connected to the control module and is used to monitor the real-time current and real-time voltage of the motor.

[0026] This invention provides a motor driver control method that determines a first speed and a second speed based on a target speed. At preset time intervals, it checks whether the estimated speed is less than the first speed. If so, the estimated speed is determined by injecting a high-frequency signal. If the estimated speed is greater than or equal to the first speed, it checks whether the estimated speed is greater than the second speed. If not, a first electrical angle is determined by injecting a high-frequency signal, and a second electrical angle is determined by a first sliding mode observer. The angle difference between the first and second electrical angles is calculated. Different schemes are executed based on the comparison between the angle difference and 0: if the angle difference is greater than 0, the estimated speed is determined based on the first electrical angle; if the angle difference is less than 0, the estimated speed is determined by the second sliding mode observer; if the angle difference is equal to 0, the estimated speed is determined based on the second electrical angle; if the estimated speed is greater than the second speed, the estimated speed is determined by the first sliding mode observer. By doing so, during the switching between high-frequency injection and sliding mode observer modes, i.e. within the range of the first and second speeds, at preset intervals, different methods are selected to determine the estimated speed based on the angle difference between the first and second electrical angles, until the angle difference equals 0 and the method of determining the estimated speed through the first sliding mode observer is stably switched. Only one method is selected each time to determine the estimated speed, and the trend is closer to the angle difference being 0, which solves the problem of inaccurate estimation results during the switching process. Attached Figure Description

[0027] Figure 1 A flowchart of a control method for a motor driver in one embodiment;

[0028] Figure 2 This is a structural block diagram of a control device for a motor driver in one embodiment;

[0029] Figure 3 This is a structural block diagram of a motor driver in one embodiment;

[0030] Figure 4 This is a block diagram of the internal structure of the control module in one embodiment. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0032] It is understood that the terms "first," "second," etc., used in this invention may be used to describe various elements herein, but unless specifically stated otherwise, these elements are not limited by these terms. These terms are used only to distinguish one element from another. For example, without departing from the scope of this invention, a first script may be referred to as a second script, and similarly, a second script may be referred to as a first script.

[0033] like Figure 1 As shown, in one embodiment, a control method for a motor driver is proposed, which may specifically include the following steps:

[0034] S101, determine the first speed and the second speed according to the target speed;

[0035] S102, at every preset time interval, determine whether the estimated rotational speed is less than the first rotational speed; if so, determine the estimated rotational speed by injecting a high-frequency signal.

[0036] S103, if the estimated rotational speed is greater than or equal to the first rotational speed, then determine whether the estimated rotational speed is greater than the second rotational speed. If not, determine the first electrical angle by injecting a high-frequency signal, determine the second electrical angle by using the first sliding mode observer, and calculate the angle difference between the first electrical angle and the second electrical angle.

[0037] S104, different schemes are executed according to the comparison between the angle difference and 0: if the angle difference is greater than 0, the estimated rotational speed is determined according to the first electrical angle;

[0038] S105, if the angle difference is less than 0, the estimated rotational speed is determined by the second sliding mode observer;

[0039] S106, If the angle difference is equal to 0, then the estimated rotational speed is determined based on the second electrical angle;

[0040] S107, if the estimated rotational speed is greater than the second rotational speed, the estimated rotational speed is determined by the first sliding mode observer.

[0041] In this embodiment, the target speed is related to the gear selected by the user, and each gear has a corresponding target speed.

[0042] In this embodiment, the preset time is the interval for calculating the estimated rotational speed, which can be set to 100 microseconds.

[0043] In this embodiment, the initial value of the estimated rotational speed is 0, and each subsequent determination of the estimated rotational speed is an update of the previous estimated rotational speed.

[0044] In this embodiment, during the process of estimating the rotational speed to be greater than or equal to the first tachometer and less than the second rotational speed, all three scenarios of comparing the angle difference with 0 may occur, and the comparison will be re-evaluated every preset time interval. The goal is for the angle difference to be equal to 0 and to tend to be stable, thus gradually transitioning to determining the estimated rotational speed through the first sliding mode observer.

[0045] In this embodiment, high-frequency signal injection and the first sliding mode observer are conventional practices, corresponding to low speed and high speed respectively, which are the methods for calculating and estimating the rotational speed.

[0046] In this embodiment, the difference between the second sliding mode observer and the first sliding mode observer is that the output gain K is a dynamic variable that tends to decrease.

[0047] In this embodiment, the steps of determining the first electrical angle by injecting a high-frequency signal and then determining the estimated rotational speed by injecting the first electrical angle are the same as those of determining the estimated rotational speed by injecting a high-frequency signal.

[0048] In this embodiment, the steps of determining the second electrical angle through the first sliding mode observer and then determining the estimated rotational speed through the second electrical angle are the same as the steps of determining the estimated rotational speed through the first sliding mode observer.

[0049] This invention provides a motor driver control method that determines a first speed and a second speed based on a target speed. At preset time intervals, it checks whether the estimated speed is less than the first speed. If so, the estimated speed is determined by injecting a high-frequency signal. If the estimated speed is greater than or equal to the first speed, it checks whether the estimated speed is greater than the second speed. If not, a first electrical angle is determined by injecting a high-frequency signal, and a second electrical angle is determined by a first sliding mode observer. The angle difference between the first and second electrical angles is calculated. Different schemes are executed based on the comparison between the angle difference and 0: if the angle difference is greater than 0, the estimated speed is determined based on the first electrical angle; if the angle difference is less than 0, the estimated speed is determined by the second sliding mode observer; if the angle difference is equal to 0, the estimated speed is determined based on the second electrical angle; if the estimated speed is greater than the second speed, the estimated speed is determined by the first sliding mode observer. By doing so, during the switching between high-frequency injection and sliding mode observer modes, i.e. within the range of the first and second speeds, at preset intervals, different methods are selected to determine the estimated speed based on the angle difference between the first and second electrical angles, until the angle difference equals 0 and the method of determining the estimated speed through the first sliding mode observer is stably switched. Only one method is selected each time to determine the estimated speed, and the trend is closer to the angle difference being 0, which solves the problem of inaccurate estimation results during the switching process.

[0050] In one embodiment, determining the first speed and the second speed based on the target speed includes:

[0051] Depend on Obtain the first rotational speed;

[0052] Depend on The second rotational speed was obtained;

[0053] in, The target rotational speed is given by 'a', which is the first preset ratio and 'b', where 'a' is less than 'b'.

[0054] In this embodiment, 'a' can be set to any value between 2% and 5%, and 'b' can be set to any value between 8% and 15%.

[0055] In one embodiment, determining the estimated rotational speed via high-frequency signal injection includes:

[0056] Inject a high-frequency voltage signal into the motor and use a bandpass filter to extract the high-frequency current response;

[0057] The error signal is determined based on the high-frequency current response;

[0058] The error signal is input into the proportional-integral observer to obtain the first electrical angle;

[0059] The estimated rotational speed is determined based on the change in the first electrical angle.

[0060] In this embodiment, there are multiple ways to inject high-frequency signals, such as rotational injection and pulse injection.

[0061] In this embodiment, the estimated rotational speed is determined based on the change in the first electrical angle, which is generally obtained by dividing the difference between the two latest first electrical angles by a preset time.

[0062] In one embodiment, determining the second electrical angle via a first sliding mode observer includes:

[0063] Obtain real-time current and real-time voltage;

[0064] Establish the first current observer model;

[0065] The first estimated current is obtained by inputting the real-time current and real-time voltage into the first current observer model.

[0066] The first error current is obtained based on the first estimated current and the real-time current;

[0067] The first correction value is determined based on the real-time current and the first estimated current;

[0068] The first estimated back electromotive force is obtained based on the first correction value, the first error current, and the switching function;

[0069] The second electric angle is obtained based on the first estimated back electromotive force.

[0070] In this embodiment, the back EMF, electrical angle, and rotational speed can be estimated using a sliding mode observer algorithm. The three monitored currents are transformed using a Clark transform. coordinate system, becomes and The same applies to voltage. and Further changes were made through Park. coordinate system, becomes and The same applies to voltage. and Its purpose is to facilitate tracking between two parallel PI controllers. , , and After obtaining the electrical angle and rotational speed through the sliding mode observer algorithm, estimating the back electromotive force is a quantity generated in the intermediate calculation.

[0071] In this embodiment, since a low-pass filter is used when obtaining the estimated back EMF, it will cause the estimated back EMF amplitude to be attenuated and backward lag. Therefore, phase compensation is required for the estimated angle. In addition, in order to eliminate the influence of chattering on the sliding mode observer, the winding resistance is set to Set the winding inductance to The relationship between the estimated current and the input quantity can be set as follows:

[0072]

[0073] in, , for Estimating current in a coordinate system , To estimate the back electromotive force, , for Real-time voltage in the coordinate system This is a correction value. In the initial estimation, the estimated current on the right side of the equation can be set to the actual current, and the estimated back electromotive force can be set to 0. This yields the estimated current on the left side of the equation. Sliding mode itself gradually converges within the error. Since the constructed error equation is convergent, it will gradually move closer to the sliding surface, and the error will gradually decrease. In other words, the speed calculation and position calculation are based on the convergence of the sliding mode. Therefore, the calculated estimated current needs to be repeatedly corrected.

[0074] In this embodiment, a first correction value is determined based on the real-time current and the first estimated current, where MaxSMCError is a limit value defined in the program by the SMO sliding mode observer. Based on existing technology, the expression for h is:

[0075]

[0076] Therefore, if the right-hand side of the expression is the output of the simplified sliding mode observer, satisfying the condition of being less than and (i.e., less than the maximum error in the program), it means the sliding mode observer is in a convergent state, and the estimated current will converge to the actual current, eventually reaching and remaining on the sliding surface. For error values ​​outside the linear range, the output of the sliding mode observer is... or This depends on the sign of the error. The output is the first correction value. Essentially... It is a positive value, and the sign is determined by the first error current.

[0077] In one embodiment, determining the estimated rotational speed via a second sliding mode observer includes:

[0078] Obtain real-time current and real-time voltage;

[0079] Establish a second current observer model;

[0080] The real-time current and real-time voltage are input into the second current observer model to obtain the second estimated current;

[0081] The second error current is obtained based on the second estimated current and the real-time current;

[0082] The second correction value is determined based on the first electrical angle, the second electrical angle, the real-time current, and the second estimated current.

[0083] The second estimated back electromotive force is obtained based on the second correction value, the second error current, and the switching function;

[0084] The third electrical angle is obtained based on the second estimated back electromotive force;

[0085] The estimated rotational speed is determined based on the third electrical angle.

[0086] In this embodiment, the process of the second sliding mode observer determining the electrical angle and estimating the rotational speed is the same as that of the first sliding mode observer. The difference lies in the fact that the first correction value and the second correction value are different. The second correction value is a value that tends to decrease, while the first correction value is not.

[0087] In one embodiment, determining the second correction value based on the first electrical angle, the second electrical angle, the real-time current, and the second estimated current includes:

[0088] The intermediate correction value is determined based on the real-time current and the second estimated current.

[0089] Depend on Determine the second correction value;

[0090] The second correction value is adjusted based on the changes in the angle difference and the changes in the second correction value.

[0091] in, For the first electrical angle, The second electrical angle is c1, which is the intermediate correction value, and c2 is the preset correction value.

[0092] In this embodiment, the intermediate correction value is determined in the same way as the first correction value.

[0093] In this embodiment, the preset correction value can be the average value of the first correction value in the historical records.

[0094] In one embodiment, adjusting the second correction value based on changes in the angle difference and changes in the second correction value includes:

[0095] Obtain the absolute value of the latest angle difference;

[0096] Get the absolute value of the previous angle difference;

[0097] Determine whether the absolute value of the latest angle difference is less than the absolute value of the previous angle difference. If so, do not adjust the second correction value. If not, adjust the second correction value according to the change of the latest second correction value.

[0098] In this embodiment, after the second correction value is obtained, it needs to be adjusted. This depends on whether the absolute value of the angle difference decreases. If it does, the direction of change is correct and no adjustment is needed; if not, the direction of change is incorrect and adjustment is required.

[0099] In one embodiment, adjusting the second correction value based on the latest change in the second correction value includes:

[0100] Depend on The magnitude of change, x, is obtained.

[0101] Determine if the magnitude of the change is greater than 0; if so, then proceed as follows: Obtain the adjusted second correction value; otherwise, by The adjusted second correction value is obtained;

[0102] Where C1 is the latest second correction value, and C0 is the previous second correction value of C1.

[0103] In this embodiment, if the change magnitude is greater than 0, since the second correction value is positive, then... A positive value indicates that the second correction value is increasing, but in the wrong direction. Therefore, it is necessary to greatly reduce the change in the second correction value. Hence, the following approach is adopted. Adjust the second correction value. In other words, if the magnitude of the change decreases or remains unchanged, then... A negative value indicates that the second correction value is decreasing, at which point... The adjusted second correction value is obtained, which increases slightly after adjustment.

[0104] like Figure 2 As shown, in one embodiment, a control device for a motor driver is provided, which may specifically include:

[0105] The rotational speed determination module is used to determine the first rotational speed and the second rotational speed based on the target rotational speed.

[0106] The first control module is used to determine whether the estimated rotational speed is less than the first rotational speed at preset intervals. If so, the estimated rotational speed is determined by injecting a high-frequency signal.

[0107] The difference calculation module is used to determine whether the estimated rotational speed is greater than the second rotational speed if the estimated rotational speed is greater than or equal to the first rotational speed. If not, the first electrical angle is determined by high-frequency signal injection, the second electrical angle is determined by the first sliding mode observer, and the angle difference between the first electrical angle and the second electrical angle is calculated.

[0108] The second control module is used to execute different schemes based on the comparison between the angle difference and 0: if the angle difference is greater than 0, the estimated rotational speed is determined based on the first electrical angle;

[0109] The third control module is used to determine the estimated rotational speed through the second sliding mode observer if the angle difference is less than 0.

[0110] The fourth control module is used to determine the estimated rotational speed based on the second electrical angle if the angle difference is equal to 0.

[0111] The fifth control module is used to determine the estimated speed through the first sliding mode observer if the estimated speed is greater than the second speed.

[0112] In this embodiment, the various modules of the control device of the motor driver are modularized from the method of the present invention. For a detailed explanation of each module, please refer to the corresponding content in the method section of the present invention. The embodiments of the present invention will not be repeated here.

[0113] like Figure 3 As shown, in one embodiment, a motor driver is provided, which may specifically include: a control module, a power conversion module, and a detection module;

[0114] The control module is used to execute the steps of the control method for the motor driver described above;

[0115] The power conversion module is connected to the control module and is used to control the power of the motor according to the control module.

[0116] The detection module is connected to the control module and is used to monitor the real-time current and real-time voltage of the motor.

[0117] In this embodiment, the motor driver also includes other modules such as a power supply module.

[0118] In this embodiment, the detection module consists of a current sensor and a voltage sensor. The power conversion module converts the input from the computer into the variable voltage required for the motor to operate.

[0119] This invention provides a motor driver that determines a first speed and a second speed based on a target speed. At preset time intervals, it determines whether the estimated speed is less than the first speed. If so, it determines the estimated speed by injecting a high-frequency signal. If the estimated speed is greater than or equal to the first speed, it determines whether the estimated speed is greater than the second speed. If not, it determines a first electrical angle by injecting a high-frequency signal and a second electrical angle by using a first sliding mode observer. It then calculates the angle difference between the first and second electrical angles. Different schemes are executed based on the comparison between the angle difference and 0: if the angle difference is greater than 0, the estimated speed is determined based on the first electrical angle; if the angle difference is less than 0, the estimated speed is determined by using a second sliding mode observer; if the angle difference is equal to 0, the estimated speed is determined based on the second electrical angle; if the estimated speed is greater than the second speed, the estimated speed is determined by using a first sliding mode observer. By doing so, during the switching between high-frequency injection and sliding mode observer modes, i.e. within the range of the first and second speeds, at preset intervals, different methods are selected to determine the estimated speed based on the angle difference between the first and second electrical angles, until the angle difference equals 0 and the method of determining the estimated speed through the first sliding mode observer is stably switched. Only one method is selected each time to determine the estimated speed, and the trend is closer to the angle difference being 0, which solves the problem of inaccurate estimation results during the switching process.

[0120] Figure 4 An internal structural diagram of the control module in one embodiment is shown. Figure 4As shown, the control module includes a processor, a memory, a network interface, an input device, and a display screen connected via a system bus. The memory includes a non-volatile storage medium and internal memory. The non-volatile storage medium of the control module stores an operating system and may also store a computer program. When executed by the processor, this computer program enables the processor to implement the control method for a motor driver provided in this embodiment of the invention. The internal memory may also store a computer program, which, when executed by the processor, enables the processor to execute the control method for a motor driver provided in this embodiment of the invention. The display screen of the control module can be a liquid crystal display (LCD) or an electronic ink display. The input device of the control module can be a touch layer covering the display screen, or buttons, a trackball, or a touchpad mounted on the control module's casing, or an external keyboard, touchpad, or mouse, etc.

[0121] Those skilled in the art will understand that Figure 4 The structure shown is merely a block diagram of a portion of the structure related to the present invention and does not constitute a limitation on the control module to which the present invention is applied. The specific control module may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0122] In one embodiment, the control device for a motor driver provided by the present invention can be implemented as a computer program, and the computer program can be implemented as follows: Figure 4 The control module shown operates on this system. The memory of the control module can store the various program modules that make up the control device of the motor driver, for example... Figure 2 The diagram shows a speed determination module, a first control module, a difference calculation module, a second control module, a third control module, a fourth control module, and a fifth control module. The computer program comprised of these modules causes the processor to execute the steps of a motor driver control method according to various embodiments of the present invention described in this specification.

[0123] For example, Figure 4 The control module shown can be used as follows Figure 2 The speed determination module in the control device of the motor driver shown executes step S101; the control module can execute step S102 through the first control module; the control module can execute step S103 through the difference calculation module; the control module can execute step S104 through the second control module; the control module can execute step S105 through the third control module; the control module can execute step S106 through the fourth control module; and the control module can execute step S107 through the fifth control module.

[0124] In one embodiment, a control module is provided, the control module including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to perform the following steps:

[0125] S101, determine the first speed and the second speed according to the target speed;

[0126] S102, at every preset time interval, determine whether the estimated rotational speed is less than the first rotational speed; if so, determine the estimated rotational speed by injecting a high-frequency signal.

[0127] S103, if the estimated rotational speed is greater than or equal to the first rotational speed, then determine whether the estimated rotational speed is greater than the second rotational speed. If not, determine the first electrical angle by injecting a high-frequency signal, determine the second electrical angle by using the first sliding mode observer, and calculate the angle difference between the first electrical angle and the second electrical angle.

[0128] S104, different schemes are executed according to the comparison between the angle difference and 0: if the angle difference is greater than 0, the estimated rotational speed is determined according to the first electrical angle;

[0129] S105, if the angle difference is less than 0, the estimated rotational speed is determined by the second sliding mode observer;

[0130] S106, If the angle difference is equal to 0, then the estimated rotational speed is determined based on the second electrical angle;

[0131] S107, if the estimated rotational speed is greater than the second rotational speed, the estimated rotational speed is determined by the first sliding mode observer.

[0132] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored, which, when executed by a processor, causes the processor to perform the following steps:

[0133] S101, determine the first speed and the second speed according to the target speed;

[0134] S102, at every preset time interval, determine whether the estimated rotational speed is less than the first rotational speed; if so, determine the estimated rotational speed by injecting a high-frequency signal.

[0135] S103, if the estimated rotational speed is greater than or equal to the first rotational speed, then determine whether the estimated rotational speed is greater than the second rotational speed. If not, determine the first electrical angle by injecting a high-frequency signal, determine the second electrical angle by using the first sliding mode observer, and calculate the angle difference between the first electrical angle and the second electrical angle.

[0136] S104, different schemes are executed according to the comparison between the angle difference and 0: if the angle difference is greater than 0, the estimated rotational speed is determined according to the first electrical angle;

[0137] S105, if the angle difference is less than 0, the estimated rotational speed is determined by the second sliding mode observer;

[0138] S106, If the angle difference is equal to 0, then the estimated rotational speed is determined based on the second electrical angle;

[0139] S107, if the estimated rotational speed is greater than the second rotational speed, the estimated rotational speed is determined by the first sliding mode observer.

[0140] It should be understood that although the steps in the flowcharts of the various embodiments of the present invention are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the various embodiments may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least a portion of the sub-steps or stages of other steps.

[0141] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, storage, databases, or other media used in the embodiments provided by this invention can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), Rambus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0142] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0143] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A control method for a motor driver, characterized in that, The control method for the motor driver includes: Determine the first and second rotational speeds based on the target rotational speed; At preset intervals, it is determined whether the estimated rotational speed is less than the first rotational speed. If so, the estimated rotational speed is determined by injecting a high-frequency signal. If the estimated rotational speed is greater than or equal to the first rotational speed, then determine whether the estimated rotational speed is greater than the second rotational speed. If not, determine the first electrical angle by injecting a high-frequency signal, determine the second electrical angle by using the first sliding mode observer, and calculate the angle difference between the first electrical angle and the second electrical angle. Different schemes are implemented based on the comparison between the angle difference and 0: if the angle difference is greater than 0, the estimated rotational speed is determined based on the first electrical angle; If the angle difference is less than 0, the estimated rotational speed is determined by the second sliding mode observer; If the angle difference is equal to 0, the estimated rotational speed is determined based on the second electrical angle; If the estimated rotational speed is greater than the second rotational speed, the estimated rotational speed is determined by the first sliding mode observer; The determination of the second electrical angle via the first sliding mode observer includes: Obtain real-time current and real-time voltage; Establish the first current observer model; The first estimated current is obtained by inputting the real-time current and real-time voltage into the first current observer model. The first error current is obtained based on the first estimated current and the real-time current; The first correction value is determined based on the real-time current and the first estimated current; The first estimated back electromotive force is obtained based on the first correction value, the first error current, and the switching function; The second electrical angle is obtained based on the first estimated back electromotive force; The process of determining the estimated rotational speed using a second sliding mode observer includes: Obtain real-time current and real-time voltage; Establish a second current observer model; The real-time current and real-time voltage are input into the second current observer model to obtain the second estimated current; The second error current is obtained based on the second estimated current and the real-time current; The second correction value is determined based on the first electrical angle, the second electrical angle, the real-time current, and the second estimated current. The second estimated back electromotive force is obtained based on the second correction value, the second error current, and the switching function; The third electrical angle is obtained based on the second estimated back electromotive force; The estimated rotational speed is determined based on the third electrical angle.

2. The control method for the motor driver according to claim 1, characterized in that, The process of determining the first speed and the second speed based on the target speed includes: Depend on Obtain the first rotational speed; Depend on The second rotational speed was obtained; in, The target rotational speed is given by 'a', which is the first preset ratio and 'b', where 'a' is less than 'b'.

3. The control method for the motor driver according to claim 1, characterized in that, The method of determining the estimated rotational speed by injecting a high-frequency signal includes: Inject a high-frequency voltage signal into the motor and use a bandpass filter to extract the high-frequency current response; The error signal is determined based on the high-frequency current response; The error signal is input into the proportional-integral observer to obtain the first electrical angle; The estimated rotational speed is determined based on the change in the first electrical angle.

4. The control method for the motor driver according to claim 1, characterized in that, The determination of the second correction value based on the first electrical angle, the second electrical angle, the real-time current, and the second estimated current includes: The intermediate correction value is determined based on the real-time current and the second estimated current. Depend on Determine the second correction value; The second correction value is adjusted based on the changes in the angle difference and the changes in the second correction value. in, For the first electrical angle, The second electrical angle is c1, which is the intermediate correction value, and c2 is the preset correction value.

5. The control method for the motor driver according to claim 4, characterized in that, The adjustment of the second correction value based on the changes in the angle difference and the changes in the second correction value includes: Obtain the absolute value of the latest angle difference; Get the absolute value of the previous angle difference; Determine whether the absolute value of the latest angle difference is less than the absolute value of the previous angle difference. If so, do not adjust the second correction value. If not, adjust the second correction value according to the change of the latest second correction value.

6. The control method for the motor driver according to claim 5, characterized in that, The adjustment of the second correction value based on the latest change in the second correction value includes: Depend on The magnitude of change, x, is obtained. Determine if the magnitude of the change is greater than 0; if so, then proceed as follows: Obtain the adjusted second correction value; otherwise, by The adjusted second correction value is obtained; Where C1 is the latest second correction value, and C0 is the previous second correction value of C1.

7. A control device for a motor driver, characterized in that, The control device for the motor driver includes: The rotational speed determination module is used to determine the first rotational speed and the second rotational speed based on the target rotational speed. The first control module is used to determine whether the estimated rotational speed is less than the first rotational speed at preset intervals. If so, the estimated rotational speed is determined by injecting a high-frequency signal. The difference calculation module is used to determine whether the estimated rotational speed is greater than the second rotational speed if the estimated rotational speed is greater than or equal to the first rotational speed. If not, the first electrical angle is determined by high-frequency signal injection, the second electrical angle is determined by the first sliding mode observer, and the angle difference between the first electrical angle and the second electrical angle is calculated. The second control module is used to execute different schemes based on the comparison between the angle difference and 0: if the angle difference is greater than 0, the estimated rotational speed is determined based on the first electrical angle; The third control module is used to determine the estimated rotational speed through the second sliding mode observer if the angle difference is less than 0. The fourth control module is used to determine the estimated rotational speed based on the second electrical angle if the angle difference is equal to 0. The fifth control module is used to determine the estimated rotational speed through the first sliding mode observer if the estimated rotational speed is greater than the second rotational speed. The determination of the second electrical angle via the first sliding mode observer includes: Obtain real-time current and real-time voltage; Establish the first current observer model; The first estimated current is obtained by inputting the real-time current and real-time voltage into the first current observer model. The first error current is obtained based on the first estimated current and the real-time current; The first correction value is determined based on the real-time current and the first estimated current; The first estimated back electromotive force is obtained based on the first correction value, the first error current, and the switching function; The second electrical angle is obtained based on the first estimated back electromotive force; The process of determining the estimated rotational speed using a second sliding mode observer includes: Obtain real-time current and real-time voltage; Establish a second current observer model; The real-time current and real-time voltage are input into the second current observer model to obtain the second estimated current; The second error current is obtained based on the second estimated current and the real-time current; The second correction value is determined based on the first electrical angle, the second electrical angle, the real-time current, and the second estimated current. The second estimated back electromotive force is obtained based on the second correction value, the second error current, and the switching function; The third electrical angle is obtained based on the second estimated back electromotive force; The estimated rotational speed is determined based on the third electrical angle.

8. A motor driver, characterized in that, The motor driver includes: a control module, a power conversion module, and a detection module; The control module is used to perform the steps of the control method of the motor driver according to any one of claims 1 to 6; The power conversion module is connected to the control module and is used to control the power of the motor according to the control module. The detection module is connected to the control module and is used to monitor the real-time current and real-time voltage of the motor.

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