·¢²¼Ê±¼ä : ÐÇÆÚÁù ÎÄÕµ繤¼¼ÊõÓëµç×Ó¼¼Êõ¸´Ï°º¬Ï°Ì⣨»¯Àࣩ¸üÐÂÍê±Ï¿ªÊ¼ÔĶÁ
a
Àý8 ¶Ô³ÆÐÇÐθºÔؽÓÓÚÈýÏàËÄÏßÖƵçÔ´ÉÏ£¬ÈçͼËùʾ¡£ÈôµçÔ´Ïßµç
ѹΪ380V£¬µ±ÔÚDµã¶Ï¿ªÊ±£¬U1Ϊ( )¡£ (a)220V
ABCN+U1RRR(b)380V (c)190V
D£ a
ËÄ¡¢ µç·µÄ˲±ä¹ý³Ì 1¡¢ 2¡¢
Óû»Â·¶¨ÀíÇó˲±ä¹ý³ÌµÄ³õʼֵ¡£ ÓÃÈýÒªËØ·¨Çó½âÒ»½×µç·µÄ˲±ä¹ý³Ì¡£
Àý1ͼʾµç·ÔÚÎȶ¨×´Ì¬Ï±պϿª¹ØS£¬¸Ãµç·( )¡£ (a)²»²úÉú¹ý¶É¹ý³Ì£¬ÒòΪ»»Â·Î´ÒýÆðLµÄµçÁ÷·¢Éú±ä»¯ (b)Òª²úÉú¹ý¶É¹ý³Ì£¬ÒòΪµç··¢Éú»»Â·
(c)Òª·¢Éú¹ý¶É¹ý³Ì£¬ÒòΪµç·Óд¢ÄÜÔª¼þÇÒ·¢Éú»»Â·
S+R1LR2US£
a
Àý2 ͼʾµç·ÔÚÎȶ¨×´Ì¬Ï±պϿª¹ØS£¬¸Ãµç·½«²úÉú¹ý¶É¹ý³Ì£¬ ÕâÊÇÒòΪ( )¡£ (a) µç··¢Éú»»Â·
(b) »»Â·Ê¹Ôª¼þLµÄµçÁ÷·¢Éú±ä»¯ (c)µç·Óд¢ÄÜÔª¼þÇÒ·¢Éú»»Â·
S+uS£LR1R2
b
Àý3 ͼʾµç·ÔÒÑÎȶ¨£¬t=0ʱ½«¿ª¹ØS±ÕºÏ£¬ÒÑÖª£ºR1=R2=R3=10?£¬L=4H£¬US1=10V£¬US2=20V¡£Ç󿪹ØS±ÕºÏºóµÄÏßȦµçÁ÷iL?t?¡£
R1+US1£R2iLLR3+SUS2£
½â£ºiL(0?)?iL(0?)?US1US2R2 ??R2R3R2?R3R1R2R1?R3?R2?R3R1?R2??1 A(µþ¼ÓÔÀí)
iL(?)?US1R1?1 A
??L?0.8 s R1R2R1?R2
iL(t)?iL(?)?iL(0?)?iL(?)e?
.t?1?2e?125 A
?t
Àý4 ͼʾµç·ÔÒÑÎȶ¨£¬t=0ʱ½«¿ª¹ØS¶Ï¿ª¡£Ç󿪹ØS¶Ï¿ªºóµÄ
uC(t)¡£
S+US1R1+CuCR2+US2£££
½â£ºuC(0?)?uC(0?)??US1R1?R2R2?US2R1?R2R1(µþ¼ÓÔÀí)
US1R2?US2R1R1?R2
?ttuC(?)?US2
?t
??R2C
uC(t)?uC(0?)e?US2??uC(?)(1?e?)
?R2?(US1?US2)eR2CR1?R2
Àý5 ͼʾµç·ÔÒÑÎȶ¨£¬t=0ʱ½«¿ª¹ØS¶Ï¿ª£¬ÒÑÖª£ºR1=1?£¬R2=3?£¬L=2H£¬US=4V£¬IS=5A¡£Ç󿪹ØS¶Ï¿ªºóµÄiL(t)¡£
iLR2R1+ISSUS£L
½â£º
iL(0?)?iL(0?)?US?4 A R1
?t
iL(?)?US?IS?9 A R1
??L?2 s R1
iL(t)?iL(?)?iL(0?)?iL(?)e?
?9?5e?0.5t A