A synchronous machine is an electrical machine that converts mechanical energy into electrical energy or vice versa. It operates on the principle of synchronism, where the speed of the rotor is synchronized with the frequency of the AC power supply.
A larger air gap in a synchronous machine refers to the distance between the rotor and the stator. It is an essential parameter as it affects the performance of the machine. A larger air gap means a weaker magnetic field and lower efficiency, while a smaller air gap results in a stronger magnetic field and higher efficiency.
A larger air gap helps in achieving a sinusoidal magnetic field in a synchronous machine. This is because a larger air gap reduces the saturation of the magnetic circuit, resulting in a more sinusoidal distribution of magnetic flux. This, in turn, leads to a more sinusoidal MMF (magnetomotive force) and a smoother operation of the machine.
A larger air gap offers several advantages in a synchronous machine, including:
While a larger air gap offers several advantages, it also has some disadvantages, including: