CN105116330A - Test method of motor under normal-temperature and high-pressure environment - Google Patents

Abstract

The invention relates to a test method of a motor under a normal-temperature and high-pressure environment and belongs to the technical field of motor characteristic testing under the normal-temperature and high-pressure environment. The test method includes the following steps that: a measured motor and a standby motor are arranged in a high-pressure sealed barrel; the measured motor works in a motor state, and the standby motor works in a generator state; the stator current of the measured motor is gradually decreased to 0.5-times rated current from 1.5-times rated current; the stray loss of the measured motor working in the motor state is P<Ms>; the measured motor works in a generator state, and the standby motor works in a motor state; the stator current of the standby motor is gradually decreased to 0.5-times rated current from 1.5-times rated current; the stray loss of the measured motor working in the generator state is P<Gs>; the average value P<->s of the stray loss of the load of the measured motor can be obtained based on the above measured parameters and calculation results. With the test method of the invention adopted, the parameters of the motor can be detected under the high-pressure environment. According to the test method, and stress acts on the whole motor, and therefore, the direction of the stress borne by the motor is more diverse, and thus, the test method has a very bright application prospect.

Description

The method of testing of motor under a kind of normal temperature high voltage environment

Technical field

The invention belongs to the technical field of motor characteristic test under normal temperature high voltage environment.

Background technology

Along with the mankind are to the continuous increase of resource and demand for energy, and in ocean, to contain resource and the energy of extremely abundant necessary for human, exploration for ocean resources be unable to do without the motor as execution and functional part, along with the increase of the degree of depth, the pressure that motor is subject to also strengthens gradually, therefore can motor normally work under high-pressure situations becomes the key factor of the exploration of restriction deep-sea resources and collection, it workable hyperbaric environment can carried out to testing evaluation accurately and is just seeming most important before deep sea surveying in motor application, test accurately also for motor optimization provides relevant foundation simultaneously.In view of existing electromechanical testing method is applicable to normal temperature and pressure situation more, even if some motor measuring method considers the impact of stress for motor, but the method adopted also mostly is mechanical means and provides stress needed for measurement, make the stress direction that acts on motor relatively single, in some cases and do not meet the actual working environment of motor.

Summary of the invention

The object of this invention is to provide the method for testing of motor under a kind of normal temperature high voltage environment, is that the method for testing in order to solve existing motor is applicable to normal temperature and pressure situation more, can not meet the problem of the test of motor in normal temperature high voltage situation.

Described object is realized by following scheme: the method for testing of motor under described a kind of normal temperature high voltage environment, and its method step is:

Step one: select one identical with by measured motor 1 specification, or with by measured motor 1, there is identical synchronous rotational speed but power is greater than by the motor of other specification of measured motor 1 as accompanying and serving motor 2; Be in transmission connection by the output revolving shaft of measured motor 1 by shaft coupling 3 and the output revolving shaft of accompanying and serving motor 2, then high pressure sealing bucket 4 internal fixtion is put into good, high pressure sealing bucket 4 inside is full of experiment oil, probe temperature in high pressure sealing bucket 4 is arranged on about 20 DEG C, oil pressure force value is arranged according to the force value of the actual working environment of motor, also should consider the withstand voltage degree of high pressure bucket used simultaneously;

Step 2: make to be operated in electric motor state by measured motor 1, accompany and serve motor 2 and be operated in Generator Status; First driver 5 drives by measured motor 1 operation, makes to be worked under rated frequency and rated voltage by measured motor 1; Second driver 6 driving is accompanied and served motor 2 and is worked, and makes to accompany and serve motor 2 relative to being turned to upper applying reverse drive by measured motor 1; The second driver 6 is regulated to make in nominal load situation, to be run to steady state (SS) by measured motor 1;

Step 3: by second driver 6 regulate accompany and serve motor 2, make to be changed to 0.5 times of rated current by the stator current of measured motor 1 gradually from 1.5 times of rated current, read in this course as motor running by the triple-phase line electric current I of measured motor 1 _m1, power input P _m1, stator winding resistance value R _m1, need in process of the test to keep being always ratings by the frequency and voltage of measured motor 1; Read work is in the triple-phase line electric current I of accompanying and serving motor 2 of Generator Status simultaneously _g1, output power P _g2, stator winding resistance value R _g1; The experimental data utilizing above-mentioned measurement to obtain also just can calculate by measured motor 1 and the stator copper loss of accompanying and serving motor 2 in conjunction with following formula:

$\begin{array}{cc}{P}_{Mcu1}=1.5I_{M1}{R}_{M1}^2;& P_{Gcu1}=1.5I_{G1}{R}_{G1}^2;\end{array}$

Step 4: the method measuring rotor one phase current with tong-type ammeter is determined by measured motor 1 and the revolutional slip s accompanying and serving motor 2 _mand s _g, adopt the method mainly to consider that motor measurement environment constrains other in order to determine the use of the experimental facilities of motor slip ratio; First the number of oscillations N of record current list index _m, N _g, and with stopwatch record N _m, N _gthe time t of secondary swing _m, t _g; Then following formula is used to determine by measured motor 1 and the revolutional slip s accompanying and serving motor 2 _mand s _g:

$\begin{array}{cc}{s}_M=\frac{N_M}{2t_M{f}_M}\&times;100\%;& s_G=\frac{N_G}{2t_G{f}_G}\&times;100\%,\end{array}$

In formula, f _mfor by the rated frequency of measured motor 1; f _gfor accompanying and serving the frequency of motor 2, this frequency is less than rated frequency;

Step 5: be operated in electric motor state by the rotor copper loss P of measured motor 1 _mcu2: P _mcu2=s _m(P _m1-P _mcu1-P _fe); Be operated in the rotor copper loss P accompanying and serving motor 2 of Generator Status _gcu2: P _gcu2=s _g(P _g2-P _gcu1-P` _fe);

Step 6: be operated under electric motor state by the stray loss P of measured motor 1 _ms: P _ms=∑ P _sp _mcu2/ (P _gcu2+ P _mcu2), in formula, ∑ P _sfor by measured motor 1 and total stray loss of accompanying and serving motor 2, and ∑ P _scomputing formula be:

∑P _s＝P _M1-P _G2-P _Mcu1-P _Gcu1-P _Mcu2-P _Gcu2-P _fe-P` <sub>fe</sub>-P <sub>Δ</sub>-P` _Δ；

Step 7: and motor 2 will be accompanied and served to shut down work by measured motor 1; Make to be operated in Generator Status by measured motor 1, accompany and serve motor 2 and be operated in electric motor state; Second driver 6 drives and accompanies and serves motor 2 operation, makes to accompany and serve motor 2 and works under rated voltage He under being greater than rated frequency condition; First driver 5 drives and is worked by measured motor 1, makes to be turned to upper applying reverse drive by measured motor 1 relative to accompanying and serving motor 2; The load value regulating the first driver 5 to make to accompany and serve motor 2 be worth equal situation by measured motor 1 nominal load under run to steady state (SS);

Step 8: regulated by measured motor 1 by the first driver 5, is made the stator current of accompanying and serving motor 2 change to 0.5 times of rated current gradually from 1.5 times of rated current, reads the triple-phase line electric current I of accompanying and serving motor 2 as motor running in this course _m1, power input P _m1, stator winding resistance value R _m1, need in process of the test to keep being always ratings by the frequency and voltage of measured motor 1; Simultaneously read work at Generator Status by the triple-phase line electric current I of measured motor 1 _g1, output power P _g2, stator winding resistance value R _g1; The experimental data utilizing above-mentioned measurement to obtain also just can calculate by measured motor 1 and the stator copper loss of accompanying and serving motor 2 in conjunction with following formula:

$\begin{array}{cc}{P}_{Mcu1}=1.5I_{M1}{R}_{M1}^2;& P_{Gcu1}=1.5I_{G1}{R}_{G1}^2;\end{array}$

Step 9: the method measuring rotor one phase current with tong-type ammeter is determined by measured motor 1 and the revolutional slip s accompanying and serving motor 2 _gand s _m, adopt the method mainly to consider that motor measurement environment constrains other in order to determine the use of the experimental facilities of motor slip ratio; First the number of oscillations N of record current list index _g, N _m, and with stopwatch record N _g, N _mthe time t of secondary swing _g, t _m; Then following formula is used to determine by measured motor 1 and the revolutional slip s accompanying and serving motor 2 _gand s _m:

$\begin{array}{cc}{s}_G=\frac{N_G}{2t_G{f}_G}\&times;100\%;& s_M=\frac{N_M}{2t_M{f}_M}\&times;100\%,\end{array}$

In formula, f _gfor by the rated frequency of measured motor 1; f _mfor accompanying and serving the frequency of motor 2, this frequency is greater than by the rated frequency of measured motor 1;

Step 10: the rotor copper loss P accompanying and serving motor 2 being operated in electric motor state _mcu2: P _mcu2=s _m(P _m1-P _mcu1-P` _fe); Be operated in Generator Status by the rotor copper loss P of measured motor 1 _gcu2: P _gcu2=s _g(P _g2-P _gcu1-P _fe);

Step 11: be operated under Generator Status by the stray loss P of measured motor 1 _gsfor: P _gs=∑ P _sp _gcu2/ (P _gcu2+ P _mcu2), in formula, ∑ P _sfor by measured motor 1 and total stray loss of accompanying and serving motor 2, but now P _gcu2for by measured motor 1 rotor copper loss, P _mcu2for accompanying and serving motor 2 rotor copper loss, and ∑ P _scomputing formula be:

∑P _s＝P _M1-P _G2-P _Mcu1-P _Gcu1-P _Mcu2-P _Gcu2-P _fe-P` <sub>fe</sub>-P <sub>Δ</sub>-P` _Δ；

Step 12: ask for by the mean value of measured motor 1 load stray loss in conjunction with the measurement parameter in above-mentioned steps and calculating knot for: by the approximate average of measured motor 1 at motor and Generator Status rotor electric current for: in formula, I ₁for during load test by the stator current of measured motor 1 in above-mentioned steps, namely by the stator current of measured motor 1 under electric motor state and Generator Status, I ₀for during by measured motor 1 no-load test, the stator current that rated voltage is corresponding.

The present invention can detect the parameter of motor under hyperbaric environment, and its effect of stress is on whole motor, and this stress direction that motor is subject to has more diversity, also more tallies with the actual situation; Effectively can solve some measuring equipment like this and in the problem of hyperbaric environment in normal work, application prospect widely can not be had.

Accompanying drawing explanation

Fig. 1 is the structural representation of the device that the inventive method relates to.

Embodiment

Embodiment one: shown in composition graphs 1, illustrates the technical scheme of this embodiment, and its method step is:

Step one: select one identical with by measured motor 1 specification, or with by measured motor 1, there is identical synchronous rotational speed but power is greater than by the motor of other specification of measured motor 1 as accompanying and serving motor 2; Be in transmission connection by the output revolving shaft of measured motor 1 by shaft coupling 3 and the output revolving shaft of accompanying and serving motor 2, then high pressure sealing bucket 4 internal fixtion is put into good, high pressure sealing bucket 4 inside is full of experiment oil, probe temperature in high pressure sealing bucket 4 is arranged on about 20 DEG C, oil pressure force value is arranged according to the force value of the actual working environment of motor, also should consider the withstand voltage degree of high pressure bucket used simultaneously; ;

Step 2: make to be operated in electric motor state by measured motor 1, accompany and serve motor 2 and be operated in Generator Status; First driver 5 drives by measured motor 1 operation, makes to be worked under rated frequency and rated voltage by measured motor 1; Second driver 6 driving is accompanied and served motor 2 and is worked, and makes to accompany and serve motor 2 relative to being turned to upper applying reverse drive by measured motor 1; The second driver 6 is regulated to make in nominal load situation, to be run to steady state (SS) by measured motor 1;

Step 3: by second driver 6 regulate accompany and serve motor 2, make to be changed to 0.5 times of rated current by the stator current of measured motor 1 gradually from 1.5 times of rated current, read in this course as motor running by the triple-phase line electric current I of measured motor 1 _m1, power input P _m1, stator winding resistance value R _m1, need in process of the test to keep being always ratings by the frequency and voltage of measured motor 1; Read work is in the triple-phase line electric current I of accompanying and serving motor 2 of Generator Status simultaneously _g1, output power P _g2, stator winding resistance value R _g1; The experimental data utilizing above-mentioned measurement to obtain also just can calculate by measured motor 1 and the stator copper loss of accompanying and serving motor 2 in conjunction with following formula:

$\begin{array}{cc}{P}_{Mcu1}=1.5I_{M1}{R}_{M1}^2;& P_{Gcu1}=1.5I_{G1}{R}_{G1}^2;\end{array}$

Step 4: the method measuring rotor one phase current with tong-type ammeter is determined by measured motor 1 and the revolutional slip s accompanying and serving motor 2 _mand s _g, adopt the method mainly to consider that motor measurement environment constrains other in order to determine the use of the experimental facilities of motor slip ratio; First the number of oscillations N of record current list index _m, M _g, and with stopwatch record N _m, N _gthe time t of secondary swing _m, t _g; Then following formula is used to determine by measured motor 1 and the revolutional slip s accompanying and serving motor 2 _mand s _g:

$\begin{array}{cc}{s}_M=\frac{N_M}{2t_M{f}_M}\&times;100\%;& s_G=\frac{N_G}{2t_G{f}_G}\&times;100\%,\end{array}$

In formula, f _mfor by the rated frequency of measured motor 1; f _gfor accompanying and serving the frequency of motor 2, this frequency is less than rated frequency;

Step 5: be operated in electric motor state by the rotor copper loss P of measured motor 1 _mcu2: P _mcu2=s _m(P _m1-P _mcu1-P _fe); Be operated in the rotor copper loss P accompanying and serving motor 2 of Generator Status _gcu2: P _gcu2=s _g(P _g2-P _gcu1-P` _fe);

Step 6: be operated under electric motor state by the stray loss P of measured motor 1 _ms: P _ms=∑ P _sp _mcu2/ (P _gcu2+ P _mcu2), in formula, ∑ P _sfor by measured motor 1 and total stray loss of accompanying and serving motor 2, and ∑ P _scomputing formula be:

∑P _s＝P _M1-P _G2-P _Mcu1-P _Gcu1-P _Mcu2-P _Gcu2-P _fe-P` <sub>fe</sub>-P <sub>Δ</sub>-P` _Δ；

Step 7: and motor 2 will be accompanied and served to shut down work by measured motor 1; Make to be operated in Generator Status by measured motor 1, accompany and serve motor 2 and be operated in electric motor state; Second driver 6 drives and accompanies and serves motor 2 operation, makes to accompany and serve motor 2 and works under rated voltage He under being greater than rated frequency condition; First driver 5 drives and is worked by measured motor 1, makes to be turned to upper applying reverse drive by measured motor 1 relative to accompanying and serving motor 2; The load value regulating the first driver 5 to make to accompany and serve motor 2 be worth equal situation by measured motor 1 nominal load under run to steady state (SS);

Step 8: regulated by measured motor 1 by the first driver 5, is made the stator current of accompanying and serving motor 2 change to 0.5 times of rated current gradually from 1.5 times of rated current, reads the triple-phase line electric current I of accompanying and serving motor 2 as motor running in this course _m1, power input P _m1, stator winding resistance value R _m1, need in process of the test to keep being always ratings by the frequency and voltage of measured motor 1; Simultaneously read work at Generator Status by the triple-phase line electric current I of measured motor 1 _g1, output power P _g2, stator winding resistance value R _g1; The experimental data utilizing above-mentioned measurement to obtain also just can calculate by measured motor 1 and the stator copper loss of accompanying and serving motor 2 in conjunction with following formula:

$\begin{array}{cc}{P}_{Mcu1}=1.5I_{M1}{R}_{M1}^2;& P_{Gcu1}=1.5I_{G1}{R}_{G1}^2;\end{array}$

Step 9: the method measuring rotor one phase current with tong-type ammeter is determined by measured motor 1 and the revolutional slip s accompanying and serving motor 2 _gand s _m, adopt the method mainly to consider that motor measurement environment constrains other in order to determine the use of the experimental facilities of motor slip ratio; First the number of oscillations N of record current list index _g, N _m, and with stopwatch record N _g, N _mthe time t of secondary swing _g, t _m; Then following formula is used to determine by measured motor 1 and the revolutional slip s accompanying and serving motor 2 _gand s _m:

$\begin{array}{cc}{s}_G=\frac{N_G}{2t_G{f}_G}\&times;100\%;& s_M=\frac{N_M}{2t_M{f}_M}\&times;100\%,\end{array}$

In formula, f _gfor by the rated frequency of measured motor 1; f _mfor accompanying and serving the frequency of motor 2, this frequency is greater than by the rated frequency of measured motor 1;

Step 10: the rotor copper loss P accompanying and serving motor 2 being operated in electric motor state _mcu2: P _mcu2=s _m(P _m1-P _mcu1-P` _fe); Be operated in Generator Status by the rotor copper loss P of measured motor 1 _gcu2: P _gcu2=s _g(P _g2-P _gcu1-P _fe);

Step 11: be operated under Generator Status by the stray loss P of measured motor 1 _gsfor: P _gs=∑ P _sp _gcu2/ (P _gcu2+ P _mcu2), in formula, ∑ P _sfor by measured motor 1 and total stray loss of accompanying and serving motor 2, but now P _gcu2for by measured motor 1 rotor copper loss, P _mcu2for accompanying and serving motor 2 rotor copper loss, and ∑ P _scomputing formula be:

∑P _s＝P _M1-P _G2-P _Mcu1-P _Gcu1-P _Mcu2-P _Gcu2-P _fe-P` <sub>fe</sub>-P <sub>Δ</sub>-P` _Δ；

Step 12: ask for by the mean value of measured motor 1 load stray loss in conjunction with the measurement parameter in above-mentioned steps and calculating knot for: by the approximate average of measured motor 1 at motor and Generator Status rotor electric current for: in formula, I ₁for during load test by the stator current of measured motor 1 in above-mentioned steps, namely by the stator current of measured motor 1 under electric motor state and Generator Status, I ₀for during by measured motor 1 no-load test, the stator current that rated voltage is corresponding.

Principle of work: first will by measured motor with accompany examination motor (identical with the tested rating of electric machine or identical with tested motor in synchrony rotating speed, but power ratio by large other specification motors of measured motor as accompanying examination motor) put into high pressure bucket internal fixtion good after, injection test oil in high pressure bucket, just can cover the end cap of high pressure bucket and test oil does not overflow and is advisable.Then the flexible pipe on forcing pump is connected with high pressure bucket end cap, and fixes.Forcing pump just by this flexible pipe to high pressure bucket oiling pressurization, the force value in high pressure bucket can be read by tensimeter on forcing pump, but in view of manometric precision be not very high, the present invention adopts pressure transducer to measure the force value of high pressure bucket inside.

Now measure the no-load characteristic of motor, under being allowed to condition at rated voltage and rated frequency respectively, no-load running is stablized to mechanical loss, then by regulating the voltage be applied on stator winding, carries out the no-load test of motor.No-load test is mainly determined by measured motor and core loss and the mechanical loss of accompanying examination motor.P is counted by the core loss of measured motor and mechanical loss _feand P _Δ, accompany the core loss of examination motor and mechanical loss to count and P` _Δ, owing to being operated in the motor of normal temperature high voltage state, the resistance of its stator winding can be subject to the impact of pressure, therefore must read at every turn survey parameter while read this value.

The load test of motor forms primarily of two processes, needs to calibrate measurement instrument used, in order to avoid affect measurement result before doing experiment.

Claims (1)

1. the method for testing of motor under normal temperature high voltage environment, is characterized in that its method step is:

Step one: select one identical with by measured motor (1) specification, or with by measured motor (1), there is identical synchronous rotational speed but power is greater than by the motor of other specification of measured motor (1) as accompanying and serving motor (2); Be in transmission connection by the output revolving shaft of measured motor (1) by shaft coupling (3) and the output revolving shaft of accompanying and serving motor (2), then high pressure sealing bucket (4) internal fixtion is put into good, high pressure sealing bucket (4) inside is full of experiment oil, probe temperature in high pressure sealing bucket (4) is arranged on about 20 DEG C, oil pressure force value is arranged according to the force value of the actual working environment of motor, also should consider the withstand voltage degree of high pressure bucket used simultaneously;

Step 2: make to be operated in electric motor state by measured motor (1), accompany and serve motor (2) and be operated in Generator Status; First driver (5) drives by measured motor (1) operation, makes to be worked under rated frequency and rated voltage by measured motor (1); Second driver (6) drives accompanies and serves motor (2) work, makes to accompany and serve motor (2) and turns to upper applying reverse drive relative to by measured motor (1); The second driver (6) is regulated to make in nominal load situation, to be run to steady state (SS) by measured motor (1);

Step 3: regulated by the second driver (6) and accompany and serve motor (2), make to be changed to 0.5 times of rated current by the stator current of measured motor (1) gradually from 1.5 times of rated current, read in this course as motor running by the triple-phase line electric current I of measured motor (1) _m1, power input P _m1, stator winding resistance value R _m1, need in process of the test to keep being always ratings by the frequency and voltage of measured motor (1); Read work is in the triple-phase line electric current I of accompanying and serving motor (2) of Generator Status simultaneously _g1, output power P _g2, stator winding resistance value R _g1; The experimental data utilizing above-mentioned measurement to obtain also just can calculate by measured motor (1) and the stator copper loss of accompanying and serving motor (2) in conjunction with following formula:

$\begin{array}{cc}{P}_{Mcu1}=1.5I_{M1}{R}_{M1}^2;& P_{Gcu1}=1.5I_{G1}{R}_{G1}^2;\end{array}$

Step 4: the method measuring rotor one phase current with tong-type ammeter is determined by measured motor (1) and the revolutional slip s accompanying and serving motor (2) _mand s _g, adopt the method mainly to consider that motor measurement environment constrains other in order to determine the use of the experimental facilities of motor slip ratio; First the number of oscillations N of record current list index _m, N _g, and with stopwatch record N _m, N _gthe time t of secondary swing _m, t _g; Then following formula is used to determine by measured motor (1) and the revolutional slip s accompanying and serving motor (2) _mand s _g:

$\begin{array}{cc}{s}_M=\frac{N_M}{2t_M{f}_M}\&times;100\%;& s_G=\frac{N_G}{2t_G{f}_G}\&times;100\%,\end{array}$

In formula, f _mfor by the rated frequency of measured motor (1); f _gfor accompanying and serving the frequency of motor (2), this frequency is less than rated frequency;

Step 5: be operated in electric motor state by the rotor copper loss P of measured motor (1) _mcu2: P _mcu2=s _m(P _m1-P _mcu1-P _fe); Be operated in the rotor copper loss P accompanying and serving motor (2) of Generator Status _gcu2: P _gcu2=s _g(P _g2-P _gcu1-P` _fe);

Step 6: be operated under electric motor state by the stray loss P of measured motor (1) _ms: P _ms=∑ P _sp _mcu2/ (P _gcu2+ P _mcu2), in formula, ∑ P _sfor by measured motor (1) and total stray loss of accompanying and serving motor (2), and ∑ P _scomputing formula be:

∑P _s＝P _M1-P _G2-P _Mcu1-P _Gcu1-P _Mcu2-P _Gcu2-P _fe-P` <sub>fe</sub>-P <sub>△</sub>-P` _△；

Step 7: and motor (2) will be accompanied and served to shut down work by measured motor (1); Make to be operated in Generator Status by measured motor (1), accompany and serve motor (2) and be operated in electric motor state; Second driver (6) drives and accompanies and serves motor (2) operation, makes to accompany and serve motor (2) and works under rated voltage He under being greater than rated frequency condition; First driver (5) drives by measured motor (1) work, makes to be turned to upper applying reverse drive by measured motor (1) relative to accompanying and serving motor (2); The load value regulating the first driver (5) to make to accompany and serve motor (2) be worth equal situation by measured motor (1) nominal load under run to steady state (SS);

Step 8: regulated by measured motor (1) by the first driver (5), make the stator current of accompanying and serving motor (2) change to 0.5 times of rated current gradually from 1.5 times of rated current, read the triple-phase line electric current I of accompanying and serving motor (2) as motor running in this course _m1, power input P _m1, stator winding resistance value R _m1, need in process of the test to keep being always ratings by the frequency and voltage of measured motor (1); Simultaneously read work at Generator Status by the triple-phase line electric current I of measured motor (1) _g1, output power P _g2, stator winding resistance value R _g1; The experimental data utilizing above-mentioned measurement to obtain also just can calculate by measured motor (1) and the stator copper loss of accompanying and serving motor (2) in conjunction with following formula:

$\begin{array}{cc}{P}_{Mcu1}=1.5I_{M1}{R}_{M1}^2;& P_{Gcu1}=1.5I_{G1}{R}_{G1}^2;\end{array}$

Step 9: the method measuring rotor one phase current with tong-type ammeter is determined by measured motor (1) and the revolutional slip s accompanying and serving motor (2) _gand s _m, adopt the method mainly to consider that motor measurement environment constrains other in order to determine the use of the experimental facilities of motor slip ratio; First the number of oscillations N of record current list index _g, N _m, and with stopwatch record N _g, N _mthe time t of secondary swing _g, t _m; Then following formula is used to determine by measured motor (1) and the revolutional slip s accompanying and serving motor (2) _gand s _m:

$\begin{array}{cc}{s}_G=\frac{N_G}{2t_G{f}_G}\&times;100\%;& s_M=\frac{N_M}{2t_M{f}_M}\&times;100\%,\end{array}$

In formula, f _gfor by the rated frequency of measured motor (1); f _mfor accompanying and serving the frequency of motor (2), this frequency is greater than by the rated frequency of measured motor (1);

Step 10: the rotor copper loss P accompanying and serving motor (2) being operated in electric motor state _mcu2: P _mcu2=s _m(P _m1-P _mcu1-P` _fe); Be operated in Generator Status by the rotor copper loss P of measured motor (1) _gcu2: P _gcu2=s _g(P _g2-P _gcu1-P _fe);

Step 11: be operated under Generator Status by the stray loss P of measured motor (1) _gsfor: P _gs=∑ P _sp _gcu2/ (P _gcu2+ P _mcu2), in formula, ∑ P _sfor by measured motor (1) and total stray loss of accompanying and serving motor (2), but now P _gcu2for by measured motor (1) rotor copper loss, P _mcu2for accompanying and serving motor (2) rotor copper loss, and ∑ P _scalculating fraction be:

∑P _s＝P _M1-P _G2-P _Mcu1-P _Gcu1-P _Mcu2-P _Gcu2-P _fe-P` <sub>fe</sub>-P <sub>△</sub>-P` _△；

Step 12: ask for by the mean value of measured motor (1) load stray loss in conjunction with the measurement parameter in above-mentioned steps and calculating knot for: by the approximate average of measured motor (1) at motor and Generator Status rotor electric current for: in formula, I ₁for during load test by measured motor (1) stator current in above-mentioned steps, namely by measured motor (1) stator current under electric motor state and Generator Status, I ₀for during by measured motor (1) no-load test, the stator current that rated voltage is corresponding.