In power transmission, Tesla invented the alternating current system, which is a major breakthrough in power transmission technology. Alternating current can transmit power efficiently, and it can easily change the voltage, which is impossible for direct current. Another important feature of alternating current is that it can transmit power over a long distance, which also makes power transmission more flexible and practical.

Before Tesla invented the alternating current system, power transmission used direct current. However, the transmission distance of direct current is very short, only a few hundred feet at most, which limits the range of power transmission. In addition, the voltage of DC cannot be easily changed, which makes the efficiency of power transmission low.

Tesla's AC system solves these problems. It can efficiently transmit power to far places and easily change the voltage. This makes power transmission more flexible and practical, and also lays a solid foundation for the development of power industry.

Although Tesla's AC system has achieved great success in power transmission, it is not without its shortcomings. The safety performance of AC system is relatively low, especially for high voltage transmission, which is in danger of electric shock. In addition, the installation and maintenance of air conditioning system are complicated and need professional operation.

In short, Tesla's AC system is a major breakthrough in power transmission technology, making power transmission more flexible, practical and efficient. Although it has some shortcomings, its advantages still make it one of the important inventions in the field of power transmission.