桶四线制电路，电源线电压为[tex=2.214x1.286]/jYr7pgMlBxu23Y+yPQP4w==[/tex]，不对称星形联结负载，各相复阻抗为[tex=4.071x1.286]8sF9Iuck2te9mZqcrwL3yfD2amRHuk6jWQa0E/vOutc=[/tex]，[tex=4.071x1.286]eG1W0vrkM1CwKmS/qyNCcX9sr4lsA1+/BEfWytPfBuw=[/tex]，[tex=4.071x1.286]W4+lhs1bukMPAIQPgZZS8JXxcOf7QMdm4+DqlWEAx5w=[/tex]．试计算：（1）中性线正常时各相负载电压、电流和中性线电流；（2）中性线断开时，各相负载的电压和电流．

2022-06-29

桶四线制电路，电源线电压为[tex=2.214x1.286]/jYr7pgMlBxu23Y+yPQP4w==[/tex]，不对称星形联结负载，各相复阻抗为[tex=4.071x1.286]8sF9Iuck2te9mZqcrwL3yfD2amRHuk6jWQa0E/vOutc=[/tex]，[tex=4.071x1.286]eG1W0vrkM1CwKmS/qyNCcX9sr4lsA1+/BEfWytPfBuw=[/tex]，[tex=4.071x1.286]W4+lhs1bukMPAIQPgZZS8JXxcOf7QMdm4+DqlWEAx5w=[/tex]．试计算：（1）中性线正常时各相负载电压、电流和中性线电流；（2）中性线断开时，各相负载的电压和电流．

答案：

解：设相电压[tex=6.214x1.286]OQ+s740OdqGtjRtIyxUsjxftsLO9Trq/oyBX1bN+JY4hQe+VNM6BnX6ZDi+NJB5C[/tex]，则（1）各相负载电压为[tex=6.214x1.286]OQ+s740OdqGtjRtIyxUsjxftsLO9Trq/oyBX1bN+JY4hQe+VNM6BnX6ZDi+NJB5C[/tex]，[tex=8.429x1.286]i0CyYBmO9Gsauocj8unzSunILcRTlOVvxIdr+19EJvSG6XbeyYMWRDxr+p4emyVB[/tex]，[tex=7.214x1.286]McnbJqRwU+0infgFfvi1/bTxoDpRzEBlmc8/9J0qtP6ffhAF6ECPsEuTjgrdKd4P[/tex]，各相负载电流为[tex=13.714x2.357]4W+dzcPw8opxkaA0iAuilOwcSr1yveiC3nGfMTAZA9vqrH0o8Ez4dfRPuKstZ0xJGCMXFGK3yIh0WI3uIngc036j9w1zGGlqsdcsUsFQLM9CAB2ZpGo4wFSrUpeXgXa+V0ExIQ0caCBB0iFVG6tWCw==[/tex]，[tex=16.571x2.357]ONv65Tk6o0wAeEkndvCRYMedGIWNjvzzOOCVE+KqU/P9rTpOX003+cd0N327x39RQOf1lJ3FfDIMQeVLcslGEzOTjmqcOwZQEg4R+PbhKXB0d/lBjkVTasdgfAXFPKDq1fDwOuBTjHYEQx96MQ/YWg==[/tex]，[tex=15.429x2.429]4NX+dSBV9IyU+gur1HpdjUN84HUPJqqiB4Vc7ErivwHbm/d1OVAMuZcg7v4M/cNO3j8JPb99PnpNi7sLE2gkseb+5HQVFARvlAbTIG6HFU5huvO7MoaplCRsD3myuZoP8xdp3Z1gdgBgP9kPeRBpfw==[/tex]，中性线电流[tex=7.286x1.286]piZPykw+R1UHbk7uBlTDjslAM9HHmHF+NnD596vAP3ha/xgBqeZDo11lblrRkCR+x9L18e0As7//PiN3oeNExQ==[/tex][tex=14.643x1.286]JT+xMUdF9VjKfRE4jyTiHWkH07kaPPyWDCq4C9rEPvxvPIR/P759qK+YWglTp136yYiFrGxkFrIB0HDf27ab3QwhbIocKpxe92X89vuqFG4=[/tex][tex=7.786x1.286]boDCT24Y0foefeK5degdvp/DD5rbBLno2btSHOgiKTTFEtRGa0zXmM343ane+xV+[/tex]．（2）中性线断开时，电路如图所示．[img=205x119]179828ecf1e3cf7.png[/img]中性线断开时，节点电压为[tex=9.429x3.0]y2cR/OwAPgRBCFuTn7PDFvpNL4RUlhEEg/9WhdCaFAinwkU/F1Ye1vHxrIP0hSjlHrnyN5Es2QORstjaBZ7k6eqSQmxZAwrwDYjduXV1s5nbAL9WWSVSKrCvWKEMI9JO0Vc5BDlzSFOp5XyDgZZd3mnru12EbPXa4u8kD0k4N3ugWgmzdPn8zZSNhdkB4ed11GCFJ8Dfyv0Sh1aUOKHhYOXmC2yj+g+aN3gzzpEK8Hg=[/tex][tex=14.429x2.429]1I3RrdO8Q/Y7MdtGb7HONWVXk5Pl9m1NNDH/ZjLGHGm7D9XAOmR4MWcDR2lL43vS/iueG6hYfzSgieBv3WMSaPOHGcNrOwJaXcbA/3RKB+6FrOtOc1blF6VhETtlm8d/bwum3r6soujihTvRn/RZ1ugZbVySXkM5/lgin8jn7tk=[/tex][tex=7.786x1.286]6bP6tg1omug44tGb6VgPbj8ifo5SJHOb+n2R8GosHArZxi9JtA6yscxohabd6bq7[/tex]，各相负载电流和电压为[tex=6.786x2.357]4W+dzcPw8opxkaA0iAuilDOQ/YYSOQp6jL/BfM9Qlt+le+40E8vuBMoswcya5Ub6/Cai6D9mJG/Ij5sfaDGjQJIpvk47jPXne2d/iZnof5c=[/tex][tex=12.286x2.0]aHI4OhBPGaDikCoGOxeCsyl2POwhs8r24YuXKPtqeADDRAvDUjZF662X8W2cHdLUmy6bA2/q+1V2st9NY6nbnY0DNwiulUouKciqSCyUadg=[/tex][tex=10.429x2.929]HUHZHZj8Sj6drZZN/iFqDL5zLyTukVIOi3TuXd4GGrohliL2YgSgJ+mp+PW4075INKtGwdKGMTC9ZoHDGmVixg==[/tex]，[tex=6.786x2.357]ONv65Tk6o0wAeEkndvCRYB53WQWB+NINhtgF3seeuP8hpvSTqps7VtWcOkuFxKFOupk5lma51P9JjoEPEM1OEu4PKckY7aKv4IMG8ygydSM=[/tex][tex=14.429x2.0]ZKhpvtEq2ExNl1UcB/QBOn+vTfJGMSi2Uylwbsl8EubbflllhP2fxvoaRqMwXVNBuYkMS7uqvRwWU27Id8aG0OPtmfLVvy87WUYW/47V3Zw=[/tex][tex=14.286x2.929]vVHsuGn/OD3KDS99Jyin5shWF+qe27elKLWn+JVBFaANNYRIikQfU53qPAvwZKvnvCLRP/nqo6pdV1jC9mbTNyl4jv1khyaBnJh7CeG+vuxJGEeK6vvEiKny7qhHzuwG[/tex]，[tex=6.786x2.429]4NX+dSBV9IyU+gur1HpdjXWSlqKfpZ+iZ9No+h0TAu2HprrIhPIUtbMr0q1NNM75kbZXsaQ/SbXCf/LtBeGkoXGZwyrQN0jGjqAxTUJkHMs=[/tex][tex=13.214x2.0]ZKhpvtEq2ExNl1UcB/QBOmddTbjclSjqThNt+Lr0IpZcD3lkcFujwuNOZB+Y+9yTYE5frZ9lRHijOb1pgLaKab+dDRSf0VDaoYJqc7O9yok=[/tex][tex=14.286x2.929]kjyvVUOsaEAjLeQiOs1sd3xrR5RNHc99Uotj7zN8ewLsabAeE3+SrJekg2N5q+C3ubHYk9fxYZ/GWvm0q5qgcq+4YWRgoLcDV0UKnGmBqpMZN3vaWGFqbaK+v8BSWLJj[/tex]，其有效值为[tex=4.643x1.286]NhxYmElh11IUxA1IgL9NeMi+8jZSvWKhYH64QOLSjr4=[/tex]，[tex=6.429x1.286]sLnPde1micABDNxKAF22n/wtSpDKgrLi8x1H6Zbct4AKYP2kk0l3UClILqRsBICD[/tex]，[tex=5.143x1.286]Qu+PdmBWuzh5NdlFkKGZKtJz9/9SLvjXRR0OtKlciAc=[/tex]，[tex=13.071x1.286]Fvc8uMyVw2F69Y2m5ZZr4uGmqX7dmcCt9HLn7PriMa5+2AqS107GBnW06mdwM5QUTZ89VgElWhTt6mgKNTCHGKEwfksZmXCXoXhEJzjxUCg=[/tex]，[tex=5.143x1.286]+p07LOuI2TFn1BdRKfmB8CYoXLoCkgUz2fIDyKgv78M=[/tex]，[tex=13.071x1.286]wlkSvD/Yf55XS8+AGQ5yalvRzp1FPhXwUrY28A/x/2In6z/WOth37gdZYH9Sax1XvvkhSAd9aIcKGGaCA9Aw5Q==[/tex]．

举一反三

内容

0
三相负载作 Y形连接，已知[tex=15.429x1.214]//79qMySC5TYqrK0RqHEKWB4ns4Kzq1gI/NAQYA6dp4cn6aGwVOWPhIuw6R+Nq2xdpG6bj2WVI+u0/5HfrV8S4uNqPV3tDyNYVk0G5JFCXfF0KZ5QJNQxC8llmHw3i2pEBqOIs0ZKTt1yeRCPR5Xxw==[/tex]接在对称相电源上，电源的线电压为 [tex=2.143x1.0]PTqe4Aw00JekI5pDnFLWNQ==[/tex]。求: （1）有中性线情况下各线电流和中性线电流;(2) 无中性线情况下各线电流。
1
已知三相电源的线电压[tex=3.786x1.214]i/QfSrA8GJVjtKU2ZfxQKF/c4BXjs1DmwxAkJPHbxZo=[/tex]。对称三相负载星形联结，每相负载的阻抗[tex=1.5x1.0]Hj3yOxrA+dFVodCWbjy5Wg==[/tex][tex=4.714x1.357]zcMwxUbrNzUZtGeXqR3sSqNuxZkyizRIJxRnu0FVJVM=[/tex]。试求: (1)负载的相电流及线电流; (2)画出相量图; (3)若输电线阻抗[tex=5.429x1.357]Efpfcy+Zrbt3nmySPz2nc/m2u7EXxm+ZfgTgaxbHcOE=[/tex]，再求负载的相电流及线电流。
2
某三相对称负载的每相阻抗为[tex=5.357x1.071]B+tk+4+IH3EyTJr6+cL0nPfaChmPoOcutvpRG8Vpy8Y=[/tex], 接入线电压 [tex=2.286x1.0]cf5WH/HIasG/xJniLrXMxeXj17ocBs7euJxXeg+bM40=[/tex]的三相四线制电路中。（1）如果忽略输电线阻抗, 负载作 Y形连接，计算每相负载的相电流和线电流; (2) 如果考虑输电线阻抗，且输电线阻抗为 [tex=4.929x1.214]GjhMMahjISsaswmULmA9gr+W4icgmF0AVJM/3PPVagA=[/tex]负载作[tex=0.929x1.214]X6aMYIBAO828S2oxkQ6aMw==[/tex]形连接，计算每相负载的相电流和线电流。[img=347x404]17993a5ae76f07f.png[/img]
3
6-2对称三相电路的电源线电压为380V，三角形联结的对称负载[tex=6.214x1.357]+f73GUJtm9n46ie3tv+5x5Tiqvw+GcJI9tatoak+SN0=[/tex]。试求: (1)负载的相电流和线电流; (2) 画出相量图; (3) 若输电线阻抗[tex=5.429x1.357]CNz7myOA2VLv7yG2NqCDZtkh7rT5MA+kXbd9stzm7Ok=[/tex],再求负载的相电流和线电流。
4
在图所示电路中，电源线电压 [tex=4.071x1.214]nQB2KYjJJfvUJYEBDZDhpg==[/tex]。(1) 如果图中各相负载阻抗的模都等于 [tex=1.786x1.0]pUF68XkY694UhS9Q4Q70Jg==[/tex], 是否可以说负载是对称的?(2) 试求各相电流，并用电压与电流的相量图计算中性线电流。如果中性线电流的参考方向选定同电路图上所示的方向相反，则结果有何不向?(3) 试求三相平均功率 [tex=0.786x1.286]dSWbQCTjdbLxKy7q0ps2gg==[/tex]。[img=229x233]1798e5330e8919d.png[/img]