CN102324882B - Current distribution method for hybrid excitation synchronous machine in wide range speed control system - Google Patents

Abstract

The invention discloses a wide range speed control system and current distribution method for a hybrid excitation synchronous machine. A control policy is applied to armature drive and excitation drive simultaneously. When the motor is in the starting period, a rated forward magnetism strengthening current is applied to the exciting winding to increase the starting torque of the motor, so that the motor obtains electromagnetic torque exceeding the rated torque under the condition of no overcurrent, and the transition time of motor starting is shortened. When the motor is in the low speed operating interval, if the motor load exceeds the rated load, the electromagnetic torque of the motor is increased by applied the forward magnetism strengthening current, so that the motor obtains excessive loading capacity under the condition of no overcurrent and no overheat. When the motor operates at high speed, a constant power operating interval far above the rated rotating speed can be obtained by applying an appropriate reverse exciting current to HESM (Hybrid Excitation Synchronous Machine) and performing weak magnetic regulation on the d-axis armature current.

Description

Electric current distribution method in the mixed exciting synchronization motor wide range speed control system

Technical field

The invention belongs to Motor Control Field, specifically relate to the control system of a kind of mixed exciting synchronization motor (HESM), and in this control system, how electric current is distributed the method for having proposed.

Background technology

HESM grows up on the basis of permagnetic synchronous motor and electric excitation synchronous motor, and inside comprises permanent magnet magnetic potential and two magnetic potential sources of electric excitation magnetic potential.The magnetic potential that permanent magnet produces is main magnetic potential, and the magnetic potential that excitation winding produces is auxiliary magnetic potential.Therefore this motor had both had permagnetic synchronous motor efficient height, characteristics that torque/mass ratio is big, had that the electric excitation synchronous motor adjustable magnetic is convenient, adjustable magnetic advantage capacious simultaneously again, made motor possess very wide speed adjustable range, had bigger application value.

In recent years, Chinese scholars, expert have done a large amount of research work to this class electric machine theory research and body design, have obtained a lot of significant achievements.The domestic patent that has had many about mixed excitation electric machine.As the patent No. is that 200510040938.7 patent " hybrid-exciting brush-free claw-pole motor ", the patent No. are that 200510112091.9 patent " dual-feeding mixed excitation axial magnetic field magento motor ", the patent No. are that patent " bypass mixed excitation electrical motor " of 200510112090.4 etc. is introduced different mixed excitation electric machine structures, function and adjustable magnetic characteristic.But, less relatively to the Research on Driving System of such motor.Present existing document is from control theory mostly, the angle of dynamic simulation is studied, do not provide complete optimum efficiency controlling schemes, the domestic patent disclosure of yet not seeing relevant HESM Control System Design as yet based on vector control from two aspect systems of software and hardware design.

The control of HESM is compared with permagnetic synchronous motor, and many control variables are non linear systems of a typical multivariable, close coupling.The startup of HESM is the same with permagnetic synchronous motor, needs to determine the initial position of rotor.How adopting simple and effective way to solve the startup problem of motor, how to coordinate to control the reasonable distribution of armature supply and exciting current, and adopt which kind of mode that HESM is carried out decoupling zero control, is the Several Key Problems that solves HESM control.

Summary of the invention

The purpose of this invention is to provide a kind of mixed exciting synchronization motor wide range speed control system that can coordinate to control armature supply and exciting current, and correspondingly proposed a kind of electric current distribution method.

For achieving the above object, the present invention is by the following technical solutions:

The electric current distribution method of distributing switch in a kind of mixed exciting synchronization motor wide range speed control system, phase current i gathers in this system from HESM motor main circuit _A, i _BWith exciting current i _f, the actual measurement rotation speed n of gathering from the HESM motor _r

After the described phase current process A/D module processing, in Clarke module and Park module, carry out Clarke conversion and Park conversion successively, obtain the d shaft current i under the two-phase rotation rectangular coordinate system _dWith q shaft current i _qDescribed actual measurement rotation speed n _rWith given rotating speed n _RefCompare, comparison value carries out the PID computing in speed control, obtains torque reference current i _Tref, torque reference current i _TrefWith given rotating speed n _RefWith the actual measurement rotation speed n _rSend in the distributing switch, distributing switch carries out reasonable distribution to armature torque current and exciting current, finally exports d axle reference current i _Dref, q axle reference current i _QrefWith excitation reference current i _Fref

Wherein, d axle reference current i _DrefWith q axle reference current i _QrefRespectively with d shaft current i _dWith q shaft current i _qCompare, and comparison value sent into respectively carry out the PID computing in the current controller, obtain d shaft voltage u _dWith q shaft voltage u _q, d shaft voltage u _dWith q shaft voltage u _qProcess Ipark conversion in the Ipark module, obtain the voltage signal under static two phase coordinate systems, this voltage signal is delivered in the SVPWM module through after the space voltage vector conversion, the duty cycle signals of output PWM1～6 is controlled the conducting and the shutoff of armature driver module corresponding power pipe by this PWM1～pwm signal of 6EVA module generation to PWM1～6EVA module;

The exciting current i that from HESM motor main circuit, gathers _fAfter the A/D module processing, send into exciting current PWM generation module; Simultaneously, the excitation reference current i of distributing switch output _FrefAlso be delivered in the exciting current PWM generation module; This exciting current PWM generation module calculates the duty ratio of PWM7～10 signals, and this dutyfactor value is delivered in PWM7～10EVB module and handles, and obtains the pwm control signal of excitation driver module, and this pwm control signal is delivered in the excitation driver module.

Wherein, the electric current distribution method of distributing switch, it adopts different control strategies respectively according to the residing velocity band of HESM motor, makes the HESM motor all can keep the running status of efficiency optimization in each zone:

(1) low regime control: n in this zone _r≤ n _N, wherein be n _rThe actual measurement rotating speed, n _NBe rated speed, n _BincFor increasing magnetic base speed, I _TmaxBe the maximum reference value of torque current,

$n_{\mathrm{Binc}}=\frac{{30P}_N}{\mathrm{\π}{T}_{\max }}=\frac{{20P}_N}{\mathrm{\π}{\mathrm{pI}}_{\mathrm{qN}}({\mathrm{\ψ}}_{\mathrm{pm}}+M_{\mathrm{sf}}{I}_{\mathrm{fN}})}$

$I_{T\max }=\left\{\begin{array}{c}{I}_{\mathrm{qN}}(1+I_{\mathrm{fN}}\frac{M_{\mathrm{sf}}}{{\mathrm{\&psi;}}_{\mathrm{pm}}}),n_r\&le;n_{\mathrm{Binc}}\\ I_{\mathrm{qN}}(1+I_{\mathrm{fN}}\frac{M_{\mathrm{sf}}}{{\mathrm{\&psi;}}_{\mathrm{pm}}})\frac{n_{\mathrm{Binc}}}{n_r},n_{\mathrm{Binc}}<n_r\&le;n_N\end{array}\right.,$

Wherein, P _nBe the power of rated speed, T _MaxFor motor is exported maximum torque reference, ψ _PmBe permanent magnetism magnetic linkage, M _SfBe the mutual inductance between armature and the excitation winding, I _QNBe q axle rated current, p is the number of pole-pairs of motor, I _FNBe rated exciting current;

(2) middling speed district control: n in this zone _N＜n _r≤ nBdec, wherein, n _BdecBe weak magnetic base speed, then i _Fref=0, i _Dref=0, $i_{\mathrm{qref}}=i_{\mathrm{tref}}\&le;I_{\mathrm{qN}}\frac{n_N}{n_r};$

(3) high velocity control: n in this zone _r＞n _Bdec, should further be subdivided into two subareas in the zone:

I) subarea I:n _Bdec＜n _r≤ n _Bdec2, wherein, the weak magnetic base speed of subarea II, then

$\left\{\begin{array}{c}{i}_{\mathrm{fref}}=(\frac{n_{\mathrm{Bdec}}}{n_r}-1)\frac{{\mathrm{\&psi;}}_{\mathrm{pm}}}{M_{\mathrm{sf}}}\\ i_{\mathrm{dref}}=0\\ i_{\mathrm{qref}}=i_{\mathrm{tref}}\&le;I_{\mathrm{qN}}\frac{n_N}{n_{\mathrm{Bdec}}}\end{array}\right.;$

II) subarea II:n _r＞n _Bdec2, then $\left\{\begin{array}{c}{i}_{\mathrm{fref}}=-I_{\mathrm{fN}}\\ i_{\mathrm{dref}}=\frac{1}{L_d}\left[{\mathrm{\&psi;}}_{\mathrm{pm}}(\frac{n_{\mathrm{Bdec}}}{n_r}-1){+M}_{\mathrm{sf}}{I}_{\mathrm{fN}}\right]\\ i_{\mathrm{qref}}=i_{\mathrm{tref}}\end{array}\right.,$ L _dBe d axle inductance, wherein n _Bdec2Turnover speed for subarea I and subarea II specifically is defined as

Adopt the present invention of technique scheme, armature driving and excitation driving have been applied control strategy simultaneously.In the time of the startup stage that motor is in, increase magnetoelectricity stream, can improve the detent torque of motor, make motor under the situation of overcurrent not, obtain to surpass the electromagnetic torque of nominal torque, shortened the transit time of electric motor starting by apply specified forward to excitation winding; When motor is in low cruise when interval, if motor load surpasses nominal load, increase the electromagnetic torque that magnetoelectricity stream promotes motor by applying forward, make motor under overcurrent not, not overheated situation, obtain the extra load ability; When needs motor high-speed cruising, carry out weak magnetic adjusting by apply a suitable reverse exciting current and d armature axis electric current to HESM, can obtain an output-constant operation interval far above rated speed.In sum, HESM control system of the present invention, size and Orientation by real-time regulated motor excitation electric current and d armature axis electric current, not only effectively shortened the electric motor starting time, improved the load capacity between low regime, and improved range of motor speeds greatly, be a kind of wide range speed control system with extensive engineering using value.

Description of drawings

Fig. 1 is described HESM wide range speed control system block diagram.

Fig. 2 is described distributing switch structured flowchart.

Fig. 3 is described Single-chip Controlling main program flow chart.

Fig. 4 is described keys of single chip microcomputer control subprogram flow chart.

Fig. 5 is described DSP control main program flow chart.

Fig. 6 is the interruption subroutine flow chart of described generation pwm pulse.

Fig. 7 is described HESM start-up course experiment current waveform.

Fig. 8 is described HESM weak magnetic field operation steady-state current experimental waveform.

Fig. 9 is the maximum output torque experimental result of described HESM under different rotating speeds.

Figure 10 is described HESM peak power output experiment under different rotating speeds.

Embodiment

Be illustrated in figure 1 as HESM control system block diagram, the control board of motor is a control circuit based on the DSP+MCU framework, controlled motor is a HESM motor 4, the incremental optical-electricity encoder 6 of mounting strap magnetic pole framing signal in the motor, it and the rotor coaxial installation of HESM.

Main circuit 42 mainly comprises rectification circuit 2, filter circuit 43, armature driver module 3, excitation driver module 7 etc.The operation principle of main circuit is as follows: the 220V of AC power 1 output enters drive plate by terminals, at first carry out rectification by rectification circuit 2, rectification circuit 2 high-voltage output ends are connected on the current-limiting resistance current-limiting circuit in parallel with relay 5, the current-limiting resistance other end extremely links to each other with "+" of filter capacitor 43, filter capacitor ";, the utmost point connects the low-voltage output of rectification circuit 2.The filter capacitor two ends are also in parallel Hall voltage transducer is used for busbar voltage is detected.Be input in two driver modules through the direct voltage that obtains behind the rectifying and wave-filtering, for two driver modules provide DC power supply, these two driver modules are respectively armature driver module 3 and excitation driver module 7; Wherein 3 of armature driver module 3 outputs are connected to three inputs of the armature winding of motor, and the pwm control signal of armature driver module 3 produces PWM1～6 signal controlling of output by PWM1～6EVA module 17 of DSP16.The output of excitation driver module 7 is connected on the excitation winding of motor, and the pwm control signal of excitation driver module 7 is by PWM7～10 signal controlling that produce in PWM7～10EVB module 19 of DSP16.

The concrete structure of mixed exciting synchronization motor wide range speed control of the present invention system is as follows: it gathers phase current i from HESM motor main circuit _A, i _BWith exciting current i _f, the actual measurement rotation speed n of gathering from the HESM motor.

When the initial position of rotor was determined, the data that collected by photoelectric encoder 6 were the actual measurement rotation speed n of rotor, and this is a kind of perfect condition.Generally all need to determine the initial position of rotor: photoelectric encoder 6 is installed with the rotor coaxial of HESM motor 4, it exports two group of six road pulse signal during with rotor rotation, this pulse signal is handled back output through encoder signal processing circuit 15, wherein set of pulses signal is phase phasic difference 60 electrical degree pulse signal U, V, W, each pulse duration is 180 electrical degrees, this group signal is used for the rotor magnetic pole coarse localization when electric motor starting, be input to QEP2 unit 51, QEP2 unit 51 adopts the corresponding two-phase armature winding conducting of square wave control according to the UVW value that captures, and motor is rotated; Motor turned in the time that is less than or equal to a week, can capture a reseting pulse signal, captured after the reset pulse, and the initial position of rotor has just determined that also the running status of motor is just jumped out from the square wave control mode, enters the vector control pattern.Photoelectric encoder is exported another group pulse signal and is comprised above-mentioned reset signal and two-way quadrature coding pulse signal, this group signal is admitted to QEP1 unit 22, the 22 pairs of quadrature coded pulse signals in QEP1 unit are counted, count value passes to rotor-position computing unit 25, calculates the accurate position of rotor in real time; The count value of QEP1 unit 22 also is delivered to revolution speed calculating unit 40 simultaneously, calculates rotating speed of motor n in real time.

Simultaneously; three Hall current sensors 45; the 46 pairs of electric machine phase currents and exciting current are measured; the measured value that obtains is an aanalogvoltage; carry out processing such as filtering, voltage bias and overvoltage protection through phase current treatment circuit 13 and exciting current treatment circuit 14 respectively; A/D conversion and the correction module 21 of sending into DSP16 carry out analog-to-digital conversion, carry out the adjustment of data and digital filtering then, obtain digital voltage U at last _d, phase current i _A, i _BWith exciting current i _f

Phase current i from A/D conversion and correction module 21 outputs _A, i _B,, obtain the d shaft current i under the two-phase rotation rectangular coordinate system through Clarke conversion module 23, Park conversion module 26 _dWith q shaft current i _q

The actual measurement rotation speed n that obtains from revolution speed calculating module 40 is with given rotating speed n _RefCompare, comparison value is sent to and carries out the PID computing in the speed control 32, obtains torque reference current i _Tref, torque reference current i _TrefWith given rotating speed n _RefSend in the distributing switch 31 with the actual measurement rotation speed n, 31 pairs of armature torque currents of distributing switch and exciting current carry out reasonable distribution, output d axle reference current i _Dref, q axle reference current i _QrefWith excitation reference current i _FrefWherein, d axle reference current i _DrefWith q axle reference current i _QrefRespectively with d shaft current i _dWith q shaft current i _qCompare, and comparison value sent into respectively carry out the PID computing in the current controller 29,30, obtain d shaft voltage u _dWith q shaft voltage u _q, d shaft voltage u _dWith q shaft voltage u _qIn Ipark module 28,, obtain the voltage signal u under static two phase coordinate systems through the Ipark conversion _α, u _β, this voltage signal u _α, u _βBe delivered in the SVPWM module 27 through after the space voltage vector conversion, the duty cycle signals of output PWM1～6, this signal is delivered in PWM1～6EVA module 17 of DSP, after the processing of pwm signal by this module generation through level conversion and buffer circuit I10, the conducting and the shutoff of control armature driver module 3 corresponding power pipes.Exciting current i _FrefValue is delivered to exciting current PWM generation module 39, this module calculates the duty ratio of PWM7～10 signals, this dutyfactor value is delivered in PWM7～10EVB module 19 and handles, obtain the pwm control signal of excitation driver module 7, after the processing of this pwm control signal through level conversion and buffer circuit II11, control excitation driver module 7 increases magnetic, weak magnetic or does not have one of three kinds of operating states of excitation thereby HESM motor 4 is operated in.

For guaranteeing the operate as normal of whole system, the present invention has also designed a series of safeguard measure, and it comprises: (1) is from the phase current i of A/D modular converter output _A, i _BWith exciting current i _fSend in the overcurrent protection module 24, with the current value ratio of setting; If motor produces overcurrent or overvoltage phenomenon, then export fault-signal to blocking driver module 18, block armature driver module 3 and excitation driver module 7, disable motor.(2) armature driver module 3 all is connected with fault detect warning circuit 12 with excitation driver module 7, when in armature driver module 3 and the excitation driver module 7 any one breaks down, these fault detect warning circuit 12 output drive signals are to blocking driver module 18, block armature driver module 3 and excitation driver module 7, simultaneously disable motor.(3) bus voltage signal checkout gear 44 is after measuring voltage signal; do signal condition by busbar voltage treatment circuit 8; send into A/D conversion and correction module 21; A/D conversion and correction module 21 will carry out A/D conversion, digital filtering and treatment for correcting through the bus voltage signal of conditioning; send into overcurrent and overvoltage protective module 24 then; as overvoltage takes place, and fault-signal is sent into blocked driver module 18, close armature driver module 3 and excitation driver module 7.(4) in the closed power up of mains switch of armature driver module 3 and excitation driver module 7; when filter capacitor 43 both end voltage are lower than setting voltage; the relay of controlling the current-limiting protection module 5 that powers on by the current-limiting control circuit 9 that powers on disconnects; power supply is by charging until setting voltage to electric capacity with the relay parallel resistor; relay closes then is with the resistance bypass.

The control of HESM drive system and display module 41 mainly comprise following each several part circuit: simulation rotating speed input circuit 47 and single-chip microcomputer 37, the input of single-chip microcomputer connects keyboard 35 and coding circuit 50, its output connects display module 38, also comprises being used for the dual port RAM 36 that DSP16 and single-chip microcomputer 37 communicate.

Wherein, simulation rotating speed input circuit 47 is adjustable precision potentiometers, the potentiometer output voltage is between 0～3V, this voltage signal wave circuit after filtration enters among the DSP, in the A/D of DSP modular converter, analog voltage signal is converted to digital signal, be converted to the correlation computations of rate signal through digital filtering and with voltage signal, voltage signal and given rotating speed signal are mapped the most at last.In Driving Scheme of the present invention, the corresponding 2rpm of 1mV voltage, the highest about 6000rpm of simulation rotating speed input range.

Keyboard 35 is used for importing various operational orders, as electric motor starting, stop, rotating and reverse, by button the running speed of motor, the various menu option that switchable liquid crystal shows etc. is set.After certain button is pressed, push button signalling is encoded by coding circuit 50, be input to then in the single-chip microcomputer 37, single-chip microcomputer is operated accordingly according to program command, or data are sent on the display module 38 show, or data are saved in the dual port RAM 36, so that DSP reads the execution associative operation.In the controller running, DSP leaves digital quantities such as some operational factors such as simulate given tach signal, actual measurement tach signal, voltage signal and current signal in the dual port RAM 36 in, single-chip microcomputer is carried out associative operation by the numerical value of mode reading and saving in each address of scanning.

As shown in Figure 2, distributing switch 31 is corn module in the DSP control program of HESM, this module on based on field orientation and subregion control basis, according to the residing velocity band of motor,

Adopt different control strategies respectively, make motor can both keep the running status of efficiency optimization in each zone.Concrete electric current distribution method is as follows: because HESM is similar to permagnetic synchronous motor, with rated speed n _NWith weak magnetic base speed n _BdecDivide, can be divided into 3 zones to the operation area of HESM and carry out subregion control, area I (n _r≤ n _N) be the following low cruise of rated speed zone, this zone implements to increase magnetic or do not have the excitation control mode, and motor can move under load torque exceeds the quata state; Area I I (n _N＜n _r≤ n _Bdec) be the middling speed Operational Zone between rated speed and the weak magnetic base speed, implement permanent power excitation-free current control mode, come speedup by improving armature voltage; Area I II (n _r＞n _Bdec) be the above high-speed cruising district of weak magnetic base speed, the maximum speed of Heng Gongshuaiqu and lifting motor can be expanded keeping by distributing switch exciting current and d shaft current being carried out reasonable distribution under the constant situation of winding back emf in this zone.

Below further analyze the subregion control principle of motor, be without loss of generality, for common HESM,, adopt the d-q axis coordinate system according to principle of vector control, can obtain several fundamental equations of HESM.

Circuit equation:

$\left[\begin{array}{c}{u}_d\\ u_q\\ u_f\end{array}\right]=\left[\begin{array}{ccc}{R}_s+{\mathrm{sL}}_d& -{\mathrm{\&omega;}}_e{L}_q& {\mathrm{sM}}_{\mathrm{sf}}\\ {\mathrm{\&omega;}}_e{L}_d& R_s+{\mathrm{sL}}_q& {\mathrm{\&omega;}}_e{M}_{\mathrm{sf}}\\ {\mathrm{sM}}_{\mathrm{sf}}& 0& R_f+{\mathrm{sL}}_f\end{array}\right]\&times;\left[\begin{array}{c}{i}_d\\ i_q\\ i_f\end{array}\right]+\left[\begin{array}{c}0\\ {\mathrm{\&omega;}}_{\mathrm{<figure-callout\; id="0"\; label="e"\; filenames="HSA00000575743800072.png,HSA00000575743800073.png"\; state="\{\{state\}\}">e</figure-callout>}}\\ 0\end{array}{\mathrm{\&psi;}}_{\mathrm{pm}}\right]---\left(1\right)$

Torque equation:

$T_e=\frac{3}{2}p(i_q{\mathrm{\&psi;}}_d-i_d{\mathrm{\&psi;}}_q)---\left(2\right)$

$=\frac{3}{2}p[i_a{\mathrm{\&psi;}}_{\mathrm{pm}}{+i}_d{i}_q(L_d-L_q)+M_{\mathrm{sf}}{i}_f{i}_q]$

Power equation:

$P_{\mathrm{in}}=P_s+P_f$

$=\frac{3}{2}(u_d{i}_d+u_q{i}_q)+u_f{i}_f$

$=\frac{3}{2}{\mathrm{\&omega;}}_e(i_q{\mathrm{\&psi;}}_d-i_d{\mathrm{\&psi;}}_q)+\frac{3}{2}({\mathrm{s\&psi;}}_d{i}_d+{\mathrm{s\&psi;}}_q{i}_q)+[\frac{3}{2}{R}_s(i_{\mathrm{<figure-callout\; id="2"\; label="d"\; filenames="HSA00000575743800011.png"\; state="\{\{state\}\}">d</figure-callout>}}^2+i_q^2)+R_f{i}_f^2]---\left(3\right)$

$P_e=T_e{\mathrm{\&omega;}}_r$

$=\frac{3}{2}{\mathrm{p\&omega;}}_r[i_q{\mathrm{\&psi;}}_{\mathrm{pm}}{+i}_d{i}_q(L_d-L_q)+M_{\mathrm{sf}}{i}_f{i}_q]$

In the following formula, first of input power equation is electromagnetic power, equals P _e, second is the variable quantity of magnetic field energy, the 3rd is the motor copper loss, comprises excitation loss.

The back-emf equation

E _d＝ω _eL _qi _q

E _q＝ω _e(ψ _pm+i _dL _d+i _fM _sf) (4)

In formula (1)～(4), the implication of each symbol is as follows: s is a differential operator; u _d, u _q, i _d, i _qBe respectively armature d, q shaft voltage and current component 0 ψ _d, ψ _q, ψ _PmBe respectively d, q axle magnetic linkage and permanent magnetism magnetic linkage; u _f, i _fBe respectively exciting voltage and electric current; R _s, R _fBe respectively armature winding resistance and excitation winding resistance; L _d, L _q, M _SfBe respectively the mutual inductance between armature d, q axle inductance and armature and the excitation winding; L _s, L _fBe respectively armature and excitation winding inductance; ω _e, ω _rBe respectively electric angle speed and mechanical angle speed; P is the number of pole-pairs of motor; T _eBe electromagnetic torque; P _s, P _fBe respectively armature winding input power and excitation winding input power; P _InBe input power; E _d, E _qBe respectively d, the q axle component of back-emf.

Based on above 4 fundamental equations, introduce the subregion control principle of electric current distribution module shown in Figure 2 below in detail:

1. low regime is controlled (n _r≤ n _N)

According to the electromagnetic property of HESM, as the excitation-free current speed governing, the torque reference current i of speed control output _TrefBe exactly the torque component i of armature supply _Qref, this moment, HESM just was equivalent to PMSM, can adopt i _d=0 vector control method.Therefore, torque equation (2) and torque balance relation by HESM can obtain the electromagnetic torque reference value:

$T_e^{*}=\frac{3}{2}P({\mathrm{\&psi;}}_{\mathrm{pm}}+M_{\mathrm{sf}}{i}_{\mathrm{fref}})i_{\mathrm{qref}}=\frac{3}{2}P{\mathrm{\&psi;}}_{\mathrm{pm}}{i}_{\mathrm{tref}}---\left(5\right)$

In the formula, i _FrefBe the exciting current reference value.When increasing the magnetism excitation electric current and the q shaft current is got rated value I respectively _FN, I _QNThe time, motor is exported maximum torque reference:

$T_{\max }=\frac{3}{2}P({\mathrm{\&psi;}}_{\mathrm{pm}}+M_{\mathrm{sf}}{I}_{\mathrm{fN}})I_{\mathrm{qN}}---\left(6\right)$

Can obtain the basic relations of distribution of electric current by formula (5):

$i_{\mathrm{qref}}=\frac{{\mathrm{\&psi;}}_{\mathrm{pm}}{i}_{\mathrm{tref}}}{{\mathrm{\&psi;}}_{\mathrm{pm}}+M_{\mathrm{sf}}{i}_{\mathrm{fref}}}---\left(7\right)$

In the formula, i _QrefAnd i _FrefAll be unknown, obtain optimum efficiency for making HESM, here with motor copper loss minimum as another constraints, find the solution this two current values.

In power equation (3), ignore motor magnetic hysteresis and eddy current loss, only consider copper loss and i _dHad in=0 o'clock:

$P_{\mathrm{cu}}=\frac{3}{2}{R}_s({\mathrm{<figure-callout\; id="2"\; label="i\; d"\; filenames="HSA00000575743800011.png"\; state="\{\{state\}\}">i</figure-callout>}}_d^{}+i_q^2)+R_{\mathrm{<figure-callout\; id="2"\; label="f\; i\; f"\; filenames="HSA00000575743800011.png"\; state="\{\{state\}\}">f</figure-callout>}}{i}_f^{}{}_2^{}=\frac{3}{2}{R}_s{\mathrm{<figure-callout\; id="2"\; label="i\; q"\; filenames="HSA00000575743800011.png"\; state="\{\{state\}\}">i</figure-callout>}}_q^{}+R_f{i}_f^2---\left(8\right)$

Under the certain situation of load torque, adopt lagrange's method of multipliers to ask P _CuMinimum value.Convolution (5), (8), and make i _q=i _Qref, i _f=i _Fref, obtain Lagrangian:

$L(i_q,i_f,\mathrm{\&lambda;})=P_{\mathrm{cu}}+\mathrm{\&lambda;}[\frac{3}{2}P({\mathrm{\&psi;}}_{\mathrm{pm}}+M_{\mathrm{sf}}{i}_{\mathrm{fref}})i_{\mathrm{qref}}-\frac{3}{2}{\mathrm{P\&psi;}}_{\mathrm{pm}}{i}_{\mathrm{tref}}]---\left(9\right)$

Following formula is asked i respectively _Qref, i _FrefPartial derivative, and to make it be 0, cancellation λ can get copper loss hour i _QrefWith i _FrefRelational expression:

${2R}_f{i}_{\mathrm{fref}}({\mathrm{\&psi;}}_{\mathrm{pm}}+M_{\mathrm{sf}}{i}_{\mathrm{fref}})-{3R}_s{M}_{\mathrm{sf}}{i}_{\mathrm{qref}}^2=0---\left(10\right)$

With formula (7) substitution formula (10), put in order:

${2R}_f{M}_{\mathrm{sf}}^3{i}_{\mathrm{fref}}^4+{6R}_{\mathrm{<figure-callout\; id="2"\; label="f\; M\; sf"\; filenames="HSA00000575743800011.png"\; state="\{\{state\}\}">f</figure-callout>}}{M}_{\mathrm{sf}}^{}{}_2^{}{\text{\&psi;}}_{\mathrm{pm}}{i}_{\mathrm{fref}}^3+{6R}_f{M}_{\mathrm{sf}}{\mathrm{\&psi;}}_{\mathrm{pm}}^2{i}_{\mathrm{fref}}^2+{2R}_f{\mathrm{\&psi;}}_{\mathrm{pm}}^3{i}_{\mathrm{fref}}-{3R}_s{M}_{\mathrm{sf}}{\mathrm{\&psi;}}_{\mathrm{pm}}^2{i}_{\mathrm{tref}}^2=0---\left(11\right)$

First equation of equation group (11) is a unary biquadratic equation, is difficult to direct calculating, adopts solution by iterative method, order:

$F\left(i_{\mathrm{fref}}\right)=2R_f{M}_{\mathrm{sf}}^3{i}_{\mathrm{fref}}^4+{6R}_{\mathrm{<figure-callout\; id="2"\; label="f\; M\; sf"\; filenames="HSA00000575743800011.png"\; state="\{\{state\}\}">f</figure-callout>}}{M}_{\mathrm{sf}}^{}{}_2^{}{\mathrm{\&psi;}}_{\mathrm{pm}}{i}_{\mathrm{fref}}^3+{6R}_f{M}_{\mathrm{sf}}{\mathrm{\&psi;}}_{\mathrm{pm}}^2{i}_{\mathrm{fref}}^2+{2R}_f{\mathrm{\&psi;}}_{\mathrm{pm}}^3{i}_{\mathrm{fref}}-{3R}_s{M}_{\mathrm{sf}}{\mathrm{\&psi;}}_{\mathrm{pm}}^2{i}_{\mathrm{tref}}^2---\left(12\right)$

In the formula, make x _n=i _Fref, ${\mathrm{<figure-callout\; id="4"\; label="k"\; filenames="HSA00000575743800072.png"\; state="\{\{state\}\}">k</figure-callout>}}_4={2R}_{\mathrm{<figure-callout\; id="3"\; label="f\; M\; sf"\; filenames="HSA00000575743800011.png"\; state="\{\{state\}\}">f</figure-callout>}}{M}_{\mathrm{sf}}^{}{}_3^{},$ ${\mathrm{<figure-callout\; id="3"\; label="k"\; filenames="HSA00000575743800011.png"\; state="\{\{state\}\}">k</figure-callout>}}_3=6R_{\mathrm{<figure-callout\; id="2"\; label="f\; M\; sf"\; filenames="HSA00000575743800011.png"\; state="\{\{state\}\}">f</figure-callout>}}{M}_{\mathrm{sf}}^{}{}_2^{}{\mathrm{\&psi;}}_{\mathrm{pm}},$ ${\mathrm{<figure-callout\; id="2"\; label="k"\; filenames="HSA00000575743800011.png"\; state="\{\{state\}\}">k</figure-callout>}}_2=6R_f{M}_{\mathrm{sf}}{\mathrm{\&psi;}}_{\mathrm{<figure-callout\; id="2"\; label="pm"\; filenames="HSA00000575743800011.png"\; state="\{\{state\}\}">pm</figure-callout>}}^2,$ $k_1={2R}_f{\mathrm{\&psi;}}_{\mathrm{<figure-callout\; id="3"\; label="pm"\; filenames="HSA00000575743800011.png"\; state="\{\{state\}\}">pm</figure-callout>}}^3,$ $g={\mathrm{<figure-callout\; id="2"\; label="i\; tref"\; filenames="HSA00000575743800011.png"\; state="\{\{state\}\}">i</figure-callout>}}_{\mathrm{tref}}^{},$ ${\mathrm{<figure-callout\; id="0"\; label="k"\; filenames="HSA00000575743800072.png,HSA00000575743800073.png"\; state="\{\{state\}\}">k</figure-callout>}}_0={3R}_s{M}_{\mathrm{sf}}{\mathrm{\&psi;}}_{\mathrm{<figure-callout\; id="2"\; label="pm"\; filenames="HSA00000575743800011.png"\; state="\{\{state\}\}">pm</figure-callout>}}^2,$ Arrangement can get:

$F\left(x_n\right)=k_4{\mathrm{<figure-callout\; id="4"\; label="x\; n"\; filenames="HSA00000575743800072.png"\; state="\{\{state\}\}">x</figure-callout>}}_n^{}+k_3{\mathrm{<figure-callout\; id="3"\; label="x\; n"\; filenames="HSA00000575743800011.png"\; state="\{\{state\}\}">x</figure-callout>}}_n^{}+k_2{\mathrm{<figure-callout\; id="2"\; label="x\; n"\; filenames="HSA00000575743800011.png"\; state="\{\{state\}\}">x</figure-callout>}}_n^{}+k_1{x}_n^1-k_{0}g---\left(13\right)$

With formula (13) both sides to x _nDifferentiate:

$F\&prime;\left(x_n\right)=4k_4{\mathrm{<figure-callout\; id="3"\; label="x\; n"\; filenames="HSA00000575743800011.png"\; state="\{\{state\}\}">x</figure-callout>}}_n^{}+{3k}_3{\mathrm{<figure-callout\; id="2"\; label="x\; n"\; filenames="HSA00000575743800011.png"\; state="\{\{state\}\}">x</figure-callout>}}_n^{}+{2k}_2{x}_n+k_1---\left(14\right)$

Obviously, work as x _n＞0 o'clock, F ' (x _n)＞0.Therefore formula (13) is at x _n＞0 o'clock is monotonically increasing, by motor characteristic equation F (x as can be known _n)=0 is 0 to rated value I _FNBetween unique solution is arranged, can adopt as shown in the formula (15) have 3 rank convergence rates two the step Newton iteration methods ask F (x _n)=0 separate x _n:

$z_n=x_n-\frac{F\left(x_n\right)}{F\&prime;\left(x_n\right)}---\left(15\right)$

$x_{n+1}=z_n-\frac{F\left(z_n\right)}{F\&prime;\left(x_n\right)}$

x _nInitial value can be set to 0 to rated exciting current I _FNBetween any value, under any running status, can both obtain x for guaranteeing motor faster _nValue, can set x _nInitial value be I _FN/ 2, the initial value of later on each interative computation adopts last calculated value.With each parameter substitution formula (12)～(15) of motor, emulation and experiment showed, x _nEven initial value getting under the worst case of extreme value, also only need to carry out 4 interative computations, just can obtain x _nError is less than 1% approximate solution.Therefore use general DSP to control HESM, real-time can meet the demands fully.

In above electric current distributive operation process, because whole regional rotating speed is lower, increases the magnetic operation and can not cause back-emf too high, need not consider the restriction of voltage limit ring.But, motor speed increases magnetic base speed n when surpassing _BincThe time, for preventing motor overload, answer the torque-limiting current reference value, convolution (3), (6) can get n _BincWith the maximum reference value I of torque current _Tmax:

$n_{\mathrm{Binc}}=\frac{{30P}_N}{{\mathrm{\&pi;T}}_{\max }}=\frac{{20P}_N}{{\mathrm{\&pi;pI}}_{\mathrm{qN}}({\mathrm{\&psi;}}_{\mathrm{pm}}+M_{\mathrm{sf}}{I}_{\mathrm{fN}})}$

$I_{T\max }=\left\{\begin{array}{c}{I}_{\mathrm{qN}}(1+I_{\mathrm{fN}}\frac{M_{\mathrm{sf}}}{{\mathrm{\&psi;}}_{\mathrm{pm}}}),n_r\&le;n_{\mathrm{Binc}}\\ I_{\mathrm{qN}}(1+I_{\mathrm{fN}}\frac{M_{\mathrm{sf}}}{{\mathrm{\&psi;}}_{\mathrm{pm}}})\frac{n_{\mathrm{Binc}}}{n_r},n_{\mathrm{Binc}}<n_r\&le;n_N\end{array}---\left(12\right)\right.$

2. the middling speed district controls (n _N＜n _r≤ n _Bdec)

By formula (4) as can be known, work as i _d=i _f=0 o'clock, the n of HESM _rWith E _qLinear.Therefore the motor maximum speed n that does not have excitation _MaxWith DC bus-bar voltage U _DcAlso be linear relationship, weak magnetic base speed n _BdecBe subjected to n _MaxRestriction, its value can be obtained by following formula:

n _max＝k _vU _dc+N ₀ (13)

n _Bdec＝k _bn _max

In the formula, for the experimental prototype of this paper, maximum speed voltage ratio coefficient k _v=5.69, bias N ₀=-13.Certain torque fan-out capability is arranged, weak magnetic base speed coefficient k during for assurance motor weak magnetic field operation _bValue can be made as between 0.8～0.95, the present invention makes k _b=0.85.

This regional electric current allocation strategy is fairly simple, only needs to keep i _Dref=0, i _Fref=0, HESM is used as common PMSM controls and get final product, therefore, can get each current reference value:

$i_{\mathrm{fref}}=0,i_{\mathrm{dref}}=0,i_{\mathrm{qref}}=i_{\mathrm{tref}}\&le;I_{\mathrm{qN}}\frac{n_N}{n_r}---\left(14\right)$

3. high velocity is controlled (n _r＞n _Bdec):

This district can further carefully divide two subarea i and ii into for weak magnetic controlled area, adopts different control strategies respectively, effectively expands the constant-power speed regulation scope of motor.Subarea I (n _Bdec＜n _r≤ n _Bdec2, n _Bdec2Be magnetic base speed a little less than the ii of subarea) be exciting current speed governing district, the exciting current weak-magnetic speed-regulating is only adopted in this subarea, and maximum weak magnetoelectricity stream is-I _FNSubarea II (n _r＞n _Bdec2) keep exciting current to be-I _FN, regulate the speed governing of d shaft current.Below further analyze the control strategy in these two subareas.

(1) subarea I (n _Bdec＜n _r≤ n _Bdec2)

When motor speed reaches n _BdecThe time, its back-emf adopts to keep the constant control strategy of back-emf q axle component, back-emf base value E near busbar voltage _BaseCan obtain by following formula:

E _base＝pn _Bdecψ _pmπ/30 (15)

Convolution (4), (15) make i _d=0, can get:

$i_{\mathrm{fref}}=\frac{{\mathrm{\&psi;}}_{\mathrm{pm}}}{M_{\mathrm{sf}}}(\frac{n_{\mathrm{Bdec}}}{n_r}-1)---\left(16\right)$

It is as follows to get the electric current allocation strategy thus:

$\left\{\begin{array}{c}{i}_{\mathrm{fref}}=(\frac{n_{\mathrm{Bdec}}}{n_r}-1)\frac{{\mathrm{\&psi;}}_{\mathrm{pm}}}{M_{\mathrm{sf}}}\\ i_{\mathrm{dref}}=0\\ i_{\mathrm{qref}}=i_{\mathrm{tref}}\&le;I_{\mathrm{qN}}\frac{n_N}{n_{\mathrm{Bdec}}}\end{array}\right.---\left(17\right)$

(2) subarea II (n _r＞n _Bdec2)

When motor speed reaches n _Bdec2The time, weak magnetism excitation current i _Fref=-I _FN, the magnetic field that this moment, exciting current produced is tending towards saturated, further increases reverse exciting current, and weak magnetic effect is limited, continues speed-raising as need, should keep i _FrefConstant, regulate the d shaft current, by formula (17), work as i _Fref=-I _FNThe time, can obtain n _Bdec2:

${\mathrm{<figure-callout\; id="2"\; label="n\; Bdec"\; filenames="HSA00000575743800011.png"\; state="\{\{state\}\}">n</figure-callout>}}_{\mathrm{Bdec}}=\frac{{\mathrm{\&psi;}}_{\mathrm{pm}}{n}_{\mathrm{Bdec}}}{{\mathrm{\&psi;}}_{\mathrm{pm}}-I_{\mathrm{fN}}{M}_{\mathrm{sf}}}---\left(18\right)$

By formula (4), get back-emf q axle component:

E _bq＝pn _r(ψ _pm-I _fNM _sf+i _drefL _d)π/30 (19)

Convolution (15), (19) make E _Bq=E _Base, can obtain the electric current relations of distribution:

$\left\{\begin{array}{c}{i}_{\mathrm{fref}}=-I_{\mathrm{fN}}\\ i_{\mathrm{dref}}=\frac{1}{L_d}[{\mathrm{\&psi;}}_{\mathrm{pm}}(\frac{n_{\mathrm{Bdec}}}{n_r}-1)+M_{\mathrm{sf}}{I}_{\mathrm{fN}}]\\ i_{\mathrm{qref}}=i_{\mathrm{tref}}\end{array}\right.---\left(20\right)$

Shown in Fig. 3,4, be liquid crystal display main program and button control program flow chart, liquid crystal display and button control program are Single Chip Microcomputer (SCM) program, and the single-chip microcomputer model of employing is AT89C55WD, after control board powers on, by button operation, can also can motor speed be set by pressing the key assignments motor speed by accurate adjustable potentiometer, switch each menu by button, can also check other motor operating parameter such as busbar voltage, armature supply, exciting current etc.

Be illustrated in figure 5 as DSP control program main program, its principle is as follows: after control board powers on, at first carry out the initialize routine of DSP, wait for the electric motor starting order; After value that program detects electric motor starting order " start_flag " becomes " 0x55 " by " 0xaa ", 3 road UVW magnetic pole framing signals (this 3 road pulse signal is that pin CAP4～6 seizure by DSP obtain) according to photoelectric coded disk output, binary numeral by the UVW correspondence, adopt conducting 2 phase, whenever the angle that is conducted is that 1200 control mode makes the motor rotation, motor enters the brshless DC motor operational mode, before reseting pulse signal " Z " signal of waiting for coding disk occurred, motor kept a kind of like this operational mode always.Be less than or equal in the time in a week in the HESM rotation, " CAP3 " of DSP " the pin low level pulse that will to capture a width be the quadrature coding pulse signal period; will the reset value of sign " qep1.index_sync_flag " of program is changed to " 0xf0 "; jump out the brshless DC motor operational mode then; the seizure of forbidding CAP4～6 is interrupted; the underflow that enables the timer T1 of DSP task manager A is interrupted, and HESM just enters the vector control operational mode.After program enters the vector control operational mode, program will constantly scan the appropriate address of dual port RAM, and read-write operation is carried out in these addresses, finish the data communication between DSP and the single-chip microcomputer.

Be illustrated in figure 6 as the timer T1 interruption subroutine (be 0.1ms the interrupt cycle of T1) of DSP, this program is used for finishing that armature drives and the duty ratio calculating of the pwm signal that excitation drives, in this program, mainly comprise following subprogram: speed by PID computing, electric current distribute subprogram, electric current CLARKE conversion, PARK and IPARK conversion, current PI D computing, SVPWM subprogram etc.

(exciting current is 1A/1.5V with detecting the voltage corresponding relation to the starting current waveform of HESM when being illustrated in figure 7 as load 1Nm, added the 1.5V bias voltage in the circuit design, so corresponding exciting current is 0A when detecting 1.5V), the given rotating speed of HESM is 2000rpm, greater than the weak magnetic base speed (1400rpm) of motor.For improving the detent torque of motor, consider that the excitation winding inductance is bigger, the preceding 0.5s of starter motor applies a forward rated exciting current to HESM and increases magnetic, along with motor speed rising exciting current reduces, after rotating speed reaches nBdec, the beginning weak-magnetic speed-regulating, exciting current and armature A phase current waveform are as shown in Figure 5.

As shown in Figure 8, be HESM weak magnetic field operation steady-state current experimental waveform, motor speed is 2000rpm, and exciting current if is-1A, the A phase current is sinusoidal wave, amplitude 1.6A, because of load lighter, the fundamental component of armature supply is the weak magnetoelectricity stream of d axle id, and phase current waveform is smoother, and harmonic wave is less.

As shown in Figure 9, whether apply the experimental result of rotating speed and corresponding maximum output torque under the exciting current adjustable magnetic ruuning situation for HESM.Torque and rotation speed relation waveform can be divided into three zones among the figure: area I is for increasing magnetic speed governing district, and as excitation-free current, the breakdown torque of HESM output is 9Nm, and when applying exciting current and increase the magnetic operation, breakdown torque reaches 12Nm.Area I I is no excitation speed governing district, and the motor maximum output torque descends with rotating speed is linear.The III zone is the weak-magnetic speed-regulating district, and the output torque is 0～5Nm, when excitation-free current participates in speed governing, adopts the vector control of id=0, and the characteristic of HESM approaches common PMSM, and the torque fan-out capability descends rapidly, and the maximum speed of motor is 1600rpm; And behind the exciting current participation weak-magnetic speed-regulating, maximum speed reaches 4700rpm during load 0.5Nm.This experimental result shows that HESM has low speed high torque and wide range speed control characteristic.

As shown in figure 10, provide HESM and have, excitation-free current participates in rotating speed and peak power output experimental result under the speed governing.During no excitation speed governing, the corresponding rotating speed in permanent power district is 700rpm～1300rpm, and after rotating speed surpassed 1300rpm, power output descended rapidly, after rotating speed reaches 1600rpm, has not had torque and power output capacity substantially.When applying exciting current, because it increases magnetic and weak magnetic action, Heng Gongshuaiqu is extended to 450rpm～1600rpm, and after rotating speed surpassed 1600rpm, though can not keep permanent power, power output descended slower, can also export about 200W power during turn up 4000rpm.This experimental result shows, by the regulating action of exciting current, has improved the load capacity of HESM in low speed and high-speed cruising district effectively.

Claims (1)

1. the electric current distribution method of distributing switch in the mixed exciting synchronization motor wide range speed control system, phase current i gathers in this system from HESM motor main circuit _A, i _BWith exciting current i _f, the actual measurement rotation speed n of gathering from the HESM motor _r

After the described phase current process A/D module processing, in Clarke module and Park module, carry out Clarke conversion and Park conversion successively, obtain the d shaft current i under the two-phase rotation rectangular coordinate system _dWith q shaft current f _qDescribed actual measurement rotation speed n _rWith given rotating speed n _RefCompare, comparison value carries out the PID computing in speed control, obtains torque reference current i _Tref, torque reference current it _RefWith given rotating speed n _RefWith the actual measurement rotation speed n _rSend in the distributing switch, distributing switch carries out reasonable distribution to armature torque current and exciting current, finally exports d axle reference current i _Dref, q axle reference current i _QrefWith excitation reference current i _Fref

Wherein, d axle reference current i _DrefWith q axle reference current i _QrefRespectively with d shaft current i _dWith q shaft current i _qCompare, and comparison value sent into respectively carry out the PID computing in the current controller, obtain d shaft voltage u _dWith q shaft voltage u _q, d shaft voltage u _dWith q shaft voltage u _qProcess Ipark conversion in the Ipark module, obtain the voltage signal under static two phase coordinate systems, this voltage signal is delivered in the SVPWM module through after the space voltage vector conversion, the duty cycle signals of output PWM1～6 is controlled the conducting and the shutoff of armature driver module corresponding power pipe by this PWM1～pwm signal of 6EVA module generation to PWM1～6EVA module;

The exciting current i that from HESM motor main circuit, gathers _fAfter the A/D module processing, send into exciting current PWM generation module; Simultaneously, the excitation reference current i of distributing switch output _FrefAlso be delivered in the exciting current PWM generation module; This exciting current PWM generation module calculates the duty ratio of PWM7～10 signals, and this dutyfactor value is delivered in PWM7～10EVB module and handles, and obtains the pwm control signal of excitation driver module, and this pwm control signal is delivered in the excitation driver module.

Wherein, the electric current distribution method of distributing switch is characterized in that: it adopts different control strategies respectively according to the residing velocity band of HESM motor, makes the HESM motor all can keep the running status of efficiency optimization in each zone:

(1) low regime control: n in this zone _r≤ n _N, wherein be n _rThe actual measurement rotating speed, n _NBe rated speed, n _BincFor increasing magnetic base speed, I _TmaxBe the maximum reference value of torque current,

Wherein, P _NBe the power of rated speed, T _MaxFor motor is exported maximum torque reference, ψ _PmBe permanent magnetism magnetic linkage, M _SfBe the mutual inductance between armature and the excitation winding, I _QNBe q axle rated current, p is the number of pole-pairs of motor, I _FNBe rated exciting current;

(2) middling speed district control: n in this zone _N＜n _r≤ n _Bdec, wherein, n _BdecBe weak magnetic base speed, then i _Fref=0, i _Dref=0,

(3) high velocity control: n in this zone _r＞n _Bdec, should further be subdivided into two subareas in the zone:

I) subarea I:n _Bdec＜n _r≤ n _Bdec2, wherein, the weak magnetic base speed of subarea II, then

II) subarea II:n _r＞n _Bdec2, then

L _dBe d axle inductance, wherein n _Bdec2Turnover speed for subarea I and subarea II specifically is defined as

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