8.2:
Generation of Three-Phase Voltage
A three-phase AC generator with a rotating magnet surrounded by stationary windings is used to generate three-phase voltages.
The stator houses three separate coils or windings, with their terminals placed 120 degrees apart.
As the rotor spins, its magnetic field intersects with the coils, inducing equal-magnitude voltages, each with a phase difference of 120 degrees.
Each coil acts as a single-phase generator, enabling the three-phase generator to power both single-phase and three-phase loads.
A three-phase system has three voltage sources connected to loads via three or four transmission lines. These sources can be configured in either a Y or delta connection.
For Y-connected voltage sources with the same amplitude and frequency and a phase difference of 120 degrees, the voltages between lines a, b, c, and the neutral line are the phase voltages, which are balanced, have equal magnitude, and are out of phase by 120 degrees.
In a wind turbine, the rotating blades drive the generator's rotor, inducing a three-phase voltage in the stator coils, which is then transformed and transmitted to the grid.
8.2:
Generation of Three-Phase Voltage
A three-phase AC generator has a rotor with a rotating magnet placed within the stator mounted with the stationary three-phase winding to generate three-phase voltages via mutual induction. These windings are evenly distributed around the inner circumference of the stator and are arranged 120 electrical degrees apart. Three-phase stator windings consist of three separate coils or groups of coils, known as phases, each connected in Y (star) configuration or Delta configuration.
As the rotor spins, its rotating magnetic field intersects with the stator windings and induces equal-magnitude voltages, having a phase difference of 120 degrees. Each winding acts as a single-phase generator, enabling the three-phase generator to power both single-phase and three-phase loads. The three-phase system comprises three voltage sources connected to loads using three or four conductors. In a Y-connected system, the voltage sources have identical amplitude and frequency and are separated by 120 degrees; the voltages across lines a, b, and c to the neutral line represent the phase voltages. These voltages are called balanced when equal in magnitude and phased out by 120 degrees from each other. In a Delta-connected voltage source with identical amplitude and frequency, and a phase difference of 120 degrees, the voltages between lines a, b, and c do not involve a neutral line and are known as line voltages. These line voltages are called balanced when equal in magnitude and maintain a 120-degree phase difference from each other.
In a wind turbine, the rotating blades spin the generator's rotor, inducing a three-phase voltage in the stator coils, which is then transformed and transmitted to the grid.