A new theorem for active networks
A new theorem for active networks
复制标题
主动网络的新定理
DOI：
10.1049/jiee-1.1933.0129
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发表时间：
1933
期刊：
影响因子：
--
通讯作者：
A. T. Starr
中科院分区：
文献类型：
--
作者：
A. T. Starr
证明了一个定理，该定理指出任何具有三个可访问终端的网络都可以用某些电动势和阻抗的星形或三角形来代替。这是肯尼利星三角定理和戴维南定理的延伸。该定理用于找出变压器和三相交流发电机（绕组之间存在耦合且电动势不等）的等效网络。借助该定理还可以找到使用三绕组变压器的阻抗电桥的灵敏度。最后，该定理用于找出由于接地电容引起的电压测量误差。出现的一个重要结果是，在平衡系统的衰减测量中，衰减垫之后发生的电容不平衡会导致测量电压出现误差，而该误差不会被垫衰减。这与公认的理论相矛盾，但却符合实践。
A theorem is proved which states that any network with three accessible terminals can be replaced by a star or delta of certain e.m.f.'s and impedances. This is an extension of Kennelly's star-delta theorem, and Thevenin's theorem. The theorem is applied to find the equivalent network of a transformer and a 3-phase alternator (with coupling between windings and unequal e.m.f.'s) The sensitivity of an impedance bridge, in which a 3-winding transformer is used, is also found by the help of the theorem. Finally, the theorem is used to find the errors in voltage measurement due to earth capacitances. An important result which emerges is that, in measurements of attenuation in balanced systems, an unbalance of capacitance that occurs after the attenuation pad causes an error in the measured voltage which is not attenuated by the pad. This is in contradiction to accepted theory, but agrees with practice.