PMG stands for Permanent Magnet Generator, which is a type of generator that uses a permanent magnet to generate the magnetic field required for the generation of electrical power.
The function of a PMG in a generator is to provide a stable and reliable source of excitation power for the generator’s excitation system. The PMG is responsible for producing a steady DC voltage that is used to power the excitation system and create the magnetic field required for the generator to produce electricity.
The advantage of using a PMG in a generator is that it provides a self-sustaining source of excitation power, which means that the generator can continue to produce electrical power even if the main power source is lost. This makes PMG-based generators ideal for use in remote or off-grid locations where a stable power supply may not be available.
The permanent magnet generator is a device used to convert mechanical energy to electrical with the highest efficiency. In a conventional alternator, the rotor is made of amination and the copper wire is wounded to the rotor to generate the magnetic field. On rotation the rotor cut the magnetic field, flux is cut and emf is induced to generate alternating current.
Now, that rotor has been replaced by the neodymium magnets which have a high Gauss value.
Per unit surface area of the conventional rotor if produced 3000 gausses at 100 mm sq meters will be replaced by 4 times a smaller area (25 mm at 9000 gauss value) with the help of high-strength neodymium magnets.
PMG has an efficiency of 95 percent consequently able to generate the highest form of efficiency, the conversion of electrical energy from mechanical energy. Nowadays it has a wider scope in today’s world, with the increasing fuel prizing the fossils are also getting eradicated nowadays. Due to this, the prices of non-convention resources will be increased.
COMMERCIAL USAGE
1. It is used as an exciter in alternators, like a 5-megawatt generator will be using approx. 5kw of the exciter (PMG) which will provide DC voltage to the field of the alternator, consequently size and fuel consumption get reduced from the usage of a PMG in big-sized alternators.
The Ambient temperature of the exciter is normally 80 degrees so the high-temperature magnets being used for the rotor of PMG – Alnico have a temperature range of 350 degrees.
It has IP protection 55 standard foot mounted.
2. A Permanent magnet alternator as also be used in wind turbines which rotates at lower RPM and is directly coupled with the same approx. 300 RPM having 20 poles or can be varied depending upon the requirement. Unlike the conventional having a gearbox between them to eliminate the losses and produce the highest efficiency.
3. It can also be used in generating power with the help of a hydro turbine, with the flow of water the turbine gets rotated or can be water falling from the higher heads to the turbines the potential energy of water gets converted to kinetic energy to the turbine so, as it is directly coupled with the PMG. So on rotation, the electricity is produced with the permanent magnet alternator.
4. It can be used to generate free energy, and efficiency above unity if coupled with a bldc motor with the help of a flywheel. With the intervention of an engineer, the person can achieve the result of the above unity.
