CN100487476C - Apparatus for testing reactance parameter of permanent magnet motor based on small DC attenuation - Google Patents

Abstract

The device includes DC power supply, transformer, rectification module, data acquisition card, single process and protection module, signal amplification module, computer, relay, non-inductive resistance etc.. Including two pieces of triodes, the control signal amplification module magnifies a control signal sent from the computer by the said amplifying circuit in order to realize function of attenuating DC through controlling on/off of the relay. The single process and protection module includes operational amplification circuit (OAC), control switch, regulation tube. Being obtained from input signal of passing through OAC, the amplified voltage signal subtracts difference mode signal obtained by two control switches, then is amplified in operational amplifier. Amplified attenuation signal is sent to the data acquisition card which transfers collected signal to computer for carrying out calculating parameter of reactance.

Description

Device based on little direct current attenuation method testing reactance parameter of permanent magnet motor

Technical field

The invention belongs to the motor impedance parameter test device, particularly a kind of device based on little direct current attenuation method testing reactance parameter of permanent magnet motor.

Background technology

Conventional direct current attenuation method is to utilize to reach the stable DC electric current in the armature winding and determine reactance parameter of permanent magnet motor through resistance decrement to zero transient process because of losing driving voltage; In transient process, the degree of saturation of motor is constantly to change, and is to can not get correct parameter of saturation value by handling the direct current die-away curve like this.Simultaneously, because the cross saturation phenomenon appears in magneto, and conventional direct current attenuation method is not considered this point, does not well connect with the actual motion state of motor.And, utilize this kind method to measure reactance parameter of permanent magnet motor and also be confined to usually to utilize on the basis that the limited components and parts in laboratory build, do not consider repeatability and precision, the testing tool that is specifically applied on the actual engineering does not appear in the newspapers.

Summary of the invention

There is not the deficiency of the saturated and cross saturation factor of fine consideration in order to overcome conventional direct current attenuation method, the invention provides a kind of two-circuit method of little DC current excitation, and develop the reactance parameter of permanent magnet motor testing tool that is specifically designed to practical engineering application on this basis---based on the device of little direct current attenuation method testing reactance parameter of permanent magnet motor.

The realization principle of using little direct current attenuation method testing reactance parameter of permanent magnet motor is as follows:

(1) foundation of parameter identification target equation

The unified equation of rare earth permanent-magnet synchronization motor d, q axle following (U=0 during the stator winding suddenly-applied short circuit):

0＝R _ai+p(X _a+X _s)i+pX _ai _k (1)

0＝R _ki _k+pX _ki _k+pX _ai (2)

Wherein: X _sBe stator leakage reactance, R _aBe the stator phase resistance; When measuring the d-axis reactance parameter, X _aBe the d-axis reactance of armature reaction, Xk is the reactance of equivalent d-axis damping circuit, R _kBe equivalent d-axis damping circuit main resistor, i is the direct-axis current of stator winding, i _kIt is the direct-axis current of rotor damping winding; When measuring the quadrature axis reactance parameter, X _aBe quadrature axis armature reaction reactance, X _kFor the reactance of axle damping circuit, R are handed in equivalence _kHand over axle damping circuit main resistor for equivalence, i is the friendship shaft current of stator winding, i _kIt is the friendship shaft current of rotor damping winding; P is differentiating operator d/ (dt).

A kind of conversion commonly used in the electrical engineering is done on formula (1), (2) both sides, promptly blocked loose conversion, I ₀Be the decay current initial value:

XPI ₀＝R _ai(p) ⁺XPi(p) ⁺X _aPi _k(p) (3)

X _aPI ₀＝R _ki _k(p)+X _kPi _k(p)+X _aPi(p)

Can get by equation (3):

$i\left(p\right)=I_0-\frac{(R_a{R}_k+R_a{X}_{k}P)I_0}{R_a{R}_k+(X_k{R}_a+{\mathrm{XR}}_k)P+({\mathrm{XX}}_k-X_a^2)P^2}---\left(4\right)$

Formula (4) is blocked loose inverse transformation, obtains:

$i=I_{k1}{e}^{{-P}_{k1}t}+I_{k2}{e}^{{-P}_{k2}t}---\left(5\right)$

Wherein:

${\mathrm{<figure-callout\; id="1"\; label="p\; k"\; filenames="C200510046543E00101.png"\; state="\{\{state\}\}">p</figure-callout>}}_k=\frac{A+\sqrt{A^2-{4R}_a{R}_{k}B}}{2B}---\left(6\right)$

$p_{k2}=\frac{A-\sqrt{A^2-{4R}_a{R}_{k}B}}{2B}---\left(7\right)$

$I_{\mathrm{<figure-callout\; id="1"\; label="k"\; filenames="C200510046543E00101.png"\; state="\{\{state\}\}">k</figure-callout>}1}=\frac{C-D-R_a^2{X}_k^2-R_a{X}_k\sqrt{A^2-{4R}_a{R}_{k}B}}{A^2-{4R}_a{R}_{k}B+A\sqrt{A^2-{4R}_a{R}_{k}B}}---\left(8\right)$

$I_{k2}=\frac{C-D-R_a^2{X}_k^2-R_a{X}_k\sqrt{A^2-{4R}_a{R}_{k}B}}{A^2-{4R}_a{R}_{k}B-A\sqrt{A^2-{4R}_a{R}_{k}B}}---\left(9\right)$

A＝R _aX _k+R _kX (10)

$B={\mathrm{XX}}_k-X_a^2---\left(11\right)$

C＝R _aX _kXX _k 12)

$D={2R}_a{R}_k{X}_a^2---\left(13\right)$

$P_{k1}{\mathrm{<figure-callout\; id="1"\; label="I\; k"\; filenames="C200510046543E00101.png"\; state="\{\{state\}\}">I</figure-callout>}}_k+P_{k2}{I}_{k2}=\frac{R_a{X}_k}{{\mathrm{XX}}_k-X_a^2}---\left(14\right)$

$\frac{I_{k1}}{{\mathrm{<figure-callout\; id="1"\; label="P\; k"\; filenames="C200510046543E00101.png"\; state="\{\{state\}\}">P</figure-callout>}}_k}+\frac{I_{k2}}{P_{k2}}=\frac{X}{R}$

$\frac{I_{k1}}{P_{k2}}+\frac{I_{k2}}{{\mathrm{<figure-callout\; id="1"\; label="P\; k"\; filenames="C200510046543E00101.png"\; state="\{\{state\}\}">P</figure-callout>}}_k}=\frac{X_k}{R_k}$ (15)

The stable state synchronous reactance: $X{=R}_a(\frac{I_{k1}}{{\mathrm{<figure-callout\; id="1"\; label="P\; k"\; filenames="C200510046543E00101.png"\; state="\{\{state\}\}">P</figure-callout>}}_k}+\frac{I_{k2}}{P_{k2}})---\left(16\right)$

Formula (5) is the target equation of parameter identification, wherein P _K1, P _K2, I _K1, I _K2Parameter identification method below available is tried to achieve.

(2) discrimination method of reactance parameter

The state equation form that the general mathematics model of rare earth permanent-magnet synchronization motor can be expressed as:

$\left.\begin{array}{c}\stackrel{\&CenterDot;}{X}=\mathrm{AX}+\mathrm{BU}\\ Y=\mathrm{CX}+\mathrm{DU}+E\\ X\left(t_0\right)=X_0\end{array}\right\}---\left(17\right)$

Here, X is the state variable vector of system, and Y is an output vector, t ₀Be the initial moment, A, B, C, D are respectively the matrix of coefficients of state equation, and U is an input vector, and E is by the additional vector of the output equation of starting condition decision.X, Y, A, B, C, D, E are the functions of systematic parameter to be identified.

Use the value of least squares identification parameter vector, thereby make objective function reach minimum.If the following expression of the form of objective function J:

$J={\&Integral;}_{\mathrm{to}}^{\mathrm{tf}}{(Y_r-Y)}^{T}R(Y_r-Y)\mathrm{dt}---\left(18\right)$

Wherein t is a time variable, and t0 is observation zero-time, t _fBe observation termination time, Y _rBe the output of real system, R is the symmetric positive definite weighting matrix through suitably choosing.The system parameter vector to be identified of setting up departments is α, will export Y at a certain given parameter vector value α ₀Near be launched into Taylor series:

$Y=Y|{\mathrm{\&alpha;}}_0+\frac{\&PartialD;Y}{\&PartialD;\mathrm{\&alpha;}}|{\mathrm{\&alpha;}}_0(\mathrm{\&alpha;}-{\mathrm{\&alpha;}}_0)+......---\left(19\right)$

Obtain the following form of J:

$J\left({\mathrm{\&alpha;}}_0\right)={\&Integral;}_{t_0}^{\mathrm{tr}}[Y_r-Y|{\mathrm{\&alpha;}}_0-\frac{\&PartialD;Y}{\&PartialD;\mathrm{\&alpha;}}{\left|{\mathrm{\&alpha;}}_0(\mathrm{\&alpha;}-{\mathrm{\&alpha;}}_0)\right]}^{T}R[Y_r-Y|{\mathrm{\&alpha;}}_0-\frac{\&PartialD;Y}{\&PartialD;\mathrm{\&alpha;}}\left|{\mathrm{\&alpha;}}_0(\mathrm{\&alpha;}-{\mathrm{\&alpha;}}_0)\right]\mathrm{dt}---\left(20\right)$

Identification to the α value should make J=min, that is:

$\frac{\&PartialD;J}{\&PartialD;\mathrm{\&alpha;}}=0---\left(21\right)$

By on get final product:

$\mathrm{\&Delta;\&alpha;}=\mathrm{\&alpha;}-{\mathrm{\&alpha;}}_0={\left[{\&Integral;}_{t_0}^{t_f}{\left(\frac{\&PartialD;Y}{\&PartialD;\mathrm{\&alpha;}}\right|{\mathrm{\&alpha;}}_0)}^{T}R\frac{\&PartialD;Y}{\&PartialD;\mathrm{\&alpha;}}\right|{\mathrm{\&alpha;}}_0]}^{-1}{\mathrm{dt}]}^{-1}\left({\&Integral;}_{t_0}^{t_f}{\left(\frac{\&PartialD;Y}{\&PartialD;\mathrm{\&alpha;}}\right|{\mathrm{\&alpha;}}_0)}^{T}R(Y_r-Y|{\mathrm{\&alpha;}}_0)\mathrm{dt}\right)---\left(22\right)$

α＝α ₀+Δα (23)

α when iterating for the k time _K+1=α _k+ Δ α _K+1(24)

Here select for use diagonal matrix G that following formula is revised, that is: through suitably choosing

α _k+1＝α _k+GΔα _k (25)

G is the positive definite diagonal matrix, its diagonal element g _IiSatisfy:

0≤g _ii≤1 (26)

Choose suitable parameter vector initial value α ₀, obtain modified value Δ α with formula (22) to it, calculate through the laggard row iteration of (25) formula correction, satisfy until the condition of J=min, make parameter vector little by little converge to actual value like this.

Apparatus of the present invention comprise direct supply, transformer, rectification module, data collecting card, signal Processing and protection module, control signal amplification module, computing machine, relay, noninductive resistance.Transformer by rectification module respectively with signal Processing and protection module, the control signal amplification module links to each other, for signal Processing and protection module and control signal amplification module provide direct supply, short-circuit resistance (R1 "-R9 ") and relay are formed after the parallel branch and sample resistance (R1 '-R9 '), the loop main resistor (R1 " '-R9 " ') series loop become with group of motors, sample resistance (R1 '-R9 ') two end signals are exported to signal Processing and protection module, the loop main resistor is the shunt circuit that one group of noninductive resistance and switch are formed, and short-circuit resistance is the shunt circuit of another group noninductive resistance and switch composition; Signal Processing and protection module and data acquisition card connection, data collecting card and control signal amplification module join, the control signal amplification module links to each other with relay, data collecting card is connected with computing machine, the control signal amplification module comprises two triodes, the amplifying circuit that the control signal that computing machine is sent is formed via two triodes amplifies, come pilot relay to cut-off to realize the direct current attenuation function, signal Processing and protection module comprise operational amplification circuit, gauge tap, stabilivolt, after input signal is through an operational amplification circuit, obtain the voltage signal of amplification, after this voltage signal deducted the difference mode signal that is obtained by two gauge tap, amplify by an operational amplifier again, realize amplification deamplification; Then the deamplification that amplifies is delivered to data collecting card, simultaneously, come the protected data capture card at the output terminal of the deamplification that has been exaggerated stabilivolt in parallel.Capture card sends the voltage signal that collects to computing machine, in computing machine reactance parameter is calculated then.

When using this proving installation testing reactance parameter of permanent magnet motor, at first judge the rotor d-axis or hand over the synthetic mmf axis direction of axle and armature whether to overlap.After determining good rotor shaft position, circuit is connected.Computing machine is as follows to the step of motor impedance parameter testing then: enter the control interface after the start, signals collecting number and picking rate are provided with; Click " beginning conversion " button on the control interface, computing machine trigger output voltage U makes its disconnection for the relay of control decay current switch S; By data collecting card deamplification is sampled, send into computing machine, obtain direct current die-away curve P ₁To direct current die-away curve P ₁Carry out the coordinate setting, to obtain direct current die-away curve P from first beginning that decay ₂, the data of this curve correspondence are saved in the text; Utilize software that data are carried out the least square method parameter identification to obtain relevant parameters; Friendship, the d-axis reactance parameter value of the calculation of parameter motor that obtains according to identification.

Compare with conventional direct current attenuation method, the present invention gets up with motor actual motion combinations of states better.Conventional direct current attenuation method utilizes to reach galvanic current stream in the armature winding and determine reactance parameter of permanent magnet motor through resistance decrement to zero transient process because of losing driving voltage; In transient process, the degree of saturation of motor is constantly to change, and can not get correct parameter of saturation value by handling the direct current die-away curve like this.The present invention improves direct current attenuation method in order to consider the influence of magnetic circuit degree of saturation to reactance parameter, develops into little direct current attenuation method.It mainly is that the big DC current of decision degree of saturation is remained unchanged, and in the d of this electric current or q axle component direct current decay current that amplitude is less of stack, determine parameter of saturation by identification to this little direct current decay current.Simultaneously, in order to take into account the influence of friendship, d-axis cross saturation, the two-circuit method based on the little DC current excitation of considering saturated and cross saturation effect is simultaneously proposed.An existing decision d-axis (when surveying the d-axis parameter) or friendship axle (during test cross axle parameter) saturated Constant Direct Current electric current I ₁, a friendship axle (when surveying the d-axis parameter) or d-axis (during test cross axle parameter) Constant Direct Current electric current I who considers cross saturation arranged again ₂, thereby it can the saturated influence to parameter of fine consideration, again can fine consideration cross saturation to the influence of parameter.These DC current can regulated at will, and therefore, it can record motor in working condition arbitrarily (hand over arbitrarily, the direct-axis current) rule that changes of parameter down.Simultaneously, for the influence of the inductance of eliminating other elements in the loop, the conventional, electric-resistance of measuring in the loop is replaced with noninductive resistance reactance parameter.

Description of drawings

Fig. 1 is the schematic diagram of proving installation of the present invention;

Fig. 2 is the front view of proving installation outward appearance of the present invention;

Fig. 3 is the left view of proving installation outward appearance of the present invention;

Fig. 4, Fig. 5, Fig. 6 are respectively ground floor, the second layer, the three-layered node compositions of the inner three-decker of proving installation of the present invention;

Fig. 7 is the circuit diagram of computer control signal amplification module;

Fig. 8 is signal Processing and holding circuit figure;

Fig. 9 is a software flow pattern of handling attenuation data;

Figure 10 is an armature connection layout of judging when measuring the quadrature axis reactance parameter that the synthetic mmf axis direction of armature overlaps with the rotor d-axis;

Figure 11 is an armature connection layout of judging when measuring the d-axis reactance parameter that the synthetic mmf axis direction of armature overlaps with the rotor d-axis;

Figure 12 is the circuit wiring diagram when measuring the d-axis reactance parameter;

Figure 13 is the circuit wiring diagram when measuring the quadrature axis reactance parameter;

Figure 14 uses apparatus of the present invention test reactance parameter process flow diagram;

R1 ' among the figure-R9 ' is a sample resistance, and R1 "-R9 " is a short-circuit resistance, R1 " '-R9 " ' be the loop main resistor.

Embodiment

Specify embodiments of the present invention below in conjunction with Fig. 1 to Figure 14.Realize that this proving installation comprises direct supply, transformer, rectification module, data collecting card, signal Processing and protection module, computer control signal amplification module, computing machine, relay, noninductive resistance.

Satisfy the test request of various rare earth permanent-magnet synchronization motors, the test specification of instrument is wide.Based on the rare earth permanent-magnet synchronization motor of existing various models on the market, the test specification of 0.05A～40A has substantially satisfied the various signal rare earth permanent-magnet synchronization motors of test and determined d-axis and stable state and the transient reactance value current requirements of handing over axle under the magnetic circuit state of saturation in its winding.In order to guarantee in test process, magnetic circuit degree of saturation before and after the current attenuation of the armature winding of rare earth permanent-magnet synchronization motor remains unchanged substantially, the current attenuation amplitude of then getting it for the relatively large motor of rated current is about 1/10th of a saturation current amplitude, is no more than 1A for the existing current attenuation amplitude that bigger motor is then got it of rated current.Therefore just 0.05A～40A is divided into nine grades together, tests different motors like this and require to adopt different shelves according to difference.Each shelves all is made up of three resistance: short-circuit resistance, loop main resistor and sample resistance.Short-circuit resistance is to reach when stablizing when the loop current of being made up of motor windings, loop main resistor and sample resistance, is used to seal in this loop, makes the loop current decay; The loop main resistor determines the resistance in whole measurement loop, makes the winding resistance resistance of motor not influence the resistance in whole loop; Sample resistance is used for acquired signal.

Apparatus of the present invention adopt case structure, and the front view of outward appearance, left view are respectively as Fig. 2, shown in Figure 3.Three layers of its inner main branches, inner three layers vertical view is respectively as Fig. 4, Fig. 5, shown in Figure 6, and promptly the ground floor and the second layer are the major loop main resistors, by the collocation of different noninductive resistances, realize many grades of measurements; The 3rd layer comprises computer control signal amplification module, signal Processing and protection module, data collecting card and the power supply of realizing these controls.Computer control signal amplification module in the 3rd layer comprises two triodes, its circuit diagram as shown in Figure 7, the amplifying circuit that the control signal that computing machine is sent is formed via two triodes amplifies, come pilot relay to cut-off to realize the direct current attenuation function, its power supply is to be obtained through rectification module by a transformer.Signal Processing and protection module comprise operational amplification circuit, gauge tap, stabilivolt, and its circuit diagram obtains the voltage signal of amplification as shown in Figure 8 after input signal is through an operational amplification circuit, this voltage signal is deducted by two gauge tap k ₁, k ₂, promptly behind the difference mode signal that button 1, button 2 obtain in the 3rd layer, amplify by an operational amplifier again, realize amplification to deamplification; Then the deamplification that amplifies is delivered to data collecting card, come the protected data capture card at the output terminal of the deamplification that has been exaggerated stabilivolt in parallel.Capture card sends the signal that collects to computing machine, realizes the test to reactance parameter in computing machine.

Apparatus of the present invention test reactance parameter process flow diagram as shown in figure 14.

When testing reactance parameter of permanent magnet motor, the judgement 01 of at first carrying out the rotor d-axis or handing over the synthetic mmf axis direction of axle and armature to overlap.The specific implementation step is as follows:

During the test quadrature axis reactance, B, the series connection of C two-phase armature winding with tested magneto, receive galvanometric two ends respectively with the A phase winding, rotary electric machine rotor slowly, up to the galvanometer pointer till rotary rotor moment deflects hardly, at this moment can think that the synthetic mmf direction of the armature winding that inserts overlaps with the rotor d-axis, as shown in figure 10; During the test d-axis reactance, with the B of tested magneto, C two-phase armature winding is received galvanometric two ends respectively, and the A phase winding is unsettled.At this moment rotary electric machine rotor slowly till rotary rotor moment deflects hardly, can think that the synthetic mmf direction of the armature winding that inserts overlaps with the rotor d-axis, as shown in figure 11 up to the galvanometer pointer.

After determining good rotor shaft position, circuit is connected 02, as shown in Figure 12 and Figure 13, be in closure state before the switch S action; After circuit connects, start 03; Enter the control interface, be provided with 04 gathering number and picking rate; After waiting to feed current stabilization, click " beginning conversion " button on the control interface, the computing machine output voltage signal makes it disconnect 05 for the contactor trigger voltage U of control decay current switch S; By data collecting card decay current is sampled, send into computing machine, obtain direct current die-away curve P ₁06; To direct current die-away curve P ₁Carry out the coordinate setting, to obtain direct current die-away curve P from first beginning that decay ₂, the data of this curve correspondence are saved in the text 07; Utilize software that data are carried out the least square method parameter identification to obtain relevant parameters 08; Friendship, the d-axis reactance parameter value 09 of the calculation of parameter motor that obtains according to identification; Finish 10.

Carry out software processes after by data collecting card deamplification being collected computing machine.At first change the voltage signal that collects into current signal divided by the resistance of sample resistance; With formula (5) is the identification objective function, carries out parameter identification by least square method and obtains I _K1, I _K2, P _K1, P _K2Initial value, and then obtain the time τ of die-away curve; Intercept the attenuation data of 5 τ time periods,, carry out the least square method parameter identification again based on these data, when error of fitting hour, output I _K1, I _K2, P _K1, P _K2Value, utilize formula (16) to calculate reactance value.

Claims (3)

1, a kind of device based on little direct current attenuation method testing reactance parameter of permanent magnet motor is characterized in that this device comprises direct supply, transformer, rectification module, data collecting card, signal Processing and protection module, control signal amplification module, computing machine, relay, noninductive resistance; Transformer by rectification module respectively with signal Processing and protection module, the control signal amplification module links to each other, for signal Processing and protection module and control signal amplification module provide direct supply, short-circuit resistance (R1 "-R9 ") and relay are formed after the parallel branch and sample resistance (R1 '-R9 '), the loop main resistor (R1 ' ' '-R9 ' ' ') become series loop with group of motors, sample resistance (R1 '-R9 ') two end signals are exported to signal Processing and protection module, the loop main resistor is the shunt circuit that one group of noninductive resistance and switch are formed, and short-circuit resistance is the shunt circuit of another group noninductive resistance and switch composition; Signal Processing and protection module and data acquisition card connection, data collecting card and control signal amplification module join, the control signal amplification module links to each other with relay, data collecting card is connected with computing machine, the control signal amplification module comprises two triodes, the amplifying circuit that the control signal that computing machine is sent is formed via two triodes amplifies, come pilot relay to cut-off to realize the direct current attenuation function, signal Processing and protection module comprise operational amplification circuit, gauge tap, stabilivolt, after input signal is through an operational amplification circuit, obtain the voltage signal of amplification, after this voltage signal deducted the difference mode signal that is obtained by two gauge tap, amplify by an operational amplifier again, realization is delivered to data collecting card with the deamplification that amplifies then to the amplification of deamplification; Capture card sends the voltage signal that collects to computing machine, in computing machine reactance parameter is calculated then.

2, a kind of device based on little direct current attenuation method testing reactance parameter of permanent magnet motor as claimed in claim 1 is characterized in that at the output terminal of the deamplification of described amplification stabilivolt in parallel, is used for the protected data capture card.

3, a kind of device as claimed in claim 1 based on little direct current attenuation method testing reactance parameter of permanent magnet motor, when it is characterized in that using this proving installation testing reactance parameter of permanent magnet motor, at first judge the rotor d-axis or hand over the synthetic mmf axis direction of axle and armature whether to overlap; After determining good rotor shaft position, circuit is connected; Enter the control interface after the start, signals collecting number and picking rate are provided with; Click " beginning conversion " button on the control interface, computing machine trigger output voltage U makes its disconnection for the relay of control decay current switch S; By data collecting card deamplification is sampled, send into computing machine, change voltage signal into current signal divided by the resistance of sampling resistor, obtain direct current die-away curve P ₁To direct current die-away curve P ₁Carry out the coordinate setting, to obtain direct current die-away curve P from first beginning that decay ₂, the data of this curve correspondence are saved in the text; Utilize software that data are carried out the least square method parameter identification to obtain relevant parameters; Friendship, the d-axis reactance parameter value of the calculation of parameter motor that obtains according to identification.

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