CN102393507A - Motor parameter detection method and motor parameter detection device - Google Patents

Abstract

The invention discloses a motor parameter detection method and a motor parameter detection device. The motor parameter detection method comprises the following steps: opening the circuit of one of phase windings of a motor; detecting stator leakage inductance and rotor leakage inductance; applying rated voltage with higher frequency than rated power between the other two phases of the motor; and detecting the stator leakage inductance and the rotor leakage inductance according to the computational formula of the stator leakage inductance and the rotor leakage inductance. The invention provides the off-line motor parameter detection method and the motor parameter detection device under the static condition of the rotor of an induction motor, which achieve high accuracy of motor parameter detection through reducing the influences of voltage errors and a skin effect as long as current or voltage with different frequencies is applied between the two phases of the motor in sequence.

Description

A kind of parameter of electric machine detection method and motor parameter-detecting device

Technical field

The present invention relates to a kind of parameter of electric machine detection method and motor parameter-detecting device.

Background technology

Induction motor has simple in structure, does not have winding on the rotor, and is easily manufactured, and low price is easy to maintenance, advantages such as long service life, so the application scenario is very extensive.Along with the development of Power Electronic Technique and modern control theory, the high-performance induction motor speed regulation system arises at the historic moment.Usually; The high-performance induction motor speed regulation system often adopts the vector control algorithm or the Speedless sensor algorithm of frequency converter; And the order of accuarcy of the parameter of electric machine that the performance of these Electric Machine Control algorithms depends on wherein to be used; If the parameter of electric machine is inaccurate, will directly causes the decline of control performance index even cause frequency converter failure.Therefore, how to obtain the key that induction motor parameter becomes high-performance Electric Machine Control algorithm accurately.

Parameter of electric machine detection method mainly contains online detection and two kinds of methods of offline inspection.Online test method is because process is complicated, and the program calculated amount is big, thereby requires processor to have higher processing speed, and is strict to System Hardware Requirement, is difficult on engineering, obtain practicality.

Conventional induction motor offline parameter measuring method need be carried out no load test and stall experiment to motor.But, have mechanical load in particular cases at motor, then can't carry out no load test.At this moment need motor and load be broken away from fully, and this usually is a trouble, and if motor to be controlled be the ingredient of the physical construction of load, then sometimes or even impossible.

For above-mentioned problem, based on the induction motor off-line checking method of frequency converter, stationary rotor from last century the nineties just begun one's study early stage.Induction motor parameter comprises: fixed rotor resistance, rotor leakage inductance and magnetizing inductance (claiming the rotor mutual inductance again).Induction motor equivalent circuit diagram when Fig. 1 has provided stationary rotor, wherein: r ₁Be stator resistance, r ₂Be rotor resistance, L _mBe magnetizing inductance, ω is the electric current angular frequency, L _L1Be stator leakage inductance, L _L2Be the rotor leakage inductance.Feed the setting current i of different frequency to induction motor ₁, detect motor stator voltage U ₁, can calculate the parameter of electric machine through certain algorithm.

When adopting frequency converter that the parameter of electric machine is measured, from the consideration that reduces cost, general working voltage sensor not detects DC bus-bar voltage and combines the incompatible reconstruct output voltage of frequency converter device output switches set, i.e. stator voltage but adopt.Because the influence of the Dead Time of frequency converter output switching device, stator voltage detect and have bigger error, especially when input voltage was low, error effect was bigger.In order to reduce the influence of stator voltage error, in the existing stationary rotor parameter of electric machine detection method, the accuracy that often improves parameter detecting through some voltage compensation measures.But in practical application,, be difficult to bucking voltage error accurately because switching device is non-linear.The method that another kind reduces the voltage error influence is to strengthen voltage, need improve power frequency simultaneously but strengthen voltage, when the detection rotor impedance, can produce error owing to kelvin effect like this.

Summary of the invention

The objective of the invention is to defective, a kind of parameter of electric machine detection method and motor parameter-detecting device are provided to prior art.

For realizing the foregoing invention purpose, the present invention adopts following technical scheme:

A kind of parameter of electric machine detection method is opened a way a wherein phase winding of motor;

Detect stator leakage inductance and rotor leakage inductance step: between other two phases of motor, apply the high rated voltage of frequency ratio rated power, according to the computing formula detection stator leakage inductance and the rotor leakage inductance of stator leakage inductance and rotor leakage inductance.

A kind of motor parameter-detecting device; Comprise stator leakage inductance and rotor leakage inductance detecting unit; Said stator leakage inductance and rotor leakage inductance detecting unit apply the high rated voltage of frequency ratio rated power between other two phases of motor when a wherein phase winding of motor breaks off, calculate stator leakage inductance and rotor leakage inductance.

The present invention is with respect to above-mentioned prior art; Its beneficial effect is: the invention provides parameter of electric machine off-line checking method and motor parameter-detecting device under the static situation of a kind of induction electromotor rotor; Only need between two phases of motor, to apply successively the curtage of different frequency, and reach the pinpoint accuracy that the parameter of electric machine detects through the influence that reduces voltage error and kelvin effect.

Description of drawings

In order to be illustrated more clearly in the technical scheme in the embodiment of the invention, the accompanying drawing of required use is done to introduce simply in will describing embodiment below.

Fig. 1 is the equivalent circuit diagram when rotor is static in the prior art;

Fig. 2 is the control block diagram of the parameter of electric machine offline inspection of the embodiment of the invention;

Fig. 3 is the current step response wave shape synoptic diagram of the embodiment of the invention;

Fig. 4 is an induction motor schematic equivalent circuit under the high frequency of the embodiment of the invention;

Fig. 5 is embodiment of the invention induction motor equiva lent impedance figure.

Embodiment

To combine the accompanying drawing in the embodiment of the invention below, the technical scheme in the embodiment of the invention is carried out clear, intactly description, obviously, described embodiment only is the present invention's part embodiment, rather than whole embodiment.Based on the embodiment among the present invention, those of ordinary skills are not making the every other embodiment that is obtained under the creative work prerequisite, all belong to the scope of the present invention's protection.

The present invention relates to a kind of parameter of electric machine detection method; Comprise and detect stator leakage inductance and rotor leakage inductance step: between other two phases of motor, apply the high rated voltage of frequency ratio rated power, according to the computing formula detection stator leakage inductance and the rotor leakage inductance of stator leakage inductance and rotor leakage inductance.

Between other two phases of motor, apply the high rated voltage of frequency ratio rated power, detect the rotor leakage inductance, apply electric voltage frequency ω ₁Than motor rated frequency ω _NHigh a lot of rated voltage, the said frequency that applies be at least greater than four times of rated frequencies, this moment magnetizing inductance L _mElectric current can be very little, simultaneously, stator resistance r ₁With rotor resistance r ₂On pressure drop also smaller, induction motor equivalent electrical circuit shown in Figure 1 can be reduced to shown in Figure 4.Because the rotor leakage inductance is little more a lot of than magnetizing inductance, so approximately think stator leakage inductance L _L1With rotor leakage inductance L _L2Be identical, i.e. L _L1=L _L2=L ₁This moment, the amplitude ratio of voltage and current was similar to 2 ω L _lIn control block diagram shown in Figure 2, α shaft current set-point i _{A_ref}Be made as i _{A_ref}=i _NSin ω ₁T, wherein i _NBe the motor rated current.Detect DC bus-bar voltage U _Dc, utilize the voltage reconstructing method to obtain stator voltage U _aSo,, the calculation expression of rotor leakage inductance is:

$L_l=\frac{U_a}{2{\mathrm{\ω}}_1{i}_N}$

Parameter of electric machine detection method also comprises: detect motor stator resistance step: between other two phases of motor, apply pulsed dc voltage, detect motor stator resistance;

Detect rotor time constant step: between other two phases of motor, apply the step DC voltage; Measure the current value in constantly different and this moment and draw electric current-time linear equation, zero current value and said motor stator resistance substitution electric current-time linear equation constantly drawn the approximate value of rotor time constant.

Said detection motor stator resistance step also comprises: adopt formula r ₁=U _DcD/2i calculates motor stator resistance, wherein, and U _DcBe DC bus-bar voltage, i is an electric machine phase current, and the clock period is T _s, pulse width is t, duty of ratio D=t/T _s

As shown in Figure 2, make the switching tube VT1 conducting always of inverter bridge, switching tube VT2, VT3, VT5, VT6 turn-off always, and switching tube VT4 is driven by pulse train, then on a, b two phase windings, has produced a sequence of voltage pulses.If DC bus-bar voltage is U _Dc, the clock period is T _s, pulse width is t, then the theoretical dutycycle D=t/T of pulse _s, the average voltage on the winding then is U _DcD obtains the DC voltage of an equivalence, and corresponding stator resistance value is r ₁=U _DcD/2i, i are electric machine phase current.

In the actual detected process, in order to prevent the overcurrent fault of frequency converter in the testing process, the setting of dutycycle should correctly be considered.Adopt electric current loop to add its size of method control that pi regulator draws dutycycle D in this method, prevent excess current.As shown in Figure 2, in two phase rest frames, α shaft current set-point i _{A_ref}Be made as the motor load current value, detect motor biphase current i _aAnd i _b, conversion obtains α axle feedback current i through clake _{A_fbd}, obtain α shaft voltage set-point u through pi regulator _{α ref}, and β shaft voltage set-point u _{β ref}Directly be made as zero, can guarantee that identical with the control signal of c phase brachium pontis mutually (in fact, the VT5 in our control chart 2 turn-offs with the VT6 pipe all the time, and like this, the motor equivalence is that a phase and b are in series for b among Fig. 2; Otherwise, then be to be in series with a again after b and c are in parallel).So the calculation expression of stator resistance is:

Said detection rotor time constant step also comprises: measure current value at moment t1 place

I then _Step| _T=∞With

Difference be I _a, set

Draw another t2 constantly.

In Fig. 1 induction motor equivalent electrical circuit, electric current is following to transport function G (s) expression formula of the ratio of voltage,

$G\left(s\right)=\frac{1}{r_1}\frac{1+T_{r}s}{1+(T_r+T_s)s+\mathrm{\σ}{T}_s{T}_r{s}^2}$

In the formula, s is a Laplace operator, T _sBe stator time constant, T _rBe rotor time constant, magnetic leakage factor

L ₂Be inductor rotor L ₂=L _m+ L _lFor following formula, at angular frequency (T _s+ T _r)/σ T _sT _rCan be approximated to be in [rad/s] very low frequency:

$G\left(s\right)\≅\frac{1}{r_1}\frac{1+T_{r}s}{1+(T_r+T_s)s}=\frac{T_r}{r_1(T_s+T_r)}+\frac{T_s}{r_1(T_s+T_r)}\frac{1}{1+(T_r+T_s)s}$

Suppose that induction motor three-phase input voltage when original state is zero; Zero plays the input step voltage U constantly _Step, current i _StepFollowing voltage produces.This moment, current-responsive was as shown in Figure 4.Current i _StepEnd value be:

$i_{\mathrm{step}}{|}_{t=\∞}=\frac{U_{\mathrm{step}}}{r_1}$

Electric current initial value i _Step| _T=0Then get by initial-value theorem,

$i_{\mathrm{step}}{|}_{t=0}=\frac{T_r}{T_s+T_r}\·i_{\mathrm{step}}{|}_{t=\∞}=\frac{T_r}{T_s+T_r}\·\frac{U_{\mathrm{step}}}{r_1}$

Wherein the current-responsive time constant is (T _s+ T _r).

The influence of higher hamonic wave in the step voltage is at experience σ T _sT _r/ (T _s+ T _r) [sec] fully long-time moment t afterwards ₁The place is measured

i _Step| _T=∞With

Difference be I _aConfirm t ₁Afterwards, measure current i _StepAnother one t constantly ₂Obtain with following formula.

$i_{\mathrm{step}}{|}_{t=\∞}{-i}_{\mathrm{step}}{|}_{t{=t}_2}=0.5I_a$

Time constant (the T of current amplitude one half _s+ T _r) do,

$0.5=-e^{\frac{t_2-t_1}{T_s+T_r}}$

Can obtain (T according to following formula _s+ T _r) expression formula do,

$T_s+T_r=-\frac{t_2-t_1}{\ln \left(0.5\right)}=1.442(t_2-t_1)$

Among Fig. 4, A point and B point line and the longitudinal axis meet at the C point, and the C point can be similar to and replace i _Step| _T=0At this moment have,

$i_{\mathrm{step}}{|}_{t=0}=\frac{T_r}{T_s+T_r}\·\frac{U_{\mathrm{step}}}{r_1}\≅\frac{U_{\mathrm{step}}}{r_1}-I_c=\frac{U_{\mathrm{step}}}{r_1}-\frac{I_a(2t_2-t_1)}{2(t_2-t_1)}$

$T_r\≈[1-\frac{I_a(2t_2-t_1)}{2(t_2-t_1)}\·\frac{r_1}{U_{\mathrm{step}}}](T_s+T_r)$

With the T that calculates before _s+ T _rThe substitution following formula gets,

$T_r\≈1.442[\left(t_2{-t}_1\right)-\frac{I_a(2t_2-t_1)}{2}\·\frac{r_1}{U_{\mathrm{step}}}]$

The invention provides the parameter of electric machine off-line checking method under the static situation of a kind of induction electromotor rotor; Only need between two phases of motor, to apply the step DC voltage successively; And measure motor stator resistance earlier; Utilize motor stator resistance measurement rotor time constant, reduced calculation procedure, promoted work efficiency.

After detecting rotor time constant step, also comprise detection rotor resistance and magnetizing inductance step: between other two phases of motor, apply the alternating current of rated slip frequency, detection rotor resistance and magnetizing inductance.

Between other two phases of motor, apply the alternating current of rated slip frequency, detection rotor resistance and magnetizing inductance.Among induction motor equivalent electrical circuit Fig. 1, all loads can equivalence be a reactance Z.T type equivalent electrical circuit among the figure becomes and is illustrated in fig. 5 shown below.

The real part Re (Z) of Z and imaginary part Im (Z) expression formula are following among the figure,

$\mathrm{Re}\left(Z\right)=r_1+\frac{{\mathrm{\ω}}^2{L}_1{T}_r(1-\mathrm{\σ})}{1+{\mathrm{\ω}}^2{T}_r^2}$

$\mathrm{Im}\left(Z\right)=\mathrm{\ω}{L}_2+\frac{1+{\mathrm{\σ\ω}}^2{T}_r^2}{1+{\mathrm{\ω}}^2{T}_r^2}$

In the formula, L ₁Be stator inductance, L ₂Be inductor rotor, and L ₁=L ₂

Because the influence of the Dead Time of frequency converter output switching device, stator voltage detect and have bigger error, especially when input voltage was low, error effect was bigger.In order to reduce the influence of stator voltage error, can improve the accuracy of parameter detecting through the dead area compensation measure.But in practical application,, be difficult to compensate accurately the dead band voltage error because switching device is non-linear.On the other hand, the voltage error and the current polarity that are caused by Dead Time are opposite.That is to say that the stator voltage error is synchronous with stator current in the ideal case, do not have this influence with the voltage segment of electric current quadrature.Stator voltage is Re (Z) with the ratio of stator current same-phase; Stator voltage is Im (Z) with the ratio of stator current orthogonal branch; So utilize Im (Z) to remove to calculate rotor resistance and magnetizing inductance, can eliminate the influence that the voltage error that caused by frequency converter output switching device Dead Time brings fully.

In order to improve the accuracy that rotor resistance and magnetizing inductance detect, the α shaft current set-point I among Fig. 2 as much as possible _{A_ref}Frequency must select suitable value.If it is too low that this frequency is selected, then compare excitation reactance ω L with the rotor loop reactance _mBe very little.Electric current mainly passes through energized circuit like this, makes rotor resistance r ₂Be not easy to obtain.If it is too high that this frequency is selected, excitation reactance ω L _mIncrease, the electric current of flowing through diminishes, leakage inductance L _lOn voltage drop become big, Im (Z) receives leakage inductance to influence increase, and because kelvin effect, makes rotor resistance r ₂Measuring error further strengthens.Experiment is found, as α shaft current set-point i _{A_ref}Angular frequency be ω _Ref=2 π/T _rThe time, testing result is pressed close to actual value.

α shaft current set-point i _{A_ref}Be made as,

$i_{\mathrm{\α}\_\mathrm{ref}}=\sqrt{2}{I}_N\cos \left({\mathrm{\ω}}_{\mathrm{ref}}t\right)$

After electric current reached setting value, between U, V two phases, having produced a fundamental frequency was ω _Ref, fundamental voltage amplitude is U _mSine pulse width modulation (PWM) voltage.The electric current and the voltage sample value of storage one-period calculate the phase differential θ of voltage and current, current first harmonics amplitude I through FFT _mThe stator voltage amplitude can obtain through reconstruction calculations.So imaginary part Im (Z) does

$\mathrm{Im}\left(Z\right)=\frac{U_m{I}_m\sin \mathrm{\θ}}{2I_m^2}$

The imaginary part Im that obtains before this (Z) expression formula is put in order,

$\frac{{\mathrm{\ω}}_{\mathrm{ref}}^2}{r_2^2}(2{\mathrm{\ω}}_{\mathrm{ref}}{L}_l-\mathrm{Im}\left(Z\right))L_2^2+(1-\frac{{\mathrm{\ω}}_{\mathrm{ref}}^2}{r_2^2}{L}_l){\mathrm{\ω}}_{\mathrm{ref}}{L}_2-\mathrm{Im}\left(Z\right)=0$

With T _r=L ₂/ r ₂The substitution following formula gets,

${\mathrm{\ω}}_{\mathrm{ref}}{L}_2^2+[{\mathrm{\ω}}_{\mathrm{ref}}^2{T}_r^2(2{\mathrm{\ω}}_{\mathrm{ref}}{L}_l-\mathrm{Im}\left(Z\right))-\mathrm{Im}\left(Z\right)]L_2-{\mathrm{\ω}}_{\mathrm{ref}}^3{T}_r^2{L}_l=0$

Through separating the inductor rotor L that quadratic equation with one unknown obtains needs ₂, then magnetizing inductance does,

L _m＝L ₂-L _l

Rotor resistance does

$r_2=\frac{L_2}{T_r}$

The invention provides the parameter of electric machine off-line checking method under the static situation of a kind of induction electromotor rotor; This method only needs between two phases of motor, to apply successively the curtage of different frequency; And reach the pinpoint accuracy that the parameter of electric machine detects through the influence that reduces voltage error and kelvin effect, and at first calculate the rotor leakage inductance, measure motor stator resistance then earlier; Utilize motor stator resistance measurement rotor time constant; Calculate magnetizing inductance and rotor resistance at last, reduced calculation procedure, promoted work efficiency.

A kind of motor parameter-detecting device; Comprise stator leakage inductance and rotor leakage inductance detecting unit; Said stator leakage inductance and rotor leakage inductance detecting unit apply the high rated voltage of frequency ratio rated power between other two phases of motor when a wherein phase winding of motor breaks off, calculate stator leakage inductance and rotor leakage inductance.

Said stator leakage inductance and rotor leakage inductance detecting unit adopt formula

Obtain said stator leakage inductance, said rotor leakage inductance equals stator leakage inductance, wherein U _aBe stator voltage, i _NBe motor rated current, ω ₁For applying frequency.

Also comprise motor stator resistance detection unit and rotor time constant detecting unit, said motor stator resistance detection unit applies pulsed dc voltage between other two phases of motor when a wherein phase winding of motor breaks off, detect motor stator resistance; Said rotor time constant detecting unit applies the step DC voltage between other two phases of motor when a wherein phase winding of motor breaks off; The current value of measuring constantly different and this moment also draws electric current-time linear equation, and the approximate value that draws rotor time constant according to the current value and the said motor stator resistance in the zero moment.

Said motor stator resistance detection unit adopts formula r ₁=U _DcD/2i calculates motor stator resistance, wherein, and U _DcBe DC bus-bar voltage, i is an electric machine phase current, and the clock period is T _s, pulse width is t, duty of ratio D=t/T _s

Said rotor time constant detecting unit adopts formula

Be similar to and draw rotor time constant, wherein, U _StepBe zero moment to play the input step magnitude of voltage.

Also comprise rotor resistance and magnetizing inductance detecting unit, rotor resistance and magnetizing inductance detecting unit apply the alternating current of rated slip frequency, detection rotor resistance and magnetizing inductance between other two phases of motor when a wherein phase winding of motor breaks off.

Said detection rotor resistance and magnetizing inductance detecting unit adopt formula

${\mathrm{\ω}}_{\mathrm{ref}}{L}_2^2+[{\mathrm{\ω}}_{\mathrm{ref}}^2{T}_r^2(2{\mathrm{\ω}}_{\mathrm{ref}}{L}_l-\mathrm{Im}\left(Z\right))-\mathrm{Im}\left(Z\right)]L_2-{\mathrm{\ω}}_{\mathrm{ref}}^3{T}_r^2{L}_l=0$

Calculate inductor rotor L ₂, adopt formula L _m=L ₂-L _lCalculate magnetizing inductance, adopt formula Calculate rotor resistance.

The invention provides motor parameter-detecting device under the static situation of a kind of induction electromotor rotor; Only need between two phases of motor, to apply successively the curtage of different frequency; And reach the pinpoint accuracy that the parameter of electric machine detects through the influence that reduces voltage error and kelvin effect, and at first calculate the rotor leakage inductance, measure motor stator resistance then earlier; Utilize motor stator resistance measurement rotor time constant; Calculate magnetizing inductance and rotor resistance at last, reduced calculation procedure, promoted work efficiency.

Used specific case herein principle of the present invention and embodiment are set forth, the explanation of above embodiment just is used for helping to understand method of the present invention and core concept thereof; Simultaneously, for those of ordinary skill in the art, according to thought of the present invention, the part that all can change in specific embodiments and applications, in sum, this description should not be construed as limitation of the present invention.

Claims (17)

1. parameter of electric machine detection method is characterized in that:

Make the wherein phase winding open circuit of motor;

Detect stator leakage inductance and rotor leakage inductance step: between other two phases of motor, apply the high rated voltage of frequency ratio rated power, according to the computing formula detection stator leakage inductance and the rotor leakage inductance of stator leakage inductance and rotor leakage inductance.

2. parameter of electric machine detection method as claimed in claim 1 is characterized in that: detect stator leakage inductance and rotor leakage inductance step and also comprise: adopt formula

Obtain said stator leakage inductance, said rotor leakage inductance equals stator leakage inductance, wherein U _aBe stator voltage, i _NBe motor rated current, ω ₁For applying frequency.

3. parameter of electric machine detection method as claimed in claim 2 is characterized in that: the said frequency that applies is at least greater than four times of rated frequencies.

4. parameter of electric machine detection method as claimed in claim 1 is characterized in that: also comprise:

Detect motor stator resistance step: between other two phases of motor, apply pulsed dc voltage, detect motor stator resistance;

Detect rotor time constant step: between other two phases of motor, apply the step DC voltage; Measure the current value in constantly different and this moment and draw electric current-time linear equation, zero current value and said motor stator resistance substitution electric current-time linear equation constantly drawn the approximate value of rotor time constant.

5. parameter of electric machine detection method as claimed in claim 4 is characterized in that: said detection motor stator resistance step also comprises: adopt formula r ₁=U _DcD/2i calculates motor stator resistance, wherein, and U _DcBe DC bus-bar voltage, i is an electric machine phase current, and the clock period is T _s, pulse width is t, duty of ratio D=t/T _s

6. parameter of electric machine detection method as claimed in claim 4 is characterized in that: said detection rotor time constant step also comprises: measure current value at moment t1 place I then _Step| _T=∞With

Difference be I _a, set Draw another t2 constantly.

7. parameter of electric machine detection method as claimed in claim 6 is characterized in that: said detection rotor time constant step also comprises: adopt formula

Be similar to and draw rotor time constant, wherein, U _StepBe zero moment to play the input step magnitude of voltage.

8. parameter of electric machine detection method as claimed in claim 5; It is characterized in that: after said detection rotor time constant step, also comprise detection rotor resistance and magnetizing inductance step: between other two phases of motor, apply the alternating current of rated slip frequency, detection rotor resistance and magnetizing inductance.

9. parameter of electric machine detection method as claimed in claim 8 is characterized in that: said detection rotor resistance and magnetizing inductance step also comprise: apply The alternating current flow valuve, wherein, ω _Ref=2 π/T _r

10. parameter of electric machine detection method as claimed in claim 9 is characterized in that: said detection rotor resistance and magnetizing inductance step also comprise: adopt formula

${\mathrm{\ω}}_{\mathrm{ref}}{L}_2^2+[{\mathrm{\ω}}_{\mathrm{ref}}^2{T}_r^2(2{\mathrm{\ω}}_{\mathrm{ref}}{L}_l-\mathrm{Im}\left(Z\right))-\mathrm{Im}\left(Z\right)]L_2-{\mathrm{\ω}}_{\mathrm{ref}}^3{T}_r^2{L}_l=0$

Calculate inductor rotor L ₂, adopt formula L _m=L ₂-L _lCalculate magnetizing inductance, adopt formula

Calculate rotor resistance.

11. motor parameter-detecting device; It is characterized in that: comprise stator leakage inductance and rotor leakage inductance detecting unit; Said stator leakage inductance and rotor leakage inductance detecting unit apply the high rated voltage of frequency ratio rated power between other two phases of motor when a wherein phase winding of motor breaks off, calculate stator leakage inductance and rotor leakage inductance.

12. motor parameter-detecting device as claimed in claim 11 is characterized in that: said stator leakage inductance and rotor leakage inductance detecting unit adopt formula

Obtain said stator leakage inductance, said rotor leakage inductance equals stator leakage inductance, wherein U _aBe stator voltage, i _NBe motor rated current, ω ₁For applying frequency.

13. motor parameter-detecting device as claimed in claim 11 is characterized in that: also comprise motor stator resistance detection unit and rotor time constant detecting unit,

Said motor stator resistance detection unit applies pulsed dc voltage between other two phases of motor when a wherein phase winding of motor breaks off, detect motor stator resistance;

Said rotor time constant detecting unit applies the step DC voltage between other two phases of motor when a wherein phase winding of motor breaks off; The current value of measuring constantly different and this moment also draws electric current-time linear equation, and the approximate value that draws rotor time constant according to the current value and the said motor stator resistance in the zero moment.

14. motor parameter-detecting device as claimed in claim 13 is characterized in that: said motor stator resistance detection unit adopts formula r ₁=u _DcD/2i calculates motor stator resistance, wherein, and U _DcBe DC bus-bar voltage, i is an electric machine phase current, and the clock period is T _s, pulse width is t, duty of ratio D=t/T _s

15. motor parameter-detecting device as claimed in claim 13 is characterized in that: said rotor time constant detecting unit adopts formula

Be similar to and draw rotor time constant, wherein, U _StepBe zero moment to play the input step magnitude of voltage.

16. motor parameter-detecting device as claimed in claim 11; It is characterized in that: also comprise rotor resistance and magnetizing inductance detecting unit; Rotor resistance and magnetizing inductance detecting unit apply the alternating current of rated slip frequency, detection rotor resistance and magnetizing inductance between other two phases of motor when a wherein phase winding of motor breaks off.

17. parameter of electric machine detection method as claimed in claim 16 is characterized in that: said detection rotor resistance and magnetizing inductance detecting unit adopt formula

${\mathrm{\ω}}_{\mathrm{ref}}{L}_2^2+[{\mathrm{\ω}}_{\mathrm{ref}}^2{T}_r^2(2{\mathrm{\ω}}_{\mathrm{ref}}{L}_l-\mathrm{Im}\left(Z\right))-\mathrm{Im}\left(Z\right)]L_2-{\mathrm{\ω}}_{\mathrm{ref}}^3{T}_r^2{L}_l=0$

Calculate inductor rotor L ₂, adopt formula L _m=L ₂-L _lCalculate magnetizing inductance, adopt formula Calculate rotor resistance.

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