3-PHASE INDUCTION MOTOR TESTS (SI 2)

Transcription

1 WASAW NVESTY OF TECHNOLOGY NSTTTE OF ELECTCAL MACHNES ELECTCAL MACHNES LABOATOY -HASE NDCTON MOTO TESTS (S 2) 2.. Load characteritic of iductio motor Meaurig circuit of the motor: - two-poitio dicoector Scheme of geerator beig a load to the motor: Separately excited geerator, applied a the load to the motor, operate at load cot. egulatio of it output power - hece the cotrol of motor output power - ca be realized by the variatio of geerator excitig curret. Durig the tet the motor i upplied with it rated voltage, while the load i varied from the o-load tate to full load. The meauremet hould allow calculatig the motor output power by mea of the loe ad power balace.

2 2 N No of V W a b T i coϕ out η read A A A W W Nm rpm A W pu - W % 2... i coϕ a + + V + b i ; N W out ; ; η 9.55T out i 00% η coϕ Draw the characteritic: ; ; coϕ; η f() 0 N ad determie omial value of motor curret, peed, power factor, efficiecy ad torque Temperature-rie tet ϑf(t) for N ; N Aim of the tet: determiatio of the average temperature rie for tator widig durig the load operatio of the motor, for N. Widig temperature meauremet method: by mea of the tator widig reitace meauremet ad calculatio of temperature rie from the relatio of the reitace a a fuctio of temperature. Motor data: N.7 kw N 220/80 V (teted motor i already Y coected) N 6.6/.8 A N 420 rpm. Meaurig circuit of the motor: a i p. 2. but for quirrel-cage motor ad with oly oe voltmeter ad ammeter (to implify the tet). Ambiet temperature ϑ a... o C

3 T M MEASEMENTS OF ESSTANCE AND TEMEATE E ϑ mi V A Ω Ω K tart ed... ϑ ; h c 2 c 25 The equece of meauremet ad calculatio:. Meaure the reitace of oe phae of tator widig i the cold tate c ; 2. Start the motor ad load it to it rated curret ( N ; N ),. At choe iterval of time (for example 20 mi) de-eergize ad top the machie, meaure the reitace of tator widig ad tart machie agai (poibly miimum time i uggeted for thi operatio). the meatime calculate the temperature rie correpodig to the reitace icreae, 4. At the ed of the tet top the machie ad meaure the tator widig reitace i the hot tate h ϑ Draw the calculated temperature rie poit a a fuctio of time t mi 2.. CAM temperature-rie tet ϑf(t) for N ; N Aim of the tet: determiatio of temperature rie i differet poit of the motor tructure durig operatio with omial curret uder omial voltage. Temperature meauremet method: Computer-aided-meauremet (CAM) ytem coit of: a) ro-cotata thermocouple (thermocouple of J type) ierted iide the tator of teted motor (ee figure); b) Multiplexer ad amplifier board (card) CLD-779 providig: - acquiitio (iput) of 7 thermocouple aalogue igal (7 chael), - galvaic eparatio (iolatio) of thermocouple circuit ad computer hardware circuit (by mea of capacitor), - relay multiplexig of chael, - amplificatio of DC igal, - oftware compeatio ad liearizatio of thermocouple igal;

4 4 c) DC igal covertig board (card) CL-7 providig: - DC voltage igal meauremet (thoe from CLD-779), - aalogue to digital (A/D) coverio of igal), - multiplexer cotrol; d) LABTECH-NOTEBOOK oftware for cotrollig the operatio of CLD-779 ad CL-7 card, data acquiitio ad viual preetatio i real time. Teted motor i loaded by mea of DC geerator. Durig the temperature-rie tet the load of the motor hould be a to have N for N. Circuit diagram of motor ad DC geerator coectio: a i p Locatio of thermocouple i the tator: Drive ed Coectio of thermocouple eor ad prit detail: No of chael No of eor Ch 0 Locatio Surroudig (ambiet temperature) Colour of curve how Mark applied at the prit Black Ch 2 0 Stator houig Black? Ch 2 Slot top Gree + Ch 4 4 Ed part of tator widig ed * Ch 5 6 Slot bottom ( core cetre) Blue Ch 6 8 Slot bottom (core ed) Turquoie Ch 7 9 Stator iro violet

5 5 rocedure of tet: Switch o the C with floppy dic LABTECH NOTEBOOK SET- ierted i drive B ad follow the procedure by appropriate commad: - pre ay key to cotiue, - SAVE/ECALL moue, - ECALL ENTE, - il800 write i & ENTE, - N - moue; Start the motor, excite DC geerator ad adjut the load a to have N i the motor upplyig circuit (check N ); Oberve the behaviour of temperature-rie curve at the moitor; After ½ hour (800 ) the programme i cocluded ad pritig i made automatically; ESC Quit Norto Commader Switch off C. BBLOGAHY. Fitzgerald A., Kigley C., ma S.: Electric machiery. McGraw-Hill Book Co Say M.G.: Alteratig curret machie. itma, 976. Naar S.A., ewehr L.E.: Electromechaic ad Electric Machie. Joh Wiley, Latek W.: Teoria mazy elektryczych. WNT, Latek W.: Badaie mazy elektryczych w przemyśle. WNT, Kamińki G., Kok J., rzyborowki W.: Laboratorium mazy elektryczych. Oficya W, Kraue. C., Wayczuk O., Sudhoff S. D.: Aalyi of Electric Machiery ad Drive Sytem. Joh Wiley & So, NC. BLCATON. 2002