Introduction of AC Motors basic theory and application.pptx

introduction to AC motors

1. AC Motors Pelatihan pengoperasian motor Listrik di area P-VI

2. What is an AC Motor? An AC motor is a device that converts electrical energy into mechanical motion. It operates on the principle of changing electric current direction periodically. AC motors use the back-and-forth flow of electricity to generate a rotating motion. They consist of two main parts: a stationary stator and a rotating rotor. When AC power is supplied, it creates a magnetic field in the stator that interacts with the magnetic field of the rotor, causing it to turn and drive mechanical systems. AC motors are widely used in appliances, industrial machinery, and various applications due to their efficiency and versatility.

3. AC Motor Diagram AC motor consists of a Stator, Rotor, Motor shaft, Bearings, and Enclosures. The diagram of an AC motor is given below:

4. Stator

5. Rotor The rotor is the moving part of the motor, situated inside the stator. It is usually made of conductive material, like copper, and is free to rotate. As the magnetic field from the stator interacts with the rotor, it induces a rotational motion.

6. Motor Shaft The motor shaft is a rod or spindle that extends from the rotor. When the rotor turns due to the magnetic interaction, the motor shaft also rotates. This rotational motion is what can be harnessed for various applications.

7. Bearings Bearings are components that support and facilitate the smooth rotation of the motor shaft. They reduce friction between the shaft and the motor housing. Bearings contribute to the overall efficiency and durability of the motor.

8. Enclosure The enclosure is the outer casing or housing that contains and protects the internal components of the motor. It shields the motor from external elements like dust and moisture. The enclosure also provides safety by preventing accidental contact with moving parts.

9. Working principle of AC Motor AC motors receive electric power from a source, typically an electrical outlet. The motor consists of two main parts: the stator and the rotor. Coils of wire in the stator carry an electric current, generating a magnetic field.

10. Working principle of AC Motor The rotor, a rotating component made of conductive material, interacts with the stator’s magnetic field. The interaction induces a turning force on the rotor, causing it to rotate around the motor shaft.

11. Working principle of AC Motor The motor shaft, connected to the rotor, transfers the rotational motion generated by the rotor. This rotating motor shaft can be utilized for various tasks, depending on the application. Bearings support and facilitate smooth rotation, enhancing the motor’s efficiency and durability. An enclosure surrounds the motor, providing protection against external elements and ensuring safety. AC motors are versatile and find application in devices like fans, pumps, and other machinery.

12. Types of AC Motor AC Motor is broadly classified into two types namely: Synchronous Motor Induction Motor

13. Synchronous Motor A synchronous motor is an electrical device that maintains a constant speed, synchronizing with the frequency of the power source. It’s widely used in appliances and industrial machinery. The motor’s rotor rotates at the same rate as the magnetic field, ensuring precise and efficient operation in various applications.

14. Speed Formula of Synchronous Motor The speed (Ns) of a synchronous motor is given by the formula:

15. Working Principle Synchronous motors operate at a constant speed determined by the frequency of the AC power supply. The key feature is synchronization between the rotational speed of the motor and the frequency of the power source. They have a rotor that turns at the same speed as the rotating magnetic field produced by the stator.

16. Application Power Factor Correction Systems Precision Timing Devices (e.g., Synchronous Clocks) Industrial Processes Requiring Constant Speed Synchronous Generators in Power Plants

17. Induction Motor An induction motor is a common type of electric motor. It operates on the principle of electromagnetic induction, where electrical energy is transferred to the rotor (rotating part) without a direct electrical connection. Known for their reliability and simplicity in converting electrical energy to mechanical power. The Induction motor is further divided into two types based on the rotor construction, namely: Squirrel Cage Motor Slip Ring Motor

18. Components of Induction Motor

19. Working Principle Induction motors are the most common type of AC motor. They work on the principle of electromagnetic induction. When AC power is applied to the stator, it creates a rotating magnetic field. This magnetic field induces a current in the rotor (usually a short-circuited coil or squirrel cage). The interaction between the stator and rotor magnetic fields causes the rotor to rotate, driving the mechanical load connected to the motor.

20. Application Household Appliances (e.g., Washing Machines, Refrigerators) Industrial Machinery (e.g., Conveyor Systems, Pumps) Fans and Blowers in Ventilation and HVAC Systems Electric Vehicles for Propulsion Water Pumps for Agriculture, Irrigation, and Domestic Use

21. Applications of AC Motor Powering various household devices like fans, air conditioners, refrigerators, and washing machines. Driving conveyor belts, pumps, compressors, and other equipment in factories. Running water pumps for agricultural irrigation, residential water supply, and industrial cooling systems. Providing the motive force for heating, ventilation, and air conditioning (HVAC) systems in buildings. Used in some electric vehicles for propulsion and to drive ancillary systems.

22. Applications of AC Motor Running blenders, food processors, and other kitchen gadgets. Driving automated systems like automated doors, gates, and conveyor systems. Providing the rotational force for various machine tools like lathes and milling machines in manufacturing processes. Powering medical devices such as pumps and centrifuges in healthcare settings. Playing a role in some renewable energy applications, such as in the generators of wind turbines.

23. Advantages of AC Motor Simple Design: AC motors have a straightforward design, making them easy to understand and maintain. Reliability: They are known for their reliability and durability, requiring minimal maintenance over their lifespan. Cost-Effective: AC motors are often more cost-effective to manufacture and purchase compared to some other types of motors. Widely Available: AC motors are widely available in the market, making them easily accessible for various applications. High Efficiency: AC motors can operate with high efficiency, converting a significant portion of electrical energy into mechanical work.

24. Advantages of AC Motor Variable Speed Control: AC motors can be easily controlled to operate at different speeds, providing flexibility for various applications. Quiet Operation: AC motors generally operate quietly, making them suitable for applications where noise is a concern. Versatility: They can be adapted for use in a wide range of applications, from household appliances to industrial machinery. Compatibility with Power Grids: AC motors are well-matched with the AC power supplied by most electrical grids, simplifying their integration into existing systems. Long Lifespan: With proper maintenance, AC motors can have a long operational lifespan, contributing to cost savings over time.

25. AC vs DC Motor AC motors use Alternating Current as their power source whereas DC motors use Direct Current for the same. However, both have a wide range of applications and uses in machines but are different from each other at the same time.

26. Difference Between AC and DC Motors Aspect AC Motor DC Motor Power Source Runs on Alternating Current (AC) Runs on Direct Current (DC) Common Usage Widely used in household appliances, fans, etc. Commonly found in small appliances, tools, etc. Speed Control Generally harder to control speed smoothly Easier to control speed smoothly Starting May require external devices to start Can start on its own, simple to control Maintenance Generally lower maintenance Requires more maintenance, especially brushes Size and Weight Usually compact and lightweight Tends to be bulkier and heavier Cost Often more cost-effective for large systems Can be cost-effective for smaller applications Efficiency Efficient at high power levels Efficient at low to moderate power levels Applications HVAC systems, industrial machinery Power tools, small appliances, automotive