Now I don't think plugs will be unified all over the world. Although the number of global exchanges has increased due to work or various reasons. I need to go to work and communicate all over the world, but for people who often go abroad, it is no big problem to bring a few plugs when they are used to it. It will be very difficult to unify the whole world. Unless the global voltage is consistent.

The power supply voltage used around the world is different, so there is no way to unify the legends around the world. The difference is mainly caused by historical reasons. If you want to unify the plug, you must first unify the voltage all over the world, and then you can unify the plug model. In the United States, Edison insisted on using 1 10V DC instead of alternating current in the power supply system he built in new york. In China, the voltage to the ground is about 220V, that is, it is normal in the range of 2 15-235V, even if it is lower.

The world electricity consumption is only about 100 years. During this 100 year, no international organization has ever questioned and unified this power transmission mode. So basically, plugs in various countries are independently developed. To a certain extent, plugs cannot be unified in so many countries unless there is a very powerful organization to unify the world.

In fact, this plug is not a very uncomfortable thing for many people. People who go out for a long time will prepare several plugs with different powers according to the applicable situation. People who don't go out often can overcome this situation, so it is difficult for the world to unify plugs in this case. The design of plugs varies from country to country, so unification will be a big project.