The connection of several generating stations in a network of particular transmission voltage level is commonly known as electrical grid system. By interconnecting different power generating stations we can solve various difficulties arise in power system. The structure, or “network topology” of a grid can vary depending on the the load and generation characteristics, constraints of budget and the requirements for system reliability. The physical layout is often forced by the geology and land availablility.
Although, forming a grid by interconnecting different generating stations located at different places is significantly expensive since the protections and operations of the entire system become more complicated. But untill modern power system demands the interconnected grid between the power stations because of its tremendous benefits against the power stations which are running individually. There are some advantages of interconnected grid system listed below one by one.
- The interconnected grid increases the reliability of power system significantly. In case of failure of any generating station, the network (grid) will share the load of that generating plant. Increased reliability is the most significant advantage of a grid system.
- The arrangement can exchange the peak load of a plant. In case of individual operation of a generating station, if the peak load increases beyond the capacity of the generating station, we have to impose partial load shedding on the system. But when we connect the generating station to a grid system the grid carries the extra load of the station. There is no need for partial load shedding or no need for enhancement of the capacity of that particular generating station.
- Sometimes there are numbers of inefficient old generating stations available with a generating authority which they cannot run in continuous basis from the commercial point of view. If the entire load of the system exceeds the grid capacity, the generating authority can run these old, and inefficient plants for a short duration to meet the excess demand of the network. In this way, the authority can utilize the old and inefficient plants up to some extent without keeping them entirely idle.
- The grid covers a large number of consumers than that of an individual generating station. So the fluctuation of load demand of a grid is much less than that of a single generating plant. That means the load imposed on the generating station from a grid is much consistent. Depending on the consistency of the load, we can choose the installed capacity of the generating station in such a manner that the plant can run with nearly its full capacity for a significant period of time during each day. Hence the generation of electricity would be economical.
- The grid system can improve the diversity factor of each generating station connected to the grid. The diversity factor gets improved because the maximum demand of the grid shared by the generating station is much lesser than the maximum demand imposed on the generating station if it runs individually.