Electricity and Power Systems, Lecture notes of Electrical Engineering

Download Electricity and Power Systems and more Lecture notes Electrical Engineering in PDF only on Docsity! ALTERNATING CURRENT (AC) AND DIRECT CURRENT (DC) BY GROUP 13. GROUP MEMBERS INDEX NUMBER • Tettey Elikem Cyril 01210600B • Adjetey Nii Larbi Mensah Eric 01210214B • Tetteh Eric 01210215B • Sando Vincent Womborasang 01210876B • Nartey Kwabena Collins 01210367B APPLICATIONS OF ALTERNATING CURRENT • Alternating current is mainly used for power distribution and transmission. • Power outlets in various homes and offices are powered by alternating current. • Alternating current is also used to power electric motors which is used in large appliances such as refrigerators, dishwashers and many more. WHY IS ALTERNATING CURRENT MORE DOMINANT? • It is easier to generate alternating current than direct current. • Alternating current voltage can be changed more easily. DIRECT CURRENT (DC) • Direct current is an electric current which flows in only one direction (electrons flow in the same direction all the time). • Direct voltage is a voltage that forces electrons to move through a circuit in the same direction continuously. • SYMBOL: ADVANTAGES OF ALTERNATING CURRENT OVER DIRECT CURRENT. • Alternating current can be transmitted over a long distance. • Alternating current can be stepped down and up through a transformer. • Alternating current machines are very robust. • Alternating current is relatively cheaper than direct current. DIFFERENCES BETWEEN ALTERNATING CURRENT AND DIRECT CURRENT ALTERNATING CURRENT • Flows back and forth(direction of flow is alternating). • Produces a magnetic field whose size and polarity continuously changes. • Induces emf in other coils within the magnetic field. DIRECT CURRENT • Flows in only one direction. • Produces a magnetic field with constant size and polarity. • Does not induce emf in other coils within the magnetic field.