AC and DC current!

                                                             AC and DC current:

                                                            Alternating current:
                                     Type of electrical current that periodically changes its direction and polarity. AC has established itself in the transmission of electricity in the early twentieth century and is the most used for the transmission power in the world. Since the ac supply lines can be connected, so they are suitable for operation within a mesh network. The present AC the advantage that the voltage may be increased or reduced with the aid of a transformer. To transport energy with the least possible losses over long distances, high voltages are used which are then converted to lower voltages to the end consumer.
             






     DC:
 In the case of direct current, the direction of current does not change. The disadvantage of direct current lines lies in the fact that they can not be connected without the need for a cumbersome and expensive technique. This is why they are not suitable for use in a mesh network. They are currently used for point to point and connected to the supply network to 50 Hertz through converter stations. These positions convert energy to carry alternating current into direct current and then at the end of the new transmission section of the direct current into alternating current so that energy can again be carried in the alternating current network. These converter stations require much space. Because of the very high investment costs several hundred million Swiss francs and losses in the converter stations, not DC line is economically profitable from a transmission distance of several hundred kilometers. This type of line is interesting for a small country like Switzerland as part of a European network.