Free Expert Guides on Power Systems, Circuit Design & Electrical Troubleshooting

Definition of Separately Excited DC GeneratorA separately excited DC generator is defined as a DC generator where the field winding is powered by an external source.Magnetic or Open Circuit CharacteristicThe curve which gives the relation between field current (If) and the generated voltage (E0) in the armature on no load is called magnetic or open circuit characteristic of a DC generator. The plot of this curve is practically same for all types of generators, whether they are separately excited

What is Lap Winding ?Lap Winding DefinitionLap Winding Definition: A lap winding is defined as a winding where successive coils overlap and connect to the same commutator segment under the same magnetic pole.Simplex Lap Winding: In Simplex Lap Winding, the number of parallel paths between the brushes equals the number of poles.Duplex Lap Winding: In Duplex Lap Winding, the number of parallel paths between the brushes is twice the number of poles.Lap Winding Formula: Important formulae include Ba

How dose a DC Generator Work?DC Generator DefinitionA DC generator is a device that converts mechanical power into direct electrical power using the principle of electromagnetic induction.Faraday’s LawThis law states that when a conductor moves in a magnetic field it cuts magnetic lines of force, which induces an electromagnetic force (EMF) in the conductor.The magnitude of the induced EMF depends on the rate of change of the magnetic flux linkage with the conductor. This EMF will cause a curren

Performance Curves DefinitionPerformance curves of a DC generator are graphs that show how the output voltage changes as the load current varies from no load to full load. These are also known as characteristic curves. These curves help us understand the voltage regulation of different types of DC generators. Better performance is indicated by lower voltage regulation.Separately Excited DC GeneratorThough this type of DC generators are rarely used due to its cost for the separate excitation but

What are Self Excited DC Generators?Self-excited DC generatorA modern DC generator with an exciting coil is a self-excited generator, which starts with the initial current in the exciting coil. When the generator is turned off, a small magnetic force is generated in the rotor iron, which induces an electromotive force in the armature and therefore generates a current in the field windings. Initially, the weak magnetic field produces a small current in the coil, but in order to maintain self-exci

What is the EMF Equation of DC Generator?EMF definitionElectromotive force (EMF) in a DC generator is defined as the voltage generated by the movement of a conductor through a magnetic field.Faraday's lawThis law explains that the induced electromotive force in a generator conductor is proportional to the rate at which it crosses the magnetic field line.Generator groupA DC generator consists of a conductor, a magnetic field, an armature, a magnetic pole, and a winding path, which together affect

What is the Parallel Operation of DC Generators?Parallel operation definition of DC generatorIn modern power systems, power is usually provided by many parallel synchronous generators to ensure continuous operation of the plant. The use of single large generators is now obsolete. Having two generators in parallel helps keep them in sync. Adjusting their armature currents and properly connecting them to the bus bars can solve any synchronization problems.Busbar connectionGenerators in power plant

What is the Hopkinson Test?The Hopkinson test definitionThe Hopkinson test is a useful method to test the efficiency of DC motors. It requires two identical machines, one acting as a generator and the other as a motor. The generator provides mechanical power to the motor, which then drives the generator. This setup is why the Hopkinson test is also known as back-to-back or regenerative testing.If there is no loss, no external power supply is required. However, since the generator output voltage

Winding factor definitionThe winding factor is defined as the product of the pitch factor and the distribution factor.Pitch factorThe pitch factor is the phasor of the induced electromotive force and its ratio to its arithmetic sum, and is always less than the unit.This pitch factor is the fundamental component of the electromotive force. Magnetic flux waves can also be composed of spatial field harmonics, which produce corresponding time harmonics in the generated voltage waveform.Full pitch co

Dc generator definitionA DC generator is defined as an electrical device that converts mechanical energy into direct current (DC) electricity. It works according to the principle of electromagnetic induction, when a conductor passes through a magnetic field, it creates a potential difference in the conductor, which, if connected to a closed circuit, causes a current to flow.Structure of DC generatorYokeThe yoke is usually made of cast iron or cast steel, depending on the size and weight of the g