阻抗 [tex=4.714x1.214]zoBj9vQJGFMRlifq/bT4uQ==[/tex]的三角形负载, 经阻抗[tex=5.5x1.214]NFBQ0k1rTSYy+2yl1a/HvFso7PdE/w2LOpN33IhDO68=[/tex]的输电线接到相电下 [tex=4.357x1.286]MCzEowTTRGHDjfOjt5SaWtIL9Y+W10yU4Bsy9/BoHmo=[/tex]的对称三相电源上。如例图 ( a ) 所示 : 当负载端 [tex=1.0x1.143]/JEgcwcW8SygobTl2dHQNA==[/tex]和 [tex=1.071x1.143]RWK/o99TQtm3j8CICtDzvQ==[/tex] 之间发生线间短路时,问线电流将为正常工作电流的多少倍。[img=339x255]17999792a6217ad.png[/img]

2022-06-18

阻抗 [tex=4.714x1.214]zoBj9vQJGFMRlifq/bT4uQ==[/tex]的三角形负载, 经阻抗[tex=5.5x1.214]NFBQ0k1rTSYy+2yl1a/HvFso7PdE/w2LOpN33IhDO68=[/tex]的输电线接到相电下 [tex=4.357x1.286]MCzEowTTRGHDjfOjt5SaWtIL9Y+W10yU4Bsy9/BoHmo=[/tex]的对称三相电源上。如例图 ( a ) 所示 : 当负载端 [tex=1.0x1.143]/JEgcwcW8SygobTl2dHQNA==[/tex]和 [tex=1.071x1.143]RWK/o99TQtm3j8CICtDzvQ==[/tex] 之间发生线间短路时,问线电流将为正常工作电流的多少倍。[img=339x255]17999792a6217ad.png[/img]

答案：

解：正常情况下，用一相电路计算如图（b）所示[img=302x231]1799979f4bfe82e.png[/img][tex=14.286x2.857]DBxsvUgMJVrQV6dPZckRQ2zc9Cq0L+VuGvxa9bn+yjPdq0i/VefrafOUij/Hp0N2Lr60s6SkAYnlo6a0DOdfdytgmz6NpW449WF/w4sDDSr2IERj1Ajs+iZUBGgCLLZfvp+K97XPQV3roHCBXBi0pg==[/tex]当[tex=2.071x1.143]60mlEmKRednDSRDDKLjmphptSbTO33Vc9I6B6sYGNw4=[/tex] 短路时，其工作电路如例图(c)所示[img=418x251]179997a0da03b79.png[/img][tex=17.5x3.929]d6KW8e9BANOP2BcXdIibJzJlk+DgUxIHryWkwmhUDpDfsG90/UJeIkjMR9rwx9tQANz607wmt+Plsk5tOigYHG4vgDH5ZAei0jI9/gWWpyyfL5PPWzDgov3iUPYFLN6zALo/WcxWiq9ZZjwB4auQsi6U17SJ2dug9ZJXez51Q+cWa8XKKi7vV+RyiqjiuSziIl0cJY6cdtKp20459xKqUyJNnW8CS9rWJsOhPn5+PDHjXKF5Rn3aHNNByug/CSGLeSbPCXce3LdIctINcl8HCUXygFtYn0munyEentF9enM=[/tex][tex=28.143x11.143]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[/tex][tex=13.571x2.571]9XAGSO2DA1brjpZzymceYEA/HjytASLiQyK6SwFvNzmBQOY/ZqSf3kyX0n8Cni/hqS8SunRoJ3hl9y/5ROo4w3qK8MHlEN1NYWfGkQnkB66wU8nGOsTVe4puIGVPohzfQhgqFrjeNMtP2zbdRlYjXg==[/tex]同理[tex=8.929x2.357]HbsC9SQNVIUwpR+gTmP7BuCWHYNTo5I0SpNK8pkBYesd8MoaXAvWj8YxK3VWSDZTq5rBOUV+dBHR4ns4LmSEIg==[/tex][tex=6.357x2.357]NA/yvTIuJbGvZVQ+/cHMHRiBzDb2Ab2LQj8PJphjsKPv7YbP2tJyXWT00sDc9EF4[/tex]

举一反三

内容

0
每相阻抗 [tex=5.286x1.214]8awIc5w7K5nh21vC+9l0Cb7eiNlNMZpIbRDH/yQvXHc=[/tex] 的对称 [tex=0.643x1.0]O+viFNA0oHTwnBtQyi80Zw==[/tex] 形负载连接到线电压为 [tex=2.286x1.0]nuhxSh4oOE2lFJHmHjbckpbQZerDcI78d+O0deHe8gw=[/tex] 的对称三相电源上，试求：正常情况下负载的电压和电流。[img=470x306]179a95446d6d5a8.png[/img]
1
如题图所示三相四线制电路,电源线电压为[tex=2.143x1.0]umH6kAqJLeq6+ZBSkeITDQ==[/tex],已知[tex=3.286x1.214]t5LFue+zod29Y6NubHDAPoe89Uw0cSq345kd/VnpbbY=[/tex],[tex=3.857x1.214]2+hqaHHKN7cplPDhY5B7NbzmhNtZlbeoEgo6iTgc9ps=[/tex],[tex=3.571x1.214]/IzDts2IdqzPZpuccgQbrKF+/9/gm46nKGMPQwa96vk=[/tex],在有中性线和无中性线两种情况下,分别求: (1)负载的相电压、相电流及中性线电流; (2) [tex=0.786x1.0]Yn3GgEZev6SOu2r4v1WnCw==[/tex]相短路时负载的相电压和相电流; (3)[tex=0.786x1.0]0n/exa/GJbrRDYeGuV1vRg==[/tex]相开路时负载的相电压和相电流[img=390x218]17994aef8ea903c.png[/img]
2
[tex=0.643x1.0]yiKSuEZSf0pGVWn/suob3g==[/tex] 形连接的对称负载每相阻抗[tex=4.571x1.214]rw2ZhioF/ilUXeMv/jGCwfce3tmmfZc+xMYtchlrX8c=[/tex] 接到线电压为[tex=2.286x1.0]cf5WH/HIasG/xJniLrXMxeXj17ocBs7euJxXeg+bM40=[/tex]的三相电源上，求各相负载的相电流和线电流。
3
有两组对称三相负载，一组连接成星形，每相阻抗为[tex=6.714x1.286]MceLFRNWh9xwYL9ES0zUHJiXdpuWuZl3XR2GH0JjGTY=[/tex]；一组连接成三角形，每相阻抗为[tex=7.786x1.286]PQthtY0ICtYYW2VZ2+3/6ao5J3Qo1QnuTFJAccDwSX73uv01grpqB10G2abLbd0F[/tex]，接到线电压为[tex=2.214x1.286]/jYr7pgMlBxu23Y+yPQP4w==[/tex]的电源上，试求三相电路的线电流．
4
如图所示，三相电源的相电压为[tex=2.286x1.0]+1AJ+QxPgY6HhqplYsXCgA==[/tex]，每相负载的阻抗均为[tex=1.786x1.0]KUBF6+aKLpXnjuD5AAx2lg==[/tex]。(1) 是否可以说负载是对称的，为什么？(2) 试求各相电流及中线电流，并画出向量图(电压、电流)；(3) 试求三相平均功率[tex=0.857x1.0]sKuuIgoU/ynFEIl8B2/CpA==[/tex]。[img=297x249]179e0898852a9b1.png[/img]