架空輸電線路功率損耗問題 P=電壓平方/電阻P=電流平方*電阻為什麼在架空輸電線路中，往往是通過提高電壓降低電流來减少線路功率損耗，而不是通過提高電流，降低電壓來减少線路功率損耗？

架空輸電線路功率損耗問題 P=電壓平方/電阻P=電流平方*電阻為什麼在架空輸電線路中，往往是通過提高電壓降低電流來减少線路功率損耗，而不是通過提高電流，降低電壓來减少線路功率損耗？

如果按照降低電壓，提高電流的辦法，若要保持輸送容量不變，電壓每降低一倍，電流就要新增一倍，根據你列出的第二個公式，線路損耗就要新增3倍（是原來的4倍）了.明顯不划算.如果採用第一個公式“P=電壓平方/電阻”的話，其…

為什麼中國要發展超高壓輸電線路
全文用英文寫

I know，I know！
High-voltage transmission lines are used to transmit electric power over relatively long distances，usually from a central generating station to mainsubstations.Theyare also used for electric power transmission from one central station to another for loadsharing.Highvoltage（HV）transmission lines are made of high voltage（between 138 and 765 kilovolts）overhead and underground conducting lines of either copper or aluminum.
One of the key concerns in transmission of electricity is power loss in transmission lines（called line loss or transmission loss），dissipated as heat due to the resistance of theconductors.Thesmaller the surface area of the conductors，the smaller the loss to heatdissipation.Highvoltages require less surface area，resulting in reduced lineloss.Withhigh-voltage lines，the voltage can be stepped up at the generating station，transmitted through the transmission grid to a load center，and there stepped down to the lower voltages required by distribution lines.

减小輸電線路有功損耗可通過
A，增大線路有功功率B，，增大線路無功功率
C，提高線路兩端電壓D，增大輸電線路電阻

C，提高線路兩端電壓

n>n0時，哪個高手能解釋一下三相非同步電動機的轉子轉子大於旋轉磁場的轉速時，電機是如何發點電

利用轉子的剩磁旋轉切割定子繞組感生出電動勢，就能發出微弱電能；若在電機輸出端並接電容器，該微弱電能作用於電容器上充放電，就能提供激勵轉子磁能增强，繞組感生出略大的電動勢，再作用於電容器上充放電，就能提供激勵轉子磁能進一步增強，如此迴圈遞增，就能發出足够電能.