The smart grid brings the international grid from regional monitoring and local electromechanical control to an unknown new world of real-time, software-defined networks. In this article, we will briefly understand this immense change: the measurement and control network that connects the grid intelligence unit. When it comes to the term “smart grid,†many people will first think of new types of electricity meters that have recently appeared outside their homes. However, ask a power engineer who will describe the most profound changes in power distribution since AC replaced DC.
Development of the power grid
The world's power grid is not designed but gradually developed. In most regions, the grid is initially a point-to-point connection between the power plant and the load. The load may be a special large user, for example, a factory or tram power line, or a substation that distributes electricity to residents. The location of the power plant and the location of the user determine the topology of the network.
In the beginning, these connections are layered: the more energy that is transmitted, the longer the distance, the higher the voltage. The interfaces between different connection segments require switches, circuit breakers and transformers. Over time, these connections have evolved into a star topology where the substation is located at the center of each star, and then redundant links are added at higher levels.
The control network evolves with the power transmission network. Initially, it used mechanical switches; electromechanical meters were used for voltage, current, phase and volt-ampere reaction (VAR) measurements; controlled by personnel. Since people are not always able to react quickly to prevent damage to the network, the grid uses automatic circuit breakers at key points. With the development of technology, the network has increased the local smart device circuit breakers such as telemeters, remote activation switches, central control rooms, and relays to automatically shut down and restore the circuit in a timely manner.
In the next phase of development, this patchwork network of smart local devices, telemeters, and remote controls has gradually evolved into an early smart grid (Figure 1). In some of the more remote areas, the substations buzzed and there was ozone smell. These places were the first to apply smart grids.
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