Commercial Electric Power Systems
An electrical power systems are networks made up of electrical components. These components are part of the supply, transmission and use of electric power. The network can be divided into commercial and residential power supply systems.
Commercial power system is mostly used in industries and commercial buildings. These systems are usually monitored to ensure a constant flow of electricity, to prevent voltage drop, and to ensure that the equipment, and the appropriate conductors are in proper order. In the past, residential power supply systems were fed using two cables: a live cable, and a neutral cable. The live cable would be passed through the main isolating switch in the fuse box before being split to feed other circuits. Depending on the size of the wire used, circuits would be fused appropriately. Nowadays, though, all residential systems are connected to a three phase distribution system, and to miniature circuit breakers installed in the fuse boxes.
An electrical power system is composed of many elements. These include supply loads, SCADA systems, protective devices, power electronic, capacitors, reactors, and conductors. Supplies primarily refer to the source that is supplying power, whether it is AC or DC power. DC power is supplied by batteries, photovoltaic cells, fuel cells. AC power is supplied by a turbo generator that can be moved in a variety of ways; for instance by using nuclear power, wind, water or even fossil fuel. The speed of rotation determines the frequency of the produced current. If there is an increase in loads in the system, for the generator to maintain the speed, it will need more torque.
Loads are anything that consumes electric power, ranging from household gadgets to industrial equipment. For loads to run, their current, voltage, and frequency rating must be fulfilled. There are some standards that determine these ratings, and they, however, vary from place to place. It is therefore important to ensure that the expected voltage, power and frequency are supplied to the loads. This is a challenging exercise.
Conductors are the elements that carry power from the source to the load. In a sizeable region where the electrical system is called a grid, conductors can be classified according to the voltage they carry; hence we have high voltage, and low voltage conductors. High voltage conductors are those that supply high voltage from supply to load centers, while the low power conductors are those that transmit power from load centers to consumers.
There are several factors to consider while choosing a conductor: The cost, power losses during transmission, and the tensile strength used in manufacturing it. Capacitors are used to provide reactive power, while reactors, on the other hand, since they consume reactive power, are useful in the regulation of voltage on long transmission lines. Power electronics are primarily used to rectify current or convert AC to DC.
Being a large system, an electrical power system has many stakeholders. Safety of the whole system depends on the safety of all the components. Therefore, it is necessary that all the components are handled appropriately.
