What is a synchronous and asynchronous generator?

Following the nationwide power outage that lasted virtually the entire day on Monday, April 28, more and more people are seeking solutions and alternatives to avoid relying solely on the grid and being completely cut off from the power grid.

One of the options that has gained traction in recent hours is that of generators, specifically synchronous and asynchronous generators . A synchronous generator and an asynchronous generator are two main types of rotating electrical machines that convert mechanical energy into alternating current (AC) electrical energy.

The main difference between them is and the different speed of rotation of the rotor and the frequency of the generated electric current. This means that in a synchronous generator, the rotor rotates at a constant speed, called synchronous speed, while in an asynchronous generator, the rotor speed is not equal to the synchronous speed of the stator's magnetic field.

Advantages:

• Ability to control the power factor.
• High efficiency.
• Constant speed under constant load.

Disadvantages:

• More complex and expensive construction.
• Requires an excitation system (DC source for the rotor).
• May require synchronization with the power grid before connection.

Advantages:

• Simpler and more robust construction, generally resulting in lower cost and lower maintenance.
• Self-excitation possible in certain configurations (requires connected capacitors).
• It does not require complex synchronization with the network if it is designed to connect directly.

Disadvantages:

• It has no inherent power factor control; it generally draws reactive power from the grid.
• The output frequency is determined by the grid to which it is connected, and the rotor speed must be slightly higher than synchronous.
• Efficiency may be slightly lower than synchronous generators in some applications.