阅读说明：本技术 一种电机启动方法及相关装置 (Motor starting method and related device ) 是由 张三艳 于 2020-06-17 设计创作，主要内容包括：本申请实施例提供一种电机启动方法及相关装置。该方法包括：接收启动指令,所述启动指令用于启动电机；利用电流环和强制角度启动所述电机,直至所述电机的当前转速大于第一切换转速；利用速度环和强制角度启动所述电机,直至所述电机的当前转速不小于第二切换转速；利用磁链观测器输出的角度启动所述电机。本申请所提供的方法和装置,能够有效解决在电机的转子磁链位置未知的情况下启动电机时风扇扇叶的回摆问题,提高了电机启动的成功率,也提高了电机的效率,进而提高了电机的安全性及可靠性。(The embodiment of the application provides a motor starting method and a related device. The method comprises the following steps: receiving a starting instruction, wherein the starting instruction is used for starting a motor; starting the motor by utilizing a current loop and a forced angle until the current rotating speed of the motor is greater than a first switching rotating speed; starting the motor by using the speed ring and the forced angle until the current rotating speed of the motor is not less than a second switching rotating speed; and starting the motor by utilizing the angle output by the flux linkage observer. The method and the device provided by the application can effectively solve the problem of swinging back of the fan blade when the motor is started under the condition that the position of the rotor flux linkage of the motor is unknown, improve the success rate of starting the motor, improve the efficiency of the motor and further improve the safety and the reliability of the motor.)

1. A method of starting a motor, comprising:

receiving a starting instruction, wherein the starting instruction is used for starting a motor;

starting the motor by utilizing a current loop and a forced angle until the current rotating speed of the motor is greater than a first switching rotating speed;

starting the motor by using the speed ring and the forced angle until the current rotating speed of the motor is not less than a second switching rotating speed;

and starting the motor by utilizing the angle output by the flux linkage observer.

2. The method of claim 1, wherein the starting the motor with the current loop and the forced angle comprises:

starting the current loop according to a first factor, wherein the first factor comprises that the rotor angle of the motor is the forced angle and the q-axis current is a non-zero constant value.

3. The method of claim 1 or 2, wherein the starting the motor with the speed loop and the forcing angle comprises:

and starting the speed loop according to a second element, wherein the second element comprises the closed loop of the current loop, the rotor angle of the motor is the forced angle, and the output of the speed loop is used as the value of the q-axis current.

4. The method of claim 3, wherein the starting the motor with the angle of the flux linkage observer output comprises:

and starting the motor according to a third element, wherein the third element comprises the current loop closed loop, the speed loop closed loop and the rotor angle of the motor are the angles output by a flux linkage observer.

5. Method according to claim 4, characterized in that the value of said forcing angle is incremented starting from zero, with an acceleration different from zero.

6. A motor starting device, comprising:

the motor starting device comprises a receiving unit, a starting unit and a control unit, wherein the receiving unit is used for receiving a starting instruction which is used for starting a motor;

the starting unit is used for starting the motor by utilizing the current loop and the forced angle until the current rotating speed of the motor is greater than a first switching rotating speed;

the starting unit is also used for starting the motor by utilizing the speed ring and the forced angle until the current rotating speed of the motor is not less than a second switching rotating speed;

the starting unit is also used for starting the motor by utilizing the angle output by the flux linkage observer.

7. The device according to claim 6, characterized in that the starting unit is in particular adapted to start the current loop according to a first factor comprising that the rotor angle of the electrical machine is the forced angle and that the q-axis current is a non-zero constant value.

8. The device according to claim 6 or 7, wherein the starting unit is further configured to start the speed loop according to a second factor, the second factor including the closed loop of the current loop, the rotor angle of the motor being the forced angle, and the output of the speed loop being the value of the q-axis current.

9. An electronic device, comprising: a processor and a memory, wherein the memory stores program instructions that, when executed by the processor, cause the processor to perform the method of any of claims 1-5.

10. A computer-readable storage medium, in which a computer program is stored which, when run on one or more processors, performs the method of any one of claims 1-5.

Technical Field

The present application relates to the field of motor technologies, and in particular, to a motor starting method and a related device.

Background

For the existing motor without a position sensor, the starting method generally includes the steps of initially positioning the rotor, then executing current dragging on the rotor of the motor, and then switching to closed-loop control, namely when the current frequency is larger than a preset target current value, and the motor has enough counter electromotive force, the motor can be controlled to be switched to the closed-loop control, so that the starting work of the motor is completed.

However, in practical application scenarios, the estimation of the rotor flux linkage position of the motor is inaccurate. When the motor is started under the condition that the position of a rotor flux linkage of the motor is unknown, fan blades of the fan have the problem of backswing, and the backswing of the motor is not allowed to be started in the control of the fan, because the backswing of the motor is easy to cause the overcurrent of the motor of the fan, a controller is damaged, the demagnetization of the motor is caused, and the starting failure of the fan is caused.

Therefore, how to solve the problem of the fan blade swinging back when the motor is started under the condition that the rotor flux linkage position of the motor is unknown is an important research subject in the technical field.

Disclosure of Invention

The embodiment of the application discloses a motor starting method and a related device, which omit direct current positioning of a motor rotor, adopt a strategy of starting a motor by a direct current closed loop and a forced angle or an angle estimated by a flux observer according to different conditions of the rotating speed of the motor rotor, effectively solve the problem of swinging back of fan blades when the motor is started under the condition that the position of a rotor flux of the motor is unknown, improve the success rate of starting the motor, improve the efficiency of the motor, and further improve the safety and reliability of the motor.

In a first aspect, an embodiment of the present application discloses a motor starting method, including:

receiving a starting instruction, wherein the starting instruction is used for starting a motor;

starting the motor by utilizing a current loop and a forced angle until the current rotating speed of the motor is greater than a first switching rotating speed;

starting the motor by using the speed ring and the forced angle until the current rotating speed of the motor is not less than a second switching rotating speed;

and starting the motor by utilizing the angle output by the flux linkage observer.

In the embodiment of the application, the motor is not started according to the traditional direct current positioning, but the motor is dragged by directly adding the forced angle in the current closed loop, the motor is added in the speed loop closed loop after reaching the first switching rotating speed, the forced angle is continuously used at the moment, and the motor is dragged by calculating the angle estimated by the flux linkage observer after reaching the second switching rotating speed. Therefore, according to different conditions of the rotating speed of the motor rotor, a strategy of starting the motor by a direct current closed loop plus a forced angle or an angle estimated by a flux observer is respectively adopted, the problem of swinging back of fan blades when the motor is started under the condition that the position of the flux of the rotor of the motor is unknown is effectively solved, the success rate of starting the motor is improved, the efficiency of the motor is also improved, and the safety and the reliability of the motor are further improved.

In one possible implementation of the first aspect, the starting the motor with the current loop and the forced angle includes:

starting the current loop according to a first factor, wherein the first factor comprises that the rotor angle of the motor is the forced angle and the q-axis current is a non-zero constant value.

In the embodiment of the application, when the current rotating speed of the motor is not greater than the first switching rotating speed, the motor is started by using the current loop and the forced angle, the specific mode is that the current loop is started, the speed loop is opened, the angle of a rotor of the motor adopts the forced angle, and the motor is controlled by giving a nonzero constant value to the q-axis current; on the other hand, the current rotation speed of the motor may be estimated by a position estimation algorithm, specifically by using a long locked loop (PLL) observer and a Phase Locked Loop (PLL). Through this embodiment, the problem of the back swing of fan flabellum when the motor is started under the condition that the rotor flux linkage position of the motor is unknown can be effectively solved, the success rate of motor starting is improved, and the efficiency of the motor is also improved.

In yet another possible implementation of the first aspect, the starting the motor with the speed loop and the forcing angle includes:

and starting the speed loop according to a second element, wherein the second element comprises the closed loop of the current loop, the rotor angle of the motor is the forced angle, and the output of the speed loop is used as the value of the q-axis current.

In the embodiment of the application, when the current rotating speed of the motor is greater than the first switching rotating speed and less than the second switching rotating speed, the motor is started by using the speed ring and the forced angle, the specific mode is that the speed ring is started, the current ring and the speed ring are closed, the rotor angle of the motor adopts the forced angle, and the output of the speed ring is used as the value of the q-axis current to control the motor; on the other hand, the current rotation speed of the motor can be obtained by a position estimation algorithm, and the current rotation speed can be obtained by estimation through a humper observer and a phase-locked loop (PLL). Through this embodiment, the backswing problem of fan flabellum when can effectively solve the starting motor under the unknown condition of the rotor flux linkage position of motor, improves the success rate that the motor started, also improves the efficiency of motor.

In yet another possible implementation manner of the first aspect, the starting the motor with the angle output by the flux linkage observer includes:

and starting the motor according to a third element, wherein the third element comprises the current loop closed loop, the speed loop closed loop and the rotor angle of the motor are the angle output by a flux linkage observer.

In the embodiment of the present application, when the current rotation speed of the motor is not less than the second switching rotation speed, the motor is started by using the angle output by the flux linkage observer, specifically, the angle output by the flux linkage observer is used as the rotor angle of the motor to start the motor, and meanwhile, both the current loop and the speed loop are closed, and after that, the starting process is ended, and the motor enters field-oriented control (FOC); on the other hand, the current rotational speed of the motor may be obtained by a position estimation algorithm, specifically by estimation through a humper observer and a phase-locked loop PLL. Through this embodiment, the backswing problem of fan flabellum when can effectively solve the starting motor under the unknown condition of the rotor flux linkage position of motor, improves the success rate of motor start-up, also improves the efficiency of motor.

In a further possible implementation of the first aspect, the value of the forcing angle is incremented starting from zero with an acceleration different from zero.

In the embodiment of the application, the forced angle is limited, and the value of the forced angle is increased in an acceleration which is not zero from zero until a target threshold value is reached, wherein the target threshold value is a maximum value amplitude limit which is carried out according to the motor starting limit rotating speed, so that the motor starting efficiency can be improved, and the safety and the reliability of the motor can be improved.

In a second aspect, an embodiment of the present application discloses a starting apparatus for preventing a motor from swinging back, including:

the motor starting device comprises a receiving unit, a starting unit and a control unit, wherein the receiving unit is used for receiving a starting instruction which is used for starting a motor;

the starting unit is used for starting the motor by utilizing the current loop and the forced angle until the current rotating speed of the motor is greater than a first switching rotating speed;

the starting unit is also used for starting the motor by utilizing the speed ring and the forced angle until the current rotating speed of the motor is not less than a second switching rotating speed;

the starting unit is also used for starting the motor by utilizing the angle output by the flux linkage observer.

In the embodiment of the application, when the current rotating speed of the motor is not more than the first switching rotating speed, the motor is started by using the current loop and the forced angle, the specific mode is that the current loop is started, the speed loop is opened, the angle of a rotor of the motor adopts the forced angle, and a non-zero constant value is given to the q-axis current to control the motor; on the other hand, the current rotational speed of the motor can be obtained by a position estimation algorithm, specifically by estimation through a humper observer and a phase-locked loop PLL. Through the embodiment, the problem of backswing of fan blades when the motor is started under the condition that the position of the rotor flux linkage of the motor is unknown can be effectively solved, the success rate of starting the motor is improved, and the efficiency of the motor is also improved.

In a possible embodiment of the second aspect, in starting the motor with a current loop and a forcing angle, the starting unit is specifically configured to start the current loop according to a first factor, the first factor including that a rotor angle of the motor is the forcing angle and a q-axis current is a non-zero constant value.

In the embodiment of the application, when the current rotating speed of the motor is not greater than the first switching rotating speed, the motor is started by using the current loop and the forced angle, the specific mode is that the current loop is started, the speed loop is opened, the angle of a rotor of the motor adopts the forced angle, and the motor is controlled by giving a nonzero constant value to the q-axis current; on the other hand, the current rotation speed of the motor can be obtained by a position estimation algorithm, specifically by estimation through a humper observer and a phase-locked loop PLL. Through this embodiment, the problem of the back swing of fan flabellum when the motor is started under the condition that the rotor flux linkage position of the motor is unknown can be effectively solved, the success rate of motor starting is improved, and the efficiency of the motor is also improved.

In another possible embodiment of the second aspect, in starting the motor by using a speed loop and a forced angle, the starting unit is further specifically configured to start the speed loop according to a second element, where the second element includes the current loop closed loop, the rotor angle of the motor is the forced angle, and the output of the speed loop is a value of the q-axis current.

In the embodiment of the application, when the current rotating speed of the motor is greater than the first switching rotating speed and less than the second switching rotating speed, the motor is started by using the speed ring and the forced angle, the specific mode is that the speed ring is started, the current ring and the speed ring are closed, the rotor angle of the motor adopts the forced angle, and the output of the speed ring is used as the value of the q-axis current to control the motor; on the other hand, the current rotation speed of the motor can be obtained by a position estimation algorithm, and the current rotation speed can be obtained by estimation through a humper observer and a phase-locked loop (PLL). Through this embodiment, the backswing problem of fan flabellum when can effectively solve the starting motor under the unknown condition of the rotor flux linkage position of motor, improves the success rate that the motor started, also improves the efficiency of motor.

In a further possible embodiment of the second aspect, in terms of starting the electric machine by using the angle output by the flux linkage observer, the starting unit is further configured to start the electric machine according to a third element, where the third element includes the current loop closed loop and the speed loop closed loop, and the rotor angle of the electric machine is the angle output by the flux linkage observer.

In the embodiment of the application, when the current rotating speed of the motor is not less than the second switching rotating speed, the motor is started by using the angle output by the flux linkage observer, specifically, the angle output by the flux linkage observer is used as the rotor angle of the motor to start the motor, and meanwhile, both a current loop and a speed loop are closed, and after that, the starting process is finished, and the motor enters FOC magnetic field directional control; on the other hand, the current rotational speed of the motor can be obtained by a position estimation algorithm, specifically by estimation by a humper observer and a phase-locked loop PLL. Through this embodiment, the problem of the back swing of fan flabellum when starting the motor under the unknown condition of the rotor flux linkage position of motor can be effectively solved, the success rate of motor start is improved, and the efficiency of motor is also improved.

In a further possible embodiment of the second aspect, the value of the forcing angle is incremented starting from zero with an acceleration different from zero.

In the embodiment of the application, the forced angle is limited, and the value of the forced angle is increased in an acceleration which is not zero from zero until a target threshold value is reached, wherein the target threshold value is a maximum value amplitude limit which is carried out according to the motor starting limit rotating speed, so that the motor starting efficiency can be improved, and the safety and the reliability of the motor can be improved.

In a third aspect, an embodiment of the present application discloses a motor-started electronic device, which includes a memory and a processor, where the memory stores a computer program, and when the computer program runs on the processor, the computer program performs the method according to the first aspect or any one of the possible implementation manners of the first aspect.

In a fourth aspect, this application discloses a computer-readable storage medium, in which a computer program is stored, which, when running on one or more processors, performs the method as set forth in the first aspect or any one of the possible implementations of the first aspect.

In a fifth aspect, embodiments of the present application disclose a computer program product containing instructions, which when run on a computer, causes the computer to perform the method of the first aspect and any optional implementation manner thereof.

In the application, the motor is not started according to the traditional direct current positioning, but the strategy of starting the motor by adopting the direct current closed loop and the forced angle or the angle estimated by the flux observer respectively according to different conditions of the rotating speed of the rotor of the motor, the problem of the swinging back of fan blades when the motor is started under the condition that the position of the flux linkage of the rotor of the motor is unknown is effectively solved, the success rate of starting the motor is improved, the efficiency of the motor is also improved, and the safety and the reliability of the motor are further improved.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments or background art of the present application, the drawings required to be used in the embodiments or background art of the present application will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative efforts.

Fig. 1 is a schematic flowchart of a motor starting method according to an embodiment of the present disclosure;

fig. 2 is a schematic flow chart of another motor starting method according to an embodiment of the present disclosure;

fig. 3a is a schematic structural diagram of a motor start according to an embodiment of the present disclosure;

fig. 3b is a schematic structural diagram of another motor start provided in the embodiment of the present application;

fig. 3c is a schematic structural diagram of another motor start provided in the embodiment of the present application;

fig. 4a is a schematic diagram of a physical model of a motor according to an embodiment of the present disclosure;

fig. 4b is a schematic structural diagram of a progressive state observer according to an embodiment of the present application;

fig. 4c is a schematic diagram illustrating a PLL position detection principle according to an embodiment of the present disclosure;

fig. 5 is a schematic structural diagram of a motor starting device according to an embodiment of the present disclosure;

fig. 6 is a schematic structural diagram of a motor starting apparatus according to an embodiment of the present application.

Detailed Description

In order to make the embodiments of the present application better understood, the technical solutions in the embodiments of the present application will be clearly described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only some embodiments of the present application, but not all embodiments.

The terms "first," "second," and "third," etc. in the description embodiments and claims of the present application and the above-described drawings are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. The terms "comprises" and "comprising," and any variations thereof, in the description examples and claims of this application, are intended to cover a non-exclusive inclusion, such as, for example, a list of steps or elements. A method, system, article, or apparatus is not necessarily limited to those steps or elements explicitly listed, but may include other steps or elements not explicitly listed or inherent to such process, system, article, or apparatus.

Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. It is explicitly and implicitly understood by one skilled in the art that the embodiments described herein can be combined with other embodiments.

In order to describe the scheme of the present application more clearly, some knowledge related to the starting of the motor is introduced below.

Hump viewer: the method is a technique for establishing an estimated value of a state vector, determining a proper approximate value of the state vector and substituting the value into an ideal control law. The humper observer method is suitable for situations in which the available measurements are less heavily contaminated by noise and produces a dynamic system of a lower order than the order of the system being observed. The method comprises the following steps of optimally controlling an electro-hydraulic control system, carrying out pole allocation and other control modes, wherein all the control modes need to adopt a system state feedback mode, but all the states of the system cannot be obtained, so that a state estimator needs to be adopted to obtain state estimation, and a required control rule is further realized; in view of the characteristics of the electro-hydraulic system, the LONGBERG observer is adopted to carry out dimensionality reduction state estimation, and the device is applied to the electro-hydraulic control system of the material testing machine and obtains a satisfactory result. The problem that a current sensor is additionally arranged on a pulse width modulation rectifier by adopting a feedforward control strategy is solved, the feedforward control strategy of the current sensor-free based on the Longberg observer theory is generated, namely, a method based on the Longberg state observer is adopted to replace a current sensor to measure the load current, the problems of increased line inductance, difficult installation position and the like caused by the installation of the current sensor are avoided, and particularly when a plurality of sensors are needed by hanging a plurality of inverter loads on a bus, the method can greatly reduce the cost and improve the reliability of the system.

A phase-locked loop: the negative feedback control system is used for tuning a voltage-controlled oscillator by utilizing a voltage generated by phase synchronization so as to generate a target frequency. The feedback control circuit is a typical feedback control circuit, controls the frequency and the phase of an internal oscillation signal of a loop by using an externally input reference signal, realizes automatic tracking of the frequency of an output signal to the frequency of an input signal, and is generally used for a closed-loop tracking circuit. The method for stabilizing frequency in radio transmission mainly includes VCO (voltage controlled oscillator) and PLL IC (phase-locked loop integrated circuit), in which the voltage controlled oscillator can give out a signal, one portion can be used as output, another portion can be used for making phase comparison with local oscillator signal produced by PLLIC by means of frequency division, in order to keep frequency constant, the phase difference must not be changed, if the phase difference is changed, the voltage of voltage output end of PLL IC can be changed, and the VCO can be controlled until the phase difference can be recovered so as to attain the goal of phase-locking, and can make the frequency and phase of controlled oscillator and input signal retain a defined relationship.

Low-pass filtering: the filtering method is characterized in that low-frequency signals can normally pass through the filtering method, and high-frequency signals exceeding a set critical value are blocked and weakened. But the magnitude of the blocking and attenuation will vary depending on the frequency and filtering procedure (purpose). It is sometimes also called high frequency or maximum removal filtering, low pass filtering being the opposite of high pass filtering. Low-pass filtering can be simply considered to set a frequency point which cannot pass when the signal frequency is higher than the frequency, and in the digital signal, the frequency point is a cut-off frequency, and all values are assigned to 0 when the frequency domain is higher than the cut-off frequency, and the low-frequency signal is allowed to pass all through in the process, so that the low-pass filtering is called. The concept of low-pass filtering is commonly used in various fields such as electronic circuits, data smoothing, acoustic blocking, image blurring, etc. In the field of digital image processing, from the aspect of frequency domain, low-pass filtering can perform smooth denoising processing on an image.

The embodiments of the present application will be described below with reference to the drawings.

Referring to fig. 1, fig. 1 is a schematic flow chart of a motor starting method according to an embodiment of the present application, where the method includes, but is not limited to, the following steps:

step 101: the motor receives a starting instruction.

The motor is commonly called as a motor, and mainly has the function of generating driving torque to serve as a power source of electric appliances or various machines. The motor is very widely applied in the related application scenarios in the mechanical field, and is not described herein. In the present embodiment, a fan is taken as a main application scenario of the motor to describe the non-backswing starting method of the motor. First, the motor receives a start command, which may be sent by a user via a remote control, for starting the motor.

Step 102: and starting the motor by utilizing the current loop and the forced angle until the current rotating speed of the motor is greater than the first switching rotating speed.

In a traditional motor starting method, the starting problem of a permanent magnet synchronous motor under the condition that the position of a rotor is unknown is always a difficult problem, because in the control of a fan, the motor is not allowed to swing back to start, and if the traditional direct current positioning starting motor is adopted, the fan blades of the fan are inevitably swung back, so that the control requirement of the fan cannot be met. In the step of this embodiment, after the motor receives the start instruction, the motor does not perform dc positioning on the rotor of the motor according to the conventional motor start method, but the motor is started according to different conditions of the current rotating speed of the motor rotor by adopting a strategy of directly adding the forced angle to the current loop closed loop or estimating the angle by the flux linkage observer, so that the problem of the fan blade swinging back when the motor is started under the condition that the position of the flux linkage of the rotor of the motor is unknown is effectively solved. Specifically, a specific algorithm is used to estimate the current rotation speed of the motor, where the specific algorithm may be a luneberg observer algorithm or other effective algorithms, and is not limited herein, and then a corresponding start strategy is adopted according to the current rotation speed of the motor.

When the current rotating speed of the motor is not more than the first switching rotating speed, starting the motor by using a current loop and a forcing angle, wherein the specific implementation mode is that the current loop is directly started, the motor is dragged by the additional forcing angle, the rotor angle of the motor adopts the forcing angle, the q-axis current is given a non-zero constant value, the non-zero constant value is a current reference value of the stator current of the motor on a q axis, the value of the forcing angle is increased from zero by an acceleration which is not zero until a target threshold value is reached, the target threshold value is a maximum value amplitude limit which is carried out according to the starting limiting rotating speed of the motor, the setting can be carried out according to different application scenes, and the rotating speed of the motor is also increased steadily; the first switching speed is set according to the motor start-up scenario, and may be set to 5r/s, for example, and the value of the first switching speed may be different in different application scenarios.

Step 103: and starting the motor by utilizing the speed ring and the forced angle until the current rotating speed of the motor is not less than the second switching rotating speed.

Starting the motor under the combined action of the current loop and the forcing angle, wherein the rotating speed of the motor is steadily increased, and when the current rotating speed of the motor is estimated to be greater than the first switching rotating speed and less than the second switching rotating speed, the combined action of the current loop and the forcing angle cannot meet the starting requirement of the motor on the continuous increase of the rotating speed, so that the motor is started by using the speed loop and the forcing angle instead, the specific implementation mode is that the speed loop is started, the forcing angle drags the motor, the current loop is closed, the rotor angle of the motor still adopts the forcing angle, the output of the speed loop is used as the value of q-axis current, and the value of the forcing angle at the moment is still increased by acceleration which is not zero until the target threshold is reached; the second switching rotation speed is set according to a motor start scene, for example, set to 50r/s, and the value of the second switching rotation speed may be different in different application scenes.

Step 104: and starting the motor by utilizing the angle output by the flux linkage observer.

The motor is started under the combined action of the current loop closed loop and the speed loop reinforced angle, the rotating speed of the motor is steadily increased, and when the current rotating speed of the motor is increased to the second switching rotating speed, the combined action of the current loop closed loop and the speed loop reinforced angle cannot meet the starting requirement of the motor on the continuous increase of the rotating speed, so that the motor is started by utilizing the angle output by the flux linkage observer instead.

According to the embodiment of the application, the motor is not started according to the traditional direct current positioning, but the strategy of starting the motor according to the different conditions of the rotating speed of the rotor of the motor by adopting the direct current closed loop plus the forced angle or the speed closed loop plus the forced angle or the angle estimated by the flux observer respectively, the problem of the back swing of fan blades when the motor is started under the condition that the position of the rotor flux of the motor is unknown is effectively solved, the success rate of starting the motor is improved, the efficiency of the motor is also improved, and the safety and the reliability of the motor are further improved.

Referring to fig. 2, fig. 2 is a schematic flow chart of another motor starting method according to an embodiment of the present application, where the method includes, but is not limited to, the following steps:

step 201: the motor receives a starting instruction.

In accordance with step 101 described above.

Step 202: and starting a current loop, wherein the rotor angle of the motor adopts a forced angle, and the q-axis current is given a nonzero constant value.

Estimating to obtain the current rotating speed of the motor, giving starting current and starting a current loop under the condition that the current rotating speed of the motor is not more than the first switching rotating speed, and dragging the motor by utilizing a current loop closed loop plus a forced angle, wherein the rotor angle of the motor adopts the forced angle and the q-axis current gives a non-zero constant value, the value of the forced angle is increased progressively from zero by acceleration which is not zero until a target threshold value is reached, the target threshold value is the maximum value amplitude limit according to the motor starting limiting rotating speed, the setting can be carried out according to different application scenes, and the first switching rotating speed is similar to the target threshold value and can also be set according to different application scenes.

Step 203: and judging whether the current rotating speed of the motor is greater than the first switching rotating speed or not.

After the current loop is started, the motor is dragged under the action of the current loop closed loop and the forcing angle, the rotating speed of the motor is steadily increased along with the increasing of the value of the forcing angle, at this time, whether the current rotating speed of the motor is greater than the first switching rotating speed or not needs to be judged, if the current rotating speed of the motor is not greater than the first switching rotating speed, the motor is continuously dragged under the action of the current loop closed loop and the forcing angle, and if the current rotating speed of the motor is greater than the first switching rotating speed, the following step 204 is executed.

Step 204: the speed loop is started, the rotor angle of the motor adopts a forced angle, and the output of the speed loop is used as the value of the q-axis current.

And starting the speed loop under the condition that the current rotating speed of the motor is greater than the first switching rotating speed, closing the current loop at the moment, adding a forced angle to drag the motor under the state of double closed loops of the speed loop and the current loop, wherein the rotor angle of the motor still adopts the forced angle, and the value of the forced angle is still increased by the acceleration which is not zero until the target threshold is reached.

Step 205: and judging whether the current rotating speed of the motor is greater than the second switching rotating speed.

With the continuous increase of the current rotation speed of the motor, it is further required to determine whether the current rotation speed of the motor is greater than a second switching rotation speed, which is similar to the first switching rotation speed and can be set according to different application scenarios, if the current rotation speed of the motor is not greater than the second switching rotation speed, the motor is continuously dragged under the action of the current loop speed loop double closed loop and the forcing angle, and if the current rotation speed of the motor is greater than the second switching rotation speed, the following step 206 is executed.

Step 206: and taking the angle output by the flux linkage observer as the rotor angle of the motor to start the motor.

And under the condition that the current rotating speed of the motor is greater than the second switching rotating speed, taking the angle output by the flux linkage observer as the rotor angle of the motor to drag the motor, wherein the current loop and the speed loop are in a closed loop state.

Step 207: the motor start-up process ends.

And ending the starting process of the motor, and carrying out FOC control on the motor by adopting the rotor position angle output by the flux linkage observer.

On the other hand, in the embodiments provided in fig. 1 and fig. 2, the process of starting the motor may be divided into three stages by taking the first switching rotation speed and the second switching rotation speed as two boundary values, the first starting stage is a stage of starting the motor by using the current loop and the forced angle, the second starting stage is a stage of starting the motor by using the speed loop and the forced angle, and the third starting stage is a stage of starting the motor by using the angle output by the flux linkage observer. Specifically, referring to fig. 3a, fig. 3a is a schematic structural diagram of a motor start provided in an embodiment of the present application, which shows a first stage of the motor start, in which a two-phase rotating coordinate system d-q axis current loop closed loop, a speed loop open loop, and an angle control motor is controlled by using a forcing angle, a value of the forcing angle is increased from zero by an acceleration that is not zero, a q axis current is given a non-zero constant value, and the non-zero constant value is a current reference value of a stator current of the motor on a q axis. Fig. 3b is another structural diagram of motor start according to an embodiment of the present application, which illustrates a second stage of the motor start, where a two-phase rotating coordinate system d-q axis current loop is used for closed loop, a speed loop is used for closed loop, but an angle is still controlled by using a forced angle, a value of the forced angle is increased from zero by an acceleration that is not zero until a target threshold is reached, the target threshold is a maximum value of amplitude limiting according to a motor start limit rotation speed, and can be set according to different application scenarios, and an output of the speed loop is used as a value of q axis current. Fig. 3c is a schematic structural diagram of another motor start provided in the embodiment of the present application, which shows a third stage of the motor start, where an angle output by a flux linkage observer is used as a rotor angle of the motor to start the motor. And at this moment, the starting process of the motor is finished, the motor enters a common control stage, a current and rotating speed double closed loop is adopted, and the rotor position angle estimated by the angle estimator is adopted to carry out FOC control.

On the other hand, in the above embodiment, the current rotation speed and the current rotation direction of the motor need to be estimated by using a specific algorithm, which may be a luneberg observer algorithm or other effective algorithms. Optionally, a humper observer and a phase-locked loop PLL are used, and a second-order low-pass filter is additionally used to accurately estimate the current rotation speed and the current rotation direction of the motor.