This problem can be traced back to the dispute between Edison and Truss. . . Edison advocated the use of direct current technology, but Truss invented alternating current. However, DC electricity has relatively big problems in transmission, and the loss is huge. Alternating current is much better, and it is easy to transform, which is conducive to high-voltage transmission. . . .
By the way, Edison is not a good bird. If the whole world used his DC technology, the patent fees paid to him would be scary. He also pressured Truss to give up the profits from his alternating current patent and make the technology public for free. At the same time, it attempts to vigorously promote the commercialization of direct current in order to earn more patent fees. However, facts still prove that in practical applications, alternating current has many advantages over direct current (mainly because of the poor efficiency of direct current and the limited long-distance transmission conditions).