CN106487303A - A kind of simple vector control method of permagnetic synchronous motor - Google Patents

Abstract

A kind of simple vector control method of permagnetic synchronous motor, comprises the following steps：Step one, according to controlled quentity controlled variable U_dAnd U_qU is obtained by Park inverse transformation_αAnd U_β；Step 2, according to the static U drawing_αAnd U_βValue carries out the projection scalar U in three phase coordinates_a、U_bAnd U_cCalculating；Step 3, according to the U drawing_a、U_bAnd U_cValue calculates three-phase dutycycle, in conjunction with the projection scalar formula U in three phase coordinates_a、U_bAnd U_cSituation of change, calculate three-phase dutycycle.The invention provides a kind of simplify loaded down with trivial details flow process, reduce size of code, the simple vector control method of the permagnetic synchronous motor of shortening conversion time.

Description

A kind of simple vector control method of permagnetic synchronous motor

Technical field

The invention belongs to Motor Control Field, more particularly, to a kind of vector control method of permagnetic synchronous motor.

Background technology

The most popular method that at present space voltage vector control controls for permagnetic synchronous motor, obtained substantial amounts of Promote.

Fig. 1 depicts the schematic diagram that three-phase PWM inverter supplies electricity to permagnetic synchronous motor, for making motor symmetrically work, must Must three-phase power simultaneously.A, b, c represent respectively three bridge walls on off state it is stipulated that：Upper bridge wall break-over of device is represented with " 1 ", Lower bridge wall break-over of device is represented with " 0 ", and is arranged in order according to UVW phase sequence.Can derive, the phase voltage of three-phase inverter output Vector [U_u、U_v、U_w]^TWith switch state vector [a, b, c]^TRelation be：

U in formula_dcIt is direct current power source voltage.

Formula is substituted into space vector of voltage formula U_out=2/3 (U_U+U_Ve^j2π/3+U_We^j4π/3) obtain corresponding inverter work Pattern and the relation of output voltage, as shown in table 1：

Table 1

By the result of calculation in table 1, obtain as shown in Figure 28 fundamental space voltage vector, wherein space voltage vector Amplitude is equal, is equal to 2U_dc/ 3, phase angle mutual deviation π/3, it is denoted as U respectively₀, U₆₀、U₁₂₀、U₁₈₀、U₂₄₀、U₃₀₀, and Zero voltage vector It is denoted as O₀₀₀, O₁₁₁.When inverter individually exports fundamental voltage space vector U₀When, the stator magnetic linkage vector Ψ of motor

Starting end from A to B along parallel to U₀Direction move, as Figure 1-4.When moving to B point, if changed Fundamental voltage space vector is U₆₀Output, then the starting end of stator magnetic linkage vector Ψ is also accordingly changed to the movement from B to C.So Go down, after whole six non-zero fundamental voltage space vectors individually export respectively successively, stator magnetic linkage vector Ψ starting end Movement locus are regular hexagons, as shown in Figure 3.

Obviously, can be only formed orthohexagonal rotating excitation field according to such power supply mode, rather than it is desirable that circle Shape magnetic field.

So we will allow regular hexagon become N side shape, and the number of times of N is bigger, is just closer to justify.So it is accomplished by More inverter switching states.One of which method is the linear session group of the fundamental voltage space vector using six non-zeros Conjunction obtains more on off states.

In the diagram, U_x+60And U_xRepresent adjacent two fundamental voltage space vector, U_outIt is the reference phase voltage arrow of output Amount, its amplitude represents the amplitude of voltage, and its angular velocity of rotation is exactly the angular frequency of the sinusoidal voltage of output.U_outCan be by U_xAnd U_x+60 Linear ageing synthesis, it is equal to t₁/T_pwmU again_xWith t₂/T_pwmU_x+60Vector.Wherein t₁And t₂It is U respectively_xWith U_x+60The time of effect.T_pwmIt is total time period, but t₁And t₂Need not be equal to T_pwm, in general, in T_pwmIn also should wrap T action time containing zero vector₀And t₇, by t₀And t₇Modulation ratio can be controlled, thus controlling the amplitude of resultant vector.Press According to this mode, in next T_pwmPeriod, still use U_xAnd U_x+60Linear session combination, but action time

t_1’And t_2’Different from last time, they must assure that the new space vector of voltage U of synthesis_out, with original voltage Space vector U_outAmplitude equal.

So on, in each T_pwmPeriod, all can change the action time of adjacent basic vector, and ensure to synthesize Space vector of voltage amplitude all equal, therefore, work as T_pwmWhen sufficiently small, the track of space vector of voltage is one and approximately justifies The regular polygon of shape.

Can be obtained according to projection on rectangular coordinate system coordinate axess for vector each in Fig. 4：

|U_out|T_pwmCos θ=t₁|U_x|+t₂|U_x+60|cosπ/3

t₂|U_x+60| sin π/3=| U_out|T_pwmsinθ

Thus, can all obtain：

|U_x+60|=| U_x|=| U_dc|

|U_out|=√ 3/2UdcM

t₁=MT_pwmsin(π/3-θ)

t₂₌MT_pwmsinθ

In formula, T_pwmCan select in advance, according to the PWM period of wave of itself, during emulation, be limited to 1, U_outCan be bent by V/F Line determines that, it is also possible to arrange according to high tension voltage, θ can be by output sinusoidal voltage angular frequency and nT_pwmProduct determine, M is Debugging ratio.Therefore, as known two adjacent fundamental space vector U_x+60And U_xAfterwards it is possible to determine t action time₁And t₂.

In figure 3, when inverter individually exports zero vector, the stator magnetic linkage vector of motor is motionless.According to this Individual feature, in T_pwmPeriod inserts the time t of zero vector effect₀, make T_pwm=t₀+t₁+t₂+t₇

By such method, angular frequency can be adjusted, thus reaching the purpose of frequency conversion.

Vector controlled enters this thinking：The control method of analog DC motor is realized come to permanent-magnet synchronous by coordinate transform Motor is controlled, and implementation step is as follows：

1) according to magnetic potential and power constant pass orthogonal transformation in principle, three phase static coordinate transform is become biphase static seat Mark, that is, Clarke conversion, the electric current of three-phase is first converted to rest frame, then by rotation transformation by biphase static seat Mark becomes two cordic phase rotators, that is, Park conversion, and in Park conversion, stator current is broken down into by rotor field-oriented 2 Individual DC component i_d、i_q(wherein i_dFor excitation current component, i_qFor torque current component).

2) by controller, electric current loop is controlled, controls i_dIt is equivalent to control magnetic flux, and control i_qIt is equivalent to control Torque processed.Adjust through PI, obtaining the component of voltage on d, q axle is U_dAnd U_q.

3) controlled quentity controlled variable U_dAnd U_qU is obtained by Park inverse transformation_αAnd U_β.

4) realize the output of vector controlled according to traditional Space vector modulation method, reach the purpose of vector controlled.

Figure it is seen that whole space can be divided into 6 sectors by these basic space vectors, wherein U₀Represent the fundamental space vector that the anglec of rotation is 0, U₆₀Represent the fundamental space vector that the anglec of rotation is 60, U₁₂₀Represent rotation Angle is 120 fundamental space vector, U₁₈₀Represent the fundamental space vector that the anglec of rotation is 180, U₂₄₀Representing the anglec of rotation is 240 fundamental space vector, U₃₀₀Represent the fundamental space vector that the anglec of rotation is 300 it is considered to the space voltage shown in figure is sweared Amount U_out, can be by U_αAnd U_βRepresent its component on the α axle and β axle in rest frame.Now with U_αAnd U_βAs input letter Number, with DC bus-bar voltage U_dcAs parameter, after calculating is processed, can get 6 required road PWM.

This voltage space be may determine that in the positive and negative of projection of space three phase coordinate system according to given space vector of voltage Which sector vector is located at.As shown in figure 5, note Ua, Ub and Uc are its projection scalar in three phase coordinates：

According to above formula, the sector N residing for space voltage vector can be determined by following rule：

N=A+2B+4C

Wherein, if U_a>0, then A=1, otherwise A=0

If U_b>0, then B=1, otherwise B=0

If Uc>0, then C=1, otherwise C=0

It is re-introduced into common variable X, Y, Z to calculate time t₁And t₂：

According to sector label N determined above, can get the sector residing for space vector and two boundary vector t₁And t₂Make With the relation of time, as shown in table 2：

Sector N

Ⅰ

Ⅱ

Ⅲ

Ⅳ

Ⅴ

Ⅵ

t1

Z

Y

-Z

-X

X

-Y

t2

Y

-X

X

Z

-Y

-Z

Table 2

But, because the amplitude that the decline of direct current power source voltage may make voltage vector reduces, therefore, calculate time t₁With t₂Sum is possible to exceed PWM cycle T_pwmHalf T, i.e. t₁And t₂>T, this situation is called saturation.Needs are repaiied as follows Just：

Now use T₁And T₂Replace t₁And t₂.

Re-define duty cycle parameters T_aon, T_bon, T_con:

Finally it may be determined that reality controls dutycycle T of required three-phase PWM ripple_a, T_b, T_c, as shown in table 3：

Sector N

Ⅰ

Ⅱ

Ⅲ

Ⅳ

Ⅴ

Ⅵ

Ta

Tbon

Taon

Taon

Tcon

Tcon

Tbon

Tb

Taon

Tcon

Tbon

Tbon

Taon

Tcon

Tc

Tcon

Tbon

Tcon

Taon

Tbon

Taon

Table 3

It is more than the flow process of traditional vector control algorithm.

But traditional control method flow process is excessively loaded down with trivial details, and software code amount is excessive, and conversion time is long.

Content of the invention

In order to overcome, the flow process of the vector control method of existing permagnetic synchronous motor is loaded down with trivial details, software code amount is excessive, conversion The deficiency of overlong time, the invention provides the permanent magnetism of a kind of loaded down with trivial details flow process of simplification, minimizing size of code, shortening conversion time is same The simple vector control method of step motor.

The technical solution adopted for the present invention to solve the technical problems is：

A kind of simple vector control method of permagnetic synchronous motor, described control method comprises the following steps：

Step one, according to controlled quentity controlled variable U_dAnd U_qU is obtained by Park inverse transformation_αAnd U_β, formula is as follows：

U α=U_dcosθ-U_qsinθ；

U β=U_qcosθ+U_dsinθ；

In formula, U_dAnd U_qFor the component of voltage on d, q axle, U_αAnd U_βRepresent dividing on the α axle and β axle in rest frame Amount, θ is space bit angle setting；

Step 2, according to the static U drawing_αAnd U_βValue carries out the projection scalar U in three phase coordinates_a、U_bAnd U_cCalculating, public Formula is as follows：

U_a=U_α

U_b=-1/2U_α+√3/2U_β

U_c=-1/2U_α-√3/2U_β

Step 3, according to the U drawing_a、U_bAnd U_cValue calculates three-phase dutycycle, public in conjunction with the projection scalar in three phase coordinates Formula U_a、U_bAnd U_cSituation of change, calculate three-phase dutycycle, formula is as follows：

Ta=T₁(1/2+1/√3U_a-1/2U₁)

Tb=T₁(1/2+1/√3U_b-1/2U₁)

Tc=T₁(1/2+1/√3U_c-1/2U₁)

U₁=1/ √ 3U_max+1/√3U_min

Wherein：T₁For PWM cycle T_pwmHalf, U_maxAnd U_minIt is U_a、U_bAnd U_cIn maximum and minimum value.

Beneficial effects of the present invention are mainly manifested in：Simplify loaded down with trivial details flow process, reduce size of code, shorten conversion time.

Brief description

Fig. 1 is the Principle of Electric Engine figure of three-phase PWM inverter.

Fig. 2 is three dimensional vector diagram.

Fig. 3 is regular hexagon magnetic linkage track.

Fig. 4 is the linear combination figure of space vector of voltage.

Fig. 5 is Traditional Space voltage vector control schematic diagram.

Fig. 6 is simple vector controlled schematic diagram.

Fig. 7 is analogous diagram.

Fig. 8 is SVPWM module composition figure.

Fig. 9 is simple vector control module figure.

Figure 10 is emulation three-phase dutycycle waveform.

Figure 11 is emulation three-phase current waveform.

Figure 12 is emulation rotation speed change waveform.

Specific embodiment

The invention will be further described below in conjunction with the accompanying drawings.

With reference to Fig. 6～Figure 12, a kind of simple vector control method of permagnetic synchronous motor, with traditional vector control algorithm Difference be that the algorithm of easy vector controlled does not need to carry out calculating action time, sector calculates and time saturation judges, letter Change loaded down with trivial details flow process, comprise the following steps：

Step one, according to controlled quentity controlled variable U_dAnd U_qU is obtained by Park inverse transformation_αAnd U_β, formula is as follows：

U α=U_dcosθ-U_qsinθ；

U β=U_qcosθ+U_dsinθ；

In formula, U_dAnd U_qFor the component of voltage on d, q axle, U_αAnd U_βRepresent dividing on the α axle and β axle in rest frame Amount, θ is space bit angle setting；

Step 2, according to the static U drawing_αAnd U_βValue carries out the projection scalar U in three phase coordinates_a、U_bAnd U_cCalculating, public Formula is as follows：

U_a=U_α

U_b=-1/2U_α+√3/2U_β

U_c=-1/2U_α-√3/2U_β

Step 3, according to the U drawing_a、U_bAnd U_cValue calculates three-phase dutycycle, and traditional vector controlled needs according to rule The first sector residing for space voltage vector to be judged, swears then in conjunction with two borders further according to the sector obtaining residing for space vector The action time of amount, calculate three-phase dutycycle.And simply vector controlled only needs to reference to the projection scalar public affairs in three phase coordinates Formula U_a、U_bAnd U_cSituation of change, calculate three-phase dutycycle, formula is as follows：

Ta=T₁(1/2+1/√3U_a-1/2U₁)

Tb=T₁(1/2+1/√3U_b-1/2U₁)

Tc=T₁(1/2+1/√3U_c-1/2U₁)

U₁=1/ √ 3U_max+1/√3U_min

Wherein：T₁For PWM cycle T_pwmHalf, U_maxAnd U_minIt is U_a、U_bAnd U_cIn maximum and minimum value.

Phantom is as follows：Through building SVPWM module, this model is added in whole illustraton of model, as Fig. 7 and Fig. 8 institute Show, Fig. 7 is vehicle simulation model, Fig. 8 is simple Vector Control Model.The flow process of whole conversion is rotating speed of target through rotating speed mould Type obtains the I of target_dAnd I_q, in conjunction with by motor three-phase current through Clark and Park the I that obtains of coordinate transform_dAnd I_qFeedback Value, obtains U through electric current loop_dAnd U_q.U_dAnd U_qBy simple Vector Control Model, obtain three-phase dutycycle T_a、T_b、T_c.T_a、T_b、 T_cPass through the three-phase current I to output of three-phase voltage model and motor model in conjunction with high tension voltage_a、I_b、I_cAnd actual speed. The three-phase dutycycle that obtains is as shown in figure 9, three-phase dutycycle T as seen from the figure_a、T_b、T_cWaveform and tradition do not have any area Not, as shown in Figure 10, three-phase current I as seen from the figure_a、I_b、I_cSine degree very good.As shown in figure 11, actual speed energy Enough steadily reach rotating speed of target, such as current goal rotating speed is 1500 turns, and after emulation, recording actual speed can steadily reach To 1500 turns.

Claims (1)

1. a kind of permagnetic synchronous motor simple vector control method it is characterised in that：Described control method comprises the following steps：

Step one, according to controlled quentity controlled variable U_dAnd U_qU is obtained by Park inverse transformation_αAnd U_β, formula is as follows：

U α=U_dcosθ-U_qsinθ；

U β=U_qcosθ+U_dsinθ；

In formula, U_dAnd U_qFor the component of voltage on d, q axle, U_αAnd U_βRepresent the component on the α axle and β axle in rest frame, θ is Space bit angle setting；

Step 2, according to the static U drawing_αAnd U_βValue carries out the projection scalar U in three phase coordinates_a、U_bAnd U_cCalculating, formula is such as Under：

U_a=U_α

U_b=-1/2U_α+√3/2U_β

U_c=-1/2U_α-√3/2U_β

Step 3, according to the U drawing_a、U_bAnd U_cValue calculates three-phase dutycycle, in conjunction with the projection scalar formula U in three phase coordinates_a、 U_bAnd U_cSituation of change, calculate three-phase dutycycle, formula is as follows：

Ta=T₁(1/2+1/√3U_a-1/2U₁)

Tb=T₁(1/2+1/√3U_b-1/2U₁)

Tc=T₁(1/2+1/√3U_c-1/2U₁)

U₁=1/ √ 3U_max+1/√3U_min

Wherein：T₁For PWM cycle T_pwmHalf, U_maxAnd U_minIt is U_a、U_bAnd U_cIn maximum and minimum value.