adminELECTRIC CURRENT
An electric current is the flow of electric charge, typically carried by electrons, through a conductor. There are two main types of electric currents, alternating and direct electric current. Alternating electric current is called so because the current flows in alternate cycles between positive and negative cyclical bands, in order words alternating electric current flows one way in a positive direction cycle then the other way in a negative cycle, as it flow continuously reversing direction.
While a direct electric current flow in one direction only but its magnitude varies. Generally, alternating current is produced by machines called alternators, while direct currents are produced by machines called dynamos. it is easier to produce electric current and transmit it using alternating current than direct current, because of the following; its scalability that is its voltage can be easily be increased or decreased by the use of a transformer. At higher voltages long distance electric transmission will result in minimal energy loss using alternating current than using direct current since it easily scalable to a higher voltage. Due to this fact, most generating station and transmitting station infrastructure are designed to produce and transmit alternating current, even though they are more dangerous to handle and may require more sub stations along the network to step up or step down these voltages as at when required.
Also the use of alternating current allow the integration of two and three phase electric to the grid network and hence two and three phase machines and motors that are not only more powerful than single phase machines , but are able to start without a starting device like a capacitor.
However, despite all the advantages of alternating current, electric energy can only be stored as direct current in batteries. Furthermore, since direct current can be obtained from and ac supply by the use of a current switching arrangement called a rectifier or an adapter. Alternating current (ac) is easily converted to direct current (dc) for use wherever it is required. In reverse direct current (dc) can be converted to Alternating current (ac) by a device known as an inverter.
Thus alternating current is used in the following; generation, transmission, electric motors and other industrial machines.
While direct current (dc) is used mostly for electronics devices, including cell phones, computers, television and lately electric vehicles.
The future of alternating current (ac) and direct current (dc) is certainly is in its growing use and adoption in a wide variety of domestic, office and industrial application. For alternating current (ac); higher voltage transmission, newer materials and technologies would enhance transmission efficiencies and reduce energy loss.
It is also expected that use of direct current (dc) power will be more prevalent in data centers, electric vehicles and renewable energy systems.
However we anticipate that the alternating current (ac) and direct current (dc ) technology will converge in the following areas; integration of Alternating current (ac) and direct current (dc ) systems, improved power or energy conversion between ac and dc systems and improved solar charging network and infrastructure not only for electric vehicles but for all use.
SOURCES
- Direct current fundamentals by C.R Snell.
- DC power system handbook by Jerry Whitaker.
- Electric circuits: AC/DC by James S. Nilsson.
- Electrical engineering: AC/DC by Allan R. Hambley.
- AC/DC electronics by Owen Bishop.
