Electricity: single generator systems – Generator control – With excitation winding and/or circuit control
Patent
1999-03-19
2000-11-14
Ponomarenko, Nick
Electricity: single generator systems
Generator control
With excitation winding and/or circuit control
322 28, H02P 910
Patent
active
061474746
DESCRIPTION:
BRIEF SUMMARY
The invention is based on a controller with phase voltage evaluation for a three-phase generator having a plurality of phase windings and one exciter winding, as generically defined by the preamble to the main claim.
PRIOR ART
In motor vehicles, to generate electrical energy, three-phase generators are typically used, whose output voltage can be regulated with the aid of a voltage controller by suitably varying the exciting current to constant values. In conventional three-phase generators, the exciting current is furnished via the exciter diodes. In three-phase generators in which the generator controller, to save on the exciter diodes, is operated directly at the battery supply terminal B+, a detection circuit is needed, which is capable of distinguishing between a generator that is rotating and one that is stopped. This distinction is necessary, because when generator rotation is detected, the controller must switchover from a preexcitation state to the actual control state. To detect whether the generator is rotating or is stopped, the voltage appearing at a phase terminal of the generator, for instance, can be evaluated. This voltage comprises a direct voltage component, which is determined substantially for instance by residual currents of the rectifier diodes and the load resistance through the phase voltage circuit, and an alternating voltage component superimposed on it, whose amplitude depends on the excitation and rpm of the generator, and whose frequency correlates directly with the rotational frequency of the generator.
To achieve reliable evaluation of generator rotation at the onset of generator rotation, it is necessary to evaluate a signal with low AC amplitude at an unknown DC potential.
Until now, methods were employed in which a compensation of the residual currents and thus of the DC component were accomplished by means of a current sink. This method does not attain the requisite operational reliability, however, because on account of aging and soiling, no practicable limit value for this current sink exists.
A current arrangement for measuring the rpm of an externally excited three-phase generator, or for detecting whether the generator is rotating or stopped, is described for instance in German Patent Disclosure DE-OS 43 27 485. In this known current arrangement, the phase voltage picked up at a phase winding, which has an rpm-dependent alternating voltage component, is evaluated for rpm determination. To improve the resolution or to increase the reliability of detection of the onset of generator rotation, a different phase winding is connected to ground via a resistor. This creates a voltage divider, at which the concatenated voltage between the two phase windings is located. This concatenated phase voltage is higher than a phase voltage alone, and therefore makes more-reliable detection of generator rotation possible. The onset of rotation is detected when the concatenated phase voltage exceeds a predeterminable threshold value.
From European Patent Disclosure EP 0 408 436, a voltage controller is known that includes a circuit which evaluates two different phase voltages of the three-phase generator. From the difference between the two phase voltages, the rpm of the three-phase generator is ascertained. The onset of generator rotation can be detected relatively fast; however, the known voltage controller has the disadvantage that two phase terminals are required.
ADVANTAGES OF THE INVENTION
The controller of the invention with phase voltage evaluation for a three-phase generator as defined by the characteristics of claim 1 has the advantage over the known versions that an especially reliable and malfunction-proof evaluation of the phase voltage and taking into account of the ascertained phase voltage in generator control is possible, which is advantageously not impeded by the direct voltage level that may be present. An especially advantageous aspect is that only one phase voltage is evaluated, and thus a second phase terminal can be omitted.
These advantages are attained in
REFERENCES:
patent: 5182511 (1993-01-01), Pierret et al.
patent: 5602470 (1997-02-01), Kohl et al.
patent: 5629606 (1997-05-01), Asada
patent: 5731689 (1998-03-01), Sato
patent: 5748463 (1998-05-01), Tsutsui et al.
patent: 5754031 (1998-05-01), Kanazawa et al.
patent: 5808451 (1998-09-01), Rndou et al.
patent: 5900722 (1999-05-01), Scott et al.
patent: 5929610 (1999-07-01), Freedlander et al.
Koss Thomas
Nasswetter Guenter
Ponomarenko Nick
Robert & Bosch GmbH
Striker Michael
LandOfFree
Controller with phase voltage evaluation for a three phase gener does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Controller with phase voltage evaluation for a three phase gener, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Controller with phase voltage evaluation for a three phase gener will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2068288