Next, with reference to Fig. 1～Figure 18, the execution mode of the control device of synchronous motor of the present invention is described.In addition, in the following embodiments, use permanent-magnet type synchronous motor (being designated hereinafter simply as the PM motor) to describe, but relate to other synchronous motor as motor, for example, coiled pipe type synchronous motor, reluctance type synchronous motor etc. can be realized too.
Execution mode 1
Fig. 1 is the block diagram of control device of the synchronous motor of embodiment of the present invention 1.The control device of present embodiment 1 at first has: rotary speed instruction generator 1, it produces the rotary speed instruction ω r of motor
*Inverter controller 2.This inverter controller 2, the alternating voltage that computing inverter 3 should be exported is transformed to pulse-width modulation (PWM) signal, exports to inverter 3.Then,, have as main circuit: DC power supply 4, it is to described inverter 3 power supplies; With permanent-magnet synchronous type synchronous motor 5 (being designated hereinafter simply as the PM motor) as controlling object.DC power supply 4 is made of AC power 41, the diode bridge 42 that constitutes rectification circuit and smoothing capacitor 43, produces direct voltage V0 at the two ends of smoothing capacitor 43.Have the current detector 6 that detects direct current IDC from this DC power supply 4 to the DC channel of inverter 3.
In controller 2, electric current reconstructor 7 is transfused to detection electric current I DC, reproduces three-phase alternating current Iu, Iv, the Iw that flows in the PM motor 5 by computing.Reproduced three-phase alternating current Iuc, the Ivc that goes out, Iwc be by coordinate converter 8, and by the phase angle θ dc at the PM motor of the inner supposition of controller, coordinate transform is d, q composition Idc, the Iqc on each.Voltage instruction arithmetic unit 9 is based on speed command ω r
*, current detection value Idc, Iqc computing be used for driving usually the voltage instruction Vdc of PM motor 5
*Dq inverse converter 10 is with voltage instruction Vdc
*Be transformed to three-phase alternating voltage instruction Vu
*Pwm pulse generator 11 is based on three-phase alternating voltage instruction Vu
*, produce pulse-width modulation (PWM) signal that is used for drive controlling inverter 3 switches.Voltage instruction switch 12 measures automatically at the common electric constant of drive pattern and PM motor/carry out the switching of voltage direct current between the adjustment modes.Equally, phase bit instruction switch 13 switches the phase bit instruction.Measure with frequency setter 14 and be set in the frequencies omega 1t that the mensuration usefulness under electric constant measuring/adjustment modes exchanges.Motor constant automatic regulator 15, incoming frequency ω 1t, produce electric constant measuring required apply voltage instruction Vdc
*, simultaneously by detecting electric constant Ld, Lq and the output that electric current I dc, Iqc calculate PM motor 5.Zero phase command generator 16 has phase place with controller inside and is fixed on zero effect when electric constant measuring/adjustment.At last, mode switch 17, according to instruction from the outside, the pattern of switch controller 2 between common drive pattern and the automatic mode determination of electric constant.
Then, use Fig. 1 that the operating principle of present embodiment 1 is described.
In the present embodiment, as the action of controller 2, have common drive pattern and these two kinds of patterns of electric constant autosensing mode of PM motor 5, these switch according to the signal from mode switch 17.Usually during drive pattern, voltage instruction switch 12 switches in illustrated state " 0 " side with bit instruction switch 13 mutually, in addition, in mode determination automatically, switches in " 1 " side.
At first, common drive pattern is described.From the communication agency of rotary speed instruction generator 1, provide motor speed instruction ω r to voltage instruction arithmetic unit 9 by numeral or simulation etc.
*In voltage instruction arithmetic unit 9, based on rotary speed instruction ω r
*With detection electric current I dc, Iqc, carry out the required voltage instruction Vdc of PM mode activated
*And to the computing of the interchange phase theta dc that applies voltage of PM motor 5.
In electric current reconstructor 7, based at current detector 6 detected source current IDC and pwm signals, open the method for records such as flat 8-19263 communique by the spy, the three-phase alternating current of PM motor is reproduced in computing.Then, in coordinate converter 8, reproduced alternating current Iuc, the Ivc that goes out, Iwc are transformed to angular frequency 1 based on exchanging phase theta dc
*Electric current composition Idc, the Iqc of the rotatable coordinate axis (dq axle) of rotation.On the other hand, Vdc
*Be transformed to of ac again by dq coordinate inverter 10, and then, in pwm pulse generator 11, be transformed to the pulse width modulated wave signal, send to inverter 3.About this elemental motion, be that to open the method for putting down in writing in the 2002-272194 communique same with the spy.
Then, the action to the automatic mode determination of feature of the present invention describes.
In automatic mode determination, the a-c cycle that changes with the angular frequency 1t that sets in measuring with frequency setter 14 is applied to Vdc
*, in PM motor 5, flow through electric current.According to the relation of this electric current and voltage, the d axle inductance L d of computing PM motor 5 and q axle inductance L q.The phase current waveform of the handling process of use Fig. 2 and the PM motor of Fig. 3 illustrates this action.
Fig. 2 is the automatic mensuration process chart of the synchronous motor control device of this execution mode 1.At first, in step 201, will measure with frequencies omega 1t and be made as zero, in step 202, direct voltage Vd will be applied to gradually the Vdc of PM motor
Fig. 3 is the motor dc waveform figure in the synchronous motor control device of this execution mode 1.At first, shown in (1) during Fig. 3, direct current Iu～Iw is increased lentamente, tiltedly hummock increase voltage Vdc
*Like this, the rotor-position of PM motor 5 is consistent with the dc axle (magnetic flux axle) in the control.
Then, in step 203, will measure with frequencies omega 1t and be set in electric angle frequencies omega 1max, this electric angle frequencies omega 1max is the consistent electric angle frequency of employed maximum speed in the common driving with PM motor 5.And, in step 204, by the d shaft voltage being instructed Vdc
*As the simple sinusoidal ripple, and the three-phase imbalance alternating voltage is applied to PM motor 5.In step 205, based on detected current value computing d axle inductance L d this moment.
Then, in step 206, with d shaft voltage instruction Vdc
*Be made as zero, with q shaft voltage instruction Vqc
*Be made as sine wave, the PM motor is applied the three-phase imbalance alternating voltage.In step 207, same, based on detecting current value, calculate q axle inductance L q.
Above step 204～207 are apply (2) during the automatic mode determination of motor constant that three-phase imbalance exchanges among Fig. 3, and the current waveform of PM motor 5 is the alternating current of illustrated three-phase imbalance.
Then, enter (3) during the common drive pattern, supply with three-phase equilibriums from inverter 3 to PM motor 5 and exchange, drive PM motor 5.
The most important thing is to measure setting in the present embodiment with frequencies omega 1t.Even on the d axle, apply alternating voltage, in PM motor 5, do not produce torque yet, produce basic torque for the electric current on the q axle.But, be set in the frequency (ω 1t=ω 1max) identical by measuring, the change of the rotor when suppressing q axle inductance L q mensuration with PM motor maximal rate frequencies omega 1max with frequencies omega 1t.Use Fig. 4 that this principle is described.
Fig. 4 is that torque current in the controller for ac motor of expression embodiments of the present invention 1 is to the block diagram of the transfer function of rotor phase.This figure (a) is the figure that represents the phase change from torque current Iq to the PM motor with transfer function.The function representation of the relation of Iq and phase angle θ dc number of poles P, the magnetic flux Φ of motor, the inertia J of mechanical system etc.In addition, the symbol among the figure, Tm: the torque that expression produces, the rotating speed of ω r:PM motor; ω 1: expression electric angle frequency.Here, establish the alternating component Δ Iq of Iq change, transfer function becomes shown in Fig. 4 (b).Changing its maximum by Δ Iq phase angle is Δ θ.Shown in figure (c), the quadratic power of Δ θ and ω 1t is inversely proportional to.
That is, do not change rotor as far as possible, for the state estimating inductance to fix, the a-c cycle when preferably measuring is high as much as possible.But, under the frequency that with common driving the time, falls far short, influence the frequency characteristic of PM motor on the contrary, may enlarge evaluated error, preferred undue raising.For the motor of the idle call of market sale, just can be with 25% mensuration of the highest speed of this motor with the constant of enough precision determination motor with frequency.
But, in execution mode 1,,, be can be with the constant of enough precision determinations/adjustment motor so long as not the motor of special purpose with measuring when being made as the highest driving frequency ω 1max of PM motor with frequencies omega 1t.If consider, even also can not have big problem than the high several one-tenth of maximal rate frequency from the angle of the magnetic loop characteristic of PM motor.
In addition, the purposes of PM motor for example, as refrigerator or air-conditioning, if there is some restriction, is imagined some qualification from its capacity and rotating speed to the inertia J of mechanical system.At this moment, the amplitude of fluctuation of phase angle θ for example is defined in ± 5 degree in, shown in Fig. 4 (d), can set to measure according to following formula (1) and use frequencies omega 1t.
In addition, at this moment, if the capacity of PM motor, rated voltage, rotating speed are if known, required magnetic flux Φ can be made as the value of general knowledge, also can set.
And then, in present embodiment 1, direct current is tiltedly hummock increased, carry out the location of rotor, still, the oil pressure pump during low temperature etc. are if the strong load of viscosity, even it is also no problem to apply the direct current of oblique wave shape.And, even, suppose if known d shaft position then can not pass through direct current not by direct current.For example, can use the spy and open the initial position estimation method shown in the 2002-078392 communique, need not pass through direct current.
More than, according to the 1st execution mode of the present invention, the fixing rotor of PM motor, inductance that can high-precision measuring/electric constant of adjustment.Especially, in mensuration, needn't pass through direct current, can reduce burden, can prevent the fault of inverter owing to the formation contravariant equipment that causes by direct current.
In addition, in the present embodiment (and, at execution mode after this), as electric current detecting method, use the method that detects the inverter direct current, still, detect direct phase current if having the phase current detector of PM motor, can not need electric current reconstructor 7.
Execution mode 2
Then, use Fig. 5～Fig. 7, embodiments of the present invention 2 are described.
In described execution mode 1, the mensuration in automatic mode determination is consistent with the maximum drive frequency (maximum electric angle frequency) of PM motor with frequency.At this moment, which kind of degree the rotor of PM motor changes, and which kind of error is measurement result exist, and depends on the inertia J of mechanical system.Therefore, in present embodiment 2, provide the control device of having examined these problems.
Fig. 5 is the partial graph of control block diagram of the synchronous motor control device of embodiments of the present invention 2.Only represented the relation of the mensuration in the present embodiment with frequency setter 14B and motor constant automatic regulator 15B, execution mode 2 uses it to replace 14,15 of Fig. 1.Its action uses the handling process of Fig. 6 and the waveform of Fig. 7 to describe.
Fig. 6 is the flow process that the automatic mensuration of the synchronous motor control device of embodiments of the present invention 2 is handled.
Fig. 7 is frequency, the current waveform of motor and the time changing curve of inductance measurement result that the mensuration in the synchronous motor control device of expression embodiments of the present invention 2 exchanges.
At first, in Fig. 6, step 201～205 are steps of using prosign with Fig. 2, measure inductance L d.
In step 601, measure the frequency arbitrarily that is set in the driving frequency scope of PM motor 5 with frequencies omega 1t, with d shaft voltage instruction Vdc
*Be made as zero, the Vqc of q shaft voltage instruction simultaneously
*Be made as simple sine wave, thus PM motor 5 applied the three-phase imbalance alternating voltage.In step 602, based on detected current value this moment, computing q axle inductance L q.With the value Lq0 of this measurement result, be stored in step 603 as the 1st time Lq in Fig. 7.Then, in step 604, will measure increases somely with frequencies omega 1t, in step 605, based on detected current value once more, calculate q axle inductance L q.In step 606, the inductance L q0 of this inductance L q that obtains and last stored is compared, big if its difference DELTA Lq becomes, if for example surpass 5%, return step 603 and repeat this action.In this repeats, increase to measure and use frequency, make the convergence of Lq value.At this moment, the phase current of PM motor 5 shown in Fig. 7 (b), progressively becomes high-frequency.Before the value that once obtains and this value that obtains poor, when converging in for example 5% the scope of regulation, do not have frequency dependence, promptly can think not to be subjected to the rotor influence of change.Therefore, enter step 607, this value that obtains is decided to be q axle inductance L q, shown in Fig. 7 (c), receive and measure.
Employed frequency in the mensuration is preferably the frequency that as far as possible is close with the real-world operation condition.But, during rotor oscillation, there is the influence of Ld in the measured value of Lq, it is big that error becomes.By adopting present embodiment, can improve these problems significantly.
Execution mode 3
Then, use Fig. 8～9 pair embodiments of the present invention 3 to describe.
As implement shown in the mode 1,2, in order to measure electric constant, need in motor, flow through interchange.But when suddenly flowing through the interchange near rated current, taking this as an opportunity, may cause rotor and begin vibration.
Fig. 8 is the part control block diagram of the synchronous motor control device of the embodiments of the present invention 3 that address the above problem.By using the motor constant automatic regulator 15C of Fig. 8, replace the motor constant automatic regulator 15 among Fig. 1, can realize being difficult to vibrative device.
In Fig. 8, motor constant automatic regulator 15C is made of Ld analyzer 18 and Lq analyzer 19.It is the same that the inside of the two constitutes, and only represents the concrete formation of Ld analyzer 18.At first, have: decision applies the mensuration voltage amplitude instruction device 20 of the amplitude of voltage when constant measuring; The rate of change of this instruction is provided the speed limiting device 21 of restriction.Then, also have: receive the interchange function generator of measuring with the function of frequencies omega 1t sine wave output shape 22; The long-pending multiplier 23 of the output of this interchange function generator 22 of computing and the output of described speed limiting device 21.Further, based on detecting Ld (or Lq) arithmetic unit 24 that electric current I dc (or Iqc) calculates inductance L d (perhaps Lq).
Fig. 9 is the motor current oscillogram in the electric constant measuring pattern in the synchronous motor control device of embodiments of the present invention 3.
Then, for the action of Fig. 8, the limit describes with reference to the motor current waveform limit of Fig. 9.Measure voltage, apply with the order of d axle → q axle, this action is programmed in mensuration voltage amplitude instruction device 20.Export the voltage of oblique wave shapes from measuring voltage amplitude instruction device 20, but speed limiting device 21 limits its rate of change.The confined amplitude instruction of rate of change is multiplied each other at multiplier 23 with the sinusoidal wave function that exchanges function generator 22 outputs, as Vdc
*), Dui Ying mensuration is applied to the PM motor with uneven three-phase alternating current therewith.Apply voltage owing to be the interchange that amplitude slowly increases, so as shown in Figure 9, this current value also slowly increases.Its result reduces the influence of disturbance, does not produce vibration.In addition, when measuring end, voltage amplitude slowly reduces, and prevents motor oscillating.
More than, according to present embodiment 3, can slowly increase and decrease the AC amplitude of the constant measuring that is used for inductance etc., can prevent the vibration of rotor effectively.In addition, when measuring d axle inductance, owing to reduce the effect of rate limit, so use rate limit also can only measure the time to q axle inductance.
Execution mode 4
Then, use Figure 10 that embodiments of the present invention 4 are described.
As implement shown in the mode 1～3, in order to measure electric constant, need to measure motor constant according to the detected value that applies current/voltage and alternating current therewith.At this moment, need to introduce phase information and analyze the relation that applies voltage and detect electric current.Usually, generally be to import fourier progression expanding method.But, handle by numerical operation, correctly realize fourier progression expanding method, the problem that exists the software processes load to increase.Especially, when changing mensuration with frequencies omega 1t, differential cycle or integration period etc. need be set suitably according to the motor nominal parameter.Therefore, in the present embodiment, provide a kind of, carried out the generation of alternating voltage waveform and the constituent analysis of detection electric current simultaneously, tried to achieve the method for inductance and impedance composition simultaneously by simple method.
Figure 10 is the functional block diagram of Ld analyzer of the synchronous motor control device of embodiments of the present invention 4.Also prepared the same Lq analyzer that constitutes,, can realize high-precision constant automatic regulating apparatus by the execution mode 1～3 before using with this Ld analyzer 18D.
Ld analyzer 18D shown in Figure 10 is by constituting with the same mensuration voltage amplitude instruction device 20 of Fig. 8, speed limiting device 21, multiplier 23, the resistance R of calculating PM motor 5 and the RL arithmetic unit 25 of inductance.This RL arithmetic unit 25 has: carry out integration with frequencies omega 1t, the integrator 26 of output phase angle θ 1t to measuring; Based on the sinusoidal wave cosine wave generator of measuring with frequencies omega 1t difference sine wave output and cosine wave 27,28.In addition, also have the multiplier 29,30 that these sine wave/cosine waves and current detection value Idc are multiplied each other; Import these product values, the first-order lag filtering ripple device 31,32 of excision pulse composition.And then, also have: based on the output of measuring voltage amplitude instruction Vt, first-order lag filter 31,32 and mensuration frequencies omega 1t, the constant arithmetic unit 33 of the electric constant Ld (perhaps Lq) of computing motor.
Then, the action to Ld analyzer 18D describes.
The action of measuring voltage amplitude instruction Vt and execution mode 3 constitutes equally.Long-pending by the output of this Vt and cosine wave generator 28, Vdc
*With following formula (2) expression, PM motor 5 is applied alternating voltage.
On the other hand, detect electric current I dc because for Vdc
*Be phase retardation, so become following formula (3).
(3) formula can be carried out the conversion of (4).
For this Idc, when for example multiply by sinusoidal wave function, become following (5), be separated into the ripple component of flip-flop and 2 times.
In this waveform, the first-order lag filter 31 in Figure 10 when only exporting flip-flop, obtains Idsin (sine-wave components).
Equally, in (4) formula, multiply by cosine wave,, can extract Idcos (cosine wave composition) by filter 32.At this moment, if the time constant TLF of first-order lag filter 31,32 is set in some more than the value, there is not big problem even change frequencies omega 1t yet.Thereby, even, also can realize easily without fourier progression expanding method or the such processing of FFT.
Therefore, two first-order lag filters 31,32 form sine-wave components Idsin, the cosine wave composition Idcos of Idccos respectively.As Vdc
*,,, in constant arithmetic unit 33, ask for Ld or R by following (6) according to this relation because cosine wave is provided.
In addition, in the present embodiment, be that example describes with the electric constant of d axle, the q axle also fully equally can computing Lq, R.
Like this, according to embodiment of the present invention 4, the electric current that is flow through by alternating voltage can be in the hope of the electric constant of motor with simply constituting separated component.
Execution mode 5
Then, use Figure 11, embodiments of the present invention 5 are described.
Described execution mode 4 in order to measure electric constant, applies alternating voltage, and the detected value of following its alternating current is separated into the same phase constituent of alternating voltage and differs 90 compositions of spending phase places, the electric constant of computing.
Known: electric constant, particularly inductance as motor are subjected to magnetically saturated influence easily, and according to measuring current value, its value changes as can be known.Therefore, do not apply voltage originally, current value as only flowing through the motor rated current, was measured electric constant.
According to present embodiment, current value as parameter, can be realized the automatic mensuration of electric constant.
Figure 11 is the Ld analyzer 18E functional block diagram in the synchronous motor control device of embodiments of the present invention 5.By using present embodiment to replace Ld analyzer 18D in the above-mentioned execution mode, can realize the constant automatic regulating apparatus of current value as parameter.
In as Figure 11,, set the size of current-order by measuring current amplitude instruction device 34.In this embodiment, not additional speed limiting device, but also can be additional as execution mode before.In the present embodiment, carry out the add operation of signal or the adder-subtractor 35,36 of subtraction, integral compensation device 37,38, constant arithmetic unit 39, adder 40 and multiplier 44,45 use as new parts.In addition, also have: the zero phase command generator 16 that before illustrated in the execution mode, integrator 26, sine-wave generator 27, cosine wave generator 28, multiplier 29,30 and first-order lag filter 31,32.
Then, the action to Ld analyzer 18E describes.
For current detection value Idc, multiply each other by multiplier 29,30 and cosine wave function, sinusoidal wave function, its value of multiplying each other is imported first-order lag filter 31,32 respectively, only exports flip-flop.Action so far, identical with described simple type fourier progression expanding method.Then, for the composition separately of Idsin and Idcos, the difference in adder-subtractor 35,36 between the computing and instruction value.For Idsin, calculate and It and the difference of measuring 34 outputs of current amplitude instruction device, calculate output voltage V dsin so that this difference is zero by integral compensation device 37.Equally, calculate Vdcon so that it is controlled to be zero for Idcon by zero phase command generator 16.Vdsin, Vdcos multiply each other with the function of sine wave/cosine wave respectively in multiplier 44,45.These after adder 40 is carried out the two addition, become the voltage instruction Vdc that imposes on motor
*It is characterized in that in the present embodiment, the sine wave of current value/cosine wave composition carry out FEEDBACK CONTROL in the mode of and instruction unanimity separately.In the constant arithmetic unit 39, use the value of Vdsin, Vdcos, ω 1t and It, according to following (7) computing motor constant.
In addition, in the present embodiment, be that example describes with the electric constant of d axle, but the q axle is also identical, can calculate Lq, R.
So, according to the 5th execution mode of the present invention, with the size of electric current as parameter, with simple formation just can calculating motor electric constant.Thus, can measure magnetic saturation characteristic, further improve control precision for current value.
Execution mode 6:
Then, use Figure 12, embodiments of the present invention 6 are described.
Above-mentioned execution mode 5 is measured constant with current amplitude automatically as constant.So, by importing FEEDBACK CONTROL, current value can be measured as parameter.In the establishing method of feedback oscillator, have problems.That is, for current value is stable at setting apace, must be according to the parameter of controlling object, (the gain KiL of the integral compensation device 34 among Figure 11) is set in suitable value with ride gain.But, under the situation that electric constant is not known fully, can not carry out the best and set, need to make in the response sacrifice to a certain degree.In the worst case, possible diverging oscillation is not restrained, and is absorbed in and can not measures.The motor that refrigerator is used etc. if its purposes is limited, can carry out gain setting to a certain degree, still, further, in the wide field of scope, are carrying out the automatic mensuration existing problems of constant.
Therefore, in the present embodiment, provide a kind of and can further enlarge versatility, and with the control device of current value as parametric measurement.
Figure 12 is the functional block diagram of Ld analyzer of the synchronous motor control device of embodiments of the present invention 6.With the execution mode of basic comprising as Figure 10, but there is very big difference in Ld analyzer 18F providing of voltage amplitude direct current.The Ld analyzer 18F of Figure 12 as new parts, appends and measures voltage amplitude increment rate setting apparatus 46, integrator 47, measures current amplitude setting apparatus 48, current amplitude arithmetic unit 49 and signal comparator 50.RL arithmetic unit 25 is fully different with above-mentioned execution mode 4 (Figure 10), and difference is that Idsin and Iqsin are with 49 outputs of current amplitude arithmetic unit.
Then, the action to Ld analyzer 18F describes.
Measure in the voltage amplitude increment rate setting apparatus 46 and set increment rate dV, increment rate dV is used for slowly increasing the amplitude of the alternating voltage that the PM motor is applied.For example, 10% grade that increases rated voltage in the second is such, carries out dV and sets.In the switch 13, according to the output of comparator 50, switch is switched to  or , when , dV directly exports, and output zero when .In the integrator 47, carry out integration according to the output of switch 13.On the other hand, in current amplitude arithmetic unit 49, based on the value of Idcos, Idsin, by following formula (8) operation current amplitude I0.
Relatively this is worth and measures the output It of current amplitude setting apparatus 48 with comparator 50, if It＞I0 switches to  side with switch 13, if It＜I0 switches to  side with switch 13.Its result, the alternating voltage of constant measuring, its amplitude slowly continues to increase from null value, when becoming I0=It, stops to increase.That is, do not import Current Feedback Control, feedforward ground is set in setting with current value.Its result enlarges the electric constant scope as the motor of the object of measuring automatically, no matter be the PM motor of which kind of purposes all can not need mensuration constant with adjusting.This method be broad sense FEEDBACK CONTROL, its maximum characteristics are, by sacrificing linearity, enlarge the versatility to unknown motor.
In addition, in the present embodiment, be that example describes with the electric constant of d axle, even the q axle also can fully similarly calculate Lq, R at that time.
So, according to the 6th execution mode of the present invention, the size of electric current as parameter, can be realized the automatic mensuration of the electric constant that versatility is high.
Then, use Figure 13～Figure 16, embodiments of the present invention 7 are described.
As described in the execution mode 1, use the current detector of current detector conduct in this control device of the direct current of the detection inverter of in Fig. 1, representing.In fact current detector 6 can use cheap current detector that can small-sized installation such as shunt resistor.
In the present embodiment, relate to mechanism according to this direct current detection motor current.
Figure 13 A, Figure 13 B are the common drive pattern in the synchronous motor control device of embodiment of the present invention 7 and the comparison diagram that applies the power supply instruction of constant measuring pattern, are illustrated in the difference of two voltage waveforms under the pattern.Here, during the common driving of Figure 13 A, apply the balance three-phase alternating voltage, on the other hand, in the constant measuring pattern that comprises the automatic adjustment of Figure 13 B (adjusting automatically), apply extremely unbalanced three-phase imbalance voltage.Especially, among near the regional P the zero cross point of Figure 13 B, simultaneously, all voltage instructions are zero.Problem on the current detecting that accompanies therewith describes with reference to Figure 14.
Figure 14 be the expression embodiments of the present invention 7 the synchronous motor control device in electric current and voltage oscillogram.In the drawings, apply voltage Vu and Iu and have the almost phase difference of 90 degree.That is, measuring with frequencies omega 1t is high frequency waves, is almost inductive load thus.Its result, near the regional P the peak value of electric current I u, phase voltage Vu are approximately zero.All phase voltages are under zero the condition, not flow through electric current in the current detector 6, and near the regional P current peak does not flow through direct current IDC, can not observe.Like this, omit near the current detecting of current peak, reduced its precision.
Figure 15 is the partial function block diagram of the synchronous motor control device of embodiments of the present invention 7, expression motor constant automatic regulator 15G.The maximum difference of Figure 15 and before execution mode (for example, Fig. 8 etc.) is for the Vdc from Ld analyzer 18 and 19 outputs of Lq analyzer
*, set its maximum lower limit 51,52.Its result can stop near the reduction of the voltage instruction of zero cross point, carries out current detecting.
Figure 16 is electric current, the voltage oscillogram in the synchronous motor control device of embodiments of the present invention 7.As shown in the figure, limit the lower limit of each phase voltage among near the regional P zero cross point, have the electric current of the DC path of following PWM control.On the other hand, voltage instruction is revised, near the error the zero cross point of voltage to almost not influence of overall situation, can be carried out current detecting accurately, and the manner is very effective gimmick in practicality.
In addition, when the actual IGBT of use constituted inverter circuit, the width that will export pulse as the lower limit of voltage instruction absolute value got final product as target.Consider to follow the connection phenomenon of switch motion, minimum is guaranteed the energising width of 10 μ s, can carry out current detecting.
Execution mode 8
Figure 17 is the overall appearance pie graph of control device of the synchronous motor of embodiments of the present invention 8.
In Figure 17, comprise rotary speed instruction generator 1 and the mode switch 17 of Fig. 1 in the microcomputer 53.Below, similarly represent identical parts with symbol 2,3,5,6,41,42,43 identical the meeting of Fig. 1.Pass through 54 pairs of power model 55 transfer instructions of order wire from microcomputer 53.This power model 55 is with the module after the controller 2 of Fig. 1, inverter 3, current detector 6 and diode bridge 42 integrated smallizations.In addition, connect the control device that AC power 41, smmothing capacitor 43 and PM motor 5 can be realized synchronous motor by wiring in power model 55, it can measure/adjust the electric constant of PM motor 5 automatically.
In the present embodiment, by controller 2 or inverter 3 modularizations, miniaturization that can implement device integral body, which kind of motor 5 no matter all can improve the mobility of simple driving control device, can enlarge its versatility.
Execution mode 9
Then, use Fig. 8, embodiments of the present invention 9 are described.
The outward appearance formation of the control device of the execution mode 9 behind application the present invention in air-conditioning during Figure 18.In Figure 18, meet 2,3,6,42 and 43 respectively with execution mode 1 (Fig. 1) and the identical part of execution mode 8 (Figure 17).The off-premises station 57 of air-conditioning that present embodiment constitutes is: controlled the compressor 56 of motor built-in with power model 55, power model 55 is equipped with controller 2, inverter 3, current detector 6 and diode bridge 42.The compressor 56 of air-conditioning etc. is equipped with PM motor 5 in the inside of the compressor 56 of air-tight state, the detection difficult of the rotating speed of PM motor or the position of magnetic flux etc.
But, by control device of the present invention is installed as power model 55, needn't detect the rotating speed or the position of motor, in addition, can measure/adjust the electric constant of motor 5 automatically with motor 5 the state in the compressor 56 of being built in.
In addition, as execution mode, be that example describes with the air-conditioning, other electric equipment for example, under the situations such as discrete air-conditioning, refrigerator, can obtain same effect.