Motor startup control method, system, circuit and cleaning equipment

Abstract

The present invention relates to a motor startup control method, system, circuit, and cleaning device. The method comprises: obtaining a line voltage duty cycle data table of a saddle wave; performing PWM modulation on the line voltage duty cycle data table based on a table lookup modulation method to obtain a first phase voltage duty cycle data sequence of a sine wave; and controlling the motor startup according to the first phase voltage duty cycle data sequence. The present invention performs PWM modulation on the line voltage duty cycle data table of a saddle wave based on a table lookup modulation method to output a first phase voltage duty cycle data sequence of a sine wave, and then controls the motor startup according to the first phase voltage duty cycle data sequence. The startup process is smooth, without jitter or noise, effectively improving the user experience.

Description

Technical Field

[0001] The present invention relates to the technical field of cleaning equipment, and in particular to a motor startup control method, system, circuit and cleaning equipment. Background Art

[0002] As people's living conditions improve, their requirements for household cleaning effects are getting higher and higher, and therefore their requirements for household cleaning tools are also getting higher and higher. As an efficient cleaning tool, cordless vacuum cleaners are popular among people for their features such as easy and simple operation and strong dust removal ability.

[0003] Brushless DC motors (Brushless DC motors) offer advantages such as high efficiency, compact size, simple structure, and fast dynamic response, making them widely used in cordless vacuum cleaner designs. Currently, the main control method for brushless DC motors is square wave control. This method is simple, requires low chip computing power, and therefore offers low control costs. It is widely used in brushless DC motor control for vacuum cleaners. However, when using this method to control brushless DC vacuum cleaners, the traditional six-step square wave starting method is used. This can cause torque pulsation and commutation noise during the motor startup process, significantly impacting the user experience. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is to enable the DC brushless motor to start smoothly and without abnormal noise when the motor for the vacuum cleaner generates torque pulsation and commutation noise during the startup process.

[0005] To solve the above technical problems, the present invention provides a motor startup control method, comprising:

[0006] Obtain the line voltage duty cycle data table of the saddle wave;

[0007] Performing PWM modulation on the line voltage duty cycle data table based on a table lookup modulation method to obtain a first phase voltage duty cycle data sequence of a sinusoidal wave;

[0008] The motor is controlled to start according to the first phase voltage duty cycle data sequence.

[0009] Preferably, in the above startup control method, the step of obtaining a line voltage duty cycle data table of a saddle wave includes:

[0010] Calculate the duty cycle data of the three-phase line voltage of the saddle wave according to the duty cycle calculation formula;

[0011] Discretizing the three-phase line voltage duty cycle data according to a preset discrete accuracy to obtain a three-phase line voltage duty cycle discrete data sequence;

[0012] The line voltage duty cycle data table is generated according to the three-phase line voltage duty cycle discrete data sequence.

[0013] Preferably, in the above-mentioned startup control method, the three-phase line voltage duty cycle discrete data sequence includes three-phase line voltage duty cycle discrete data under a plurality of discrete data sequence numbers; the three-phase line voltage duty cycle discrete data includes A-phase line voltage duty cycle discrete data, B-phase line voltage duty cycle discrete data and C-phase line voltage duty cycle discrete data;

[0014] The line voltage duty cycle data table includes an A-phase line voltage duty cycle data sub-table, a B-phase line voltage duty cycle data sub-table and a C-phase line voltage duty cycle data sub-table, and the A-phase line voltage duty cycle data sub-table includes the A-phase line voltage duty cycle discrete data under each discrete data sequence number, the B-phase line voltage duty cycle data sub-table includes the B-phase line voltage duty cycle discrete data under each discrete data sequence number, and the C-phase line voltage duty cycle data sub-table includes the C-phase line voltage duty cycle discrete data under each discrete data sequence number.

[0015] Preferably, in the above startup control method, obtaining the first phase voltage duty cycle data sequence of the sinusoidal wave includes:

[0016] Extracting, according to a preset table lookup control speed, discrete data of the phase A line voltage duty cycle, discrete data of the phase B line voltage duty cycle, and discrete data of the phase C line voltage duty cycle under a plurality of discrete data sequence numbers from the phase A line voltage duty cycle data sub-table, the phase B line voltage duty cycle data sub-table, and the phase C line voltage duty cycle data sub-table, respectively;

[0017] The first phase voltage duty cycle data sequence of the sine wave is calculated based on the preset PWM modulation period and the extracted discrete data of all A-phase line voltage duty cycles, all B-phase line voltage duty cycle and all C-phase line voltage duty cycle.

[0018] Preferably, the above-mentioned startup control method, wherein controlling the motor startup according to the first phase voltage duty cycle data sequence, includes:

[0019] generating, according to the first phase voltage duty cycle data sequence, sinusoidal three-phase phase voltage component vectors at both ends of the winding of the motor;

[0020] synthesizing the three-phase voltage component vectors to obtain a phase voltage rotating total vector;

[0021] The motor is started by rotating a total vector according to the phase voltage.

[0022] Preferably, the above startup control method, after controlling the motor to start, further comprises:

[0023] Increasing the preset table lookup control speed to obtain an accelerated table lookup control speed;

[0024] According to the accelerated table lookup control speed, respectively, from the A phase line voltage duty cycle data sub-table, the B phase line voltage duty cycle data sub-table, and the C phase line voltage duty cycle data sub-table, the discrete data of the A phase line voltage duty cycle, the discrete data of the B phase line voltage duty cycle, and the discrete data of the C phase line voltage duty cycle under a plurality of discrete data sequence numbers are extracted again;

[0025] Calculating a second phase voltage duty cycle data sequence according to the preset PWM modulation period and all the A-phase line voltage duty cycle discrete data, all the B-phase line voltage duty cycle discrete data, and all the C-phase line voltage duty cycle discrete data extracted again;

[0026] The motor is controlled to accelerate according to the second phase voltage duty cycle data sequence.

[0027] Preferably, the above startup control method, after controlling the motor to start, further comprises:

[0028] When the motor is started and rotates to a preset speed, the back electromotive force information of the motor is detected in real time;

[0029] Performing PWM modulation on the back electromotive force information based on a square wave control method to obtain a third phase voltage duty cycle data sequence;

[0030] The motor is controlled to rotate according to the third phase voltage duty cycle data sequence.

[0031] In addition, the present invention also provides a motor starting control system, comprising:

[0032] A data table acquisition module is used to obtain a line voltage duty cycle data table of a saddle wave;

[0033] a PWM modulation module, communicatively connected to the data table acquisition module, configured to perform PWM modulation on the line voltage duty cycle data table based on a table lookup modulation method to obtain a sinusoidal first phase voltage duty cycle data sequence;

[0034] The motor starting control module is in communication with the PWM modulation module and is used to control the starting of the motor according to the first phase voltage duty cycle data sequence.

[0035] In addition, the present invention also provides a motor starting control circuit, comprising:

[0036] Controller;

[0037] an inverter, electrically connected to the controller and the motor;

[0038] Wherein, the controller is used for:

[0039] Obtain the line voltage duty cycle data table of the saddle wave;

[0040] Performing PWM modulation on the line voltage duty cycle data table based on a table lookup modulation method to obtain a first phase voltage duty cycle data sequence of a sinusoidal wave;

[0041] The inverter is used to:

[0042] The motor is controlled to start according to the first phase voltage duty cycle data sequence.

[0043] In addition, the present invention also provides a cleaning device, comprising the aforementioned start-up control circuit, and further comprising:

[0044] Equipment body and motor;

[0045] The controller, the inverter and the motor are all arranged in the device body.

[0046] The technical solution provided by the present invention has the following advantages:

[0047] The motor starting control method, system, circuit and cleaning equipment provided by the present invention perform PWM modulation on the line voltage duty cycle data table of the saddle wave based on the table lookup modulation method, output the first phase voltage duty cycle data sequence of the sinusoidal wave, and then control the motor starting according to the first phase voltage duty cycle data sequence. The starting process is smooth, without jitter or noise, which effectively improves the user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0049] Figure 1 Schematic diagram of the flow of the motor startup control method in the first embodiment of the present invention;

[0050] Figure 2 This is a schematic diagram of a process for generating a line voltage duty cycle data table in the first embodiment of the present invention;

[0051] Figure 3 Schematic diagram of the waveform of the saddle wave generated in the first embodiment of the present invention;

[0052] Figure 4 Schematic diagram of the process of obtaining a first phase voltage duty cycle data sequence in the first embodiment of the present invention;

[0053] Figure 5This is a schematic diagram of a process for controlling the start-up of a motor in the first embodiment of the present invention;

[0054] Figure 6 Schematic diagram of waveforms of three-phase phase voltage vectors generated in the first embodiment of the present invention;

[0055] Figure 7 Schematic diagram of the process of starting the control method in the second embodiment of the present invention;

[0056] Figure 8 This is a schematic diagram of a process for controlling the motor to accelerate rotation in the second embodiment of the present invention;

[0057] Figure 9 Schematic diagram of the process of the startup control method in the third embodiment of the present invention;

[0058] Figure 10 Schematic diagram of the structure of the motor starting control system in the fourth embodiment of the present invention;

[0059] Figure 11 Schematic diagram of the structure of the motor starting control circuit in the fifth embodiment of the present invention;

[0060] Figure 12 Schematic diagram of the structure of the inverter in the fifth embodiment of the present invention;

[0061] Figure 13 Schematic diagram of the complete structure of the startup control circuit in the fifth embodiment of the present invention.

[0062] Description of reference numerals:

[0063] 100. Controller, 200. Inverter, 300. Motor, 400. Back-electromotive force detection circuit. DETAILED DESCRIPTION

[0064] The technical solutions of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments. It should be noted that the embodiments of the present invention and the features therein may be combined with each other unless there is a conflict.

[0065] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence.

[0066] In the present invention, unless otherwise specified, the directional words used, such as "up, down, top, bottom", usually refer to the directions shown in the drawings, or to the components themselves in the vertical, perpendicular or gravity direction; similarly, for ease of understanding and description, "inside and outside" refer to the inside and outside relative to the outline of each component itself, but the above directional words are not used to limit the present invention.

[0067] Traditionally, square-wave control methods have been widely used for starting vacuum cleaner motors due to their simple algorithms and low chip computing power requirements. However, this method can cause problems such as torque pulsation and commutation noise during the motor startup process, significantly impacting the user experience. To address these technical issues, the present invention proposes a motor startup control method, system, circuit, and cleaning device.

[0068] The motor startup control method and system proposed in the present invention can be applied not only to vacuum cleaners equipped with motors (such as DC brushless vacuum cleaners), but also to other machines and equipment equipped with motors. In the following embodiments, the present invention is described using the application of a DC brushless vacuum cleaner as an example.

[0069] Example 1

[0070] like Figure 1 As shown, this embodiment provides a motor startup control method, the method comprising:

[0071] S100: Obtaining a data table of line voltage duty cycles of a saddle-shaped wave;

[0072] S200: performing PWM modulation on the line voltage duty cycle data table based on a table lookup modulation method to obtain a first phase voltage duty cycle data sequence of a sinusoidal wave;

[0073] S300: Control the motor to start according to the first phase voltage duty cycle data sequence.

[0074] First, a line voltage duty cycle data table of a specific waveform is obtained, that is, a line voltage duty cycle data table of a saddle wave. On the one hand, it is convenient to generate the phase voltage at both ends of the motor winding according to the modulation principle of line voltage control PWM (i.e. pulse width modulation), so as to control the motor start-up through the phase voltage; on the other hand, it is convenient to use a table lookup modulation method to look up the table in the line voltage duty cycle data table of the saddle wave, thereby ensuring the smooth implementation of PWM modulation; based on the table lookup modulation method, a first phase voltage duty cycle data sequence of a sinusoidal wave is output, and the first phase voltage duty cycle data sequence contains multiple groups of three-phase phase voltage duty cycle data that can generate a sine wave. Controlling the motor start-up according to these three-phase phase voltage duty cycle data can effectively overcome the problems of torque pulsation and commutation noise generated in the traditional square wave starting method. The motor starting process is smooth, without jitter or noise, which effectively improves the user experience.

[0075] Preferably, if Figure 2 As shown, S100 includes:

[0076] S101: Calculate the duty cycle data of the three-phase line voltage of the saddle wave according to the duty cycle calculation formula;

[0077] S102: Discretize the three-phase line voltage duty cycle data according to a preset discrete accuracy to obtain a three-phase line voltage duty cycle discrete data sequence;

[0078] S103: Generate a line voltage duty cycle data table according to the three-phase line voltage duty cycle discrete data sequence.

[0079] In order to obtain a line voltage duty cycle data table of a saddle wave, it is first necessary to obtain three-phase line voltage duty cycle data that can generate a saddle wave. In S101 of this embodiment, the three-phase line voltage duty cycle data is calculated according to the duty cycle calculation formula. These three-phase line voltage duty cycle data are continuous input values ​​that change with time. In the subsequent PWM modulation process, corresponding continuous output values ​​can be generated. In S102 of this embodiment, by discretizing these data, continuous input and output can be converted into discrete input and output, that is, a three-phase line voltage duty cycle discrete data sequence is obtained. These discrete three-phase line voltage duty cycle discrete data sequences can facilitate the generation of a corresponding line voltage duty cycle data table, which in turn facilitates subsequent PWM modulation based on a table lookup modulation method.

[0080] Specifically, the three-phase line voltage duty cycle data includes the A-phase line voltage duty cycle, the B-phase line voltage duty cycle, and the C-phase line voltage duty cycle.

[0081] Specifically, the three-phase line voltage duty cycle discrete data sequence includes three-phase line voltage duty cycle discrete data under a plurality of discrete data sequence numbers; the three-phase line voltage duty cycle discrete data includes A-phase line voltage duty cycle discrete data, B-phase line voltage duty cycle discrete data, and C-phase line voltage duty cycle discrete data;

[0082] The line voltage duty cycle data table includes an A-phase line voltage duty cycle data sub-table, a B-phase line voltage duty cycle data sub-table, and a C-phase line voltage duty cycle data sub-table, and the A-phase line voltage duty cycle data sub-table includes the A-phase line voltage duty cycle discrete data under each discrete data sequence number, the B-phase line voltage duty cycle data sub-table includes the B-phase line voltage duty cycle discrete data under each discrete data sequence number, and the C-phase line voltage duty cycle data sub-table includes the C-phase line voltage duty cycle discrete data under each discrete data sequence number.

[0083] Specifically, the duty cycle calculation formula in S101 is:

[0084]

[0085] Among them, u x_duty 、u y_duty and u z_duty are the A-phase line voltage duty cycle, B-phase line voltage duty cycle and C-phase line voltage duty cycle respectively, ω is the angular frequency of the saddle wave, and t is the time variable.

[0086] Using the input ωt in the above duty cycle calculation formula as the horizontal coordinate and the calculated three-phase line voltage duty cycle data of the saddle wave as the vertical coordinate, a saddle wave with a phase difference of 120 degrees between adjacent phases can be generated. The waveform of the saddle wave is as follows: Figure 3 shown.

[0087] Specifically, the preset discrete precision in S102 can be set and adjusted according to actual conditions.

[0088] In this embodiment, the range of the input ωt is [-30°, 330°], and the corresponding output A phase line voltage duty cycle u x_duty , B phase line voltage duty cycle u y_duty and C phase line voltage duty cycle u z_duty , are all continuous values. Within this 360-degree cycle, according to the preset discrete accuracy of 1 / 360, the input ωt is discretized into 360 discrete values, that is, discretized into -30°, -29°, -28°, ... 328°, 329° and 330° in sequence, increasing by 1 degree, and the corresponding 360 sets of u can be output. x_duty 、u y_duty and u z_duty , the output of 360 groups u x_duty 、u y_duty and u z_duty are all discrete values, denoted as u' x_duty 、u' y_duty and u' z_duty , to show the difference, the three-phase line voltage duty cycle data is discretized, and the three-phase line voltage duty cycle discrete data, u' x_duty 、u' y_duty and u' z_duty That is, they are the discrete data of the duty cycle of the line voltage of phase A, the discrete data of the duty cycle of the line voltage of phase B and the discrete data of the duty cycle of the line voltage of phase C. x_duty 、u' y_duty and u' z_duty Number each group u' x_duty 、u' y_duty and u' z_duty Each of them sets a corresponding discrete data number, and finally obtains u' under 360 sets of discrete data numbers x_duty 、u' y_duty and u' z_duty, these u' with discrete data sequence numbers x_duty 、u' y_duty and u' z_duty , which is the final discrete data sequence of the three-phase line voltage duty cycle. The discrete data sequence number can be a conventional digital number, such as 1, 2, 3, ..., 360, etc., or a character number, such as L_1, L_2, ..., L_360, etc., or other sequence numbers or numbers that can distinguish 360 groups of data.

[0089] Specifically, in S103, the discrete data u' of the phase A line voltage duty cycle under the 360 ​​discrete data numbers are x_duty By compiling the table, you can generate a Phase A line voltage duty cycle data sub-table (denoted as Table_A). The tabular format of Table_A is shown in Table 1 (the specific values ​​of each discrete data point of Phase A line voltage duty cycle are not shown). The Phase B line voltage duty cycle data sub-table (denoted as Table_B) and the Phase C line voltage duty cycle data sub-table (denoted as Table_C) are generated using the same method. Their tabular formats are similar to Table 1 and are not further described here. The generated Phase A line voltage duty cycle data sub-table Table_A, Phase B line voltage duty cycle data sub-table Table_B, and Phase C line voltage duty cycle data sub-table Table_C are collectively referred to as the line voltage duty cycle data tables.

[0090] Table 1: Phase A line voltage duty cycle data sub-table Table_A in this embodiment

[0091]

[0092] Preferably, if Figure 4 As shown, S200 includes:

[0093] S201: extracting discrete data of the phase A line voltage duty cycle, discrete data of the phase B line voltage duty cycle, and discrete data of the phase C line voltage duty cycle under a plurality of discrete data sequence numbers from the phase A line voltage duty cycle data sub-table, the phase B line voltage duty cycle data sub-table, and the phase C line voltage duty cycle data sub-table, respectively, according to a preset table lookup control speed;

[0094] S202: Calculate a first phase voltage duty cycle data sequence of a sine wave according to a preset PWM modulation period and all extracted discrete data of the A-phase line voltage duty cycle, all discrete data of the B-phase line voltage duty cycle, and all discrete data of the C-phase line voltage duty cycle.

[0095] In the process of PWM modulation based on the table lookup modulation method, by inputting a discrete data serial number, the corresponding u' can be extracted from the A phase line voltage duty cycle data sub-table Table_A, the B phase line voltage duty cycle data sub-table Table_B and the C phase line voltage duty cycle data sub-table Table_C.x_duty 、u' y_duty and u' z_duty , extracted u' x_duty 、u' y_duty and u' z_duty Multiplying by the preset PWM modulation period respectively, the corresponding three-phase phase voltage duty cycle data can be obtained, which are respectively recorded as u a_duty 、u b_duty and u c_duty By changing the input discrete data sequence number and controlling the table lookup speed according to the preset table lookup control speed, a series of three-phase phase voltage duty cycle data u can be obtained in the same way. a_duty 、u b_duty and u c_duty ; These series of three-phase phase voltage duty cycle data u a_duty 、u b_duty and u c_duty This is the final first-phase voltage duty cycle data sequence, which can facilitate the subsequent generation of the corresponding sine wave for controlling the motor start-up.

[0096] Based on the above-mentioned preset table lookup control speed, the speed of controlling the table lookup and data extraction can not only ensure that the first-phase voltage duty cycle data sequence used to generate the sinusoidal wave corresponding to the control motor start-up is obtained to ensure that the motor can start normally, but also control the speed of the motor when starting, ensuring that the motor starting process is smooth, without jitter and noise.

[0097] Specifically, the above-mentioned preset table lookup control speed and preset PWM modulation period can be set and adjusted according to actual conditions.

[0098] Preferably, if Figure 5 As shown, S300 includes:

[0099] S301: Generate sinusoidal three-phase voltage component vectors at both ends of the winding of the motor according to the first phase voltage duty cycle data sequence;

[0100] S302: synthesizing the three-phase voltage component vectors to obtain a phase voltage rotation total vector;

[0101] S303: Control the motor to start according to the phase voltage rotation total vector.

[0102] The first phase voltage duty cycle data sequence obtained based on the table lookup modulation method includes multiple groups u a_duty 、u b_duty and u c_duty , and finally generate sinusoidal three-phase voltage vectors at both ends of the motor winding. These three-phase voltage vectors are three vectors U with a difference of 120 degrees and a size that changes sinusoidally with time. a 、Ub and U c By synthesizing the three component vectors, the total phase voltage rotation vector used to control the motor rotation start is obtained, so that the motor starts smoothly without abnormal noise.

[0103] Specifically, in S301 of this embodiment, the three component vectors U are 120 degrees apart and their magnitudes change sinusoidally with time. a 、U b and U c The waveform diagram is as follows Figure 6 shown.

[0104] Example 2

[0105] like Figure 7 As shown, this embodiment also provides a motor startup control method, the method comprising:

[0106] S110: Obtaining a line voltage duty cycle data table of a saddle wave;

[0107] S210: Performing PWM modulation on the line voltage duty cycle data table based on a table lookup modulation method to obtain a first phase voltage duty cycle data sequence of a sinusoidal wave;

[0108] S310: Control the motor to start according to the first phase voltage duty cycle data sequence;

[0109] S410: performing PWM modulation on the line voltage duty cycle data table again based on the table lookup modulation method to obtain a second phase voltage duty cycle data sequence of a sine wave; and controlling the motor to accelerate according to the second phase voltage duty cycle data sequence.

[0110] Based on the table lookup modulation method, the line voltage duty cycle data table of the saddle wave is PWM modulated again to output a sinusoidal second-phase voltage duty cycle data sequence. This can control the acceleration of the motor according to the second-phase voltage duty cycle data sequence. On the basis of ensuring smooth start-up of the motor without jitter and noise, it can also meet the high-speed operation requirements, further improving the user experience.

[0111] Preferably, if Figure 8 As shown, S410 includes:

[0112] S411: increasing the preset table lookup control speed to obtain an accelerated table lookup control speed;

[0113] S412: extracting, according to the accelerated table lookup control speed, the discrete data of the phase A line voltage duty cycle, the discrete data of the phase B line voltage duty cycle, and the discrete data of the phase C line voltage duty cycle under the plurality of discrete data sequence numbers from the phase A line voltage duty cycle data sub-table, the phase B line voltage duty cycle data sub-table, and the phase C line voltage duty cycle data sub-table, respectively;

[0114] S413: Calculate a second phase voltage duty cycle data sequence based on the preset PWM modulation period and all the A-phase line voltage duty cycle discrete data, all the B-phase line voltage duty cycle discrete data, and all the C-phase line voltage duty cycle discrete data extracted again;

[0115] S414: Control the motor to accelerate according to the second phase voltage duty cycle data sequence.

[0116] By increasing the preset table lookup control speed and speeding up the table lookup and data extraction based on the accelerated table lookup control speed, a second-phase voltage duty cycle data sequence of a sinusoidal wave corresponding to the motor's accelerated rotation can be generated on the basis of a smooth start, thereby achieving accelerated motor start-up and meeting high-speed operation requirements.

[0117] S110 to S310 in this embodiment are the same as S100 to S300 in the first embodiment. The specific implementation method of controlling the motor to accelerate according to the second phase voltage duty cycle data sequence in S410 is similar to S301 to S303 in the embodiment. For details not covered in this embodiment, please refer to the first embodiment and Figures 1 to 6 The detailed description is omitted here.

[0118] Example 3

[0119] like Figure 9 As shown, this embodiment also provides a motor startup control method, the method comprising:

[0120] S120: Obtaining a line voltage duty cycle data table of a saddle wave;

[0121] S220: Performing PWM modulation on the line voltage duty cycle data table based on a table lookup modulation method to obtain a first phase voltage duty cycle data sequence of a sinusoidal wave;

[0122] S320: Control the motor to start according to the first phase voltage duty cycle data sequence;

[0123] S420: performing PWM modulation on the line voltage duty cycle data table again based on a table lookup modulation method to obtain a second phase voltage duty cycle data sequence of a sinusoidal wave; and controlling the motor to accelerate according to the second phase voltage duty cycle data sequence;

[0124] S620: When the motor starts and rotates to a preset speed, detecting back electromotive force information of the motor in real time;

[0125] S720: Perform PWM modulation on the back electromotive force information based on a square wave control method to obtain a third phase voltage duty cycle data sequence;

[0126] S820: Control the motor rotation according to the third phase voltage duty cycle data sequence.

[0127] When the motor starts and rotates to the preset speed, the table lookup modulation method is switched to the square wave control method based on the real-time detected back electromotive force information, PWM modulation is performed, and the motor rotation is controlled by the generated third-phase voltage duty cycle data sequence. This can ensure the smooth start of the motor without jitter and noise, and meet the high-speed operation requirements. Based on the low control cost of the traditional square wave control method, the purpose of reducing the motor starting control cost is achieved.

[0128] Similarly, S120 to S320 in this embodiment are the same as S100 to S300 in the first embodiment, S420 in this embodiment is the same as S410 in the second embodiment, and the specific implementation method of S720 for PWM modulation based on the square wave control method adopts the existing implementation method; for details not covered in this embodiment, please refer to the first embodiment, the second embodiment and the Figures 1 to 8 The detailed description is omitted here.

[0129] Example 4

[0130] like Figure 10 As shown, this embodiment provides a motor starting control system, the system comprising:

[0131] A data table acquisition module is used to obtain a line voltage duty cycle data table of a saddle wave;

[0132] a PWM modulation module, communicatively connected to the data table acquisition module, for performing PWM modulation on the line voltage duty cycle data table based on a table lookup modulation method to obtain a first phase voltage duty cycle data sequence of a sinusoidal wave;

[0133] The motor starting control module is in communication with the PWM modulation module and is used to control the starting of the motor according to the first phase voltage duty cycle data sequence.

[0134] The motor starting control system provided in this embodiment uses a PWM modulation module to perform PWM modulation on the line voltage duty cycle data table of the saddle wave based on a table lookup modulation method, outputs a sinusoidal first-phase voltage duty cycle data sequence, and then controls the motor starting according to the first-phase voltage duty cycle data sequence. The starting process is smooth, without jitter or noise, effectively improving the user experience.

[0135] Preferably, the data table acquisition module includes:

[0136] The first calculation unit is used to calculate the duty cycle data of the three-phase line voltage of the saddle wave according to the duty cycle calculation formula;

[0137] a discretization unit, communicatively connected to the first calculation unit, configured to discretize the three-phase line voltage duty cycle data according to a preset discrete accuracy to obtain a three-phase line voltage duty cycle discrete data sequence;

[0138] The data table generating unit is in communication with the discretization unit and is used to generate a line voltage duty cycle data table according to the three-phase line voltage duty cycle discrete data sequence.

[0139] Preferably, the system further comprises:

[0140] The storage module is in communication with the data table generating unit and is used to store the line voltage duty cycle data table.

[0141] Specifically, the three-phase line voltage duty cycle data includes an A-phase line voltage duty cycle, a B-phase line voltage duty cycle, and a C-phase line voltage duty cycle.

[0142] Specifically, the three-phase line voltage duty cycle discrete data sequence includes three-phase line voltage duty cycle discrete data under a plurality of discrete data sequence numbers; the three-phase line voltage duty cycle discrete data includes A-phase line voltage duty cycle discrete data, B-phase line voltage duty cycle discrete data, and C-phase line voltage duty cycle discrete data;

[0143] The line voltage duty cycle data table includes an A-phase line voltage duty cycle data sub-table, a B-phase line voltage duty cycle data sub-table, and a C-phase line voltage duty cycle data sub-table, and the A-phase line voltage duty cycle data sub-table includes the A-phase line voltage duty cycle discrete data under each discrete data sequence number, the B-phase line voltage duty cycle data sub-table includes the B-phase line voltage duty cycle discrete data under each discrete data sequence number, and the C-phase line voltage duty cycle data sub-table includes the C-phase line voltage duty cycle discrete data under each discrete data sequence number.

[0144] Specifically, the duty cycle calculation formula is:

[0145]

[0146] Among them, u x_duty 、u y_duty and u z_duty are the A-phase line voltage duty cycle, B-phase line voltage duty cycle and C-phase line voltage duty cycle respectively, ω is the angular frequency of the saddle wave, and t is the time variable.

[0147] Preferably, the PWM modulation module includes:

[0148] a table lookup unit, communicatively connected to the storage module, for extracting, according to a preset table lookup control speed, discrete data of the phase A line voltage duty cycle data, discrete data of the phase B line voltage duty cycle data, and discrete data of the phase C line voltage duty cycle data under a plurality of discrete data sequence numbers from the phase A line voltage duty cycle data sub-table, the phase B line voltage duty cycle data sub-table, and the phase C line voltage duty cycle data sub-table;

[0149] The second calculation unit is communicatively connected to the table lookup unit and is used to calculate the first phase voltage duty cycle data sequence of the sinusoidal wave based on the preset PWM modulation period and the extracted discrete data of all A-phase line voltage duty cycles, all B-phase line voltage duty cycle discrete data and all C-phase line voltage duty cycle discrete data.

[0150] Preferably, the motor starting control module includes:

[0151] a component vector generating unit, communicatively connected to the second calculating unit, for generating a sinusoidal three-phase phase voltage component vector at both ends of the winding of the motor according to the first phase voltage duty cycle data sequence;

[0152] a synthesis unit, communicatively connected to the component vector generation unit, for synthesizing the three-phase voltage component vectors to obtain a phase voltage rotating total vector;

[0153] The starting control unit is in communication with the synthesis unit and is used to rotate the total vector according to the phase voltage to control the starting of the motor.

[0154] Preferably, the system further comprises:

[0155] The motor acceleration control module is in communication with the starting control unit and is used to perform PWM modulation on the line voltage duty cycle data table again based on the table lookup modulation method to obtain a second phase voltage duty cycle data sequence of a sinusoidal wave; and control the motor to accelerate rotation according to the second phase voltage duty cycle data sequence.

[0156] Preferably, the motor acceleration control module is specifically used to:

[0157] Increasing the preset table lookup control speed to obtain an accelerated table lookup control speed;

[0158] According to the accelerated table lookup control speed, the discrete data of the phase A line voltage duty cycle, the discrete data of the phase B line voltage duty cycle, and the discrete data of the phase C line voltage duty cycle under the plurality of discrete data sequence numbers are extracted again from the phase A line voltage duty cycle data sub-table, the phase B line voltage duty cycle data sub-table, and the phase C line voltage duty cycle data sub-table respectively;

[0159] A second phase voltage duty cycle data sequence is calculated based on the preset PWM modulation period and all the A-phase line voltage duty cycle discrete data, all the B-phase line voltage duty cycle discrete data, and all the C-phase line voltage duty cycle discrete data extracted again;

[0160] The motor is controlled to accelerate according to the second phase voltage duty cycle data sequence.

[0161] Preferably, the system further comprises:

[0162] The motor square wave control module is in communication with the motor acceleration control module and is used to detect the back electromotive force information of the motor in real time when the motor starts and rotates to a preset speed; perform PWM modulation on the back electromotive force information based on the square wave control method to obtain a third-phase voltage duty cycle data sequence; and control the rotation of the motor according to the third-phase voltage duty cycle data sequence.

[0163] The motor start control system described in this embodiment corresponds to the motor start control method described above. For details not included in this embodiment, please refer to the first embodiment, the second embodiment, the third embodiment and the fourth embodiment. Figures 1 to 9 The detailed description is omitted here.

[0164] Example 5

[0165] like Figure 11 As shown, this embodiment provides a motor starting control circuit, which includes:

[0166] Controller 100;

[0167] The inverter 200 is electrically connected to the controller 100 and the motor 300;

[0168] The controller 100 is used for:

[0169] Obtain the line voltage duty cycle data table of the saddle wave;

[0170] Performing PWM modulation on the line voltage duty cycle data table based on a table lookup modulation method to obtain a first phase voltage duty cycle data sequence of a sinusoidal wave;

[0171] The inverter 200 is used for:

[0172] The motor is controlled to start according to the first phase voltage duty cycle data sequence.

[0173] The motor starting control circuit provided in this embodiment, through a combination of software and hardware, performs PWM modulation on the line voltage duty cycle data table of the saddle wave based on a table lookup modulation method, outputs a sinusoidal first-phase voltage duty cycle data sequence, and then controls the motor starting according to the first-phase voltage duty cycle data sequence. The starting process is smooth, without jitter or noise, effectively improving the user experience.

[0174] Preferably, the structure diagram of the inverter 200 and the motor 300 in this embodiment is as shown in FIG. Figure 12 As shown, the inverter 200 is specifically a three-phase rectifier bridge including six MOS tubes, and the motor 300 is specifically a three-phase DC brushless motor including three coils.

[0175] Preferably, the complete structure of the motor starting control circuit in this embodiment is as follows: Figure 13 As shown, the circuit also includes:

[0176] The back electromotive force detection circuit 400 is electrically connected to the controller 100 , the inverter 200 and the motor 300 .

[0177] The back electromotive force detection circuit 400 adopts the existing technology, and the specific details are not repeated here.

[0178] Preferably, the specific internal structure of the controller 100 is as follows Figure 13 As shown, within the controller 100, the memory is used to store the line voltage duty cycle data table; the A / D circuit is used to collect the bus current in the inverter 200; the comparator is used to provide overcurrent protection for the entire controller; and the back-electromotive force sampling circuit is used to collect back-electromotive force information detected by the back-electromotive force detection circuit 400.

[0179] It should be noted that the circuits of the above modules can adopt existing circuit designs or select existing product models, and the specific details are not repeated here.

[0180] Similarly, for details not included in this embodiment, please refer to Example 1, Example 2, Example 3, Example 4 and Figures 1 to 10 The detailed description is omitted here.

[0181] Example 6

[0182] This embodiment provides a cleaning device, which includes a device body and a motor;

[0183] The controller, inverter and motor are all arranged in the device body.

[0184] Similarly, for details not included in this embodiment, please refer to Example 1, Example 2, Example 3, Example 4, Example 5 and Figures 1 to 13 The detailed description is omitted here.

[0185] Obviously, the embodiments described above are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, those skilled in the art may make other different forms of changes or modifications without making any creative work, and all of these should fall within the scope of protection of the present invention.

Claims

1. A motor startup control method, characterized in that: include: Obtain the line voltage duty cycle data table of the saddle wave; Calculate the duty cycle data of the three-phase line voltage of the saddle wave according to the duty cycle calculation formula; The duty cycle calculation formula is as follows: Among them, u x_duty 、u y_duty and u z_duty The line voltage duty cycles of phase A, phase B, and phase C are calculated respectively, ω is the angular frequency of the saddle wave, and t is the time variable; the input ωt in the above duty cycle calculation formula is used as the horizontal coordinate, and the calculated three-phase line voltage duty cycle data of the saddle wave is used as the vertical coordinate to generate a saddle wave with a phase difference of 120 degrees between adjacent phases; Discretizing the three-phase line voltage duty cycle data according to a preset discrete accuracy to obtain a three-phase line voltage duty cycle discrete data sequence; generating the line voltage duty cycle data table according to the three-phase line voltage duty cycle discrete data sequence; Performing PWM modulation on the line voltage duty cycle data table based on a table lookup modulation method to obtain a first phase voltage duty cycle data sequence of a sinusoidal wave; The motor is controlled to start according to the first phase voltage duty cycle data sequence.

2. The motor startup control method according to claim 1, characterized in that: The three-phase line voltage duty cycle discrete data sequence includes three-phase line voltage duty cycle discrete data under a plurality of discrete data sequence numbers; the three-phase line voltage duty cycle discrete data includes A-phase line voltage duty cycle discrete data, B-phase line voltage duty cycle discrete data and C-phase line voltage duty cycle discrete data; The line voltage duty cycle data table includes an A-phase line voltage duty cycle data sub-table, a B-phase line voltage duty cycle data sub-table and a C-phase line voltage duty cycle data sub-table, and the A-phase line voltage duty cycle data sub-table includes the A-phase line voltage duty cycle discrete data under each discrete data sequence number, the B-phase line voltage duty cycle data sub-table includes the B-phase line voltage duty cycle discrete data under each discrete data sequence number, and the C-phase line voltage duty cycle data sub-table includes the C-phase line voltage duty cycle discrete data under each discrete data sequence number.

3. The motor startup control method according to claim 2, characterized in that: The step of obtaining a first phase voltage duty cycle data sequence of a sine wave includes: Extracting, according to a preset table lookup control speed, discrete data of the phase A line voltage duty cycle, discrete data of the phase B line voltage duty cycle, and discrete data of the phase C line voltage duty cycle under a plurality of discrete data sequence numbers from the phase A line voltage duty cycle data sub-table, the phase B line voltage duty cycle data sub-table, and the phase C line voltage duty cycle data sub-table, respectively; The first phase voltage duty cycle data sequence of the sine wave is calculated based on the preset PWM modulation period and the extracted discrete data of all A-phase line voltage duty cycles, all B-phase line voltage duty cycle and all C-phase line voltage duty cycle.

4. The motor startup control method according to claim 3, characterized in that: The step of controlling the motor to start according to the first phase voltage duty cycle data sequence includes: generating, according to the first phase voltage duty cycle data sequence, sinusoidal three-phase phase voltage component vectors at both ends of the winding of the motor; synthesizing the three-phase voltage component vectors to obtain a phase voltage rotating total vector; The motor is started by rotating a total vector according to the phase voltage.

5. The motor startup control method according to claim 4, characterized in that: After the controlling of the motor starting, the method further includes: Increasing the preset table lookup control speed to obtain an accelerated table lookup control speed; According to the accelerated table lookup control speed, respectively, from the A phase line voltage duty cycle data sub-table, the B phase line voltage duty cycle data sub-table, and the C phase line voltage duty cycle data sub-table, the discrete data of the A phase line voltage duty cycle, the discrete data of the B phase line voltage duty cycle, and the discrete data of the C phase line voltage duty cycle under a plurality of discrete data sequence numbers are extracted again; Calculating a second phase voltage duty cycle data sequence according to the preset PWM modulation period and all the A-phase line voltage duty cycle discrete data, all the B-phase line voltage duty cycle discrete data, and all the C-phase line voltage duty cycle discrete data extracted again; The motor is controlled to accelerate according to the second phase voltage duty cycle data sequence.

6. The motor startup control method according to any one of claims 1 to 5, characterized in that: After the controlling of the motor starting, the method further includes: When the motor is started and rotates to a preset speed, the back electromotive force information of the motor is detected in real time; Performing PWM modulation on the back electromotive force information based on a square wave control method to obtain a third phase voltage duty cycle data sequence; The motor is controlled to rotate according to the third phase voltage duty cycle data sequence.

7. A motor starting control system, characterized in that: include: A data table acquisition module is used to obtain a line voltage duty cycle data table of a saddle wave; Calculate the duty cycle data of the three-phase line voltage of the saddle wave according to the duty cycle calculation formula; The duty cycle calculation formula is as follows: Among them, u x_duty 、u y_duty and u z_duty The line voltage duty cycles of phase A, phase B, and phase C are calculated respectively, ω is the angular frequency of the saddle wave, and t is the time variable; the input ωt in the above duty cycle calculation formula is used as the horizontal coordinate, and the calculated three-phase line voltage duty cycle data of the saddle wave is used as the vertical coordinate to generate a saddle wave with a phase difference of 120 degrees between adjacent phases; Discretizing the three-phase line voltage duty cycle data according to a preset discrete accuracy to obtain a three-phase line voltage duty cycle discrete data sequence; generating the line voltage duty cycle data table according to the three-phase line voltage duty cycle discrete data sequence; a PWM modulation module, communicatively connected to the data table acquisition module, configured to perform PWM modulation on the line voltage duty cycle data table based on a table lookup modulation method to obtain a sinusoidal first phase voltage duty cycle data sequence; The motor starting control module is in communication with the PWM modulation module and is used to control the starting of the motor according to the first phase voltage duty cycle data sequence.

8. A motor starting control circuit, characterized in that: include: Controller; an inverter, electrically connected to the controller and the motor; Wherein, the controller is used for: Obtain a saddle wave line voltage duty cycle data table; calculate the three-phase line voltage duty cycle data of the saddle wave according to the duty cycle calculation formula; the duty cycle calculation formula is specifically: Among them, u x_duty 、u y_duty and u z_duty The line voltage duty cycles of phase A, phase B, and phase C are calculated respectively, ω is the angular frequency of the saddle wave, and t is the time variable; the input ωt in the above duty cycle calculation formula is used as the horizontal coordinate, and the calculated three-phase line voltage duty cycle data of the saddle wave is used as the vertical coordinate to generate a saddle wave with a phase difference of 120 degrees between adjacent phases; Discretizing the three-phase line voltage duty cycle data according to a preset discrete accuracy to obtain a three-phase line voltage duty cycle discrete data sequence; generating the line voltage duty cycle data table according to the three-phase line voltage duty cycle discrete data sequence; Performing PWM modulation on the line voltage duty cycle data table based on a table lookup modulation method to obtain a first phase voltage duty cycle data sequence of a sinusoidal wave; The inverter is used to: The motor is controlled to start according to the first phase voltage duty cycle data sequence.

9. A cleaning device, characterized in that: The circuit according to claim 8, further comprising: Equipment body and motor; The controller, the inverter and the motor are all arranged in the device body.

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