以ä¸è§£çä¸ï¼æä½åæ¯è¡¨ç¤ºç¸éã
6-5ã解ï¼è®¾Uab=380â 30°Vï¼åUa=220â 0°Vï¼Ub=220â -120°Vï¼Uc=220â 120°Vã
ç±äºä¸æ§çº¿çåå¨ï¼å¼ºå¶äºæ¯ç¸è´è½½ççµåå°±æ¯ç¸çµåã
ï¼1ï¼Ia=Ua/R=220â 0°/20=11â 0°ï¼Aï¼ã
Ib=Ub/ï¼-jXcï¼=220â -120°/ï¼-j20ï¼=11â -30°ï¼Aï¼ã
Ic=Uc/ï¼jXLï¼=220â 120°/j20=11â 30°ï¼Aï¼ã
ï¼2ï¼KCLï¼In=Ia+Ib+Ic=11â 0°+11â -30°+11â 30°=11+11ï¼cos30°-jsin30°+cos30°+jsin30°ï¼=11+11â3=30.052ï¼Aï¼ã
6-7ã解ï¼ï¼1ï¼ç±P=â3ULÃILÃcosÏ=â3Ã380ÃILÃ0.76=5000ã
æ以线çµæµä¸ºï¼IL=10ï¼Aï¼ã
ç¸çµæµä¸ºï¼Ip=IL/â3=10/â3=5.771ï¼Aï¼ã
è´è½½æ¯ç¸çé»æ为ï¼|Z|=UL/Ip=380/5.771=65.85ï¼Î©ï¼ã
å³åï¼Z=65.85â arccos0.76=65.85â 40.54°ï¼Î©ï¼ã
ï¼2ï¼è´è½½åYåè¿æ¥ï¼åç¸çµå为ï¼Up=UL/â3=380/â3ï¼Vï¼ã
线çµæµIL=ç¸çµæµIp=Up/|Z|=ï¼380/â3ï¼/65.85=3.33ï¼Aï¼ã
å¸æ¶çæååç为ï¼P=â3ULÃILÃcosÏ=â3Ã380Ã3.33Ã0.76=1665.7ï¼Wï¼ãåå°ä¸ºï¼1ï¼ä¸â³æ¥æ³ç1/3ã