CN102882448A - Bilateral magnetic flux switching permanent magnet linear motor driver - Google Patents

Abstract

The invention discloses a bilateral magnetic flux switching permanent linear motor driver. The driver comprises a rectifier module, a direct current side filter link unit, an inverter, a grating ruler, a differential signal modulation circuit, a CPLD (Complex Programmable Logic Device) and a controller DSP, wherein the rectifier module rectifies three-phase alternating current to direct current, and the direct current passes the direct current side link unit for voltage stabilization and rectifier, as a result, a direct current power source is provided for a power device inverter; and the controller DSP receives an analog signal and a power source voltage signal of the direct current side filter link unit, converts the analog signal and the power source voltage signal into a numerical signal with the corresponding size, also receives a signal converted by the grating ruler via the differential signal modulation circuit and another signal calculated by the CPLD, and outputs a control signal for accurately controlling the motion position and the size of pushing force of a linear motor rotor via processing the three signals. The driver has a simple, reasonable and practical structure, and can accurately control the pushing force, the speed and the positions of bilateral magnetic flux switching permanent magnet linear motor motion.

Description

A kind of bilateral magnetic flux switches the permanent-magnetism linear motor driver

Technical field

The invention belongs to the permanent-magnetism linear motor control field, specifically a kind of bilateral magnetic flux that is suitable for the precision machined occasions such as high accuracy, unconventional size, high cutting speed switches the permanent-magnetism linear motor driver.

Background technology

The Numeric Control Technology technology that to be the method that adopts digital control (Numerical Control) control automatically to mechanical movement or a certain course of work, be during modernization industry is produced one develop rapidly high-tech.It is the technology that enables of the most advanced and sophisticated technique of development and new high-tech industry, at aspects such as Cost reduction, lifting productivity ratio and raising crudies, outstanding advantage is arranged ^[1]

Digit Control Machine Tool (Computer Numerical Control Machine Tools) then is a kind of lathe of using Numeric Control Technology.Develop rapidly along with modern science and technology, Aero-Space, auto industry, national defense and military, the industries such as mould manufacturing and sophisticated technology are also in fast development, the shape of various parts or mould becomes increasingly complex, requirement to precision is also more and more higher, thin-walled parts such as space shuttle, the cylinder cover of engine in the battle wagon, microrobot, large scale integrated circuit and nano chips etc., all need precision even Ultraprecision Machining, this just has higher requirement to machining equipment, the machining accuracy of Digit Control Machine Tool, the performance index such as process velocity need to go another step.Yet traditional Digit Control Machine Tool adopts the type of drive of " turning motor+ball-screw " or with the drive system of the transmission device of the intermediate conversion such as turning motor driven gear, belt, this type of drive or system relate to many intermediate members, and belt can produce frictional force in motion process, ball-screw and gear then have the gap, these factors can be brought the shortcomings such as friction, inertia and backlass, to such an extent as to affect the machining accuracy of Digit Control Machine Tool and limit the further raising of machining accuracy.In addition, be converted to straight-line movement transforming device because have intermediate member and will rotatablely move, be certain to produce extra energy loss, affect the operating efficiency of lathe.

For making Digit Control Machine Tool in machining accuracy and working (machining) efficiency larger raising be arranged, various countries have dropped into a large amount of man power and materials and have carried out more deep research to explore new Driving technique.So, produced a kind of new feeding type of drive: linear motor direct drive.Linear electric motors can directly convert electrical energy into straight-line mechanical energy, and without any need for extra movement transforming device, and have that thrust is large, precision is high, avoid the advantages such as friction, and the suffered restriction of its speed and acceleration is also less.These advantages of linear electric motors just are so that its more and more concern that are subject to people in the Precision Machining field.

Summary of the invention

The purpose of this invention is to provide a kind of bilateral magnetic flux and switch the permanent-magnetism linear motor driver, this activation configuration advantages of simple is practical, can accurately control thrust, speed and position that bilateral magnetic flux switches the permanent-magnetism linear motor motion.

The objective of the invention is to be achieved through the following technical solutions:

A kind of bilateral magnetic flux switches the permanent-magnetism linear motor driver, it is characterized in that: this driver comprises rectification module, DC side filtering link, inverter, grating scale, differential signal modulate circuit, CPLD and controller DSP, rectification module is rectified into direct current with three-phase alternating current, through DC side filtering link voltage regulation filtering, for the power device inverter provides DC power supply; Controller DSP receives analog signal and the power supply voltage signal of DC side filtering link, and these two signals are converted to the digital signal of corresponding size, receive simultaneously grating scale through the signal of differential signal modulate circuit conversion and the signal after the CPLD computing, and by these three signals are processed, the output control signal is accurately controlled movement position and the thrust size of linear motor rotor.

Whole system of the present invention hands over orthogonal convertor assembly, sample circuit, drive circuit, control circuit and light current power supply etc. to form by the three-phase voltage source type.Convert alternating current to galvanic rectifier; Direct current is carried out the DC side filtering link of smoothing processing; Direct current is converted to the inverter IPM that three-phase alternating current drives linear electric motors; To the current detecting sampling that the linear electric motors electric current detects, carry out the controller that the linear electric motors feedback signal was accurately controlled, received to linear electric motors.Rectifier links to each other with civil power, the output of rectifier links to each other with the input of filtering link, the output of filtering link links to each other with the input of inverter IPM, the output of inverter IPM links to each other with the power input of linear electric motors, the input of current detecting part links to each other with the power input of linear electric motors, the output of current detection circuit links to each other with the ADC input of controller, and the QEP input of controller links to each other with the signal output part of linear electric motors grating scale; The signal input part of linear electric motors grating scale is connected with linear electric motors detection signal output, described controller receives analog signal and the power supply voltage signal from current detection circuit, and these two information are converted to the digital signal of corresponding size, receive simultaneously the feedback signal from the rotor position of linear electric motors grating scale, by these three data are carried out inter-process, the output control signal is accurately controlled movement position and the thrust size of linear motor rotor.

The present invention has the following advantages: adopt the negative feedback fuzzy control of three rings, can accurately control thrust, speed and the position of linear electric motors, simple and reasonable practicality.

Description of drawings

Fig. 1 is that bilateral magnetic flux switches permanent-magnetism linear motor driver schematic diagram.

Fig. 2 is that bilateral magnetic flux switches permanent-magnetism linear motor driver software schematic flow sheet.

Fig. 3 is the fuzzy controller schematic diagram.

Fig. 4 (a) three-phase bridge type converter (input termination diode rectifier), (b) linear combination of III sector space vector of voltage, (c) III sector T _PwmInterval on off sequence and contravarianter voltage waveform, (d) space voltage vector and sector chart.

Embodiment

Below in conjunction with accompanying drawing embodiment the present invention is made and to describe in further detail.

As shown in Figure 1, whole drive system hands over orthogonal convertor assembly, sample circuit, drive circuit, control circuit and light current power supply etc. to form by the three-phase voltage source type.Convert alternating current to galvanic rectifier 1; Direct current is carried out the DC side filtering link 2 of smoothing processing; Direct current is converted to the inverter IPM3 that three-phase alternating current drives linear electric motors; The current detecting that the linear electric motors electric current detects is sampled, carrying out linear electric motors accurately controls, receive the controller 8 of linear electric motors feedback signal, its rectifier 1 links to each other with civil power, the output of rectifier 2 links to each other with the input of filtering link 2, the output of filtering link 2 links to each other with the input of inverter IPM3, the output of inverter IPM3 links to each other with the power input of linear electric motors, the input of current detecting part links to each other with the power input of linear electric motors, the output of current detection circuit links to each other with the ADC input of controller 8, and the QEP input of controller 8 links to each other with the signal output part of linear electric motors grating scale; The signal input part of linear electric motors grating scale is connected with linear electric motors detection signal output.Analog signal and power supply voltage signal that controller 8 receives from current detection circuit, and these two information are converted to the digital signal of corresponding size, receive simultaneously the feedback signal from the rotor position of linear electric motors grating scale, by these three data are carried out inter-process, the output control signal is accurately controlled movement position and the thrust size of linear motor rotor 4.

As shown in Figure 2, for bilateral magnetic flux switches permanent-magnetism linear motor software flow schematic diagram, the current sampling circuit sampling obtains linear electric motors two-phase phase current i _As, i _BsThrough obtaining the current i under the two-phase rest frame after the CLARKE conversion _Ds ^s, i _Qs ^s, obtain current i under the two-phase rotating coordinate system after changing through PARK _Ds ^e, i _Qs ^eObtain A, B, Z signal behind the linear electric motors grating scale output signal process differential signal modulate circuit 6, be directly inputted to the input of the QEP circuit of dsp chip, by A, B, Z signal are counted to get linear motor rotor change in displacement, electrical degree θ _{λ r}Change and mobile speed.This drive system combines the traditional PID control strategy with fuzzy control strategy, the vector control system that switches permanent-magnetism linear motor for magnetic flux has been designed the Parameter Self-tuning Fuzzy PID Control device that parameter can be adjusted certainly, fuzzy control utilizes fuzzy control method that operating personnel's adjustment experience is deposited in the processor as knowledge, according to on-site actual situations, processor is adjusted pid parameter automatically, by shown in Figure 3, fuzzy control is by conventional PID control section, obfuscation, fuzzy reasoning and ambiguity solution four parts form, obfuscation, in fact fuzzy reasoning and ambiguity solution three parts are exactly a fuzzy controller, only deviation e and deviation variation rate ec during its input, output is Δ K _p, Δ K _i, Δ K _dFuzzy control is the fuzzy relation of finding out between three parameters of PID and deviation e and the deviation variation rate ec, in actual motion, pass through constantly to detect e and ec, come three parameters are carried out online modification according to fuzzy control principle, to the different requirements of control parameter, and make controlled device that good dynamic and static performance be arranged when satisfying different e with ec.Fuzzy controller is adjusted the pid parameter computing formula:

$\left\{\begin{array}{c}{K}_P=K_P^{\′}+{\mathrm{\ΔK}}_P\\ K_I=K_I^{\′}+{\mathrm{\ΔK}}_I\\ K_D={K_D^{\′}+\mathrm{\ΔK}}_D\end{array}\right.$

K ' in the formula _P, K ' _I, K ' _DBe the pid parameter of initial setting, Δ K _P, Δ K _I, Δ K _DBe 3 outputs of fuzzy controller, can automatically adjust according to the state of controlled device the value of 3 control parameters of PID.System adopts the negative feedback control of three rings, and the speed preset amount is arranged in the speed ring Velocity feedback quantity ω _r, through fuzzy controller variation output variable be

As the input of q shaft current ring, q shaft current feedback quantity

Changing output variable through fuzzy controller is

As the input of d shaft current ring, d shaft current feedback quantity

Changing output variable through fuzzy controller is And θ _{λ r}As three input variables of contrary PARK conversion module, output variable

With

As the input of space vector control switch signaling module, vector control switching signal module is exported 6 road pwm switching signals, control IPM power device switch.Adopt i _d=0 control mode, i.e. specified rate

Be 0.

The realization of SVPWM.In the rotary synchronous motor, thereby the purpose of vector control is to close the controlling torque of conglobate rotating magnetic field stable output.In like manner, in linear electric motors, control system requires the travelling-magnetic-field of synthesizing stable, thus the thrust of motor stable output, to reach good control effect.Copy the formation of the loop circle flux track of electric rotating machine, the problem in synthetic circular magnetic field is changed into the problem of blended space voltage vector movement locus.By switching the break-make pattern control energy output of different switching devices, synthetic travelling-wave-type magnetic linkage track reaches the purpose of controlling motor.

Voltage source inverter is comprised of six pipe IGBT, shown in Fig. 4 (a).For preventing managing up and down straight-through damage system, the inverter upper and lower bridge arm need be complementary state, therefore is reduced to the operating state that represents the inverter three-phase bridge with every on off operating mode of going up mutually the brachium pontis power device.The state that the definition power tube is opened is 1, and off state is 0, and then the three-phase brachium pontis can obtain 2 ³=8 kinds of operating states according to VT1 → VT2 → VT3 → VT4 → VT5 → VT6 successively conducting, namely obtain effective operating state U ₀[100], U ₆₀[110], U ₁₂₀[010], U ₁₈₀[011], U ₂₄₀[001], U ₃₀₀[101] and the non-productive work state 0 that does not have Voltage-output ₀[000] and 0 ₁[111].

In conjunction with Fig. 4 (b), synthetic reference voltage vector U _RefIn which sector, then by two adjacent voltage vector U _xAnd U _X+60Respectively by T action time _xAnd T _X+60Length synthesize.Take the III sector as example, U _RefBy U ₀And U ₆₀Two states act on respectively T ₀And T ₆₀The time output voltage, with 0 ₀With 0 ₁Thereby the time that two states are filled up shutoff is finished PWM T wave period jointly _PwnAccording to the constant principle of power, obtain active balance and be:

U _refT _pwm＝U ₀T ₀+U ₆₀T ₆₀

According to Fig. 4 (b) and (d), obtain

In the three-phase star connection, electric current is got back to bus after by an independent winding and two winding parallels during each switch, so the amplitude of each voltage vector is

Bring in the following formula and obtain:

$\left\{\begin{array}{c}{\mathrm{<figure-callout\; id="0"\; label="T"\; filenames="120823122740.png,120823122840.png"\; state="\{\{state\}\}">T</figure-callout>}}_0=\frac{T_{\mathrm{pwm}}}{U_{\mathrm{dc}}}(\frac{3}{2}{U}_{\mathrm{\&alpha;ref}}-\frac{\sqrt{3}}{2}{U}_{\mathrm{\&beta;ref}})\\ {\mathrm{<figure-callout\; id="60"\; label="T"\; filenames="120823122814.png"\; state="\{\{state\}\}">T</figure-callout>}}_{60}=\sqrt{3}{U}_{\mathrm{\&beta;ref}}\frac{T_{\mathrm{pwm}}}{U_{\mathrm{dc}}}\end{array}\right.$

Can obtain U as stated above _RefWhen all six sectors, the temporal expression of adjacent space voltage vector effect is established time variable t _x, t _yAnd t _z, then have

$\left[\begin{array}{c}{t}_x\\ t_y\\ t_z\end{array}\right]=\frac{T_{\mathrm{<figure-callout\; id="0"\; label="pwm\; U\; dc"\; filenames="120823122740.png,120823122840.png"\; state="\{\{state\}\}">pwm</figure-callout>}}}{U_{\mathrm{dc}}}\left[\begin{array}{cc}0& \sqrt{3}\\ \frac{3}{2}& \frac{\sqrt{3}}{2}\\ -\frac{3}{2}& \frac{\sqrt{3}}{2}\end{array}\right]\left[\begin{array}{c}{U}_{\mathrm{\&alpha;ref}}\\ U_{\mathrm{\&beta;ref}}\end{array}\right]$

According to definition, T then ₀=-t _z, T ₆₀=t _xThe action time of the adjacent voltage vector of each sector, it is as shown in the table.

The action time of each adjacent voltage vector in sector of table 1

Above-mentioned assignment method need guarantee T _x+ T _X+60≤ T _PwmIf, T _x+ T _X+60＞T _Pwm, then revise according to following:

$\left\{\begin{array}{c}{T}_x=\frac{T_{\mathrm{pwm}}}{T_x+T_{x+60}}{T}_x\\ T_{x+60}=\frac{T_{\mathrm{pwm}}}{T_x+T_{x+60}}{T}_{x+60}\end{array}\right.$

Thereby the PWM ripple that guarantees to calculate is within the periodic regime of definition.

System SVPWM generating mode adopts typical seven segmentation schemes, in each PWM period of wave In, for so that voltage waveform is symmetrical, every kind of state is divided into two, Zero voltage vector is inserted respectively in beginning, centre and end, when inverter need satisfy each diverter switch state, only switch a switching device, the switching loss that causes when as far as possible reducing switch change.

Obtained voltage vector action time by above-mentioned shifting onto, then can further obtain the service time of U, V, W three phase power device and open order.If

$\left\{\begin{array}{c}{t}_{1\mathrm{on}}=\frac{T_{\mathrm{pwm}}-T_x-T_{x+60}}{4}\\ t_{2\mathrm{on}}=t_{1\mathrm{on}}+\frac{T_x}{2}\\ t_{3\mathrm{on}}=t_{2\mathrm{on}}+\frac{T_{x+60}}{2}\end{array}\right.$

According to the difference of sector, the three phase power break-over of device time gets final product its assignment, and is as shown in the table

Each sector switching device ON time of table 2

The definition of eight voltage vectors shown in Fig. 4 (d) is divided into six sectors with the space, and adjacent voltage vector changes and only to move a power device.The PWM modulation waveform that has represented this sector in the sector by above-mentioned mode.Pass through U _a, U _bAnd U _cPolarity of voltage can judge the current reference voltage vector U that synthesizes _RefThe sector number at place.Reference voltage vector U _RefComponent is respectively U in α β coordinate system _{α ref}And U _{β ref}, then the ABC coordinate system is changed in inversion has:

$\left[\begin{array}{c}{U}_a\\ U_b\\ U_c\end{array}\right]=\left[\begin{array}{cc}0& 1\\ \frac{\sqrt{3}}{2}& -\frac{1}{2}\\ -\frac{\sqrt{3}}{2}& -\frac{1}{2}\end{array}\right]\left[\begin{array}{c}{U}_{\mathrm{\&alpha;ref}}\\ U_{\mathrm{\&beta;ref}}\end{array}\right]$

Order:

$\left\{\begin{array}{cc}x=1& U_a>0\\ x=0& U_a\&le;0\end{array}\right.$

$\left\{\begin{array}{cc}y=1& U_b>0\\ y=0& U_b\&le;0\end{array}\right.$

$\left\{\begin{array}{cc}z=1& U_c>0\\ z=0& U_c\&le;0\end{array}\right.$

Then can obtain sector number Sector=x+2y+4z.So far, by narration and the calculating of preamble, can obtain order and action time that space voltage vector synthesizes, form complete vector control process.

The power device of this driver uses Mitsubishi the 5th generation IPM product type PM100CLA120.Its inner integrated six pipe IGBT devices, logic, control, detection and drive circuit, and with protective circuits such as overcurrent, overvoltage and excess temperatures, can send rapidly fault-signal and can be detected processing.Its cost performance is high, easy to use, it is desirable integrated device, complexity and the development time of system have not only been reduced, also greatly strengthened the reliability of system, the developing direction that has adapted to current power device module, Composite and power integrated circuit has obtained using more and more widely in field of power electronics.

This driver control system has adopted Intelligent Power Module as main power conversion device; because several functions such as himself integrated line under-voltage overvoltage protection, short circuit overcurrent protection and overheat protectors, therefore greatly improved to a certain extent the unfailing performance of drive system.But the integrated power device of inside modules is separate; in the protection action, do not have simultaneity; namely when one of them switch protection action; other switches might not respond and protect simultaneously; and do not have retentivity, the phenomenon that might shake after the output of error protection signal.So only rely on the defencive function of himself can not satisfy the requirement of whole system, probably cause the IPM permanent damages, then cause the damage of whole system when more serious.Therefore, reasonably designing and add protective circuit, is the necessary condition that guarantees system safety work.

This driver control system protection adopts the mode of software and hardware combining.Since the processing mode of software responses less than Hardware Response Delay rapidly, in order to protect intelligent power module and to share the disposal ability of dsp processor, system the signal of DSP output with drive between added the piece of CPLD chip and realized protecting logic.Select as required the EPS7032S type of altera corp, it has 44 pins that 36 macrocells are provided, and adopts EEPROM technique, but therefore persistence can independently use after the download, and response time 5ns satisfies simple Logic Circuit Design fully.Input signal is 6 road pwm signals of TMS320F2812 output, the guard signal of IPM self feedback output and the overcurrent conditioned signal of armature supply, is output as the constant pwm signal of 6 road phase-amplitudes.The output-current rating of its each pin can reach 25mA, satisfies the driving power of follow-up optocoupler fully.

In the CPLD chip, the logical operation of three pairs of brachium pontis is identical.Five road guard signals by with gate control PWM ripple.Every pair with the door output access basic rest-set flip-flop, obtain Q and

Just in time meet the requirement of upper and lower bridge arm signal complementation, and have anti-shake function, the new state equation of rest-set flip-flop

$Q^{n+1}=\stackrel{\&OverBar;}{S\stackrel{\&OverBar;}{{\mathrm{RQ}}^n}}=\stackrel{\&OverBar;}{S}+{\mathrm{RQ}}^n$

Identical with the output of DSP for guaranteeing output PWM wave phase, needing through inverter is not gate, so that signal is identical with the PWM wave phase amplitude of input.

During normal operation, each road guard signal is in high level state always, and output signal is normal DSP output signal.When the protection action of arbitrary road, when signal was low level by high level is drop-down, CPLD inside was blocked the output of the pwm control signal of IPM immediately, namely stopped power device and continued to open or turn-off, and stoped flowing of energy, thereby had protected IPM and whole system.

Claims (1)

1. a bilateral magnetic flux switches the permanent-magnetism linear motor driver, it is characterized in that: this driver comprises rectification module (1), DC side filtering link (2), inverter (3), grating scale (5), differential signal modulate circuit (6), CPLD(7) and controller DSP (8), rectification module (1) is rectified into direct current with three-phase alternating current, through DC side filtering link (2) voltage regulation filtering, for power device inverter (3) provides DC power supply; Controller DSP (8) receives analog signal and the power supply voltage signal of DC side filtering link (2), and these two signals are converted to the digital signal of corresponding size, receive simultaneously signal and CPLD(7 that grating scale (5) transforms through differential signal modulate circuit (6)) signal after the computing, and by these three signals are processed, the output control signal is accurately controlled movement position and the thrust size of linear motor rotor.

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