Electricity: single generator systems – Automatic control of generator or driving means – Voltage of generator or circuit supplied
Reexamination Certificate
2000-05-17
2001-11-13
Ponomarenko, Nicholas (Department: 2834)
Electricity: single generator systems
Automatic control of generator or driving means
Voltage of generator or circuit supplied
C322S036000
Reexamination Certificate
active
06316919
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a control device of an alternator, and particularly to a control device of an alternator, which controls a generated voltage of the alternator by an ON/OFF duty ratio of applied voltage to an exciting coil, and which is suitably used for, for example, a vehicle.
2. Description of the Related Art
Conventionally, with respect to feedback control of a generated voltage of an alternator to a target voltage, Japanese Patent Application Laid-open No. Hei 05-176477 discloses a control device of an alternator in which an attempt to achieve such control is made by means of digital control using a microcomputer.
In this kind of conventional control device of an alternator, in the case where feedback control is carried out by making a generated voltage of the alternator follow a target voltage, after a target exciting current corresponding to a target generating current of the alternator is calculated through an equation based on the power generation characteristics of the alternator, an estimated exciting current which may actually flow is calculated through an equation based on the electromagnetic specification of the alternator.
Then, the target exciting current based on a deviation of the value of the target exciting current obtained by this calculation from the value of the estimated exciting current is subjected to first order lead correction based on the power generation characteristics of the alternator and the electromagnetic specification (for example, number of turns of an exciting winding constituting the alternator, etc.), and a control exciting current is calculated.
Next, an ON/OFF duty ratio to the control exciting current determined by the calculation is selected and is read out from a memory including a table previously set on the basis of the electromagnetic specification of the alternator. On the basis of the ON/OFF duty ratio read out from this memory, an applied voltage to an exciting coil is controlled.
In the conventional control apparatus of an alternator constructed as described above, in the case where the power generation characteristics or electromagnetic specification of the alternator is changed or in the case where the control device is applied to an alternator having different electromagnetic specification and power generation characteristics, in the control device, it is necessary to change the table of the ON/OFF duty ratio to control the exciting current and the coefficients of calculation equations of the exciting current for every electromagnetic specification and power generation characteristics of the alternator, and to again take matching. Thus, there has been a problem that the correcting work is troublesome and it takes a long time.
SUMMARY OF THE INVENTION
The present invention has been made to overcome the foregoing problem, and an object of the invention is to provide a control device of an alternator which can easily cope with the case where the power generation characteristics or electromagnetic specification of an alternator is changed or the case where the control device is applied to an alternator having different electromagnetic specification and power generation characteristics.
According to one aspect of the present invention, in a control device of an alternator for controlling a generated voltage of the alternator based on an ON/OFF duty ratio of applied voltage to an exciting coil of the alternator, the control device comprises arithmetic means for comparing a deviation with a predetermined value in response to the deviation of the generated voltage of the alternator from a target voltage, correction means for converging the generated voltage of the alternator to the target voltage in response to a comparison result of the arithmetic means, and search means for searching an ON/OFF duty ratio of applied voltage to the alternator in response to a convergence result of the correction means and based on a binary search method between a predetermined minimum duty ratio and a predetermined maximum duty ratio.
In one form of the invention, the search means resets a search depth and again carries out a search from the first when some voltage deviation from the target voltage occurs in the generated voltage of the alternator during the search of the ON/OFF duty ratio of the applied voltage.
In another form of the invention, the search means is provided with a predetermined search depth limit, and an end of the search of the ON/OFF duty ratio by the binary search method is judged with the ON/OFF duty ratio determined by the search depth limit.
In a further form of the invention, the correction means makes fine adjustments to the ON/OFF duty ratio of the applied voltage by a predetermined increment and decrement when the binary search method in the search means reaches the predetermined search depth limit.
In a still further form of the invention, the correction means provides a predetermined time limit to a decrease amount of the ON/OFF duty ratio decreasing at the predetermined decrement, and suppresses the decrease amount temporally.
In a yet further form of the invention, the control device comprises addition means for adding a predetermined increment to the ON/OFF duty ratio of the applied voltage in response to the comparison result of the arithmetic means.
In a still another form of the invention, the addition means includes suppression means for providing a predetermined time limit to an increase amount of the ON/OFF duty ratio of the applied voltage increasing at the predetermined increment and for suppressing the increase amount temporally.
In a still another form of the invention, the suppression means releases or lessens the time suppression of the increase amount within a range of a predetermined increase amount.
In a still another form of the invention, the suppression means changes the increase amount per time according to the drive revolution speed of the alternator.
In a still another form of the invention, a temperature detecting element is provided inside the control device, and battery temperature is estimated on the basis of the inside temperature of the control device detected by the temperature detecting element.
REFERENCES:
patent: 5182511 (1993-01-01), Pierret et al.
patent: 5231344 (1993-07-01), Marumoto et al.
patent: 5256959 (1993-10-01), Nagano et al.
patent: 5608309 (1997-03-01), Hikita et al.
patent: 5637985 (1997-06-01), Kakizaki et al.
patent: 5754030 (1998-05-01), Maehara et al.
patent: 5760486 (1998-06-01), Uchinami et al.
patent: 5923151 (1999-07-01), Satoh
patent: 5-176477 (1993-07-01), None
Komurasaki Keiichi
Okamoto Yasuaki
Sumimoto Katsuyuki
Mitsubishik Denki Kabushiki Kaisha
Ponomarenko Nicholas
Sughrue Mion Zinn Macpeak & Seas, PLLC
LandOfFree
Control device of alternator does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Control device of alternator, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Control device of alternator will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2581998