CN113162490B

CN113162490B - Motor back electromotive force control method, system and equipment

Info

Publication number: CN113162490B
Application number: CN202110419957.XA
Authority: CN
Inventors: 李长水; 王升国; 赵先林
Original assignee: Hangzhou Hikvision Digital Technology Co Ltd
Current assignee: Hangzhou Hikvision Digital Technology Co Ltd
Priority date: 2021-04-19
Filing date: 2021-04-19
Publication date: 2022-07-08
Anticipated expiration: 2041-04-19
Also published as: CN113162490A

Abstract

The embodiment of the specification provides a method, a system and equipment for controlling the back electromotive force of a motor. The method comprises the following steps: acquiring a target signal acquired from a preset sampling point of a motor control system in the rotation process of a motor, wherein the target signal is used for judging whether abnormal back electromotive force occurs in the motor; if the target signal is determined to meet the preset abnormal back electromotive force occurrence condition, generating a reverse voltage based on the output voltage of the current loop; and taking the reverse voltage as an input of a reverse Park conversion process to reduce the back electromotive force. Therefore, high back electromotive force generated by the motor due to collision, blockage, locked rotation and the like and bus voltage of the driving circuit can be effectively reduced, and the driving circuit and the motor are protected.

Description

Motor back electromotive force control method, system and equipment

Technical Field

The present disclosure relates to the field of motor control, and particularly to a method, a system, and a device for controlling a back electromotive force of a motor.

Background

The permanent magnet synchronous dc brushless motor has become a popular control method at present by adopting a field oriented control FOC vector algorithm, such as a "three-loop driving control" unified or standard algorithm block diagram with a position loop, a speed loop and a current loop shown in fig. 1. In order to realize position smooth control, a position command (a desired target position of motor rotation) in the figure is subjected to smoothing processing of a position Ramp, and a deviation (Perror) of an obtained position reference signal and an actual position feedback signal of motor rotation is calculated through a position loop PI to obtain a speed command reference signal. The deviation (Verror) of the feedback signal of the actual speed of the motor rotation is calculated by a speed loop PI to obtain the motor torque reference current Iqref of the q axis. Meanwhile, the motor current is subjected to Clarke conversion and Park conversion to obtain the actual torque current Iq and excitation current Id of the motor, the deviation of the actual torque current Iqref and the actual excitation current Idref of the motor from the obtained torque reference current Iqref and the deviation of the actual excitation reference current Idref of the d axis from the standard excitation reference current Idref of the d axis are obtained, q-axis voltage and d-axis voltage (Ud and Uq) are obtained through a q-axis current loop PID and a d-axis current loop PID, and space vector SVPWM signals (three complementary paths of PWMa, PWMb and PWMc) are output to a power driving circuit through inverse Park conversion and inverse Clarke conversion to realize the vector control of the three-phase motor.

For the three-loop drive control with position loop shown in fig. 1, it is common to use in the case of precise position control with repeated start and stop, such as a pedestrian passageway gate or a pedestrian automatic door. The product is already in popular use at entrances and exits of airports, stations, intelligent buildings, communities and the like, and after legal personnel (card swiping or face recognition) authentication is obtained, a motor of the product is started to open a door wing. After the personnel pass, the door wing is automatically closed. Because the equipment is used in public places, passers-by inevitably carry large articles; the impact on the gate is easily caused during the passing process. Even a maliciously high force bump or block may occur. These large forces impact and block the windings of the motor in operation causing back emf and lifting of the drive power bus. The magnitude of the back electromotive force is affected by the magnitude of the impact force, the speed of the impact and the magnitude of the door wing load. For example, in the gateway or automatic door industry, the common motor is a 24V dc motor, but a shock may cause the bus voltage of the motor drive board to be as high as 110V or more. And the components of the driving board are often common components which can resist the pressure of 100V, so that the driving control board is easy to damage by strong impact or blocking, and the maintenance amount of a client or a manufacturer is large.

In order to solve the problem, manufacturers are forced to use devices with higher voltage resistance or add large capacitors or large resistors (usually high-power cement resistors) to absorb the high voltage, which not only increases the equipment cost, but also makes the size of the PCB very difficult to be small and exquisite due to the large size of the capacitors or resistors, thereby affecting the appearance of the equipment. Further, even if these large-capacitance or large-resistance or higher-withstand-voltage devices are used, device breakdown may occur. The reason for this is that the impact force in the use situation is difficult to estimate, and this problem cannot be solved completely by this absorption method alone.

Therefore, there is a need to provide a more reliable back emf control scheme.

Disclosure of Invention

The embodiment of the specification provides a motor back electromotive force control method, which is used for reducing high back electromotive force generated by motor abnormity and bus voltage of a driving circuit, so as to protect the driving circuit and the motor.

The embodiment of the present specification further provides a motor back electromotive force control method, which is applied to a motor control system based on FOC vector control and three-loop control, and the method includes:

acquiring a target signal acquired from a preset sampling point of a motor control system in the rotation process of a motor, wherein the target signal is used for judging whether abnormal back electromotive force occurs in the motor;

if the target signal is determined to meet the preset abnormal back electromotive force occurrence condition, generating a reverse voltage based on the output voltage of the current loop;

and taking the reverse voltage as an input of a reverse Park conversion process to reduce the back electromotive force.

An embodiment of the present specification further provides a motor back electromotive force control system, including: the device comprises a three-loop control module and a signal sampling and processing module, wherein:

the signal sampling and processing module is used for acquiring a target signal acquired from a preset sampling point of a motor control system in the rotation process of the motor, and the target signal is used for judging whether abnormal back electromotive force occurs to the motor or not;

the three-loop control module is used for generating a reverse voltage based on the output voltage of the current loop if the target signal is determined to meet the preset abnormal back electromotive force occurrence condition; and taking the reverse voltage as an input of a reverse Park conversion process to reduce the back electromotive force.

The embodiment of the specification further provides a motor, which comprises the motor back electromotive force control system.

An embodiment of the present specification further provides an electronic device, including:

a processor; and

a memory arranged to store computer executable instructions which, when executed, cause the processor to perform the steps of the method as described above.

Embodiments of the present specification also provide a computer readable storage medium storing one or more programs which, when executed by an electronic device comprising a plurality of application programs, perform the steps of the method as described above.

The method comprises the steps that firstly, a signal capable of judging abnormal back electromotive force of a motor is selected in advance, and the signal is sampled, so that the judgment process of the abnormal back electromotive force is carried out; and secondly, after the abnormal counter electromotive force of the motor is judged, the input variable converted by the counter Park is switched, so that the high counter electromotive force generated by the motor due to collision, blockage, locked rotor and the like and the bus voltage of the driving circuit can be effectively reduced, and the driving circuit and the motor are protected.

Drawings

The accompanying drawings, which are included to provide a further understanding of the specification and are incorporated in and constitute a part of this specification, illustrate embodiments of the specification and together with the description serve to explain the specification and not to limit the specification in a non-limiting sense. In the drawings:

FIG. 1 is a schematic block diagram of a standard algorithm for a three-loop drive control system provided in one embodiment of the present disclosure;

fig. 2 is a schematic flowchart of a back electromotive force control method of a motor according to an embodiment of the present disclosure;

fig. 3 is a schematic structural diagram of a back electromotive force control system of a motor according to an embodiment of the present disclosure;

fig. 4 is a schematic structural diagram of a variable switching module in a back electromotive force control system of a motor according to another embodiment of the present disclosure;

fig. 5a and 5b are schematic diagrams of comparison between waveforms provided by the prior art and the present application, respectively, according to an embodiment of the present disclosure.

Fig. 6 is a schematic structural diagram of an electronic device according to an embodiment of the present disclosure.

Detailed Description

In order to make the objects, technical solutions and advantages of the present disclosure more clear, the technical solutions of the present disclosure will be clearly and completely described below with reference to the specific embodiments of the present disclosure and the accompanying drawings. It is to be understood that the embodiments described are only a few embodiments of the present disclosure, and not all embodiments. All other embodiments obtained by a person skilled in the art based on the embodiments in the present specification without any inventive step are within the scope of the present application.

The technical solutions provided by the embodiments of the present description are described in detail below with reference to the accompanying drawings.

Fig. 2 is a schematic flowchart of a back electromotive force control method for a motor according to an embodiment of the present disclosure, which may be executed by a motor controller, and referring to fig. 2, the method may specifically include the following steps:

step 202, acquiring a target signal acquired from a preset sampling point of a motor control system in the rotation process of a motor, wherein the target signal is used for judging whether abnormal back electromotive force occurs in the motor;

the motor can be a three-phase motor, the three-phase motor is mainly a permanent magnet synchronous brushless motor PMSM, and the counter electromotive force of the three-phase motor is a sine wave. It usually adopts an external encoding disk (photoelectric encoding disk or magnetic encoding disk, etc.) as a signal acquisition device of its rotation position (angle) and obtains the feedback signal of the actual position and the feedback signal of the actual speed of the motor based on the signal acquisition device. A low cost hall sensor can also be used instead of an encoder disk to achieve a similar effect. Since the back electromotive force waveform of the actual BLDC is also similar to a sine wave due to the manufacturing process of the BLDC, the BLDC is also suitable for the FOC vector algorithm. The motor control system may be a control system based on FOC vector control and three-loop control shown in fig. 1, and since the FOC vector control principle and the three-loop control principle are well known, the description thereof is omitted; the target signal is a signal which can judge whether the motor has abnormal counter electromotive force in the motor control system determined by testing, and can be divided into an external signal and an internal signal, wherein the external signal is a signal which induces the counter electromotive force and is induced by equipment outside the motor, such as a collision signal (including collision strength) of an object colliding with a gate and induced by a collision sensor associated with the motor, and the internal signal is a signal generated by the influence of the conditions of collision, blockage and the like of internal components of the motor, such as the voltage of a driving bus power supply. The types of the target signals are not listed one by one here, and the purpose of judging whether the motor has abnormal back electromotive force can be met.

Preferentially, the embodiment preferably uses the internal signal of the motor, so as to avoid the need of additionally increasing hardware equipment required by signal acquisition, reduce the cost of the whole machine and ensure the miniaturization of the whole machine.

Further, the internal signal selected by the embodiment may be an inherent signal of the FOC vector algorithm, that is, an existing signal in the existing motor control system, and thus, additional generation of other signals may not be required, thereby effectively reducing the difficulty in determining the related abnormal back electromotive force and the computational complexity of the entire control process. Specific examples can be:

by testing, the target signals selected may include: and at least one of driving bus power supply voltage, three-phase winding currents Ia, Ib and Ic or I alpha and I beta after Clarke conversion and motor rotation acceleration. Preferably, the four signals are selectable.

The driving bus power supply voltage is obtained by performing analog-to-digital sampling and filtering on the power supply voltage used by the driving circuit, such as Vbus in fig. 1; the three-phase winding currents Ia, Ib, and Ic are obtained by sampling and filtering the motor winding, such as Clarke variable input variables in fig. 1; ia alpha and I beta are obtained by Clarke change of Ia, Ib and Ic.

For the motor rotational acceleration, it should be noted that the motor rotational acceleration may be an inlet Verror signal of the speed loop PI, and the Verror signal is a difference between an output command Vref of the position loop PI and an actual speed feedback value Vactual, see the Verror signal between the position loop and the speed loop in fig. 1. The Verror signal is selected because the calculation process is very simple, so that the control response speed of the whole back electromotive force can be effectively improved.

Step 204, if the target signal is determined to meet the preset abnormal back electromotive force occurrence condition, generating a reverse voltage based on the output voltage of the current loop;

firstly, for the case that the target signal satisfies the preset abnormal back electromotive force occurrence condition, it should be noted that:

if any one or more of the target signals meet the abnormal back electromotive force occurrence condition, determining that the target signals meet a preset abnormal back electromotive force occurrence condition;

wherein the abnormal back electromotive force occurrence condition comprises any one or more of the following conditions:

the driving bus power supply voltage exceeds a preset power supply voltage threshold;

the currents Ia, Ib and Ic of the three-phase windings or I alpha and I beta after Clarke transformation exceed a preset current threshold;

and the rotation acceleration of the motor exceeds a preset acceleration threshold value.

That is, as long as any one of the target signals satisfies the abnormal back electromotive force occurrence condition corresponding to the signal, it is determined that the target signal satisfies the preset abnormal back electromotive force occurrence condition. Therefore, the occurrence condition of abnormal back electromotive force can be effectively detected, and the safety of the motor is ensured.

Furthermore, it is understood that if it is determined that the target signal does not satisfy the abnormal back electromotive force occurrence condition, the output voltage of the current loop may be used as an input of the inverse Park conversion process without performing calculation of the reverse voltage.

Next, after determining that the target signal satisfies the preset abnormal back electromotive force occurrence condition, the following describes in detail an implementation manner of step 204:

first implementation of step 204:

and generating a reverse voltage Uq' based on the q-axis voltage Uq of the current loop. Specifically, with reference to fig. 1, Uq output by the q-axis current loop is obtained, and then, the reverse voltage Uq' is obtained by using the voltage Uq of the q-axis current loop as the input of the following formula 1.

Uq ═ sign (-Uq) × Uq1 formula 1

Wherein Uq1 is a constant calibrated by testing; the effect of sign (-Uq) × Uq1 is: when the abnormal counter electromotive force occurrence condition is met, if the output Uq of the q-axis current loop is positive, using negative Uq 1; otherwise, positive Uq1 is used.

Second implementation of step 204:

and generating reverse voltages Uq ' and Ud ' based on the voltage Uq of the q-axis current loop and the voltage Ud ' of the d-axis current loop. Specifically, referring to fig. 1, Uq output by the q-axis current loop and Ud output by the d-axis current loop are first input, and then Uq and Ud are respectively input into the above formula 1 and the following formula 2, so that Uq 'and Ud' are obtained.

Ud (-Ud) × Ud1 formula 2

Wherein the Ud1 is a constant calibrated by testing; the effect of sign (-Ud) Ud1 is: when the abnormal counter electromotive force occurrence condition is met, if the output Ud of the d-axis current loop is positive, the negative Ud1 is used; otherwise, a positive Ud1 is used.

It should be further noted that, since Idref in fig. 1 may be equal to 0, when Idref ≠ 0, Ud' can be calculated by the above formula 2; when Idref is 0, Uq' can be set to 0 directly without the calculation of formula 2, so that the calculation efficiency can be further improved and the response speed can be increased.

Based on this, in this embodiment, through the above two implementation manners of step 204, two counter electromotive force control manners are provided, and the constants Uq1 and Ud1 calibrated by the test can be combined to quickly calculate the counter voltage, so that the high counter electromotive force of the motor can be quickly and effectively reduced, and the motor can be protected. Moreover, the present embodiment shows two specific implementations of step 204. Of course, it should be understood that step 204 can be implemented in other ways, and the embodiment is not limited thereto.

And step 206, taking the reverse voltage as an input of inverse Park conversion processing to reduce the back electromotive force.

With reference to fig. 1, the reverse voltage is subjected to inverse Park transformation to obtain voltage control quantities V α and V β under a two-phase stationary coordinate system; and the voltage control quantities V alpha and V beta are calculated by a Space Vector Pulse Width Modulation (SVPWM) algorithm to obtain three-phase voltage vectors Va, Vb and Vc, and the inverter bridge is controlled to generate variable frequency voltage to drive the motor to rotate.

In summary, in the embodiment, a signal capable of judging the occurrence of the abnormal back electromotive force of the motor is selected in advance and sampled, so that the judgment process of the abnormal back electromotive force is performed; and secondly, after the abnormal counter electromotive force of the motor is judged, the input variable converted by the counter Park is switched, so that the high counter electromotive force generated by the motor due to collision, blockage, locked rotor and the like and the bus voltage of the driving circuit can be effectively reduced, and the driving circuit and the motor are protected.

Fig. 3 is a schematic structural diagram of a back electromotive force control system of a motor according to an embodiment of the present disclosure, and referring to fig. 3, the system may specifically include the following steps: variable switching module and signal sampling and processing module, wherein:

the variable switching module is used for generating a reverse voltage based on the output voltage of the current loop if the target signal is determined to meet the preset abnormal back electromotive force occurrence condition; and taking the reverse voltage as an input of a reverse Park conversion process to reduce the back electromotive force.

The signal sampling and processing module is described in detail below, and may include:

the power supply voltage detection module is used for carrying out analog-to-digital sampling and filtering processing on the power supply voltage used by the driving circuit to obtain the power supply voltage of the driving bus and judging whether the power supply voltage exceeds a preset power supply voltage threshold value or not; reporting the judgment result to the variable switching module;

the current detection module is used for sampling and filtering a motor winding to obtain three-phase winding currents Ia, Ib and Ic or I alpha and I beta of the three-phase winding currents Ia, Ib and Ic after Clarke conversion, and judging whether the three-phase winding currents Ia, Ib and Ic exceed a preset current threshold value; reporting the judgment result to the variable switching module;

the motor rotation acceleration detection module is used for detecting the rotation acceleration of the motor and judging whether the rotation acceleration exceeds a preset acceleration threshold value; and reporting the judgment result to the variable switching module.

With reference to the content shown in fig. 1 and the related description in the embodiment corresponding to fig. 2, the power (bus) voltage detection module is a driving bus power voltage Vbus _ filtered obtained by performing analog-to-digital sampling and filtering on the power voltage used by the driving circuit. The power detection module compares the voltage Vbus _ filtered with a threshold. The threshold value can be observed according to the normal operation data of the motor to obtain the maximum value, and a certain margin is taken.

The current detection module is used for sampling and filtering a motor winding motor to obtain three-phase winding currents Ia, Ib and Ic; or the results of comparing I alpha and I beta after Clarke transformation with a threshold value. The threshold value can be observed according to the normal operation data of the motor to obtain the maximum value, and a certain margin is taken.

The motor rotation acceleration detection module is used for observing the rotation acceleration of the motor and comparing the rotation acceleration with a threshold value. The threshold value can be observed according to the normal operation data of the motor to obtain the maximum value, and a certain margin is taken. Preferentially, the entry Verror signal from the speed loop PI can be taken as the motor nominal acceleration: nominal acceleration α Vref-Vactual. Verror is the nominal motor rotational acceleration, which is the difference between the output command Vref of the position loop PI and the actual speed feedback value Vactual.

It should be noted that the motor winding current samples (Ia, Ib, Ic) shown in fig. 1 may be sampled by a single resistor or a double resistor, generally without three resistor sampling (since Ia + Ib + Ic is 0, the 3 rd current may be calculated by other 2 currents), and then the currents are subjected to Clarke transformation to obtain I α and I β, where these currents are basic necessary module variables of the vector FOC algorithm. The bus driving power supply voltage Vbus also needs to be sampled and filtered frequently to monitor whether the power supply voltage is normal or not, and may be used for voltage compensation of anti-Clarke/SVPWM. And the motor rotation angle and speed calculation module obtains an actual position feedback signal and an actual speed feedback signal. Alternatively, the actual acceleration signal may also be obtained. The present invention also recommends using the input Verror of the velocity loop PI as the nominal "acceleration signal". This Verror is taken as the nominal motor rotational acceleration, which is the difference between the output command Vref of the position loop PI and the actual speed feedback value, and is therefore very simple to calculate.

The variable switching module is explained in detail as follows:

through the comprehensive results of the detection modules, the variable switching module can easily obtain the output instruction Condition for identifying the abnormity:

condition true; if any real-time value of the judging module exceeds a corresponding threshold value;

condition is false; and if the judgment modules do not exceed the corresponding threshold values.

In conjunction with fig. 4, the variable switching module may include: a first switching logic module, wherein:

the input end of the first switching logic module is connected with the q-axis current loop, and the output end of the first switching logic module is connected with the inverse Park conversion module;

the first switching logic module is configured to generate a reverse voltage Uq 'based on a voltage Uq of a q-axis current loop if it is determined that the target signal meets the preset abnormal back electromotive force occurrence condition, and use the reverse voltage Uq' as an input of a reverse Park conversion process; and conversely, the voltage Uq of the q-axis current loop is used as the input of the inverse Park conversion processing.

Further, the variable switching module may further include: a second switching logic module, wherein:

the input end of the second switching logic module is connected with the d-axis current loop, and the output end of the second switching logic module is connected with the inverse Park conversion module;

the second switching logic module is configured to generate a reverse voltage Ud 'based on a voltage Ud of a d-axis current loop if it is determined that the target signal meets the preset abnormal back electromotive force occurrence condition, and use the reverse voltage Ud' as an input of a reverse Park conversion process; and conversely, the voltage Ud of the d-axis current loop is used as the input of the inverse Park conversion processing.

The logic for switching the input of the "inverse Park transform" according to the recognition output command Condition based on the first switching logic module and the second switching logic module may include:

wherein the sign (x) function is 1 when x > 0; and when x < ═ 0, the number is-1.

Uq1 is a predetermined constant that can be selected based on the test results.

The effect of sign (-Uq) × Uq1 is: when the Condition of Condition ═ true is satisfied, if the output Uq of the q-axis current loop at this time is positive, then negative Uq1 is used; otherwise, positive Uq1 is used.

Further, the "inverse Park transform" performs a standard transform using Ud 'and Uq' as described above, i.e.:

Uα＝Ud’*cosθ-Uq’*Sinθ

Uβ＝Ud’*sinθ+Uq’*cosθ

theta is the current electrical angle of the motor.

Therefore, comparing with fig. 1 and fig. 3, the present embodiment is based on Condition as the output result of the judgment of the large force impact, blocking and locked rotor on the motor operation, and only between the output of the current loop PI and the input of the "inverse Park conversion", a switching logic which is very easy to implement is added, so that the standard algorithm architecture is changed very little, and the implementation is easy. In addition, as for the device embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and for the relevant points, reference may be made to part of the description of the method embodiment. Further, it should be noted that, among the respective components of the apparatus of the present specification, the components thereof are logically divided according to the functions to be implemented, but the present specification is not limited thereto, and the respective components may be newly divided or combined as necessary.

Further, see fig. 5a and 5b for a comparison of waveforms provided for a test result for a pedestrian passageway gate cycle switch gate.

First, referring to the test waveform of the gate cycle switching gate of the prior art provided in fig. 5a, the waveform includes 5 segments from top to bottom, wherein the 1 st segment shown in the first row includes 2 waveforms, the solid line waveform refers to the output command _ GtMt [0]. trcposit.qout of the position Ramp, and the dotted line waveform refers to the actual position feedback signal _ GtMt [0]. qposaact. For the 1 st waveform, the initial stage is the normal door opening and closing test of the gate. And a large force collision is carried out in the middle stage. The tail stage is the motor control automatic recovery and the return door opening and closing test. The second row shows the 2 nd waveform which is the nominal acceleration _ GtMt [0]. tpidvel. qerr waveform, which is a small fluctuation variation (<0.1) during the door opening and closing test phase of the initial phase, and a large force impact will cause the acceleration variation to reach above 0.6. The third row shows the waveform of segment 3, which is the current waveform of motor 2, the black line refers to the waveform of _ GtMt [0]. tClarke.qBs, the gray line refers to the waveform of _ GtMt [0]. tClarke.qAs, and the current for normally opening and closing the door is about +/-5A. The current abnormality is not caused by the collision. The fourth row shows the 4 th waveform, which is referred to as _ GtMt [0]. tufix. The 5 th waveform shown in the fifth row is the supply voltage _ GtMt [0]. tubuslowpass.qout waveform, and it can be seen that this impact causes the supply voltage to reach above 100V and last for a longer time (>10 seconds) to slowly release this impact energy.

Then, referring to the test waveform of the gate cycling switching gate provided in fig. 5b based on the present specification, 5-segment waveforms are included from top to bottom, wherein the 1 st segment waveform shown in the first row includes 2 waveforms, the solid line waveform refers to the output command _ GtMt [0]. trcposit.qout of the position Ramp, and the dotted line waveform refers to the actual position feedback signal _ GtMt [0]. qposaact). For the 1 st waveform, the initial stage is the normal door opening and closing test of the gate. And a large force collision is carried out in the middle stage. The tail stage is the motor control automatic recovery and the return door opening and closing test. The second row shows the 2 nd segment waveform as the nominal acceleration _ GtMt [0]. tpidvel.qerr waveform. In the initial door opening and closing test stage, the fluctuation variation is small (<0.1), and the acceleration variation can reach more than 1.0 due to large force impact. The third row shows the waveform of segment 3, which is the motor's 2 current waveforms, the black line refers to the waveform _ GtMt [0]. tClarke. qBs, the gray line refers to the waveform _ GtMt [0]. tClarke. qAs, and the current for normally opening and closing the gate is about +/-5A. This impact resulted in a current exceeding 10A. The fourth row shows the 4 th segment of the waveform, which is the Uq waveform applied to the inverse Park transform, GtMt [0]. tUfix. In the normal stage, the Uq waveform is positive when the door is opened and closed in the forward direction; the reverse door opening and closing is negative. After a large impact, the door is in the reverse opening phase, and a positive Uq 1-to-reverse Park conversion is applied, so that the power voltage is released in a short time. The 5 th waveform shown in the fifth row is the supply voltage waveform _ GtMt [0]. tubuslowpass.qout, and it can be seen that this time the supply voltage reaches above 100V as a result of the bump, the voltage waveform appears to have a glitch-like waveform. It represents a safe voltage that drops from above 100V to below 30V in a very short time (20 ms).

It can be seen that, without the solution of the present invention, the maximum value of the power bus voltage of the driving circuit board reaches 117V due to the impact of a large force on the gate of the gate, and this high voltage carries a great risk to the reliable operation of the driving circuit (exceeding the device withstand voltage of the circuit board, for example, 100V). After the method of the invention is started, the maximum value of the bus voltage obtained by the same test is only a short (about 20ms) 89V pulse and quickly drops below 50V, which brings great redundancy for the reliable operation of the driving circuit device.

In summary, the present application can achieve at least the following technical effects:

(1) on the basis of a standard three-loop control module of an FOC vector algorithm, whether a condition that any one of a plurality of judgment modules exceeds a threshold is detected in the running process of the motor through a power supply (bus) voltage detection module, a current detection module and a motor rotation acceleration detection module, and then the input variable of subsequent standard reverse Park conversion is switched. Since these detection modules are essential modules of the FOC vector algorithm, the present embodiment is skillfully applied to the identification condition of large-force impact, blocking or stalling of the motor.

(2) The embodiment belongs to a pure software method, and a standard FOC vector algorithm based three-loop control module only needs to switch an opposite Ud1 to input subsequent inverse Park conversion after any one of the judgment modules identifies that the threshold exceeds a corresponding threshold, so that the implementation is easy, and the code switching is simple.

(3) The method described in this example has been verified in the corresponding product (motor control of the pedestrian passageway gate), to reduce the bus voltage exceeding 110V, which occurs with a large force impact, block or stall, to an extremely short pulse peak of around 80V or below, and rapidly to below 50V. The circuit does not need to additionally increase a large-capacity capacitor or a high-power resistor, not only is the cost low, but also the circuit size is small and exquisite, and the circuit device protection is more reliable.

Fig. 6 is a schematic structural diagram of an electronic device provided in an embodiment of the present disclosure, and referring to fig. 6, the electronic device includes a processor, an internal bus, a network interface, a memory, and a non-volatile memory, and may also include hardware required by other services. The processor reads a corresponding computer program from the nonvolatile memory to the memory and then runs the computer program to form the motor back electromotive force control system on a logic level. Of course, besides the software implementation, the present specification does not exclude other implementations, such as logic devices or a combination of software and hardware, and the like, that is, the execution subject of the following processing flow is not limited to each logic unit, and may be hardware or logic devices.

The network interface, the processor and the memory may be interconnected by a bus system. The bus may be an ISA (Industry Standard Architecture) bus, a PCI (Peripheral Component Interconnect) bus, an EISA (Extended Industry Standard Architecture) bus, or the like. The bus may be divided into an address bus, a data bus, a control bus, etc. For ease of illustration, only one double-headed arrow is shown in FIG. 6, but that does not indicate only one bus or one type of bus.

The memory is used for storing programs. In particular, the program may include program code comprising computer operating instructions. The memory may include both read-only memory and random access memory, and provides instructions and data to the processor. The Memory may include a Random-Access Memory (RAM) and may also include a non-volatile Memory (non-volatile Memory), such as at least 1 disk Memory.

The processor is used for executing the program stored in the memory and specifically executing the following steps:

acquiring a target signal acquired from a preset sampling point of a motor control system in the rotation process of a motor, wherein the target signal is used for judging whether abnormal back electromotive force occurs in the motor or not;

The method performed by the back emf control system or manager (Master) node of the motor as disclosed in the embodiment of fig. 4 of the present specification may be implemented in or by a processor. The processor may be an integrated circuit chip having signal processing capabilities. In implementation, the steps of the above method may be performed by integrated logic circuits of hardware in a processor or instructions in the form of software. The Processor may be a general-purpose Processor, including a Central Processing Unit (CPU), a Network Processor (NP), and the like; but also Digital Signal Processors (DSPs), Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs) or other Programmable logic devices, discrete Gate or transistor logic devices, discrete hardware components. The various methods, steps and logic blocks disclosed in the embodiments of the present specification may be implemented or performed. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like. The steps of a method disclosed in connection with the embodiments of the present specification may be embodied directly in a hardware decoding processor, or in a combination of hardware and software modules in the decoding processor. The software module may be located in ram, flash memory, rom, prom, or eprom, registers, etc. storage media as is well known in the art. The storage medium is located in a memory, and a processor reads information in the memory and completes the steps of the method in combination with hardware of the processor.

The motor back emf control system may also perform the method illustrated in fig. 2 and implement the method performed by the manager node.

Based on the same inventive creation, the present specification also provides a computer readable storage medium storing one or more programs, which when executed by an electronic device including a plurality of application programs, cause the electronic device to execute the motor back electromotive force control method provided by the corresponding embodiment of fig. 2.

Based on the same invention, the embodiment of the specification further provides a motor, and the motor comprises a motor back electromotive force control system provided by the embodiment corresponding to fig. 3 or fig. 4.

The embodiments in the present specification are described in a progressive manner, and the same and similar parts among the embodiments are referred to each other, and each embodiment focuses on the differences from the other embodiments. In particular, for the system embodiment, since it is substantially similar to the method embodiment, the description is simple, and for the relevant points, reference may be made to the partial description of the method embodiment.

The foregoing description has been directed to specific embodiments of this disclosure. Other embodiments are within the scope of the following claims. In some cases, the actions or steps recited in the claims may be performed in a different order than in the embodiments and still achieve desirable results. In addition, the processes depicted in the accompanying figures do not necessarily require the particular order shown, or sequential order, to achieve desirable results. In some embodiments, multitasking and parallel processing may also be possible or may be advantageous.

As will be appreciated by one skilled in the art, embodiments of the present description may be provided as a method, system, or computer program product. Accordingly, the description may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the description may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and so forth) having computer-usable program code embodied therein.

The description has been presented with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the description. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

In a typical configuration, a computing device includes one or more processors (CPUs), input/output interfaces, network interfaces, and memory.

The memory may include forms of volatile memory in a computer readable medium, Random Access Memory (RAM) and/or non-volatile memory, such as Read Only Memory (ROM) or flash memory (flash RAM). Memory is an example of a computer-readable medium.

Computer-readable media, including both non-transitory and non-transitory, removable and non-removable media, may implement information storage by any method or technology. The information may be computer readable instructions, data structures, modules of a program, or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), Static Random Access Memory (SRAM), Dynamic Random Access Memory (DRAM), other types of Random Access Memory (RAM), Read Only Memory (ROM), Electrically Erasable Programmable Read Only Memory (EEPROM), flash memory or other memory technology, compact disc read only memory (CD-ROM), Digital Versatile Discs (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices, or any other non-transmission medium that can be used to store information that can be accessed by a computing device. As defined herein, a computer readable medium does not include a transitory computer readable medium such as a modulated data signal and a carrier wave.

It should also be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

As will be appreciated by one skilled in the art, embodiments of the present description may be provided as a method, system, or computer program product. Accordingly, the description may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the description may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

The above description is only an example of the present specification, and is not intended to limit the present specification. Various modifications and alterations to this description will become apparent to those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present specification should be included in the scope of the claims of the present specification.

Claims

1. A motor back electromotive force control method is characterized by being applied to a motor control system based on FOC vector control and position, speed and current three-closed-loop control, and comprising the following steps:

taking the reverse voltage as an input of reverse Park conversion processing to reduce back electromotive force;

the generating a reverse voltage based on the output voltage of the current loop comprises:

generating a reverse voltage Uq' based on the voltage Uq of the q-axis current loop; alternatively, the first and second electrodes may be,

and generating reverse voltages Uq ' and Ud ' based on the voltage Uq of the q-axis current loop and the voltage Ud ' of the d-axis current loop.

2. The method of claim 1, wherein the target signal is an intrinsic signal of the FOC vector control, comprising: at least one of driving bus power supply voltage, three-phase winding currents Ia, Ib and Ic or I alpha and I beta after Clarke conversion and motor rotation acceleration;

the driving bus power supply voltage is obtained by performing analog-to-digital sampling and filtering processing on the power supply voltage used by the driving circuit, and the three-phase winding currents Ia, Ib and Ic are obtained by performing sampling and filtering processing on the motor windings.

3. The method of claim 2, wherein the determining that the target signal meets a preset abnormal back electromotive force occurrence condition comprises:

4. The method of claim 3,

the motor rotation acceleration is an inlet Verror signal of the speed loop PI, and the Verror signal is the difference between an output instruction Vref of the position loop PI and an actual speed feedback value Vactual.

5. The method of claim 1,

and if the target signal is determined not to meet the abnormal back electromotive force occurrence condition, taking the output voltage of the current loop as the input of the reverse Park conversion processing.

6. The method of claim 1, further comprising:

the reverse voltage is subjected to reverse Park conversion to obtain voltage control quantities V alpha and V beta under a two-phase static coordinate system;

and the voltage control quantities V alpha and V beta are calculated by a Space Vector Pulse Width Modulation (SVPWM) algorithm to obtain three-phase voltage vectors Va, Vb and Vc, and the inverter bridge is controlled to generate variable frequency voltage to drive the motor to rotate.

7. A motor back emf control system, comprising: variable switches module and signal sampling and processing module, wherein:

the variable switching module is used for generating a reverse voltage based on the output voltage of the current loop if the target signal is determined to meet the preset abnormal back electromotive force occurrence condition; taking the reverse voltage as an input of reverse Park conversion processing to reduce back electromotive force;

the reverse voltage is generated based on the voltage Uq of the q-axis current loop; or the reverse voltage is generated based on the voltage Uq of the q-axis current loop and the voltage Ud' of the d-axis current loop.

8. The system of claim 7, wherein the signal sampling and processing module comprises:

the power supply voltage detection module is used for carrying out analog-digital sampling and filtering processing on the power supply voltage used by the driving circuit to obtain the power supply voltage of the driving bus and judging whether the power supply voltage exceeds a preset power supply voltage threshold value or not; reporting the judgment result to the variable switching module;

9. The system of claim 7, wherein the variable switching module comprises: a first switching logic module, wherein:

10. The system of claim 7 or 9, wherein the variable switching module comprises: a second switching logic module, wherein:

11. An electronic device, comprising:

a processor; and

a memory arranged to store computer executable instructions that, when executed, cause the processor to perform the steps of the method of any one of claims 1 to 6.

12. A computer readable storage medium, characterized in that the computer readable storage medium stores one or more programs which, when executed by an electronic device comprising a plurality of application programs, perform the steps of the method according to any one of claims 1 to 6.