阅读说明：本技术 基于开关霍尔传感器的永磁体分段同步直线电机及矢量控制方法 (Permanent magnet segmented synchronous linear motor based on switch Hall sensor and vector control method ) 是由 欧阳庆生 王安鹏 祝宇 于 2020-07-29 设计创作，主要内容包括：本发明涉及一种基于开关霍尔传感器的永磁体分段同步直线电机及矢量控制方法,属于电机控制领域。采用了两组开关霍尔位置传感器,设计了互为备用的信号采集方案,解决了永磁体分段间隔带来了的霍尔信号故障的问题；其次借鉴了无刷直流电机(BLDC)方波控制技术,将三相六状态120°控制方法应用于正弦波永磁同步直线电机的启动阶段,解决了启动阶段位置估计误差给矢量控制带来的启动抖动甚至无法启动的问题；对于速度给定的不同模态(恒速态或非恒速态),本发明分别采用平均速度法和平均加速度法估计动子速度和电角,从而进行矢量闭环控制,增强系统的速度控制性能,兼顾了算法的简易性和可靠性。(The invention relates to a permanent magnet segmented synchronous linear motor based on a switch Hall sensor and a vector control method, and belongs to the field of motor control. Two groups of switch Hall position sensors are adopted, a signal acquisition scheme which is mutually standby is designed, and the problem of Hall signal faults caused by interval of permanent magnet sections is solved; secondly, a brushless direct current motor (BLDC) square wave control technology is used for reference, a three-phase six-state 120-degree control method is applied to the starting stage of the sine wave permanent magnet synchronous linear motor, and the problem that starting jitter even cannot be started due to vector control caused by position estimation errors in the starting stage is solved; for different modes (constant speed state or non-constant speed state) with given speed, the invention respectively adopts an average speed method and an average acceleration method to estimate the speed and the electric angle of the rotor, thereby carrying out vector closed-loop control, enhancing the speed control performance of the system and giving consideration to the simplicity and the reliability of the algorithm.)

1. The utility model provides a synchronous linear electric motor of permanent magnet segmentation based on switch hall sensor which characterized in that: the Hall element comprises a primary component, a secondary component and a Hall element; the primary assembly consists of a primary iron core (1) and an armature winding (2), and the secondary assembly consists of a plurality of secondary permanent magnets (3) which are arranged in sections; the Hall elements are divided into two groups by adopting 6 switching Hall elements, the Hall elements in the groups are distributed at equal intervals, the distance is 2 tau/3, tau is a polar distance, the corresponding positions of the two groups of Hall elements are separated by 2 kttau, and k is an integer which is preset to be more than 1; the Hall element is placed on the outer side of the winding, the distance between the central axis of the Hall element at the end part close to the primary assembly and the central axis of the groove at the end part of the primary assembly is N tau/6, and N is a preset integer.

2. The switched hall sensor based permanent magnet segmented synchronous linear motor of claim 1 wherein: the installation position of the Hall element is fixed relative to the position of the primary assembly.

3. The switched hall sensor based permanent magnet segmented synchronous linear motor of claim 1 wherein: the coil sequence of the armature winding (2) is C-Y-A-Z-B-X.

4. A vector control method of a permanent magnet segmented synchronous linear motor based on a switch Hall sensor is characterized by comprising the following steps:

(1) detecting 6 paths of Hall signals, judging and selecting a group of normal Hall signals as main signals, and estimating the speed and the position of the rotor;

(2) when the third or more Hall signal jumps, entering a vector control mode; before the speed of the rotor reaches a rated value, the rotor accelerates to the rated speed at a preset acceleration; in the stage of uniform acceleration, the speed and the position of the rotor are estimated by adopting an average acceleration method, and in the stage of uniform speed, the speed and the position of the rotor are estimated by adopting an average speed method;

(3) the speed of the rotor is fed back to the PI controller, an alternating current given value is output, coordinate transformation is carried out on three-phase current according to the position estimation result of the rotor to obtain an alternating current feedback value and a direct current feedback value, the PI controller is adopted to output an alternating current given voltage value and a direct current given voltage value, given voltage under a two-phase static coordinate system is obtained through coordinate transformation and is output to SVPWM to be modulated into 6-path switching tube driving signals, and an inverter is driven to apply a specific voltage vector to the motor, so that speed and current double closed loop vector control of the permanent magnet linear motor is completed.

5. The vector control method of the permanent magnet segmented synchronous linear motor based on the switch hall sensor as claimed in claim 4, characterized in that: the vector control mode in the step (2) comprises the following specific steps:

step one, each time the Hall signal jumps, firstly, the holding time delta t of the interval of the two Hall signals needs to be recorded_p2And Δ t_p1And updating the initial electrical angle theta of the Hall interval_r0；

Step two, obtaining the product based on an average velocity methodAverage angular velocity ω to the first two Hall signal intervals_p2And ω_p1The formula is as follows:

step three, judging whether the speed given state is an acceleration state or a constant speed state:

when the mover is in an accelerated state, the average angular acceleration a of the first two Hall intervals is calculated₁The formula is as follows:

mover electrical angle theta for calculating mover acceleration state based on average acceleration method_rAnd mover velocity v, the formula is as follows:

where Δ t_cKeeping time for the current Hall interval;

when the rotor is in a constant speed state, calculating the electrical angle theta of the rotor based on an average speed method_rAnd mover velocity v, the formula is as follows:

where Δ t_cAnd keeping time for the current Hall interval.

6. The vector control method of the permanent magnet segmented synchronous linear motor based on the switch hall sensor as claimed in claim 4, characterized in that: before the third jump of the Hall signal occurs, a PI current controller is adopted to control the current value of a bus, a conducting winding is selected according to the state of the Hall signal, three-phase six-state 120-degree phase change control is adopted, the modulation mode adopts an on-PWM mode, for a switching tube conducting 120 degrees, the first 60-degree interval is kept in a conducting state, and the second 60-degree interval adopts PWM chopping, so that the on-off of the corresponding switching tube of the inverter is controlled.

7. The vector control method of the permanent magnet segmented synchronous linear motor based on the switch hall sensor as claimed in claim 4, characterized in that: in the step (1), 20ns is used as a fault detection period to detect whether the main signal is in fault or not, when the main signal is detected to be in fault, the standby Hall signal is set as the main signal, the previous main signal is set as the standby signal, and the speed and the position of the rotor are estimated according to the main signal.

8. The vector control method of the permanent magnet segmented synchronous linear motor based on the switch hall sensor as claimed in claim 7, wherein: and in a fault detection period, detecting whether the 3 paths of Hall signal combinations of the main signals are in one of basic Hall signal combination states, and if not, judging that the main signals are in a fault state.

Technical Field

The invention belongs to the technical field of motor drive control, and particularly relates to a permanent magnet segmented synchronous linear motor vector control method based on a switch Hall sensor.

Background

The permanent magnet synchronous linear motor is simple in structure, high in upper limit of speed and excellent in speed adjusting capacity, and can meet the increasing speed requirement of a logistics sorting system. The primary of the linear motor is fixed, and the secondary of the linear motor is segmented and fixed at the bottom of the mobile device to form a basic power unit for logistics sorting; according to the logistics sorting stroke, the segmentation number of the permanent magnets can be flexibly adjusted.

However, due to the long stroke characteristic of secondary segmentation and logistics sorting, the traditional encoder position feedback scheme has the problems of difficult installation, increased cost and reduced reliability, and the low-speed control performance and the anti-jamming capability of the position-sensor-free control technology need to be improved.

The position feedback scheme based on the switch Hall position sensor has low cost, simple structure and high reliability, and can realize the vector control of the permanent magnet synchronous motor by combining the control technology without the position sensor, thereby exerting the superiority of the speed regulation performance of the permanent magnet synchronous linear motor.

The technical scheme of the invention patent with patent number 201010166572.9 needs to adopt a large number of switch hall sensors to feed back the position of the rotor, which not only increases the production and manufacturing cost, but also improves the probability of damage and the maintenance difficulty due to the complex structure. Patent application CN201910377391.1 utilizes three switching hall elements equidistantly distributed in three continuous coils, estimates the speed and position of the mover based on the average speed method, and is not applicable to a permanent magnet segmented linear motor system because the hall signal abnormal phenomenon caused by the secondary segmentation interval is not considered.

Disclosure of Invention

The invention aims to provide a permanent magnet segmented synchronous linear motor based on a switch Hall sensor and a vector control method, so as to reduce the cost of the permanent magnet segmented synchronous linear motor used in a logistics sorting system and improve the linear motion speed control performance.

In order to solve the technical problems, the invention adopts a technical scheme that: a permanent magnet segmented synchronous linear motor based on a switch Hall sensor comprises a primary component, a secondary component and a Hall element; the primary assembly consists of a primary iron core and an armature winding, and the secondary assembly consists of a plurality of secondary permanent magnets which are arranged in sections; the Hall elements are divided into two groups by adopting 6 switching Hall elements, the Hall elements in the groups are distributed at equal intervals, the distance is 2 tau/3, tau is a polar distance, the corresponding positions of the two groups of Hall elements are separated by 2 kttau, and k is an integer which is preset to be more than 1; the Hall element is placed on the outer side of the winding, the distance between the central axis of the Hall element at the end part close to the primary assembly and the central axis of the groove at the end part of the primary assembly is N tau/6, and N is a preset integer.

Further, the installation position of the Hall element is fixed relative to the position of the primary assembly.

Further, the sequence of the armature winding coils is C-Y-A-Z-B-X.

The invention also provides a vector control method of the permanent magnet segmented synchronous linear motor based on the switch Hall sensor, which comprises the following steps:

(1) detecting 6 paths of Hall signals, judging and selecting a group of normal Hall signals as main signals, and estimating the speed and the position of the rotor;

(2) when the third or more Hall signal jumps, entering a vector control mode; before the speed of the rotor reaches a rated value, the rotor accelerates to the rated speed at a preset acceleration; in the stage of uniform acceleration, the speed and the position of the rotor are estimated by adopting an average acceleration method, and in the stage of uniform speed, the speed and the position of the rotor are estimated by adopting an average speed method;

(3) the speed of the rotor is fed back to the PI controller, an alternating current given value is output, coordinate transformation is carried out on three-phase current according to the position estimation result of the rotor to obtain an alternating current feedback value and a direct current feedback value, the PI controller is adopted to output an alternating current given voltage value and a direct current given voltage value, given voltage under a two-phase static coordinate system is obtained through coordinate transformation and is output to SVPWM to be modulated into 6-path switching tube driving signals, and an inverter is driven to apply a specific voltage vector to the motor, so that speed and current double closed loop vector control of the permanent magnet linear motor is completed.

Further, the vector control mode in step (2) includes the specific steps of:

step one, each time the Hall signal jumps, firstly, the holding time delta t of the interval of the two Hall signals needs to be recorded_p2And Δ t_p1And updating the initial electrical angle theta of the Hall interval_r0；

Step two, obtaining the average angular velocity omega of the first two Hall signal intervals based on an average velocity method_p2And ω_p1The formula is as follows:

step three, judging whether the speed given state is an acceleration state or a constant speed state:

when the mover is in an accelerated state, the average angular acceleration a of the first two Hall intervals is calculated₁The formula is as follows:

mover electrical angle theta for calculating mover acceleration state based on average acceleration method_rAnd mover velocity v, the formula is as follows:

where Δ t_cKeeping time for the current Hall interval;

when the rotor is in a constant speed state, calculating the electrical angle theta of the rotor based on an average speed method_rAnd mover velocity v, the formula is as follows:

where Δ t_cAnd keeping time for the current Hall interval.

Further, before the third jump of the Hall signal occurs, a PI current controller is adopted to control the current value of a bus, a conducting winding is selected according to the state of the Hall signal, three-phase six-state 120-degree phase change control is adopted, the modulation mode adopts an on-PWM mode, for a switching tube conducting 120 degrees, the first 60-degree interval is kept in a conducting state, and the second 60-degree interval adopts PWM chopping, so that the on-off of the corresponding switching tube of the inverter is controlled.

Further, in the step (1), with 20ns as a fault detection period, whether the main signal is faulty or not is detected, when the main signal is detected to be faulty, the standby hall signal is set as the main signal, the previous main signal is set as the standby signal, and the speed and the position of the mover are estimated according to the main signal.

Further, in a fault detection period, whether the combination of the 3 paths of Hall signals of the main signal is one of basic Hall signal combination states is detected, and if not, the main signal is judged to be a fault.

The advantages of the invention are as follows:

(1) the invention adopts the switch Hall position sensor to carry out closed-loop vector control on the permanent magnet segmented linear motor, thereby simplifying the structure of a motion system and improving the reliability; aiming at the characteristics of the permanent magnet segments, the scheme of installation and signal processing of two groups of Hall elements is provided, and the problem of position signal errors caused by the gaps of the permanent magnet segments is solved;

(2) in the first Hall interval, a BLDC control mode is adopted, and the direct current of the corresponding winding is controlled according to the state of the Hall interval, so that the permanent magnet synchronous motor is ensured to be started smoothly; in different motion states of the rotor, different position estimation algorithms are adopted, so that the accuracy of speed and position estimation is improved, and finally the vector control performance of the permanent magnet synchronous linear motor based on the Hall switch sensor is improved.

Drawings

Fig. 1 is a schematic structural diagram of a permanent magnet segment synchronous linear motor according to the present invention.

Fig. 2 is a schematic diagram of a hall element mounting scheme according to the present invention.

Fig. 3 is a schematic diagram of a PWM modulation method of a hall signal and a start period according to the present invention.

FIG. 4 is a vector control flow diagram of the present invention.

Description of reference numerals: 1-a primary core; 2-armature winding; 3-secondary permanent magnet.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, however, the present invention may be embodied in other specific forms than those described herein, and it will be apparent to those skilled in the art that the present invention may be practiced without departing from the spirit and scope of the present invention.