Conventional automotive generators have a low generating efficiency of 50 %. It is also difficult to install vehicles with larger high-power generators that are able to satisfy electrical demand. Although permanent-magnet generators have a high generating efficiency, the voltage rises as the rotor-speed increases. This development has succeeded in creating a permanent-magnet generator with a new mechanical controller that obtains a generating efficiency of 90 %, and is capable of maintaining a constant voltage. An air-gap controller between the rotor and the stator was adapted to control the magnetic force in order to adjust the voltage to changes in speed and load. In order to realize a high power generator, a high generating efficiency is the most important issue, which depends on an improvement in cooling capacity. As the permanent magnet of this generator is deprived of the magnetic force above 220 degrees, and the maximum energy product of the PM decreases on high temperature, the generator requires a low temperature. In order to remove the cooling fan, the heat balance of the generator was studied. The structure of this generator is a sealed type for protection against dust, salt, oxides, and water. The generator has a simple structure and is able to maintain a constant voltage when rotor speed increases. The effect of the magnetic force controlling regulator located between the rotor and the stator was confirmed, and a voltage descent without load of 60 % was obtained. It was confirmed that it was possible to maintain a constant voltage under changes in speed and demand current by rotating the regulator. Since it was possible to obtain a generating efficiency of 90 %, a sealed type generator without a fan was created by making alterations to the structure.
Permanent magnet generator with mechanical controller
Permanentmagnet-Generator mit mechanischem Regler
Review of Automotive Engineering (JSAE) ; 26 , 2 ; 143-146
2005
4 Seiten, 10 Bilder, 3 Quellen
Article (Journal)
English
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