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

Pole Pitch DefinitionPole pitch is defined as the peripheral distance between the center of two adjacent poles in a DC machine. This distance is measured in terms of armature slots or armature conductors that come between two adjacent pole centers.Pole Pitch is equal to the total number of armature slots divided by the total number of poles in the machine.For example, if there are 96 slots on the armature periphery and 4 poles, the number of armature slots that come between two adjacent pole cen

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

Hunting in Synchronous MotorKey learnings: Hunting Defined: Hunting in a synchronous motor is the phenomenon where the rotor oscillates around a new equilibrium position due to sudden changes in load. Causes of Hunting: Hunting can be caused by abrupt load changes, sudden field current adjustments, harmonic torque loads, or faults in the supply system. Effects of Hunting: This instability may cause the motor to lose synchronism, induce mechanical stresses, increase losses, and elevate temperatur

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

Synchronous Motor ExcitationPrior to understanding this synchronous motor excitation, it should be remembered that any electromagnetic device must draw a magnetizing current from the AC source to produce the required working flux. This magnetizing current lags by almost 90o to the supply voltage. In other words, the function of this magnetizing current or lagging VA drawn by the electromagnetic device is to set up the flux in the magnetic circuit of the device.The synchronous motor is doubly fed

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