Lundell generator (alternator). Increasing comfort and safety in cars, trucks, and buses driven by combustion engines require more installed. PDF | Due to the increasing power demands in automotive applications, the conventional power generator (Lundell alternator) is rapidly reaching its limits. Abstract—Thermal analysis of Lundell alternators used in automobiles is presented. An analytical thermal model for Lun- dell alternators is proposed, and .
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The casing has distinctive radial vent slots at each end and now encloses the fan. Conversely, a nonlinear field model could be used. Rewound alternator with BSMR. These include the use of reconfigurable windings and replacement of the diode rectifier by different electronic converters such as a synchronous rectifier or an interleaved PWM rectifier will be considered. The content is copyrighted to EEP and may not be reproduced on other websites.
Lundelll average efficiency has been improved by Alternator parameters Delcotron 22si type 12va. The first Model Ts used the magneto solely for the trembler coil ignition. Click the button below to return to the English version of the page.
Simulation limitations The use of a PWM controlled rectifier altrrnator. When the same stator is rewound with m three-phase windings and N conductors per slot, the new electrical parameters can be expressed as:. For the eight-diode rectifier, the phase voltage third harmonic in the phase current occurs.
Usually six diodes in a full-bridge configuration are used to rectify the output current. This is partly due to the magnetic saturation and significant voltage drops across active switches. Hence the simplest control mode consists in driving all the switches of the first converter with the same gate signal and all the switches of the second converter with the same complementary signal.
Field winding inductance, Lf — Inductance scalar. It also shows the output current curves obtained with original and rewound alternators connected to a conventional diode rectifier. To reduce magnetic losses in the rotor, it is possible to use a laminated material but the assembly process is more complex Bretta, Field voltage max, Vfmax — Maximum field voltage scalar.
Alternator efficiency Generally, Lundell alternators are characterized by low efficiency due to important mechanical, copper, and magnetic losses. Rewound alternator with BSBR. Alternator modeling for performance analysis In order to evaluate the performance of the alternator under variable load conditions, both the machine and rectifier systems shall be modeled with appropriate magnetic and electrical models.
Power Electronic Solutions to Improve the Performance of Lundell Automotive Alternators
The approximate cost estimation for each solution can be derived from the number and ratings of the semiconductors and from the output filter size. Alternagor comparison To compare the power improvement provided by the different rectifier topologies, the average power output P avg.
Mechanical losses Mechanical losses are generated by brush and bearing friction and losses created by the claw pole rotor and fan windage losses. This page has been translated by MathWorks. A synchronous rectifier is an interesting alternative to conventional diode rectifiers. The coil is mounted altefnator inside this and field current is supplied by slip rings and carbon brushes.
Built by scientists, for scientists. Active switch rms current IQ.
Despite their names, both ‘DC generators’ or lundel and ‘alternators’ initially produce alternating current. Until in the early s, automobiles used a DC generator called dynamo. The alternator parameters are given in Table 2. Retrieved from ” https: This can be achieved by a winding reconfiguration to modify the number of turns per phase. The back-electromotive force EMF voltage is proportional to the input velocity and field current. With two oversized shaft bearings as the only wearing parts, these can provide extremely long lunrell reliable service, even exceeding the engine overhaul intervals.
The MEC approach, however, requires at least two orders of magnitudes times less computer time. Semiconductor parts count and normalized current ratings for each topology. Typical passenger vehicle and light truck alternators use Lundell or ‘claw-pole’ field construction. Modern designs do away with the voltage regulator altogether; voltage regulation is now a function of the engine control unit ECU.
In the case of interleaved structures, semiconductor parts are multiplied by two. Premium Membership Get access to premium electrical guides, technical articles and much more!
Reduced Lundell (claw-pole) alternator with an external voltage regulator – Simulink
Double-winding alternator with interleaved BSBR. The number of turns in the stator winding has a significant effect on the output performances of an alternator connected to a Conventional Diode Rectifier CDR and a battery. Conclusion The low efficiency and the limitation of the output power are major drawbacks of the Lundell alternator. The efficiency of the alternator varies widely depending on load conditions, alternator speed and alternator size.
Select the China site in Chinese or English for best site performance. One solution is to divide each phase winding in several coil groups and to modify the winding configuration by using several switches.
Another way is to rewind the alternator with a lower number of turns and to replace the conventional diode rectifier by an active PWM rectifier. At nominal excitation current and at lower speeds, the output current is low and the stator is fully saturated due to the weak magnetic reaction. Many alternatives are being considered to replace the Lundell alternator such as the salient pole machines, however they require large investments in manufacturing infrastructure.
The main advantage of such converters is the reduced rectifier losses particularly at higher speeds if MOSFETs with low on-resistance e. Coulomb friction, Kc — Friction scalar. Alternator output voltage command, in V.