History:

Before 1880, the power distribution was not needed because the usage of electricity was very minimal. Nevertheless, when the industries started producing electricity, the demand of electricity distribution increased and became essential for daily use. In Europe and the United States, the first power systems were built to provide the arc lighting with electricity. Indirectly, the transmission of power, in the past, used the same criteria as the modern way as the arc lighting consume great amount of voltage (3000V), therefore, the station can transmit electricity for long distances (11 km). However, stepping down the voltage to supply electrical devices became an issue. Later in 1880s transformers were invented to play a significant role in the power distribution system as they were used to transfer the power for a longer distance and to step up or down the voltage depending on the use [2].

High-Rise Buildings:

As the time passes, the demand of electricity increased because of the industrial development, which was the reason why the power system expanded, and more substations were built to provide electricity for the consumers. Another evolvement was the rapid growth in population, that affected the buildings’ architecture since the high-rise buildings started to arise to replace the typical low floor buildings. The high-rise buildings consist of three or more floors and over the years they had gone through changes in architectural development in order to cope with the lifestyle evolution and economic fluctuations. These factors had greatly affected the way these buildings were operated. As a result, these changes complicated the load study and the electricity distribution method of the high-rise buildings. One of these changes, is designing a distribution substation along with the multi-storey building to supply it with electricity and meet the consumer needs. Moreover, the distribution substation should be equipped with protection devices to prevent any occurrence of short circuit, which was not one of the engineers concerns in the past because the demand was much less. Another new difficulty in distributing the electricity to the whole building is the cable change. Instead of using normal wiring, rising main is used for vertical power supply and the ring main method used for horizontal supply [3].

To cope with the economic variations and keep up with the modern development some of the electrical devices had gone through major improvements to reduce the power consumption and increase the efficiency of the devices such as air conditional, LED lights, and security system [2].

Evolution of Protection System:

At the beginning of the power distribution in 1880s, protection devices were not introduced to protect the system from faults. However, due to many blackouts and damages in the electrical equipment, the importance of the protection system was realized after few years. Since the power, in the past, was transferred for short distances, small generators were utilized to form many small power systems. Because of that, the first automatic protection device used was the fuse that protect these generators by isolating the faulty devices. Fuses can protect small power systems, but they have many disadvantages such as they should be replaced to restore the power again in the system, they are slow if they operate in large power system, and they are noneconomical . To overcome these disadvantages, the circuit breaker and the relays were introduced to provide protection to the power system. The electromechanical overcurrent relay was the first relay to be employed to protect the system from overcurrent or fault current. In the beginning of the last century, many types of relays were established such as overcurrent relay, directional relay, distance relay, and differential relay to operate under any protection principle. Additionally, the relays and the circuit breakers are still used, nowadays, because they act rapidly, and they are economical [4].