CN103018577A - Method for measuring parameters of permanent magnet synchronous motor - Google Patents

Abstract

The invention discloses a method for measuring parameters of a permanent magnet synchronous motor and belongs to the field of motor parameter measurement. The method includes utilizing the A phase no-load counter EMF (Electromotive Force) of a motor and the electric angular velocity of the motor to obtain a permanent magnet flux linkage, utilizing the wave form of the A phase no-load counter EMF and a position sensor to read the corresponding electric angular positions of the 90-degree angle and 0-degree angle of a motor rotor, changing the connection type of a stator winding, and utilizing the alternating voltage, current and frequency to respectively obtain corresponding direct-axis inductance and quadrature-axis inductance. The apparatus used in the method are conventional apparatus and the method has the advantages of clear physical concept, easy operation, high measurement accuracy and the like.

Description

A kind of method of measuring the permagnetic synchronous motor parameter

Technical field

The invention belongs to the parameter identifier field, relate to a kind of method of measuring the permagnetic synchronous motor parameter.

Background technology

Permagnetic synchronous motor (Permanent magnet synchronous machine, PMSM) does not need exciting current, has the advantages such as simple in structure, that volume is little, efficiency is high, power factor is high, moment of inertia is low.Along with the raising of permanent magnetic material magnetic property, in the servo special purpose device of middle low power, high precision, high reliability, wide speed regulating range, permagnetic synchronous motor obtains application widely.The control methods such as Speedless sensor control, weak magnetic control system and loss balancing control are widely used in permanent-magnet synchronous and drive in special purpose device.The electric parameter of motor is very large on the control performance impact of these control strategies.Therefore Measurement accuracy permagnetic synchronous motor parameter is necessary, and wherein the Measurement accuracy of inductance parameters is particularly important.At present, permagnetic synchronous motor inductance parameter measuring method mainly contains two classes: 1) use the LCR tester to measure the motor inductance; 2) pulse voltage experimental method.While using LCR tester measured motor inductance, stator winding one be disconnected mutually, measure the inductance between other two-phase.In order to obtain motor ac-dc axis inductance parameters value, the inductance that also this will be measured is converted.Reduction formula is relevant with the motor rotor position angle, and for magnetic circuit different magneto, reduction formula is different, this makes measuring process complicated undoubtedly.The pulse voltage experimental method is to change motor three-phase winding connection, at rotor, adds DC pulse voltage during in d-axis and quadrature axis, record current, and the recycling integration method is obtained respectively d-axis inductance and quadrature axis inductance.When the pulse voltage experimental method is surveyed inductance, to the selection of voltage magnitude and action time, to accurately hold.It is too little that voltage magnitude is selected, and affects accuracy of detection, excessively may make electric current surpass the special purpose device amplitude limit value to affect special purpose device safety.Action time is too short, and sampled point is few, and the current information obtained is few, also can affect accuracy of detection, and action time is long, and electric current equally may the excessive special purpose device safety that affects.This operability that makes the method is not fine.

Summary of the invention

The object of the present invention is to provide a kind of method of measuring the permagnetic synchronous motor parameter, particularly in not with utilizing alternating-current voltage source to measure permagnetic synchronous motor d-axis and quadrature axis inductance parameters in LCR tester and DC pulse voltage situation.

Technical scheme: the operating process following steps of measurement permagnetic synchronous motor parametric technique of the present invention:

Step 101: High Precision Multimeter is measured the resistance value R of three-phase stator winding _s;

Step 102: determine permanent magnetism magnetic linkage ψ _pM;

Step 103: prime mover drags permagnetic synchronous motor no-load running, obtains A phase no-load voltage u _sawaveform and corresponding position transducer position readings, draw u _sacorresponding position sensor signal reading during minimum value, calculate θ _mea=90 ° of position readings x that position increases with respect to the permagnetic synchronous motor initial position, thereby motor is while getting back to initial position, rotary electric machine makes the position transducer reading increase x, and this position is θ _mea=90 ° of rotor-positions; The position transducer umber of pulse that turns around is a, and the permagnetic synchronous motor number of pole-pairs is p, and 90 ° of position readings corresponding to electrical angle are a/ (4p), at θ _mea=90 ° of rotor-position places are manual rotation round about, makes the position transducer reading reduce a/ (4p), and this position is θ _mea=0 ° of rotor-position;

Step 104: permagnetic synchronous motor is static, stator winding B phase and C mutually and Lian Houzai and A be in series, the alternating-current voltage source u of external given frequency f _s, permagnetic synchronous motor three-phase current i under this condition _sa, i _sb, i _scwith three-phase line voltage u _sab, u _sbc, u _scameet following formula: $\left\{\begin{array}{c}{i}_{\mathrm{sa}}=-(i_{\mathrm{sb}}+i_{\mathrm{sc}})\\ u_{\mathrm{sab}}=u_s\\ u_{\mathrm{sbc}}=0\\ u_{\mathrm{sca}}=-u_s\end{array}\right.,$ Utilize three-phase line voltage to obtain three-phase phase voltage u _sa, u _sb, u _scand obtain straight, quadrature-axis voltage electric current u _sd, u _sq, i _sd, i _sq;

Step 105: permagnetic synchronous motor is static, motor actual electrical angular velocity omega _d/sequal 0, the voltage equation under application permagnetic synchronous motor synchronous rotary dq coordinate system: $\left\{\begin{array}{c}{u}_{\mathrm{sd}}=R_s{i}_{\mathrm{sd}}+L_{\mathrm{sd}}\frac{{\mathrm{di}}_{\mathrm{sd}}}{\mathrm{dt}}\\ u_{\mathrm{sq}}=R_s{i}_{\mathrm{sq}}+L_{\mathrm{sq}}\frac{{\mathrm{di}}_{\mathrm{sq}}}{\mathrm{dt}}\end{array}\right.;$ When permanent-magnetic synchronous motor rotor forwards θ to _mea=0 ° of position, meet $\left\{\begin{array}{c}{u}_{\mathrm{sd}}=\frac{2}{3}{u}_s\\ i_{\mathrm{sd}}=i_{\mathrm{sa}}\end{array}\right.,$ Measure alternating-current voltage source u _seffective value u _{s_RMS}with A phase current effective value i _{sa_RMS}, the application following formula calculates stator d-axis inductance L _sd: when permanent-magnetic synchronous motor rotor forwards θ to _mea=90 ° of positions, meet $\left\{\begin{array}{c}{u}_{\mathrm{sq}}=-\frac{2}{3}{u}_s\\ i_{\mathrm{sq}}=-i_{\mathrm{sa}}\end{array}\right.,$ Measure alternating-current voltage source u _seffective value u _{s_RMS}with A phase current effective value i _{sa_RMS}, the application following formula calculates stator quadrature axis inductance L _sq: $L_{\mathrm{sq}}=\frac{\sqrt{{\left(\frac{{2u}_{s\_\mathrm{RMS}}/3}{i_{\mathrm{sa}\_\mathrm{RMS}}}\right)}^2-R_s^2}}{2\mathrm{\πf}}.$

In described step 102, the three-phase stator winding zero load of described permagnetic synchronous motor, measure permagnetic synchronous motor A phase no-load voltage u _saamplitude U _m; The rotor-position signal θ that the receiving position sensor transmits _mea, calculate motor actual electrical angular velocity omega _d/s; Voltage equation in conjunction with described permagnetic synchronous motor under synchronous rotary dq coordinate system, described permagnetic synchronous motor zero load obtain i _sd=i _sq=0 o'clock three-phase voltage equation and magnetic linkage equation calculate the permanent magnetism magnetic linkage ψ of described permanent-magnetic synchronous motor rotor _pM, wherein

${\mathrm{\ψ}}_{\mathrm{PM}}=\frac{U_m}{{\mathrm{\ω}}_{d/s}}.$

Described prime mover can be any one in direct current generator, asynchronous machine, synchronous motor.

Beneficial effect: compared to the prior art the present invention, has following advantage:

1, measure motor inductance method with existing use LCR tester and compare, this measuring method clear physics conception, take full advantage of the voltage equation of permagnetic synchronous motor under synchronous rotating frame, according to voltage equation at motor rotor position θ _mea=0 ° and θ _meathe special shape of=90 °, by changing the connected mode of motor three phase windings, then the alternating-current voltage source of external given frequency, can directly obtain corresponding d-axis, quadrature axis inductance by the relevant voltage current effective value.

2, survey inductance with existing pulse voltage experimental method commonly used and compare, this method does not need to adopt direct voltage source, do not need the record current waveform to ask inductance for integration, and measuring accuracy is higher yet.The permagnetic synchronous motor parameter of utilizing the inventive method to record is set up permagnetic synchronous motor generator experimental model, the voltage waveform that emulation obtains and current waveform and actual permagnetic synchronous motor generator experimental under same case must voltage current waveform overlap finely, this has illustrated that the parameter of electric machine precision of utilizing this method to measure is high.

The accompanying drawing explanation

Fig. 1 is the block diagram of measuring method device of the present invention;

Fig. 2 is the FB(flow block) of measuring method of the present invention;

Motor stator winding connection diagram when Fig. 3 is the inventive method measurement d-axis, quadrature axis inductance;

Fig. 4 is line voltage experimental waveform and simulation waveform;

Fig. 5 is phase current experimental waveform and simulation waveform.

Embodiment

The present invention will be described below with reference to accompanying drawings.

The device block diagram of embodiments of the invention as shown in Figure 1, this measurement mechanism comprises: comprise threephase asynchronous machine 2, permagnetic synchronous motor 3 and DSP5, be provided with shaft coupling 4 between threephase asynchronous machine 2 and permagnetic synchronous motor 3, be provided with position transducer 7 between permagnetic synchronous motor 3 and DSP5; Threephase asynchronous machine 2 is connected with three-phase regulator 1, also comprises the three-phase stator winding 6 of permagnetic synchronous motor 3.The basic parameter of threephase asynchronous machine is: specified phase voltage U _n=220V, specified phase current I _n=11.8A, number of pole-pairs p=2, rated speed n _n=1500r/min; The basic parameter of permagnetic synchronous motor is: specified phase voltage U _n=220V, specified phase current I _n=11A, number of pole-pairs p=2, rated speed n _n=1500r/min.Surveying instrument used: High Precision Multimeter and reometer.

The method of measurement permagnetic synchronous motor parameter of the present invention, clear physics conception, easy and simple to handle, without using the LCR tester, do not need to adopt direct voltage source yet, measuring accuracy is higher.This method takes full advantage of the voltage equation of permagnetic synchronous motor under synchronous rotating frame, according to voltage equation at motor rotor position θ _mea=0 ° and θ _meathe special shape of=90 °, the connected mode of change motor three phase windings, then external AC potential source, can obtain corresponding d-axis, quadrature axis inductance by the relevant voltage current effective value.The FB(flow block) of this measuring method is shown in Fig. 2, and concrete steps are as follows:

1) High Precision Multimeter is measured the resistance value R of stator phase winding _s;

2) drag permagnetic synchronous motor by asynchronous motor and rotate, permanent-magnetic synchronous motor stator three phase winding zero loads, measure motor A phase no-load voltage u _saamplitude U _m.The rotor-position signal θ that velocity calculator receiving position sensor transmits _mea, and obtain according to the following formula motor actual electrical angular velocity omega _d/s:

${\mathrm{\ω}}_{d/s}=\frac{{\mathrm{d\θ}}_{\mathrm{mea}}}{\mathrm{dt}};$

3) voltage equation of permagnetic synchronous motor under synchronous rotary dq coordinate system is:

$\left\{\begin{array}{c}{u}_{\mathrm{sd}}=R_s{i}_{\mathrm{sd}}+\frac{{\mathrm{d\ψ}}_{\mathrm{sd}}}{\mathrm{dt}}-{\mathrm{\ω}}_{d/s}{\mathrm{\ψ}}_{\mathrm{sq}}\\ u_{\mathrm{sq}}=R_s{i}_{\mathrm{sq}}+\frac{{\mathrm{d\ψ}}_{\mathrm{sq}}}{\mathrm{dt}}+{\mathrm{\ω}}_{d/s}{\mathrm{\ψ}}_{\mathrm{sd}}\end{array}\right.$

U _sd, i _sd, ψ _sddirect-axis component for stator voltage, electric current, magnetic linkage; u _sq, i _sq, ψ _sqquadrature axis component for stator voltage, electric current, magnetic linkage; R _sstator resistance, ω _d/selectric angle speed.The magnetic linkage equation is:

$\left\{\begin{array}{c}{\mathrm{\ψ}}_{\mathrm{sd}}=L_{\mathrm{sd}}{i}_{\mathrm{sd}}+{\mathrm{\ψ}}_{\mathrm{PM}}\\ {\mathrm{\ψ}}_{\mathrm{sq}}=L_{\mathrm{sq}}{i}_{\mathrm{sq}}\end{array}\right.$

ψ _pMfor rotor permanent magnet magnetic linkage, L _sd, L _sqfor stator inductance d-axis and quadrature axis component;

4) step 2), the unloaded i of permagnetic synchronous motor _sd=i _sq=0, voltage equation is rewritten as:

$\left\{\begin{array}{c}{u}_{\mathrm{sd}}=0\\ u_{\mathrm{sq}}={\mathrm{\ω}}_{d/s}{\mathrm{\ψ}}_{\mathrm{PM}}\end{array}\right.$

Obtain three-phase voltage U by following formula _sabc, described three-phase voltage is u _sabcby A phase voltage u _sa, B phase voltage u _sbwith C phase voltage u _scthe tri-vector formed:

Wherein

u _sa＝u _sd?cosθ _mea+u _sqsin(-θ _mea)＝-ω _d/sψ _PMsinθ _mea

Utilize step 2) in the A phase no-load voltage u that obtains _saamplitude U _mwith the electric angle speed omega calculated _d/scalculate according to the following formula the rotor permanent magnet magnetic linkage:

${\mathrm{\ψ}}_{\mathrm{PM}}=\frac{U_m}{{\mathrm{\ω}}_{d/s}};$

5) known θ step 4) _meaa phase no-load voltage u in the time of=90 ° _sareach minimum value, the position when mark motor starts to rotate, drag permagnetic synchronous motor no-load running by asynchronous machine, the A phase no-load voltage u of permagnetic synchronous motor _saintroduce the A/D thief hatch of DSP by the voltage sample plate, preserve u _sawaveform and corresponding position transducer position readings, find out u _sacorresponding position transducer position signalling reading during minimum value, the position readings a complementation of turning around divided by position transducer, can obtain θ thus _mea=90 ° of position readings x that position increases with respect to the permagnetic synchronous motor initial position, thereby motor is while getting back to initial position, the hand rotation motor makes the position transducer position readings increase x, and this position is θ _mea=90 ° of rotor-positions;

6) the position transducer used umber of pulse that turns around is a, and the permagnetic synchronous motor number of pole-pairs is p, and 90 ° of position readings corresponding to electrical angle are a/ (4p), from step 5) determine θ _mea=90 ° of rotor-position places are manual rotation round about, makes the position transducer reading reduce a/ (4p), and this position is θ _mea=0 ° of rotor-position;

7) permagnetic synchronous motor is static, and connected mode is as Fig. 3, and stator winding B phase is with the C phase and connect, then is in series with A, the alternating-current voltage source u of external given frequency f _s, permagnetic synchronous motor three-phase current i under this condition _sa, i _sb, i _scwith three-phase line voltage u _sab, u _sbc, u _scameet following formula:

$\left\{\begin{array}{c}{i}_{\mathrm{sa}}=-(i_{\mathrm{sb}}+i_{\mathrm{sc}})\\ u_{\mathrm{sab}}=u_s\\ u_{\mathrm{sbc}}=0\\ u_{\mathrm{sca}}=-u_s\end{array}\right.,$

Utilize three-phase line voltage, by following formula, obtain three-phase phase voltage u _sa, u _sb, u _sc:

$\left\{\begin{array}{c}{u}_{\mathrm{sa}}=\frac{2}{3}{u}_s\\ u_{\mathrm{sb}}=u_{\mathrm{sc}}=-\frac{1}{3}{u}_s\end{array}\right.$

By lower two formulas obtain directly, quadrature-axis voltage electric current u _sd, u _sq, i _sd, i _sq:

71) permagnetic synchronous motor is static, motor actual electrical angular velocity omega _d/sequal 0, step 3) in voltage equation under permagnetic synchronous motor synchronous rotary dq coordinate system be rewritten as following formula:

$\left\{\begin{array}{c}{u}_{\mathrm{sd}}=R_s{i}_{\mathrm{sd}}+L_{\mathrm{sd}}\frac{{\mathrm{di}}_{\mathrm{sd}}}{\mathrm{dt}}\\ u_{\mathrm{sq}}=R_s{i}_{\mathrm{sq}}+L_{\mathrm{sq}}\frac{{\mathrm{di}}_{\mathrm{sq}}}{\mathrm{dt}}\end{array}\right.;$

72) forward permanent-magnetic synchronous motor rotor to θ _mea=0 ° of position, step 7) in, the ac-dc axis electric current and voltage is rewritten as following formula:

$\left\{\begin{array}{c}{u}_{\mathrm{sd}}=\frac{2}{3}{u}_s\\ i_{\mathrm{sd}}=i_{\mathrm{sa}}\end{array}\right.,$

Bring above formula into step 71) in voltage equation obtain following formula:

$\frac{2}{3}{u}_s=R_s{i}_{\mathrm{sa}}+L_{\mathrm{sd}}\frac{{\mathrm{di}}_{\mathrm{sa}}}{\mathrm{dt}},$

Measure alternating-current voltage source u _seffective value u _{s_RMS}with A phase current effective value i _{sa_RMS}, utilize step 1) and gained phase winding resistance value R _sand u _sknown frequency f, be calculated as follows stator d-axis inductance L _sd:

$L_{\mathrm{sd}}=\frac{\sqrt{{\left(\frac{{2u}_{s\_\mathrm{RMS}}/3}{i_{\mathrm{sa}\_\mathrm{RMS}}}\right)}^2-R_s^2}}{2\mathrm{\πf}};$

73) forward permanent-magnetic synchronous motor rotor to θ _mea=90 ° of positions, step 7) in, the ac-dc axis electric current and voltage is rewritten as following formula:

$\left\{\begin{array}{c}{u}_{\mathrm{sq}}=-\frac{2}{3}{u}_s\\ i_{\mathrm{sq}}=-i_{\mathrm{sa}}\end{array}\right.,$

Bring above formula into step 71) in voltage equation obtain following formula:

$\frac{2}{3}{u}_s=R_s{i}_{\mathrm{sa}}+L_{\mathrm{sq}}\frac{{\mathrm{di}}_{\mathrm{sa}}}{\mathrm{dt}},$

Measure alternating-current voltage source u _seffective value u _{s_RMS}with A phase current effective value i _{sa_RMS}, utilize step 1) and gained phase winding resistance value R _sand u _sknown frequency f, be calculated as follows stator quadrature axis inductance L _sq:

$L_{\mathrm{sq}}=\frac{\sqrt{{\left(\frac{{2u}_{s\_\mathrm{RMS}}/3}{i_{\mathrm{sa}\_\mathrm{RMS}}}\right)}^2-R_s^2}}{2\mathrm{\πf}}.$

Compared to the prior art the present invention, has following advantage:

The present invention takes full advantage of the voltage equation of permagnetic synchronous motor under synchronous rotating frame, according to voltage equation at motor rotor position θ _mea=0 ° and θ _meathe special shape of=90 °, by changing the connected mode of motor three phase windings, then the external AC potential source, can directly obtain corresponding d-axis, quadrature axis inductance by the relevant voltage current effective value.Do not need to adopt direct voltage source, do not need the record current waveform to ask inductance for integration, and measuring accuracy is higher yet.As accompanying drawing 4 and accompanying drawing 5 known, the permagnetic synchronous motor parameter of utilizing the inventive method to record is set up permagnetic synchronous motor generator experimental model, the voltage waveform that emulation obtains and current waveform and actual permagnetic synchronous motor generator experimental under same case must voltage current waveform overlap fine.This has illustrated that the parameter of electric machine precision of utilizing this measurement special purpose device to obtain is high.

The foregoing is only better embodiment of the present invention; protection scope of the present invention is not limited with above-mentioned embodiment; in every case the equivalence that those of ordinary skills do according to disclosed content is modified or is changed, and all should include in the protection domain of putting down in writing in claims.

Claims (3)

1. a method of measuring the permagnetic synchronous motor parameter is characterized in that: described method is measured according to the voltage equation under permagnetic synchronous motor synchronous rotary dq coordinate system, comprises the following steps:

Step 101: High Precision Multimeter is measured the resistance value Rs of three-phase stator winding _;

Step 102: determine permanent magnetism magnetic linkage ψ _pM;

Step 103: described prime mover drags permagnetic synchronous motor no-load running, obtains A phase no-load voltage u _sawaveform and corresponding position transducer position readings, draw u _sacorresponding position sensor signal reading during minimum value, calculate θ _mea=90 ° of position readings x that position increases with respect to the permagnetic synchronous motor initial position, thereby motor is while getting back to initial position, rotary electric machine makes the position transducer reading increase x, and this position is θ _mea=90 ° of rotor-positions; The described position transducer umber of pulse that turns around is a, and described permagnetic synchronous motor number of pole-pairs is p, and 90 ° of position readings corresponding to electrical angle are a/ (4p), at θ _mea=90 ° of rotor-position places are manual rotation round about, makes the position transducer reading reduce a/ (4p), and this position is θ _mea=0 ° of rotor-position;

Step 104: described permagnetic synchronous motor is static, stator winding B phase and C mutually and Lian Houzai and A be in series, the alternating-current voltage source u of external given frequency f _s, permagnetic synchronous motor three-phase current i under this condition _sa, i _sb, i _scwith three-phase line voltage u _sab, u _sbc, u _scameet following formula: $\left\{\begin{array}{c}{i}_{\mathrm{sa}}=-(i_{\mathrm{sb}}+i_{\mathrm{sc}})\\ u_{\mathrm{sab}}=u_s\\ u_{\mathrm{sbc}}=0\\ u_{\mathrm{sca}}=-u_s\end{array}\right.,$ Utilize three-phase line voltage to obtain three-phase phase voltage u _sa, u _sb, u _scand obtain straight, quadrature-axis voltage electric current u _sd, u _sq, i _sd, i _sq;

Step 105: described permagnetic synchronous motor is static, motor actual electrical angular velocity omega _d/sequal 0, the voltage equation under application permagnetic synchronous motor synchronous rotary dq coordinate system: $\left\{\begin{array}{c}{u}_{\mathrm{sd}}=R_s{i}_{\mathrm{sd}}+L_{\mathrm{sd}}\frac{{\mathrm{di}}_{\mathrm{sd}}}{\mathrm{dt}}\\ u_{\mathrm{sq}}=R_s{i}_{\mathrm{sq}}+L_{\mathrm{sq}}\frac{{\mathrm{di}}_{\mathrm{sq}}}{\mathrm{dt}}\end{array}\right.;$ When permanent-magnetic synchronous motor rotor forwards θ to _mea=0 ° of position, meet $\left\{\begin{array}{c}{u}_{\mathrm{sd}}=\frac{2}{3}{u}_s\\ i_{\mathrm{sd}}=i_{\mathrm{sa}}\end{array}\right.,$ Measure alternating-current voltage source u _seffective value u _{s_RMS}with A phase current effective value i _{sa_RMS}, the application following formula calculates stator d-axis inductance L _sd:

when permanent-magnetic synchronous motor rotor forwards θ to _mea=90 ° of positions, meet $\left\{\begin{array}{c}{u}_{\mathrm{sq}}=-\frac{2}{3}{u}_s\\ i_{\mathrm{sq}}=-i_{\mathrm{sa}}\end{array}\right.,$ Measure alternating-current voltage source u _seffective value u _{s_RMS}with A phase current effective value i _{sa_RMS}, the application following formula calculates stator quadrature axis inductance L _sq: $L_{\mathrm{sq}}=\frac{\sqrt{{\left(\frac{{2u}_{s\_\mathrm{RMS}}/3}{i_{\mathrm{sa}\_\mathrm{RMS}}}\right)}^2-R_s^2}}{2\mathrm{\πf}}.$

2. a kind of method of measuring the permagnetic synchronous motor parameter according to claim 1 is characterized in that: in described step 102, the three-phase stator winding zero load of described permagnetic synchronous motor, measure permagnetic synchronous motor A phase no-load voltage u _saamplitude U _m; The rotor-position signal θ that the receiving position sensor transmits _mea, calculate motor actual electrical angular velocity omega _d/s; Voltage equation in conjunction with described permagnetic synchronous motor under synchronous rotary dq coordinate system, described permagnetic synchronous motor zero load obtain i _sd=i _sq=0 o'clock three-phase voltage equation and magnetic linkage equation calculate the permanent magnetism magnetic linkage ψ of described permanent-magnetic synchronous motor rotor _pM, wherein

${\mathrm{\ψ}}_{\mathrm{PM}}=\frac{U_m}{{\mathrm{\ω}}_{d/s}}.$

3. a kind of method of measuring the permagnetic synchronous motor parameter according to claim 1, it is characterized in that: described prime mover can be any one in direct current generator, asynchronous machine, synchronous motor.

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