CN103780187A - Permanent magnet synchronous motor high-dynamic response current method and system - Google Patents

Abstract

This invention discloses a method and a system for permanent magnet synchronous motor high-dynamic response current control. The method comprises: preferably adopting an improved dutyfactor updating strategy, namely updating and calculating a new dutyfactor at the peak value of a calculator in first half control cycle and combining the fact that adopting various current inner ring adjustment strategies according to the characteristics of a q axis and a d axis, realizing feedback values following upper command by half a control cycle ahead of time; adopting predictive control in a torque current ring to connect the pure integration to eliminate the influence caused by inaccurate parameters and adopting PI control in exciting current to grantee the stability and easy reliability of the system. As a result, the invention can further shorten control delay and sensitivity of system parameters.

Description

Permagnetic synchronous motor high dynamic response current control method and system

Technical field

The present invention relates to a kind of permanent magnet synchronous electric machine technology, particularly permagnetic synchronous motor high dynamic response current control method and system.

Background technology

Due to high efficiency, high power density, the advantage such as non-carbonate, permagnetic synchronous motor is applied widely in the servo occasion of high-performance, the applications such as numerical control machining center, industrial robot driving require electromagnetic torque fast to respond to guarantee the high dynamic performance of whole system, therefore, the electric current loop dynamic characteristic directly related with electromagnetic torque become one of most important index of measurement servo performance.

Permagnetic synchronous motor is a multivariable, close coupling, nonlinear system, for the ease of research, often does following hypothesis: three-phase stator winding full symmetric; Ignore iron core saturated, disregard eddy current and magnetic hysteresis loss; On rotor, there is no damping winding, the every phase magnetic potential of air gap of rotor is Sine distribution in space, and under synchronous rotating frame, PMSM stator voltage equation is:

u _d＝Ri _d+L _ddi _d/dt-ωL _qi _q (1)

u _q＝Ri _q+L _qdi _q/dt+ωL _di _d+ωψ _f (2)

In formula, ud, uq are stator d, q shaft voltage, and id, iq are stator currents, and R is stator resistance, and Ld, Lq are stator inductances, and ψ f is permanent magnet flux linkage, and ω is rotor electric angle speed.

As shown in Figure 1, be the block diagram of existing permanent magnet synchronous motor vector control system, system is twin nuclei, is respectively speed outer shroud and current inner loop, to surface-mount type permagnetic synchronous motor, generally adopts the control strategy of id=0; In order to make system have dynamic property, require electric current loop to there is dynamic responding speed fast.

Generally the control method of permagnetic synchronous motor electric current loop is mainly contained to PID (or PI) adjuster, stagnant ring control, PREDICTIVE CONTROL etc., PID controller structure is simple, reliable and stable, in servo system, be most widely used at present, in PID adjuster principle, it is a kind of linear regulator, improve PID controller gain and can improve dynamic performance, but excessive gain can affect the stability of a system, bring hyperharmonic noise, in practical application, be difficult to take into account rapidity and the stability of response, be difficult to reach needed electric current loop dynamic property at the servo middle employing PID adjuster of high-performance.

Stagnant ring control rapidity is good, but this Bang-Bang control mode exists ripple large, the defects such as switching frequency is unfixing, be not suitable for high performance control occasion, for permagnetic synchronous motor Digitizing And Control Unit, the angle that has scholar to control time delay from reducing is carried " two (the double sampling anddouble update of renewal of two samplings, DSDU) " strategy, double sampling electric current in one-period, upgrade PWM duty ratio twice, improve electric current dynamic responding speed, its cost is that amount of calculation doubles, control chip processing speed is had relatively high expectations, there is scholar to adopt the mode of feedforward to realize d, q axle is full decoupled to improve the dynamic control performance of electric current.

PREDICTIVE CONTROL can realize the quick tracking to command signal non-overshoot, but it relies on the mathematical models of controlled device, this is proposed to various improving one's methods, as obtained the mathematical models of controlled device by the method for on-line parameter identification, eliminate the inaccurate impact on PREDICTIVE CONTROL effect of parameter, there is scholar based on dead beat PREDICTIVE CONTROL principle, a kind of Robust Current control algolithm is proposed, strengthen the stability of system in the time that model parameter is inaccurate, the current deviation constraints that has scholar to adopt to loosen and level and smooth output voltage Forecasting Methodology, system robustness while having strengthened motor inductance parameters mismatch, but reduce to a certain extent the dynamic property of PREDICTIVE CONTROL, for Digitizing And Control Unit, based on dead beat control program, adopt the single renewal of single sampling current loop control time delay can be foreshortened to 2 control cycles.

Existing current control method, be illustrated in figure 1 permanent magnet synchronous motor vector control system block diagram: ignore in the situation of position ring, permagnetic synchronous motor vector control structure generally includes speed outer shroud and current inner loop, speed detector (such as code-disc) obtains motor speed, send after itself and speed command into speed ring pi regulator, after overregulating, the instruction of speed ring output q shaft current is the iqr in Fig. 1; D axle aspect, owing to conventionally adopting id=0 control mode, therefore d shaft current instruction idr is set to zero conventionally.Two current-orders respectively with current feedback value iq, the id of corresponding axis relatively and be input to corresponding electric current loop adjuster, these two adjusters are exported respectively again needs the voltage uq, the ud that apply on corresponding axis.Such uq, ud voltage calculate three-phase duty ratio through steps such as coordinate inverse transformations, finally become suitable three-phase voltage waveform to be applied on motor, realize the control to motor; The adjuster (one of speed ring, two of electric current loops) adopting in the prior art is not necessarily realized with PI, they can be realized by other control method, in Fig. 1, why be drawn as pi regulator, because pi regulator simply, easily realize, thereby is widely used and is familiar with by majority.

Existing basic PMSM electric current loop forecast Control Algorithm, as shown in Figure 2, shown that PWM when electric current loop is digital control upgrades sequential, DSP enters in master and has no progeny, detection obtains electric current currency (id (k), iq (k)) and angular velocity omega.Speed of service ring obtains given value of current value (idr, iqr), and further running current ring obtains the voltage vector that need to apply; Be subject to hardware constraints, during will waiting until (k+1) individual control cycle ((k+1) Ts) conventionally, the voltage vector (ud (k+1), uq (k+1)) that k control cycle (kTs) calculates applies again.By the time when this end cycle, electric current was just likely followed the tracks of the current command signal (idr, iqr) in upper this cycle.

In digital control approach principle, just exist and control time delay: because in the sampling period (control cycle in other words), by sampling (such as herein to current i d, the sampling of iq) to calculating needed controlled quentity controlled variable (such as voltage ud herein, uq) be to need (how soon having regardless of DSP arithmetic speed of time certainly, always need the time), this is just unavoidable in digital control approach principle, in addition, for this special occasions of Electric Machine Control herein, interpretation process above is mentioned " uq, ud voltage calculates three-phase duty ratio through steps such as coordinate inverse transformations, finally becoming suitable three-phase voltage waveform is applied on motor, realize the control to motor." hardware constraints of this voltage applying mode and DSP determined applying and must carrying out in the control cycle of a complete length of controlled quentity controlled variable (voltage) herein; Take Fig. 2 as example, such as DSP enters the voltage (ud (k) that starts to apply certain value after current period (kTs) (i.e. " this cycle " mentioned above), uq (k)), this applies process must continue a complete sampling period or control cycle, can not arbitrarily change midway; If want to apply new magnitude of voltage, such as (ud (k+1), uq (k+1)), must wait until that next cycle starts just can carry out afterwards, this controlled quentity controlled variable (being voltage (ud (k+1), uq (k+1))) likely makes value of feedback in the time of next end cycle, follow the tracks of the command value in this cycle; Therefore " the tracking time delay of current-order is two control cycles the soonest ", comprises unalterable cycle and next cycle of playing major control effect.

Summary of the invention

The object of the invention is provides one can shorten Current Control delay time in order to solve above-mentioned the deficiencies in the prior art, reduces permagnetic synchronous motor high dynamic response current control method and the system of system parameters sensitiveness simultaneously.

To achieve these goals, the permagnetic synchronous motor high dynamic response current control method that the present invention is designed, comprise the speed outer shroud of q axle and d axle is regulated and current inner loop adjusting, aspect q axle, Negotiation speed detects and obtains motor speed, regulate after overregulating speed outer shroud output q shaft current instruction iqr by sending into speed outer shroud after itself and speed command, aspect d axle, owing to conventionally adopting id=0 control mode, therefore d shaft current instruction idr is set to zero conventionally, two current-order iqr and idr respectively with the current feedback value iq of corresponding axis, id relatively and be input to corresponding current inner loop and regulate to export respectively after overregulating and on corresponding axis, need the voltage uq that applies, ud, such uq, ud voltage calculates three-phase duty ratio through steps such as coordinate inverse transformations, finally becoming suitable three-phase voltage waveform is applied on motor, realize the control to motor, the update strategy of described duty ratio adopts in front half control cycle and upgrades at counter peak value place and calculate the duty ratio making new advances, and combination is to q, d axle is taked to be applicable to the different current inner loop of features and is regulated control strategy, realize value of feedback and follow the tracks of upper command value half control cycle in advance.

Control time delay in order further to reduce, improve dynamic response, the current inner loop of described q axle regulates control strategy to adopt fundamental forecasting control, and id to electromagnetic torque without contribution, require not high to its dynamic property, the current inner loop of described d axle regulates control strategy to adopt PI to regulate, with avoid PREDICTIVE CONTROL because parameter arranges the inaccurate problems such as steady-state error that cause.

During due to PREDICTIVE CONTROL, the use of plant model causes PREDICTIVE CONTROL more responsive to system parameters, if it is inaccurate that parameter has a little, the voltage calculating is not so just that we expect and have wished the magnitude of voltage that obtains, therefore pure integral element in parallel in fundamental forecasting control method.

By shifting to an earlier date half control cycle, carry out combination with fundamental forecasting control, voltage vector (the ud (k+1) that k control cycle (kTs) calculated, uq (k+1)) apply again during can waiting until (k+0.5) individual control cycle ((k+0.5) Ts) ", therefore the computing formula of described q shaft voltage is:

$\frac{(U_q\left(k\right)+2U_q(k+1))}{3}=R\frac{(i_q\left(k\right)+i_{q}r)}{2}+$

$L_q\frac{(i_{q}r-i_q\left(k\right))}{1.5T_s}+\mathrm{\ω}{L}_d\frac{(i_d\left(k\right)+i_{d}r)}{2}+\mathrm{\ω}{\mathrm{\ψ}}_f---\left(5\right)$

Wherein, (id (k), iq (k)) is the sampled value of current period, and (idr, iqr) is that desired value, R are that resistance, Lq are inductance, the ψ of q axle _ffor the permanent magnet flux linkage of described permagnetic synchronous motor.

A kind of system of permagnetic synchronous motor high dynamic response Current Control, comprise the speed detector, speed PI adjusting device, current PI adjusting device, fundamental forecasting control device, inverter and the coordinate transformation device that couple together by signal, between fundamental forecasting control device output and the input of inverter, add the output signal that has pure integral control device; Described speed detector obtains the tach signal of permagnetic synchronous motor and speed command signal given in advance compares after stack, is connected with the input of speed PI adjusting device; Described coordinate transformation device is connected the current feedback value iq, the id that obtain q, d axle with permagnetic synchronous motor; The output of described speed PI adjusting device compares after stack with corresponding current feedback value iq, is connected with the input of pure integral control device; The output of described speed PI adjusting device is also connected with the input of fundamental forecasting control device; The input of described fundamental forecasting control device is also connected with corresponding current feedback value iq; After the output end signal of the output of described fundamental forecasting control device and pure integral control device superposes; Obtain the voltage uq of q axle and be connected with the input of inverter; The d shaft current instruction idr with it current feedback value id of correspondence compares after stack, is connected with the input of current PI adjusting device, obtains the voltage ud of d axle; And be connected with the input of inverter; The output of described inverter connects permagnetic synchronous motor;

Permagnetic synchronous motor high dynamic response current control method and system that the present invention obtains, first, a kind of improved duty ratio update strategy is proposed, under the prerequisite that unitary sampling single PWM comparison value upgrades within the electronic power switch cycle, make Current Control time delay further shorten to 1.5 control cycles; Secondly, adopt PREDICTIVE CONTROL link integrator in parallel to eliminate the impact bringing because parameter is inaccurate at torque current ring, simultaneously for keeping system stability and easy implementation, adopt PI to control at exciting current ring, realize the present invention and can further shorten control time delay, reduced system parameters sensitiveness simultaneously.

Accompanying drawing explanation

Fig. 1 is permanent magnet synchronous motor vector control system block diagram in prior art;

Fig. 2 is that in prior art, PWM duty ratio is upgraded sequential chart;

Fig. 3 is the system block diagram for high dynamic response Current Control of the present invention;

Fig. 4 upgrades sequential chart for PWM duty ratio of the present invention;

Fig. 5 is that R increases 50% two kind of control method simulation result figure;

Fig. 6 is that ψ f increases 50% two kind of control method simulation result figure;

Fig. 7 is the simulation result figure of two kinds of control method transient processes;

Fig. 8 is that resistance increases 50% two kind of control method experimental result picture;

Fig. 9 is the transient-wave figure of pi regulator control strategy;

Figure 10 is the transient-wave figure of fundamental forecasting control method;

Figure 11 is the transient-wave figure of the control method that proposes of the present invention.

In figure: speed detector 1, speed PI adjusting device 2, current PI adjusting device 3, fundamental forecasting control device 4, inverter 5, coordinate transformation device 6, pure integral control device 7.

Embodiment

Below in conjunction with drawings and Examples, the present invention is further described.

Embodiment:

As shown in Figure 3, Figure 4, permagnetic synchronous motor high dynamic response current control method provided by the invention, comprise speed outer shroud is regulated and current inner loop adjusting, aspect q axle, Negotiation speed detects and obtains motor speed, regulate after overregulating speed outer shroud output q shaft current instruction iqr by sending into speed outer shroud after itself and speed command, aspect d axle, owing to conventionally adopting id=0 control mode, therefore d shaft current instruction idr is set to zero conventionally, two current-order iqr, idr respectively with the current feedback value iq of corresponding axis, id relatively and be input to corresponding current inner loop and regulate to export respectively after overregulating and on corresponding axis, need the voltage uq that applies, ud, such uq, ud voltage calculates three-phase duty ratio through steps such as coordinate inverse transformations, finally becoming suitable three-phase voltage waveform is applied on motor, realize the control to motor, the update strategy of described duty ratio adopts in front half control cycle and upgrades at counter peak value place and calculate the duty ratio making new advances, and combination is to q, d axle is taked to be applicable to the different current inner loop of features and is regulated control strategy, realize value of feedback and follow the tracks of upper command value half control cycle in advance, the current inner loop of described q axle regulates control strategy to adopt fundamental forecasting control, and the current inner loop of described d axle regulates control strategy to adopt PI to regulate, the basic principle of fundamental forecasting control is if with the current period sampled value (id (k) of electric current, iq (k)) and desired value (idr, iqr) be two points at the whole story, acquiescence rotating speed remains unchanged within the 2Ts time period, formula (1) and formula (2) are carried out to discretization, obtain formula (3) and formula (4), owing to entering after k control cycle, (id (k), iq (k)), (idr, iqr), (ud (k), uq (k)), ω etc. are known, therefore can obtain (ud (k+1), uq (k+1)), due to (ud (k+1), uq (k+1)) solution procedure to meet permagnetic synchronous motor Mathematical Modeling be formula (1) and formula (2), therefore this magnitude of voltage can be motor d in theory, q shaft current is from current state (id (k), iq (k)) adjust to expectation state (idr, iqr), time delay is two control cycles.

$\frac{(U_d\left(k\right)+U_d(k+1))}{2}=R\frac{(i_d\left(k\right)+i_{d}r)}{2}+$

$L_d\frac{(i_{d}r-i_d\left(k\right))}{2T_s}-\mathrm{\ω}{L}_q\frac{(i_q\left(k\right)+i_{q}r)}{2}---\left(3\right)$

$\frac{(U_q\left(k\right)+U_q(k+1))}{2}=R\frac{(i_q\left(k\right)+i_{q}r)}{2}+$

$L_q\frac{(i_{q}r-i_q\left(k\right))}{{2T}_s}+\mathrm{\ω}{L}_d\frac{(i_d\left(k\right)+i_{d}r)}{2}+{\mathrm{\ω\ψ}}_f---\left(4\right)$

By shifting to an earlier date half control cycle, the new duty ratio obtaining in front half control cycle is upgraded at counter peak value place, no longer wait until that next cycle upgrades after starting again, and carry out combination with fundamental forecasting control, such way does not increase any software and hardware expense, be only required in the dutyfactor value that front half computation of Period makes new advances, like this response of current-order is shifted to an earlier date to control cycle half, do not improving under the prerequisite of sample rate and PWM renewal frequency, make total control time delay foreshorten to 1.5 control cycles, obtain discrete voltage equation suc as formula shown in (5) according to above-mentioned formula (4),

$\frac{(U_q\left(k\right)+2{U_q}_{}(k+1))}{3}=R\frac{(i_q\left(k\right)+i_{q}r)}{2}+$ $L_q\frac{(i_{q}r-i_q\left(k\right))}{1.5T_s}+\mathrm{\ω}{L}_d\frac{(i_d\left(k\right)+i_{d}r)}{2}+{\mathrm{\ω\ψ}}_f---\left(5\right)$

Wherein, (id (k), iq (k)) is the sampled value of current period, and (idr, iqr) is that desired value, R are that resistance, Lq are inductance, the ψ of q axle _ffor the permanent magnet flux linkage of described permagnetic synchronous motor.

In practical application, the permagnetic synchronous motor mathematical model parameter that fundamental forecasting control uses is not necessarily accurate, will make fundamental forecasting control effect not reach perfect condition; Therefore be necessary to analyze the sensitivity to parameter of basic PREDICTIVE CONTROL, because d shaft current is used pi regulator control, there is not sensitivity to parameter problem, for this reason only for the amperometry of q shaft torque, suppose that resistance settings exist error delta R, the voltage U q (k+1) calculating by formula (4) should be as shown in formula (6), and actual electric current still press the rule variation of formula (4), as shown in formula (7).

$\frac{(U_q\left(k\right)+{\hat{U}}_q(k+1))}{2}=(R+\mathrm{\ΔR})\frac{(i_q\left(k\right)+i_{q}r)}{2}$

$+L_q\frac{(i_{q}r-i_q\left(k\right))}{2T_s}+\mathrm{\ω}{L}_d\frac{(i_d\left(k\right)+i_{d}r)}{2}+{\mathrm{\ω\ψ}}_f---\left(6\right)$

$\frac{(U_q\left(k\right)+{\hat{U}}_q(k+1))}{2}=R\frac{(i_q\left(k\right)+{\hat{i}}_{q}r)}{2}$

$+L_q\frac{({\hat{i}}_{q}r-i_q\left(k\right))}{2T_s}+{\mathrm{\ωL}}_d\frac{(i_d\left(k\right)+i_{d}r)}{2}+{\mathrm{\ω\ψ}}_f---\left(7\right)$

Formula (7) subtracts formula (6), can derive following relation

$\frac{{\hat{i}}_{q}r-i_{q}r}{i_{q}r}=\frac{\frac{\mathrm{\ΔR}}{R}}{\frac{1}{2}+\frac{L_q}{2T_{s}R}}---\left(8\right)$

In like manner, can derive magnetic linkage ψ f and inductance L (think Ld=Lq=L) and exist the error of q shaft current in error delta ψ f and Δ L situation, respectively if formula (9) is with as shown in (10)

${\hat{i}}_{q}r-i_{q}r=\frac{\mathrm{\&omega;\&Delta;}{\mathrm{\&psi;}}_{\mathrm{<figure-callout\; id="2"\; label="f\; R"\; filenames="DEST\_PATH\_HSB00001038457500012.png,DEST\_PATH\_HSB00001038457500021.png"\; state="\{\{state\}\}">f</figure-callout>}}}{\frac{R}{}}---\left(9\right)$ ${\hat{i}}_{q}r-i_{q}r=\frac{\frac{\mathrm{\&Delta;L}}{L}(i_{q}r-i_q\left(k\right))}{1+\frac{{\mathrm{RT}}_s}{L}}---\left(10\right)$

From formula (8) to formula (10), the deviation of resistance will cause the steady-state error of q shaft current, and the relative error of the two is linear; Therefore impact and the motor operating state of magnetic linkage deviation on electric current has direct relation, show in formula (9) and comprise motor speed, rotating speed is higher, the impact that magnetic linkage deviation is brought is also larger, the impact being brought by the known inductance deviation of formula (10) is mainly reflected in transient process, and excessive inductance will cause current overshoot.

Therefore in order to eliminate because of the inaccurate error that may occur of parameter, pure integral element in parallel in fundamental forecasting control, utilize integration item to guarantee the accurate tracking of q shaft current to command signal to the accumulative action of error, in like manner, the forecast Control Algorithm of improving PWM update strategy to using is that formula (5) is analyzed, result is as formula (11)---as shown in formula (13), can find out, the shortening of controlling time delay can reduce the sensitivity to parameter to resistance, magnetic linkage, but the impact of inductance error is substantially constant.

$\frac{{\hat{i}}_{q}r-i_{q}r}{i_{q}r}=\frac{\frac{\mathrm{\&Delta;R}}{R}}{\frac{1}{2}+\frac{L_q}{1.5T_{s}R}}---\left(11\right)$

${\hat{i}}_{q}r-i_{q}r=\frac{\mathrm{\&omega;\&Delta;}{\mathrm{\&psi;}}_{\mathrm{<figure-callout\; id="2"\; label="f\; R"\; filenames="DEST\_PATH\_HSB00001038457500012.png,DEST\_PATH\_HSB00001038457500021.png"\; state="\{\{state\}\}">f</figure-callout>}}}{\frac{R}{}}---\left(12\right)$

${\hat{i}}_{q}r-i_{q}r=\frac{\frac{\mathrm{\&Delta;L}}{L}(i_{q}r-i_q\left(k\right))}{1+\frac{1.5R{T}_s}{2L}}---\left(13\right)$

A kind of system of permagnetic synchronous motor high dynamic response Current Control, comprise the speed detector 1, speed PI adjusting device 2, current PI adjusting device 3, fundamental forecasting control device 4, inverter 5 and the coordinate transformation device 6 that couple together by signal, between fundamental forecasting control device 4 outputs and the input of inverter 5, add the output signal that has pure integral control device 7; Described speed detector 1 obtains the tach signal of permagnetic synchronous motor and speed command signal given in advance compares after stack, is connected with the input of speed PI adjusting device 2; Described coordinate transformation device 6 is connected the current feedback value iq, the id that obtain q, d axle with permagnetic synchronous motor; The output of described speed PI adjusting device 2 compares after stack with corresponding current feedback value iq, is connected with the input of pure integral control device 7; The output of described speed PI adjusting device 2 is also connected with the input of fundamental forecasting control device 4; The input of described fundamental forecasting control device 4 is also connected with corresponding current feedback value iq; After the output end signal of the output of described fundamental forecasting control device 4 and pure integral control device 7 superposes; Obtain the voltage uq of q axle and be connected with the input of inverter 5; The d shaft current instruction idr with it current feedback value id of correspondence compares after stack, is connected with the input of current PI adjusting device 3, obtains the voltage ud of d axle; And be connected with the input of inverter 5; The output of described inverter 5 connects permagnetic synchronous motor; The signal that the motor speed of the permagnetic synchronous motor that described speed PI adjusting device 2 detects speed detector 1 and speed command signal given in advance compare after stack carries out PI adjusting, obtains q shaft current instruction iqr; The d shaft current instruction idr signal that the current feedback value id of correspondence compares after stack is with it carried out Current Control by described current PI adjusting device 3, obtains the voltage ud of d axle; Described fundamental forecasting control device 4 by q shaft current instruction iqr with it corresponding current feedback value i follow the tracks of fast; Described pure integral control device 7 carries out the q shaft current instruction iqr signal that corresponding current feedback value iq compares stack with it after integration, and superposes with the signal that fundamental forecasting control device 4 is followed the tracks of, and obtains the voltage uq of q axle; Described inverter 5 is applied on motor becoming suitable three-phase voltage waveform after voltage signal ud, the uq conversion of d, q axle, realizes the control to motor.

Carry out the simulation experiment result according to control method of the present invention: in Simulink environment, build permagnetic synchronous motor Vector Control Model and carry out emulation, the parameter of electric machine is as shown in table 1, control cycle 125 μ s, current command signal is arranged to as shown in Figure 5 with the rotating of simulation real electrical machinery, be specially boost phase time 0.375s, amplitude is 7A, is smoothly down to 1.75A through 0.25s, start reverse acceleration through the constant-speed operation stage of 0.25s again, and so forth; Load torque is 2Nm, and direction is contrary with rotary speed direction; Moment of inertia summation is 0.08408kg.m2.

Table 1 parameter of electric machine

Tab.l Parameters of the PMSM

The d shaft current that q shaft current PREDICTIVE CONTROL uses is its sampled value, and the concrete control method of therefore controlling effect and d shaft current is irrelevant; Show as shown in Figure 5 in the situation of resistance R increase 50%, two kinds of forecast Control Algorithm control effect to q shaft current, comparison diagram 4 (a), (b) are known, and in the improvement PREDICTIVE CONTROL that the present invention obtains, the inaccurate impact bringing of parameter has been eliminated in the effect of pure integral element in parallel.

As shown in Figure 6: displaying be that magnetic linkage ψ f increases in 50% situation, two kinds of forecast Control Algorithm departure to q shaft current, the improved forecast Control Algorithm that same known the present invention obtains has been eliminated the impact that magnetic linkage error is brought, as shown in Figure 7: be (a) and (b) transient-waves of two kinds of forecast Control Algorithm to q shaft current, current-order at a time steps to 1.5A from-1.5A.Tu Zhong abscissa unit is the i.e. 125 μ s of system control cycle, can find out, the improved forecast Control Algorithm that the present invention obtains has shifted to an earlier date control cycle half to the response of command signal, and time delay is 1.5 control cycles, coincide with the result of theory analysis; With respect to the time delay of 2 control cycles of fundamental forecasting control method, the response of current command signal is obviously accelerated.

Control method according to the present invention experimental results show that: in experiment, use a surface-mount type permagnetic synchronous motor, parameter is consistent with table 1, use the DSP experiment porch of TMS320LF28335, dominant frequency 8kHz is control cycle 125 μ s, set experiment condition consistent with emulation, motor drags the constant torque load of dynamometer machine simulation, and then experimental data is sent to computer by the mode of communication by DSP.

As shown in Figure 8, shown that resistance increases in 50% situation, two kinds of forecast Control Algorithm control effect to q shaft current, can see that the present invention has eliminated the impact that parameter error brings.

Obtain having shown pi regulator, fundamental forecasting control method and having improved the transient state control waveform of forecast Control Algorithm to q shaft current as Fig. 9, Figure 10, Figure 11 are followed successively by according to experimental result, current-order in the 0.0375s moment from-1.5A step to 1.5A.In figure, each point represents the i.e. 125 μ s of a control cycle, therefore can see, common overshoot and vibration have appearred in pi regulator.And fundamental forecasting control method will could respond to command signal after next cycle starts, time delay is two cycles, and our forecast Control Algorithm of the present invention is owing to having adopted novel duty ratio update strategy, in the time that current period finishes, electric current has reached the median of step signal, tracking to instruction is rapider, therefore according to emulation and experimental results show that the present invention can effectively shorten control cycle.

Claims (5)

1. a permagnetic synchronous motor high dynamic response current control method, comprise the speed outer shroud of q axle and d axle is regulated and current inner loop adjusting, aspect q axle, Negotiation speed detects and obtains motor speed, regulate sending into speed outer shroud after itself and speed command, after overregulating, speed outer shroud output q shaft current instruction iqr, aspect d axle, d shaft current instruction idr is set to zero, two current-order iqr and idr respectively with the current feedback value iq of corresponding axis, id relatively and be input to corresponding current inner loop and regulate to export respectively after overregulating and on corresponding axis, need the voltage uq that applies, ud, such uq, ud voltage calculates three-phase duty ratio through coordinate inverse transformation step, finally exporting three-phase voltage waveform is applied on motor, realize the control to motor, it is characterized in that: it is to adopt to calculate at counter peak value place the duty ratio making new advances in front half control cycle that described process coordinate inverse transformation step calculates three-phase duty ratio, and combination is to q, d axle takes different separately current inner loop to regulate control, realize value of feedback and follow the tracks of upper command value half control cycle in advance.

2. permagnetic synchronous motor high dynamic response current control method according to claim 1, is characterized in that: the current inner loop of described q axle regulates to control and adopts fundamental forecasting control, the current inner loop of described d axle to regulate control to adopt PI to regulate.

3. permagnetic synchronous motor high dynamic response current control method according to claim 2, is characterized in that: pure integral element in parallel in fundamental forecasting control.

4. permagnetic synchronous motor high dynamic response current control method according to claim 3, it is characterized in that: carry out combination by advance half control cycle and fundamental forecasting control, voltage vector (the ud (k+1) that k control cycle (kTs) calculated, uq (k+1)) apply again during can waiting until (k+0.5) individual control cycle ((k+0.5) Ts), the computing formula of described q shaft voltage is:

$\frac{(U_q\left(k\right)+2U_q(k+1))}{3}=R\frac{(i_q\left(k\right)+i_{q}r)}{2}+$

$L_q\frac{(i_{q}r-i_q\left(k\right))}{1.5T_s}+\mathrm{\&omega;}{L}_d\frac{(i_d\left(k\right)+i_{d}r)}{2}+\mathrm{\&omega;}{\mathrm{\&psi;}}_f---\left(5\right)$

Wherein, (id (k), iq (k)) is the sampled value of current period, and (idr, iqr) is that desired value, R are that resistance, Lq are inductance, the ψ of q axle _ffor the permanent magnet flux linkage of described permagnetic synchronous motor.

5. a permagnetic synchronous motor high dynamic response current control system, comprise the speed detector (1), speed PI adjusting device (2), current PI adjusting device (3), fundamental forecasting control device (4), inverter (5) and the coordinate transformation device (6) that couple together by signal, it is characterized in that: between fundamental forecasting control device (4) output and the input of inverter (5), add the output signal that has pure integral control device (7); Described speed detector (1) obtains the tach signal of permagnetic synchronous motor and speed command signal given in advance compares after stack, is connected with the input of speed PI adjusting device (2); Described coordinate transformation device (6) is connected the current feedback value iq, the id that obtain q, d axle with permagnetic synchronous motor; The output of described speed PI adjusting device (2) compares after stack with corresponding current feedback value iq, is connected with the input of pure integral control device (7); The output of described speed PI adjusting device (2) is also connected with the input of fundamental forecasting control device (4); The input of described fundamental forecasting control device (4) is also connected with corresponding current feedback value iq; After the output end signal of the output of described fundamental forecasting control device (4) and pure integral control device (7) superposes; Obtain the voltage uq of q axle and be connected with the input of inverter (5); The d shaft current instruction idr with it current feedback value id of correspondence compares after stack, is connected with the input of current PI adjusting device (3), obtains the voltage ud of d axle; And be connected with the input of inverter (5); The output of described inverter (5) connects permagnetic synchronous motor.

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