In this article, we shall discuss the advantages and disadvantages of AC (Alternating Current) over DC (Direct Current). Let us start with the basic introduction of electric current, alternating current, and direct current.
Electric Current
Electrical current
is defined as the directed flow of electric charge (mainly electrons). In other
words, the rate of directed flow of electrons is known as electric current.
Based on the nature of the movement of electrons, electric current is
classified into two types namely, direct current (DC) and alternating current
(AC).
(1). Direct Current:
When electric current flows only in one direction, it is called direct current.
Direct current may be further classified into two types, i.e. constant direct
current and time-variable direct current. The electric current produced by a
battery or a cell is an example of a constant direct current, and the electric
current at the output of a rectifier before filtering is an example of a time-varying direct current.
(2). Alternating
Current: When the magnitude of the electric current changes continuously and
direction changes periodically, it is called alternating current or AC.
Alternating current is always a time-varying current. An electric current
produced by an alternator or ac generator or an inverter is an example of
alternating current.
As we know, in our everyday life, we mostly use alternating
current. The electric current that we obtain from electrical outlets in homes and
offices is alternating current. This is because the alternating current has
several advantages over the direct current that we are going to discuss in upcoming
sections of this article.
What are the Advantages of Alternating Current?
Alternating current (AC) offers many advantages over direct
current (DC). The following are some of the advantages of alternating current:
- The generation of alternating current (AC) is more economical and efficient than that of direct current (DC).
- We can increase or decrease the level of alternating voltage and alternating current more efficiently by using an electrical transformer.
- AC electrical machines such as AC motors are mechanically stronger, cheaper, more efficient, and simple in construction.
- Alternating current can be easily and economically converted into direct current by using electronic circuits like rectifiers.
- The generation, transmission and distribution of electrical power using alternating current can be done at low losses.
- TV and radio communication can be done using alternating current signals.
What are the Disadvantages of Alternating Current?
However, AC has several advantages over DC, but it also has some disadvantages. Some of the disadvantages of alternating current are given as follows:
- The maximum value of alternating current is greater than its effective value. Hence, it is more dangerous than DC, thus it requires better insulation.
- We cannot use alternating current for several applications such as charging a battery, electric vehicles, automobile electrical, electrolysis, electroplating, etc.
- The initial setup for the generation of alternating current is very expensive as it requires an alternator.
- Due to the skin effect, the resistance offered by the transmission line to the alternating current is high.
- Transmission lines carrying alternating currents are very sensitive towards the corona effect.
- Transmission and distribution lines offer inductive and capacitive reactance to the alternating current.
Hence, this is all about the important advantages and
disadvantages of alternating current (AC) over direct current (DC).
