CN103208965A - Method for identifying asynchronous motor parameters offline under stationary state - Google Patents

Abstract

The invention provides a method for identifying asynchronous motor parameters offline under a stationary state. The method comprises the steps of firstly, identifying a stator resistance value of a motor by using a direct current voltammetry; and then taking a single-phase rated-frequency alternating voltage and a single-phase low-frequency alternating voltage as an excitation source respectively to perform a single-phase alternating current test, obtaining steady-state response currents of the motor through detection, and obtaining a motor stator leakage inductance, a rotor inductance, a rotor resistance and a stator-rotor mutual inductance value through calculation. According to the method, calculation is performed in strict accordance with a motor classic equivalent circuit model, the accuracy is high, additionally, the condition that a reference voltage output by a motor controller is not accordant with the actual voltage and effects of the skin effect are further considered, corresponding compensation measures are taken, and the parameter identifying accuracy is further improved.

Description

Non-synchronous motor parameter off-line identification method under the inactive state

Technical field

The present invention's design relates to a kind of parameter of electric machine identification technique, relates in particular to the non-synchronous motor parameter off-line identification method under a kind of inactive state.

Background technology

In Induction Motor Vector Control System, particularly do not have the PG(rotary encoder) in vector control or the direct Torque Control, the parameter of electric machine occupies important status.The accuracy of the parameter of electric machine directly has influence on flux observation, key links such as parameter adjusting are estimated, controlled to rotating speed.The parameter of electric machine that needs in the vector control in motor nameplate, inquire about less than, even extrapolate the part parameter of electric machine according to the data of motor product handbook, also have than large deviation with real data usually.Therefore, parameter of electric machine identification is very important problem in the Motor Control Field always.

Parameter of electric machine identification comprises offline parameter identification and on-line parameter rectification two parts.The offline parameter identification refers to before the motor operation it be applied a series of pumping signals, by detecting the relevant parameter that motor responds to obtain motor.What the parameter of electric machine self-setting function of general general purpose controller adopted all is traditional off-line identification method, need carry out locked rotor test and blank experiment to motor.But for part specific work environments, heavy-duty motor, particularly high-voltage motor, above-mentioned two experiments all are difficult to carry out.This be because: at first, heavy-duty motor moment is excessive, manually is difficult to pin its output revolving shaft, so locked rotor test is difficult to realize; Secondly, the part motor is finished with the load fixed installation before system debug, and the state that belongs to non-dismountable or be difficult to dismantle is so no-load test also is difficult to carry out.

Aspect the static parameter identification technique of motor, Chinese patent " based on the non-synchronous motor parameter identification method of adaptive equalization ", publication number is CN201110191565.9, a kind of asynchronous machine parameter identification method is under static state disclosed, this method adopts approximate formula to calculate the rotor mutual inductance, and do not consider kelvin effect to the influence of rotor resistance identification precision, the identification accuracy is not good enough.

Summary of the invention

The objective of the invention is the inaccurate problem of poor practicability, accuracy of detection that exists in the existing non-synchronous motor parameter identification method, the offline parameter discrimination method under a kind of motor inactive state is provided.

To achieve these goals, the present invention adopts following technical scheme:

Non-synchronous motor parameter off-line identification method under a kind of inactive state, this method reaches the inverter that is connected with this asynchronous machine input based on described asynchronous machine and realizes, wherein, described asynchronous machine comprises rotor and has the stator of polyphase windings that this method may further comprise the steps:

Step 1, by following steps identification stator resistance:

S11 applies the excitation of first direct voltage to any two phase windings of described stator;

S12 gathers first direct current of two phase windings when first direct voltage excitation is issued to stable state among the described step S11 by described inverter;

S13 applies the excitation of second direct voltage to any two phase windings of described stator;

S14 gathers second direct current of two phase windings when second direct voltage excitation is issued to stable state among the described step S13 by described inverter;

S15 according to described first direct voltage and second direct voltage and corresponding described first direct current and second direct current, calculates and obtains described stator resistance;

Step 2, by following steps identification rotor resistance, stator leakage inductance and rotor leakage inductance:

S21 applies first alternating voltage excitation of single-phase rated frequency to any two phase windings of described stator;

S22, obtain two phase windings among the described step S21 when the excitation of this first alternating voltage is issued to stable state first phase current and first phase angle between described first alternating voltage and described first phase current;

S23 calculates acquisition described rotor resistance, stator leakage inductance and rotor leakage inductance according to effective value and described first phase angle of the effective value of described first alternating voltage, described first phase current;

Step 3 is revised the described rotor resistance that calculates in the described step 2, to suppress kelvin effect to the influence of described rotor resistance identification precision;

Step 4, total reactance of calculating the T type equivalent electric circuit that obtains the every phase winding of described motor by following steps:

S41 applies the single-phase first low-frequency ac voltage excitation of frequency in 0.1～0.5Hz scope to any two phase windings of described stator;

S42, obtain two phase windings among the described step S41 when the excitation of described first low-frequency ac voltage is issued to stable state the first low-frequency phase electric current and the first low-frequency phase parallactic angle between described first low-frequency ac voltage and the described first low-frequency phase electric current;

S43, according to effective value and the described first low-frequency phase parallactic angle of the effective value of described first low-frequency ac voltage, the described first low-frequency phase electric current, calculate real part and the imaginary part of first total reactance of the T type equivalent electric circuit of every phase winding under described first low-frequency ac voltage excitation that obtains described motor stator;

Step 5, by the mutual inductance of following steps identification rotor:

S51, adopt the second low-frequency ac voltage excitation of frequency in 0.1～0.5Hz scope to repeat described step 4, calculate the imaginary part of second total reactance of the T type equivalent electric circuit of every phase winding under described second low-frequency ac voltage excitation that obtains described motor stator;

S52, adopt the three low-frequency ac voltage excitation of frequency in 0.1～0.5Hz scope to repeat described step 4, calculate the imaginary part of the 3rd total reactance of the T type equivalent electric circuit of every phase winding under described the 3rd low-frequency ac voltage excitation that obtains described motor stator;

S53 according to the imaginary part of described rotor mutual inductance and described first total reactance, second total reactance and the 3rd total reactance, calculates and obtains described rotor mutual inductance.

Non-synchronous motor parameter off-line identification method under aforementioned a kind of inactive state, described step S15 comprises:

Set described first direct voltage and second direct voltage and be respectively U1, U2, set corresponding described first direct current and second direct current and be respectively I ₁, I ₂, calculate the described stator resistance R of acquisition according to formula (1) _s,

$R_s=\frac{U_2-U_1}{I_2-I_1}\×\frac{1}{2}---\left(1\right).$

Non-synchronous motor parameter off-line identification method under aforementioned a kind of inactive state,

Described step S21 comprises: any two phase windings of described motor stator are applied described first alternating voltage excitation of single-phase rated frequency, and the phase current that this first alternating voltage is raise gradually up to described two phase windings reaches rated current;

Described step S22 comprises: detect the instantaneous value of first phase current of two phase windings when this first alternating voltage excitation is issued to stable state among the described step S21, and calculate the effective value U of described first alternating voltage and described first phase current _Sn1And I _Sn1, adopt the phase place of phase-locked described first alternating voltage of a phase-locked loop and described first phase current then, and calculate the phase difference that obtains between described first alternating voltage and described first phase current

Described step S23 comprises: calculate according to formula (21), (22) and obtain the rotor resistance first identifier R _R1, stator leakage inductance L _{σ s}With rotor leakage inductance L _{σ r}:

In the formula, f ₁The frequency of representing described first alternating voltage.

Further, described step 3 may further comprise the steps:

S31, any two phase windings of described motor stator are applied single-phase second alternating voltage excitation, and the phase current that this second alternating voltage is raise gradually up to described two phase windings reaches rated current, wherein, the frequency of described second alternating voltage is lower than described rated frequency, is 40～45Hz;

S32 detects the instantaneous value of second phase current of two phase windings when this second alternating voltage excitation is issued to stable state among the described step S31, and calculates the effective value U of described second alternating voltage and described second phase current _Sn2And I _Sn2, adopt the phase place of phase-locked described second alternating voltage of described phase-locked loop and described second phase current then, and calculate the phase difference between described second alternating voltage and described second phase current

Obtain rotor resistance second identifier thereby calculate

S33 according to formula (3), calculates the rotor resistance R that has obtained to overcome the kelvin effect influence _r:

$R_r=\frac{R_{r2}{f}_1-R_{r1}{f}_2}{f1-f2}---\left(3\right),$

In the formula, f ₁Be the frequency of described first alternating voltage, f ₂Frequency for described second alternating voltage.

Non-synchronous motor parameter off-line identification method under aforementioned a kind of inactive state,

Described step S41 comprises: any two phase windings of described motor stator are applied the described first low-frequency ac voltage excitation of frequency in 0.1～0.5Hz scope, and the phase current that this first low-frequency ac voltage is raise gradually up to described two phase windings reaches rated current;

Described step S42 comprises: detect the instantaneous value of the first low-frequency phase electric current of two phase windings when this first low-frequency ac voltage excitation is issued to stable state among the described step S41, and calculate the effective value U of described first low-frequency ac voltage and the described first low-frequency phase electric current _S0And I _S0, adopt the phase place of phase-locked described first low-frequency ac voltage of a phase-locked loop and the described first low-frequency phase electric current then, and calculate the phase difference that obtains between described first low-frequency ac voltage and the described first low-frequency phase electric current

Described step S43 comprises: according to formula (41), (42), calculate the real part Re (Z of first total reactance of the T type equivalent electric circuit of every phase winding under described first low-frequency ac voltage excitation that obtains described motor ₁) and imaginary part Im (Z ₁):

Non-synchronous motor parameter off-line identification method under aforementioned a kind of inactive state,

Described step S53 comprises: calculate according to formula (7) and obtain described rotor mutual inductance L _Ms:

$L_{\mathrm{ms}}=\frac{{\mathrm{\ω}}_1^3{Z}_2{Z}_3({\mathrm{\ω}}_2^2-{\mathrm{\ω}}_3^2)+{\mathrm{\ω}}_2^3{Z}_1{Z}_3({\mathrm{\ω}}_3^2-{\mathrm{\ω}}_1^2)+{\mathrm{\ω}}_3^3{Z}_1{Z}_2({\mathrm{\ω}}_1^2-{\mathrm{\ω}}_2^2)}{{\mathrm{\ω}}_1{\mathrm{\ω}}_2{\mathrm{\ω}}_3[{\mathrm{\ω}}_1{Z}_1({\mathrm{\ω}}_3^2-{\mathrm{\ω}}_2^2)+{\mathrm{\ω}}_2{Z}_2({\mathrm{\ω}}_1^2-{\mathrm{\ω}}_3^2)+{\mathrm{\ω}}_3{Z}_3({\mathrm{\ω}}_2^2-{\mathrm{\ω}}_1^2)]}-L_{\mathrm{\σs}}---\left(5\right),$

In the formula, ω ₁, ω ₂And ω ₃Be respectively the angular frequency of described first low-frequency ac voltage, second low-frequency ac voltage and the 3rd low-frequency ac voltage, and ω ₁=2 π f _Low1, ω ₂=2 π f _Low2, ω ₃=2 π f _Low3, wherein, f _Low1, f _Low2And f _Low3Be respectively the frequency of described first low-frequency ac voltage, second low-frequency ac voltage and the 3rd low-frequency ac voltage; Z ₁, Z ₂And Z ₃Be respectively the imaginary part of described first total reactance, second total reactance and the 3rd total reactance.

Eventually the above, the offline parameter discrimination method under the motor inactive state of the present invention need not the motor rotation, thus practical, be specially adapted to the Industry Control occasion.In addition, the present invention calculates in strict accordance with the classical equivalent-circuit model of motor, the accuracy height, and the present invention has also considered the influence of electric machine controller output reference voltage and the inconsistent situation of virtual voltage and kelvin effect, and taked indemnifying measure, further improved the accuracy of parameter identification.

Description of drawings

Fig. 1 is the T type equivalent circuit diagram of the single-phase winding of motor;

Fig. 2 is the two phase winding equivalent circuit diagrams of motor in the continuous current excitation test;

Fig. 3 is the two phase winding equivalent circuit diagrams of motor in single phase alternating current (A.C.) excitation test;

Fig. 4 is the two phase winding equivalent circuit diagrams of motor in the ac-excited test of single-phase rated frequency;

Fig. 5 is inverter output reference voltage and virtual voltage comparison diagram;

Fig. 6 is the phase place broken away view of inverter output voltage.

Embodiment

Below based on motor T type equivalent electric circuit shown in Figure 1 and be described in detail as follows in conjunction with Fig. 2-6 pair of technical scheme of the present invention.

Offline parameter discrimination method under the motor inactive state of the present invention is mainly used in calculating the inner parameter of motor, this method reaches the inverter that is connected with this motor input based on motor and realizes, inverter is mainly used in the output motor control signal, and the voltage and current response signal of detection motor stator winding, asynchronous machine comprises stator and rotor, and this stator has winding.Specifically, method of the present invention mainly comprises calculates stator resistance, stator leakage inductance, rotor resistance, rotor leakage inductance and rotor mutual inductance, and wherein, the concrete steps of this method are as follows;

Step 1: any two phase windings to motor stator apply the direct voltage excitation, shown in the two phase winding equivalent circuit diagrams 2 under continuous current excitation, utilize voltammetry to calculate motor stator resistance, specifically, may further comprise the steps:

S11 applies first direct voltage excitation U to any two phase windings of stator ₁

S12 is by the first direct current I of two phase windings among the inverter acquisition step S11 when the excitation of first direct voltage is issued to stable state ₁

S13 applies second direct voltage excitation U to any two phase windings of stator ₂

S14 is by the second direct current I of two phase windings among the inverter acquisition step S13 when the excitation of second direct voltage is issued to stable state ₂

S15, according to schematic diagram shown in Figure 2, by formula (1) is calculated and is obtained stator resistance R _s:

$R_s=\frac{U_2-U_1}{I_2-I_1}\×\frac{1}{2}---\left(1\right),$

In the formula (1), adopting the voltage and current increment to calculate stator resistance, is for fear of the influence to identification precision of the output reference voltage of inverter and the error between the virtual voltage.Error between hypothetical reference voltage and the virtual voltage is Δ U, and then the actual DC voltage of twice DC experiment is U ₁+ Δ U and U ₂+ Δ U, according to formula (11), the error amount Δ U that can calculate reference voltage and virtual voltage is:

$\mathrm{\ΔU}=\frac{U_2{I}_1-U_1{I}_2}{I_2-I_1}---\left(11\right),$

Then can calculate the motor stator resistance R according to the actual DC voltage and current on two phase windings _sFor:

$R_s=\frac{U_1+\mathrm{\ΔU}}{I_1}\×\frac{1}{2}=\frac{U_2-U_1}{I_2-I_1}\×\frac{1}{2}.$

Step 2: any two phase windings of motor stator are applied the alternating voltage excitation of single-phase rated frequency, calculate the rotor resistance of motor, stator leakage inductance and rotor leakage inductance specifically, may further comprise the steps:

S21, any two phase windings of motor stator are applied first alternating voltage excitation of single-phase rated frequency, and the phase current that this first alternating voltage is raise gradually up to motor stator reaches rated current, this is because consider the magnetically saturated influence of air gap, its exciter response electric current can not be higher than rated current, so the driving voltage amplitude is less;

S22 detects the instantaneous value of first phase current of two phase windings when this first alternating voltage excitation is issued to stable state among the step S21, and calculates the effective value U of first alternating voltage and first phase current _Sn1And I _Sn1, adopt the phase place of phase-locked first alternating voltage of a phase-locked loop and first phase current then, and calculate the phase difference that obtains between first alternating voltage and first phase current

S23 calculates the acquisition rotor resistance first identifier R according to formula (21), (22) _R1, stator leakage inductance L _{σ s}With rotor leakage inductance L _{σ r}:

In the formula, f ₁The frequency of representing first alternating voltage.

Calculating principle is like this: when leading to single-phase alternating current for the asynchronous machine winding, can not produce the electromagnetic torque of rotation, so motor can not rotate, its electromagnet phenomenon is similar to locked rotor test, and the two phase winding equivalent electric circuits of motor under the single phase alternating current (A.C.) excitation as shown in Figure 3.When the single phase alternating current (A.C.) driving voltage that applies is rated frequency, rotor mutual inductance L _MsMuch larger than stator leakage inductance L _{σ s}With rotor leakage inductance L _{σ r}, and driving frequency is higher, so the energized circuit induction reactance ω L of this moment _MsMuch larger than the reactance of leakage inductance loop

Therefore, in the motor equivalent electric circuit, can think that energized circuit opens circuit, that is, in this step, the equivalent electric circuit of Fig. 3 can be reduced to equivalent electric circuit shown in Figure 4, according to equivalent electric circuit shown in Figure 4, can obtain above-mentioned formula (21), (22).

Step 3: any two phase windings to motor stator apply frequency underfrequency (for example 40～45Hz) alternating voltage excitation slightly, so that the rotor resistance value that calculates in the step 2 is revised, thereby suppress kelvin effect to the influence of rotor resistance identification precision, specifically, may further comprise the steps:

S31, any two phase windings of motor stator are applied single-phase second alternating voltage excitation, and the phase current that this second alternating voltage is raise gradually up to two phase windings reaches rated current, wherein, the frequency underfrequency of second alternating voltage is 40～45Hz;

S32 detects the instantaneous value of second phase current of two phase windings when this second alternating voltage excitation is issued to stable state among the step S31, and calculates the effective value U of second alternating voltage and second phase current _Sn2And I _Sn2, adopt the phase place of phase-locked second alternating voltage of phase-locked loop and second phase current then, and calculate the phase difference between second alternating voltage and second phase current

Obtain rotor resistance second identifier thereby calculate

S33 according to formula (3), calculates the rotor resistance R that has obtained to overcome the kelvin effect influence _r:

$R_r=\frac{R_{r2}{f}_1-R_{r1}{f}_2}{f1-f2}---\left(3\right),$

In the formula, f ₁Be the frequency of first alternating voltage, f ₂It is the frequency of second alternating voltage.

The principle of Xiu Zhenging is like this: when motor is carried out single-phase rated frequency ac test in the step 2, the motor slip frequency is very high, namely, power frequency when the power frequency in the rotor is much larger than actual motion at this moment, therefore the kelvin effect of rotor winding will influence the certainty of measurement of rotor resistance, and kelvin effect is linear to the influence of rotor resistance identification, with the pass of rotor current frequency be R _Rx=R _r+ af,

In the formula, R _RxBe the rotor resistance value of identification, R _rBe real rotor resistance value, af represents that a is error linearity constant by the linearity error relevant with frequency of kelvin effect generation.

Therefore, in order to compensate this linearity error, overcome the influence of kelvin effect, this step adopts frequency, and (for example the excitation of 40～45Hz) second alternating voltage repeats above-mentioned steps two, and calculates the rotor resistance second identifier R of acquisition motor under the alternating voltage excitation of this frequency a little less than rated frequency _R2, set up linear equation in two unknowns group (31) thus:

$\left\{\begin{array}{c}{R}_{r1}=R_r+{\mathrm{af}}_1\\ R_{r2}=R_r+{\mathrm{af}}_2\end{array}\right.---\left(31\right)$

Find the solution above-mentioned equation group (31), can obtain above-mentioned formula (3).

Step 4: any two phase windings to motor stator apply the low-frequency ac voltage excitation, calculate real part and the imaginary part of total reactance of the T type equivalent electric circuit of the every phase winding of motor at this moment, specifically, may further comprise the steps:

Step S41, any two phase windings to motor stator apply the first low-frequency ac voltage excitation of frequency in 0.1～0.5Hz scope, and the phase current that this first low-frequency ac voltage is raise gradually up to motor stator reaches rated current, every phase winding equivalent electric circuit in this step is identical with Fig. 1, this is because the first low-frequency ac voltage frequency that applies is very low, energized circuit induction reactance ω L _MsCan be much larger than the reactance of leakage inductance loop

So energized circuit can not be ignored, and this moment every phase winding all loads can equivalence be a reactance, for later step in reactance distinguish, this reactance is set at first total reactance;

Step S42 detects the instantaneous value of the first low-frequency phase electric current of two phase windings when this first low-frequency ac voltage excitation is issued to stable state among the step S41, and calculates the effective value U of first low-frequency ac voltage and the first low-frequency phase electric current _S0And I _S0, adopt the phase place of phase-locked first low-frequency ac voltage of a phase-locked loop and the first low-frequency phase electric current then, and calculate the phase difference that obtains between first low-frequency ac voltage and the first low-frequency phase electric current

Step S43 according to Fig. 3, according to formula (41), (42), calculates the real part Re (Z of first total reactance of the T type equivalent electric circuit of every phase winding under the excitation of first low-frequency ac voltage that obtains motor ₁) and imaginary part Im (Z ₁):

Step 5: adopt the single-phase low-frequency ac of other two different frequencies to press excitation repeated execution of steps four respectively once, calculate the rotor mutual inductance, specifically, comprise the steps:

S51 adopts the second low-frequency ac voltage excitation repeated execution of steps four of frequency in 0.1～0.5Hz scope, calculates the real part Re (Z of second total reactance of the T type equivalent electric circuit of every phase winding under the excitation of second low-frequency ac voltage that obtains motor stator ₂) and imaginary part Im (Z ₂);

S52 adopts the three low-frequency ac voltage excitation repeated execution of steps four of frequency in 0.1～0.5Hz scope, calculates the real part Re (Z of the 3rd total reactance of the T type equivalent electric circuit of every phase winding under the excitation of the 3rd low-frequency ac voltage that obtains motor stator ₃) and imaginary part Im (Z ₃);

S53 according to formula (5), calculates and obtains rotor mutual inductance L _Ms:

$L_{\mathrm{ms}}=\frac{{\mathrm{\ω}}_1^3{Z}_2{Z}_3({\mathrm{\ω}}_2^2-{\mathrm{\ω}}_3^2)+{\mathrm{\ω}}_2^3{Z}_1{Z}_3({\mathrm{\ω}}_3^2-{\mathrm{\ω}}_1^2)+{\mathrm{\ω}}_3^3{Z}_1{Z}_2({\mathrm{\ω}}_1^2-{\mathrm{\ω}}_2^2)}{{\mathrm{\ω}}_1{\mathrm{\ω}}_2{\mathrm{\ω}}_3[{\mathrm{\ω}}_1{Z}_1({\mathrm{\ω}}_3^2-{\mathrm{\ω}}_2^2)+{\mathrm{\ω}}_2{Z}_2({\mathrm{\ω}}_1^2-{\mathrm{\ω}}_3^2)+{\mathrm{\ω}}_3{Z}_3({\mathrm{\ω}}_2^2-{\mathrm{\ω}}_1^2)]}-L_{\mathrm{\σs}}---\left(5\right),$

In the formula, ω ₁, ω ₂And ω ₃Be respectively the angular frequency of first low-frequency ac voltage, second low-frequency ac voltage and the 3rd low-frequency ac voltage, and ω ₁=2 π f _Low1, ω ₂=2 π f _Low2, ω ₃=2 π f _Low3, wherein, f _Low1, f _Low2And f _Low3Be respectively the frequency of first low-frequency ac voltage, second low-frequency ac voltage and the 3rd low-frequency ac voltage; Z ₁, Z ₂And Z ₃Be respectively the imaginary part Im (Z of first total reactance, second total reactance and the 3rd total reactance ₁), Im (Z ₂) and Im (Z ₂).

Calculating principle is as follows like this:

According to the T type equivalent electric circuit of the every phase winding of motor shown in Figure 1, the real part Re (Z) of its total reactance and imaginary part Im (Z) are respectively shown in formula (51), (52):

$\mathrm{Re}\left(Z\right)=R_s+\frac{{\mathrm{\ω}}^2\mathrm{LT}(1-\mathrm{\ζ})}{1+{\mathrm{\ω}}^2{T}^2}---\left(51\right),$

$\mathrm{Im}\left(Z\right)=\mathrm{\ωL}\frac{1+\mathrm{\ζ}{\mathrm{\ω}}^2{T}^2}{1+{\mathrm{\ω}}^2{T}^2}---\left(52\right),$

L is full inductance L=L in the formula _Ms+ L _{σ s}, T is rotor time constant

ζ is the leakage inductance coefficient

ω is the electric angle speed omega=2 π f of driving voltage.

As can be seen from the above equation, mutual inductance L _MsRelevant with L, T, three variablees of ζ, tried to achieve any one variable, can try to achieve mutual inductance L _Ms

By calculating total reactance imaginary part Im (Z of the T type equivalent electric circuit that obtains the every phase winding of motor under three different frequencies ₁), Im (Z ₂) and Im (Z ₂), set up ternary linear function group (53) thus:

$\left\{\begin{array}{c}\mathrm{Im}\left(Z_1\right)={\mathrm{\ω}}_{1}L\frac{1+\mathrm{\ζ}{\mathrm{\ω}}_1^2{T}^2}{1+{\mathrm{\ω}}_1^2{T}^2}\\ \mathrm{Im}\left(Z_2\right)={\mathrm{\ω}}_{2}L\frac{1+\mathrm{\ζ}{\mathrm{\ω}}_2^2{T}^2}{1+{\mathrm{\ω}}_2^2{T}^2}\\ \mathrm{Im}\left(Z_3\right)={\mathrm{\ω}}_{3}L\frac{1+\mathrm{\ζ}{\mathrm{\ω}}_3^2{T}^2}{1+{\mathrm{\ω}}_3^2{T}^2}\end{array}\right.---\left(53\right),$

Find the solution above-mentioned equation group (53), obtain three variate-values of L, T and ζ, can obtain rotor mutual inductance L _MsExpression formula as shown in Equation (5).

The reason of using the reactance imaginary part to calculate in step 5 mainly is for fear of the influence to identification precision of the reference voltage of inverter output and the error between the virtual voltage.As shown in Figure 5, according to electric machine controller three-phase bridge operation principle, reference voltage is opposite with error and current polarity between the virtual voltage, so I _RealBe timing, virtual voltage U _RealLess than reference voltage U _RefI _RealWhen negative, virtual voltage U _RealGreater than reference voltage U _RefDuring the counting circuit reactance, reactance real part Re (Z) equals the ratio of voltage and electric current same-phase part, and imaginary part Im (Z) equals the ratio of voltage and electric current orthogonal part branch.

Alternating voltage among Fig. 5 is split into component U'' with the synchronous component U' of electric current and quadrature, specifically as shown in Figure 6.In the curve chart of the synchronous component U' of output voltage from Fig. 6 and electric current as can be seen, one-period internal reference voltage U _1refEffective value obviously greater than output voltage U _1realEffective value; And from the curve chart of the component U'' of output voltage and electric current quadrature as can be seen, one-period internal reference voltage U _2refEffective value U with virtual voltage _2realEquate that because in-phase component is relevant with the real part of total reactance, quadrature component is relevant with the imaginary part of total reactance again, so reference voltage and the error between the virtual voltage of control inverter output only act on the reactance real part Re (Z).In addition, also contain stator resistance R in the expression formula of reactance real part _s, and resistance R _sMeasure error also can influence the identification precision of mutual inductance.

To sum up, for fear of the influence of the error between control inverter output reference voltage and the virtual voltage to rotor mutual inductance identification, adopt reactance imaginary part Im (Z) to calculate and obtain rotor mutual inductance L _Ms

Above-described, be preferred embodiment of the present invention only, be not in order to limiting scope of the present invention, the above embodiment of the present invention can also make a variety of changes.Be that simple, the equivalence that every claims according to the present patent application and description are done changes and modification, all fall into the claim protection range of patent of the present invention.

Claims (6)

1. the non-synchronous motor parameter off-line identification method under the inactive state, this method reaches the inverter that is connected with this asynchronous machine input based on described asynchronous machine and realizes that wherein, described asynchronous machine comprises rotor and has the stator of polyphase windings, it is characterized in that this method may further comprise the steps:

Step 1, by following steps identification stator resistance:

S11 applies the excitation of first direct voltage to any two phase windings of described stator;

S12 gathers first direct current of two phase windings when first direct voltage excitation is issued to stable state among the described step S11 by described inverter;

S13 applies the excitation of second direct voltage to any two phase windings of described stator;

S14 gathers second direct current of two phase windings when second direct voltage excitation is issued to stable state among the described step S13 by described inverter;

S15 according to described first direct voltage and second direct voltage and corresponding described first direct current and second direct current, calculates and obtains described stator resistance;

Step 2, by following steps identification rotor resistance, stator leakage inductance and rotor leakage inductance:

S21 applies first alternating voltage excitation of single-phase rated frequency to any two phase windings of described stator;

S22, obtain two phase windings among the described step S21 when the excitation of this first alternating voltage is issued to stable state first phase current and first phase angle between described first alternating voltage and described first phase current;

S23 calculates acquisition described rotor resistance, stator leakage inductance and rotor leakage inductance according to effective value and described first phase angle of the effective value of described first alternating voltage, described first phase current;

Step 3 is revised the described rotor resistance that calculates in the described step 2, to suppress kelvin effect to the influence of described rotor resistance identification precision;

Step 4, total reactance of calculating the T type equivalent electric circuit that obtains the every phase winding of described motor by following steps:

S41 applies the single-phase first low-frequency ac voltage excitation of frequency in 0.1～0.5Hz scope to any two phase windings of described stator;

S42, obtain two phase windings among the described step S41 when the excitation of described first low-frequency ac voltage is issued to stable state the first low-frequency phase electric current and the first low-frequency phase parallactic angle between described first low-frequency ac voltage and the described first low-frequency phase electric current;

S43, according to effective value and the described first low-frequency phase parallactic angle of the effective value of described first low-frequency ac voltage, the described first low-frequency phase electric current, calculate real part and the imaginary part of first total reactance of the T type equivalent electric circuit of every phase winding under described first low-frequency ac voltage excitation that obtains described motor stator;

Step 5, by the mutual inductance of following steps identification rotor:

S51, adopt the second low-frequency ac voltage excitation of frequency in 0.1～0.5Hz scope to repeat described step 4, calculate the imaginary part of second total reactance of the T type equivalent electric circuit of every phase winding under described second low-frequency ac voltage excitation that obtains described motor stator;

S52, adopt the three low-frequency ac voltage excitation of frequency in 0.1～0.5Hz scope to repeat described step 4, calculate the imaginary part of the 3rd total reactance of the T type equivalent electric circuit of every phase winding under described the 3rd low-frequency ac voltage excitation that obtains described motor stator;

S53 according to the imaginary part of described rotor mutual inductance and described first total reactance, second total reactance and the 3rd total reactance, calculates and obtains described rotor mutual inductance.

2. the non-synchronous motor parameter off-line identification method under the inactive state according to claim 1 is characterized in that:

Described step S15 comprises: set described first direct voltage and second direct voltage and be respectively U1, U2, set corresponding described first direct current and second direct current and be respectively I ₁, I ₂, calculate the described stator resistance R of acquisition according to formula (1) _s,

$R_s=\frac{U_2-U_1}{I_2-I_1}\×\frac{1}{2}---\left(1\right).$

3. the non-synchronous motor parameter off-line identification method under the inactive state according to claim 2 is characterized in that:

Described step S21 comprises: any two phase windings of described motor stator are applied described first alternating voltage excitation of single-phase rated frequency, and the phase current that this first alternating voltage is raise gradually up to described two phase windings reaches rated current;

Described step S22 comprises: detect the instantaneous value of first phase current of two phase windings when this first alternating voltage excitation is issued to stable state among the described step S21, and calculate the effective value U of described first alternating voltage and described first phase current _Sn1And I _Sn1, adopt the phase place of phase-locked described first alternating voltage of a phase-locked loop and described first phase current then, and calculate the phase difference that obtains between described first alternating voltage and described first phase current

Described step S23 comprises: calculate according to formula (21), (22) and obtain the rotor resistance first identifier R _R1, stator leakage inductance L _{σ s}With rotor leakage inductance L _{σ r}:

In the formula, f ₁The frequency of representing described first alternating voltage.

4. the non-synchronous motor parameter off-line identification method under the inactive state according to claim 3 is characterized in that:

Described step 3 may further comprise the steps:

S31, any two phase windings of described motor stator are applied single-phase second alternating voltage excitation, and the phase current that this second alternating voltage is raise gradually up to described two phase windings reaches rated current, wherein, the frequency of described second alternating voltage is lower than described rated frequency, is 40～45Hz;

S32 detects the instantaneous value of second phase current of two phase windings when this second alternating voltage excitation is issued to stable state among the described step S31, and calculates the effective value U of described second alternating voltage and described second phase current _Sn2And I _Sn2, adopt the phase place of phase-locked described second alternating voltage of described phase-locked loop and described second phase current then, and calculate the phase difference between described second alternating voltage and described second phase current

Obtain rotor resistance second identifier thereby calculate

S33 according to formula (3), calculates the rotor resistance R that has obtained to overcome the kelvin effect influence _r:

$R_r=\frac{R_{r2}{f}_1-R_{r1}{f}_2}{f1-f2}---\left(3\right),$

In the formula, f ₁Be the frequency of described first alternating voltage, f ₂Frequency for described second alternating voltage.

5. the non-synchronous motor parameter off-line identification method under the inactive state according to claim 1 is characterized in that:

Described step S41 comprises: any two phase windings of described motor stator are applied the described first low-frequency ac voltage excitation of frequency in 0.1～0.5Hz scope, and the phase current that this first low-frequency ac voltage is raise gradually up to described two phase windings reaches rated current;

Described step S42 comprises: detect the instantaneous value of the first low-frequency phase electric current of two phase windings when this first low-frequency ac voltage excitation is issued to stable state among the described step S41, and calculate the effective value U of described first low-frequency ac voltage and the described first low-frequency phase electric current _S0And I _S0, adopt the phase place of phase-locked described first low-frequency ac voltage of a phase-locked loop and the described first low-frequency phase electric current then, and calculate the phase difference that obtains between described first low-frequency ac voltage and the described first low-frequency phase electric current

Described step S43 comprises: according to formula (41), (42), calculate the real part Re (Z of first total reactance of the T type equivalent electric circuit of every phase winding under described first low-frequency ac voltage excitation that obtains described motor ₁) and imaginary part Im (Z ₁):

6. the non-synchronous motor parameter off-line identification method under the inactive state according to claim 5 is characterized in that:

Described step S53 comprises: calculate according to formula (7) and obtain described rotor mutual inductance L _Ms:

$L_{\mathrm{ms}}=\frac{{\mathrm{\ω}}_1^3{Z}_2{Z}_3({\mathrm{\ω}}_2^2-{\mathrm{\ω}}_3^2)+{\mathrm{\ω}}_2^3{Z}_1{Z}_3({\mathrm{\ω}}_3^2-{\mathrm{\ω}}_1^2)+{\mathrm{\ω}}_3^3{Z}_1{Z}_2({\mathrm{\ω}}_1^2-{\mathrm{\ω}}_2^2)}{{\mathrm{\ω}}_1{\mathrm{\ω}}_2{\mathrm{\ω}}_3[{\mathrm{\ω}}_1{Z}_1({\mathrm{\ω}}_3^2-{\mathrm{\ω}}_2^2)+{\mathrm{\ω}}_2{Z}_2({\mathrm{\ω}}_1^2-{\mathrm{\ω}}_3^2)+{\mathrm{\ω}}_3{Z}_3({\mathrm{\ω}}_2^2-{\mathrm{\ω}}_1^2)]}-L_{\mathrm{\σs}}---\left(5\right),$

In the formula, ω ₁, ω ₂And ω ₃Be respectively the angular frequency of described first low-frequency ac voltage, second low-frequency ac voltage and the 3rd low-frequency ac voltage, and ω ₁=2 π f _Low1, ω ₂=2 π f _Low2, ω ₃=2 π f _Low3, wherein, f _Low1, f _Low2And f _Low3Be respectively the frequency of described first low-frequency ac voltage, second low-frequency ac voltage and the 3rd low-frequency ac voltage; Z ₁, Z ₂And Z ₃Be respectively the imaginary part of described first total reactance, second total reactance and the 3rd total reactance.

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