Asynchronous generators represent an extension of technology for rotating electric machines for energy generation, along with synchronous generators made of wound rotor or permanent magnet rotor.
INDUCTION TECHNOLOGY
Starting from constructive view, an asynchronous generator is built like an induction electric motor with squirrel cage rotor, constant rotating speed and a common IP54 or IP55 protection degree.
When used as a generator, the rotor is put in operation by an external source of mechanical energy (typically, endothermic engine): the rotating magnetic field which is generated, determines the production of energy as AC current, by rotating faster than the stator magnetic field (hyper-synchronism).
EASE OF MANAGEMENT AND STURDINESS
In the rotating electric machines landscape, asynchronous generators stand out for their easy operation management, sturdiness, and small maintenance.
● They do not have nor AVRs automatic voltage and frequency regulators, nor excitation systems.
● They do have a good wave form by offering low THD total harmonic distorsion values.
● TEFC totally enclosed fan cooled closed housing ensures strong protection against dust and water sprays, if compared to open-drip proof enclosures (open housing).
● Squirrel cage rotor is more robust, stable and simple to maintain than the wound rotor of synchronous generators. Consequently, costs will be much more reduced in case of after sale.
A detail on Sincro water cooled generator for micro CHP
OPERATION
| Utility Grid Parallel
Asynchronous technology is mostly used on wind turbines with gearbox, hydro turbines and cogeneration gensets, when operation occurs in parallel with the electricity main grid.
In this case, the generator takes the reactive power directly from the main, as it cannot generate it being lacking in excitation.
| Stand Alone (off-grid)
In case of stand alone operation (no connection to the main grid), asynchronous generators are the right choice when loads are resistive (power factor 1) such as lighting systems.
In case of inductive loads (typically, the electric motors used on industrial machineries and equipment), the asynchronous technology proves to be not very suitable as, not having a self-regulating voltage system, it would involve an excessive sizing of the generator.
For stand alone, special capacitors are provided to be connected to the generator leads, as external source of reactive power.
AIR OR LIQUID COOLED, UP TO 50 KW
We are a global manufacturer of rotating electric machines for over 50 years.
Close to a complete range of induction motors and synchronous alternators with wound rotor or permanent magnets, our offering also includes a specific range of low voltage asynchronous generators with outputs from 1 to 50 kW in 4 or 2-pole execution and air or liquid cooling system.
Couplings arrangements cover IM B34, SAE and cone versions to fit all models of endothermic engines on the market.
Special and high-customization versions are developed according to the customer’s technical specifications by our R&D team.