DC Generator DC Generator DC Generator DC Generator
- 1. Direct Current Generators REPORTERS: • BANDOLES, Vincent Rey • FAUSTINO, Joshua • MONTECALVO, Dominic • OTE, Ryza • SANTIANO, Johaness
- 2. Direct Current Generators A direct current (DC) generator is a type of electrical machine used to transform mechanical energy into DC electricity. The principle of energetically induced electromotive force is used in the energy alteration process.
- 3. Direct Current Generators According to the electromagnetic induction principle of Faraday’s Laws, when a conductor cuts magnetic flux, an energetically induced electromotive force is produced in it. Even if the conductor circuit is not opened, this electromotive force can still result in a current flow.
- 4. Electromagnetic Induction Electromagnetic Induction was discovered by Michael Faraday in 1831, and James Clerk Maxwell mathematically described it as Faraday’s law of induction.
- 5. Electromagnetic Induction This either happens when a conductor is placed in a moving magnetic field (when using an AC power source) or when a conductor is constantly moving in a stationary magnetic field.
- 6. Electromagnetic Induction As per the setup given, Michael Faraday arranged a conducting wire attached to a device to measure the voltage across the circuit. When a bar magnet is moved through the coiling, the voltage detector measures the voltage in the circuit.
- 8. Stator – It is the stationary component of the system. The stator also has a core, stator winding, and an outer frame. It is an essential feature of dc generators and serves as the source of magnetic fields around which the coils spin. There are two stable magnets in this that have opposite poles facing each other.
- 9. Rotor – The rotor or armature core, which is made up of a fan, an armature, a commutator, and a shaft, is another crucial component of a DC generator. This component rotates in the magnetic field produced by the stator but is movable, unlike the stator.
- 10. Armature Windings – The armature core slots are primarily utilized to hold the armature windings. To increase the quantity of produced current, they are connected in series to parallel in the form of a closed-circuit winding. The armature winding, a unique configuration of conductors, is regarded as the brain or center of a DC generator.
- 11. Bearings – A system uses bearings to provide smooth movement of the different parts of the DC machine. The friction between the machine’s spinning and stationary components is reduced with the help of bearings. As a result, the system’s components don’t require constant lubrication and will last longer.
- 12. Commutator – In order to reinforce the armature winding, the commutator converts AC voltage to DC voltage similarly to a rectifier. Mica sheets are used to protect each copper segment in this conductive metal from the other.
- 13. Brushes – One of the key components of the DC generator is brushes. These carbon blocks make it possible to guarantee the electrical connection between the commutator and the external load circuit.
- 14. Poles – The main purpose of poles is to maintain the field windings. Typically, these windings are wound on the poles and connected to the armature windings in a specific order. As a result, the poles attach the welding procedure to the yoke using screws.
- 15. Pole Shoe – An iron or steel plate called a pole shoe is used primarily to spread the magnetic flux and prevent the spinning field coil from dropping.
- 16. Yoke – The yoke is the outside cover made up of cast iron or steel that not only secures the inner assembly to the machine’s base and offers mechanical protection for it, but also provides a conduit for the magnetic flow that the field winding generates.
- 17. Shaft – In a DC machine, the shaft is a mechanical component that causes rotation by producing torque. It has a maximum breaking strength and is made of mild steel. The shaft is one of the components of a DC generator that aids in the generator’s ability to transfer mechanical energy.
- 19. Classification of DC Generators on the Method of Excitation • Permanent Magnet • Separately Excited • Self Excited 1.Series Wound Generator 2.Shunt Wound Generator 3.Compound Wound Generator
- 20. Permanent Magnet DC Generator • Field coils are excited by permanent magnets. • Does not generate much power. Rarely found in industrial applications. Normally used in small applications – like dynamos in motorcycles.
- 21. Separately Excited DC Generator • generators whose field magnets are energized by some external DC source, such as battery.
- 22. Self-Excited DC Generator • Generators whose field magnets are energized by the current supplied by themselves. • Field coils are internally connected with the armature.
- 23. Self-Excited DC Generator • Gets started with the initial current in the field coils. When generator is switched off, a small magnetism is developed in rotor iron which induced electromotive force in the armature due to which current is produced in the field windings. Initially, weak magnetic field creates less current in the coil, but to sustain self-excitation, the additional magnetic flux increases the electromotive force in the rotor, due to which voltage keep on increasing until the machine takes the full load.
- 24. 3 Types of Self-Excited DC Generator 1.Series Wound Generator 2.Shunt Wound Generator 3.Compound Wound Generator
- 25. Series Wound Generator • Field windings are connected in series with armature conductors. • Whole current flows through the field coils as well as the load. As series field winding carries full load current, it is designed with relatively few turns of thick wire. The electrical resistance of series field winding is therefore very low (nearly 0.5Ω).
- 27. Shunt Wound Generator • Field windings are connected in parallel with armature conductors. • In shunt wound generators, the voltage in the field winding is same as the voltage across the terminal.
- 29. Compound Wound Generator • Has both series field winding and shunt field winding. One winding is placed in series with the armature, and the other is placed in parallel with the armature. • Has two types: • Short Shunt Compound Wound Generator • Long Shunt Compound Wound Generator
- 30. Short Shunt Compound Wound Generator • Are generators where only the shunt field winding is in parallel with the armature winding.
- 31. Long Shunt Compound Wound Generator • Are generators where the shunt field winding is in parallel with both series field and the armature winding.
- 33. DC generators, also known as dynamos, are electrical machines that convert mechanical energy into direct current (DC) electrical energy.
- 34. APPLICATIONS • Battery Charging • Electroplating • Welding • Emergency Power Systems • Railway Traction • Military Applications • Renewable Energy Systems • Research and Testing • Aviation • Telecommunications
- 35. Pros & Cons of a DC Generator
- 36. PROS 1. Simple Construction 2. Direct Current Output 3. Speed Regulation 4. Ease of Control 5. High Starting Torque 6. Compatibility with Battery Systems CONS 1. Commutator and Brush Wear 2. Limited Power Output 3. Sparking and Arcing 4. Voltage Regulation 5. Cooling Requirements 6. Limited Applications
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