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An Application of TRIAC to Capacitor Motor for Hermetic Compressor K

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An Application of TRIAC to Capacitor Motor for Hermetic Compressor K Purdue University Purdue e-Pubs International Compressor Engineering Conference School of Mechanical Engineering 1984 An Application of TRIAC to Capacitor Motor for Hermetic Compressor K. Nakane Y. Tozaki H. Sakamoto Follow this and additional works at: https://docs.lib.purdue.edu/icec Nakane, K.; Tozaki, Y.; and Sakamoto, H., "An Application of TRIAC to Capacitor Motor for Hermetic Compressor" (1984). International Compressor Engineering Conference. Paper 449. https://docs.lib.purdue.edu/icec/449 This document has been made available through Purdue e-Pubs, a service of the Purdue University Libraries. Please contact [email protected] for additional information. Complete proceedings may be acquired in print and on CD-ROM directly from the Ray W. Herrick Laboratories at https://engineering.purdue.edu/ Herrick/Events/orderlit.html AN APPLICA'l'ION OF 'l'RIAC TO CAPACI'l'OR 1-10'l'OR FOR lll~Rt~IC'riC COMPRSSO!l Ka.zuhiro Nakane, Yasuhiro To?.nki,. Ilirota.ka Sakamoto Shizuoka. Worlw, Mitsubishi Electri.c Corporation Shizuoka City , Ja.pan ABSTRACT oncy and output rati.ngo are 100 V ,50/60 J!v. and 100 11. It is a. 1mi 1 t-in motor for the rotary type This paper refers to a.n n.pplication study of 'l'lUAC hermetic compressor shown in Ji'ie;. 2. 'l'hore are to PSC motor for thft hermetic compessor. It is three types of the wirings of the starting device 1-1ell lcnown that 'l'HIAC rlel nys pharJa ane,le of the for thifl motor,as shown i.n lcig, 3. A shows CSR current and has no losses if it is consider(\ as moto:r,n shows P'l'C asoist CSR motor and C sho~1s ideal flwitch. 'l'herefore it is possible to c;et a PTC nssist PSC motor. The customer is able to ldncl. of variable capacitor lJy connecting ~'HIAC choono a most suitable type of them for use. Nith capacitor in series antl controlline; the fir­ ing angle of it. By use of this vari.able capa.ci.tor for PSC motor,\·11:> could obtain the performance similar to CSR motor. Therefore ~1e bel iove that this type motor should be developed as one of the single phase motor for the hermetic compressor with the progress of the electronics. JN'rRODUC'I'ION Various kinds of single phase induction motors such as PSC,CSR,CSIR,RSIR,PTC assist PSC and PTC assist CSR are used for hermetic compressors. 1-1e choice one of these according to the purpose for use. In recent years,it is prosperous to tr,y the appli­ cation studies of semiconductors to the sphere of application study of TRIAC the motor control. An Fig.1 100 W motor used for test to a single phase induction motor is one of these. As explainning in this paper,it is possible to cet a ki.nd of varialJle capacitor 1Jy connecti.ng 'l'RIAC in series with capacitor of PSC motor a.nd control­ line; the firing angle of it. We call this type motor TRIAC assist PSC motor in this paper. This paper refers to the torque characteristic of 'l'RIAC aasist PSG motor and the starting· perfor­ mance on the actual hermetic compressor,based on the experimental results. And we try to compare it with the other existing motors. In addition, we view a possibility of TRIAC assist PSC motor for hermetic compressors. TEST MOTOR ANTI CONTROL DEVICE OF 'l'RIAC induction motor shown in Fie;. 2 poles,single phase type hermetic compressor l was used for our experiment. its voltage,frequ- Fig.2 Rotary 168 Fir;. 5 shows the control device of TRIAC made for our ~xpcriment. Fir;. 6 shows its block diae;rnm, l and Fir;. 7 shows its time charts. It is possible to set 11p the firinr; o.n(\le of 'l'RIAC lJY 0. l. mace., uain~ thjs cotrol device. The detection circujt for the au:x:Uiar;v Hinrlinr; val tar,e operates to turn TRIAC into no fire. For this operation, we 1: Main winding make usc of the property which the auxiliary Hi.nd­ A: CSR motor z: Auxiliary inr; voltsr;e increases with revolution in PSC motor \>tin ding ,as ~hown in Fig. B. And the relation between the 3: Relay auxil iar;v winding voltnr;e nncl the oper;J.tinr; point 4: Starting of the detection circuit has a hysterisis charact­ capacitor eristic as shown in Fig. B. 5: Discharging resistor 6: Running capaiitor 7: P'l'C thermistor B: FTC assist CSR motor 1 C: FTC assist PSG motor Fig. 3 Wiring diagrams of the hermetic compressor motors for refrige­ Fig. 5 Control device of TRIAC rator Fir;. L1 sho~rs the Wl-rl-ng diae;ram of TRIAC assiot PSC motor described in this paper. TRIAC is conne­ cted in series with capacitor of PSC motor. Heoti fioation ht tenation Voltage comparator D TRIJ\C Main \ .---winding 0J \ Auxiliary winding A: To main •1nd1ng \. B: ~·o running c•pacitor Runn1ng C: To auxiliary winoint capacitor D: To common Fig. !1 Wiring_diagram of Fig. 6 Block diagram of the control device TRIAC assist PSG motor 169 Source voltage ~~~vvv \J'C lr I lr II 11 II (\ (\ (\ Aux. winding! V 1 AI /'\ A 1\ voltase 1 r 11 ,,v V V V~\..J\, II ll ,, 1 , ,1 I 1 I Time lr • 1 11 ---... Zero I I ditector I I I I Firing angle Firing angle Counters = o<> = 180" Latches ../ v~f· :evel "' Fig. 9 Definition of the firing angle Recti,-tion fica-:.:=:~;;~=:::::::::::::::::=:;:===::=::::: Attenation Vol tase comparator Control _uL...-JL..-L-...L.-JII__._....L.-J logic Drivers [l [\ An 1\1\1\ v v V\/\: ------- Time H nl Fig. 7 Time chart of control device ..-I {;h "0 !il :.> .0 i .5 I d Slip ...... bO ~ .. 30 '-' bO <11 r-l Main winding S... <11 60 current ..-I Speed ii'o Fire !! 0 No fire . 90 Fig. 8 Illustrating the relationship between speed-torque . Fig. 10 Illustrating the phase angle aux. voltage curves and fire relationship between main of TRIAC winding current and aux. winding current (Base is source voltage) correspo~ding to slip,for PSG motor TORQUE C!IARACTERRISTIC OF TRIAC ASSIST PSC MOTOR We define the firing angle of TRIAC as shown in Fig, 9 in this paper, i.e.,?:ero riee,ree of the firing angle corresponds to zero d.egree of the Fie,-. 11 sho~1s the measured waveforms of the source vol~ege (E ) and the auxiliary winding current source voltage. Ji'ir,. 10 shows the phase angle of 1 auxiliary winding currents the main winding and (I ) corresponding to the firing angle of 0" 1 47-5° for PSC motor used for our experiment,which the a source voltage is base. Generally,the main winding and 7 3.4 ° s,t slip~l (at starting) for TRIAC assist current lags the source voltage,and the auxiliary PSC mo·tor. As seen from this figure,the phase ' angle of I lags as the firing engle of TRIAC 1~inding current leads the source voltage. ' a. '!'here fore, in case that the firing angle of TRIAC increases. That is to say,it shows the characte;-· is zero degree, the auxiliary l·linding current is ristic of a kind of variable inductance. " chopped by angular lead for the source voltage. 170 1000 2000 3000 Speed (r.p.m.) Fig. 12 Measured speed-torque curve for TRIAC assist PSC motor The relation between the starting torque and the firinB' angle of TRIAC is sho\m in Fig. 13, These values of the starting torque were obtained from above measured speed-torque' ourves. As seen from Firing angle this figure,the maximum point of the starting =73.W torq1.1e is given at the firing angle of nearly 50 degrees. Its value is about 3·3 times as much as the starting torque of PSC motor,which i's shown as broken line'in Fig. 13. And in this figure,the sta.rting torque equals zero at the firing angle of nearly 115 degrees. It means sino<. .. 0 in the· · · · equation (1), i.e.the phase difference between the Fig. 11 Measured aux. winding current tif TBIAC assist PSC motor (slip=l) 00 0 0 000 ° 0 Starting torque of PSC motor is exp~essed as the follo~ting equation,as well known. 0 00 0 (1) 0 0 0 where 0 I r Main winding current m . 0 oo Ias Auxiliary windine; current 0 0(1 Phase difference between I and 10 m I a T s Sta~ting torque - ---- - - - --- _qo- 6 · ~Starting torque of PSC Therefore it ie possible to control Ts by control­ ling Iasin ~, i.e.,by controlling the fi~ing angle of TRIAC for TRIAC assist PSC motor. 0 0 Fig. 12 shows the measured motor speed-torque 0 curves for TRIAC assist PSC moto~,correepondine; 0 to each firing angle shown in Fig. 11. They are measured f~om firing angle of 0 degree to 140 1 I I degrees. It is apparent that the speed-torque b 3b 6b 9b 1~0 curve changes as the fir).ng angle of TRIAC changes Firing angle (degree) Fig. 13 Relation between measured starting torque and firing , angle for 'rRIAC ·assist PSG motor 171 main winding current and auxiliary winding current torque of PSC motor,whioh is shown as broken line becomes zero degree at this firing angle. Increas­ in Firr. 14. ing more than this firing angle 1 the-auxiliary the main tlinding current l'linding current lags 1 i.e, sj_nO(<O; T < 0 in'the equation (1).
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