Method and apparatus for controlling power generation in internal combustion engines

• US 5,020,491 A
• Filed: 08/08/1989
• Issued: 06/04/1991
• Est. Priority Date: 08/12/1988
• Status: Expired due to Term

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Mashino, Keiichi
• Primary Examiner(s): Kamen, Noah P.
• Application Number:
  US07/390,760
• Time in Patent Office: 665 Days
• Field of Search: 123/2, 123/179 A, 123/179 M, 123/192 R, 123/192 B, 290/34, 290/51, 290/40 A, 290/4 R
• US Class Current: 123/192.1
• CPC Class Codes: F02B 75/06 Engines with means for equalising torque
• CPC Class Codes: H02P 29/0016 Control of angular speed of one shaft without controlling the prime mover

Abstract

A method and apparatus for controlling variations of the torque developed by the crankshaft of an internal combustion engine. An ac polyphase rotating electric machine is directly connected to the crankshaft so that the ac polyphase rotating electrical machine is used as a generator when the torque of the crankshaft is increased and used as a motor when the torque is decreased. Thus, rectifiers are provided by inverters and their power supply includes a high voltage power supply capable of generating a voltage higher than a battery voltage.

Claims

1. A power generation control apparatus for an internal combustion engine comprising:

an ac generator including a plurality of armature windings and driven by said engine;

power storage means for storing power supplied from said ac generator;

a selector circuit for detecting an electromotive force difference generated by said plurality of armature windings to select one of said windings to be energized;

a plurality of rectifiers for respectively rectifying outputs of said plurality of armature windings;

a plurality of switch elements connected in parallel with said plurality of rectifiers to apply the power stored in said power storage means to said selected armature winding in response to a signal from said selector circuit;

a position sensor for detecting a rotational angle of said engine; and

a control unit responsive to a rotational speed signal generated by differentiating an engine rotational speed signal generated by said position sensor to control in such a manner that a generated output from said armature windings is supplied to said power storage means through said plurality of rectifiers to apply a rotational load to said engine when said rotational speed is greater than a time average value thereof and the power from said power storage means is selectively supplied to said armature windings through said plurality of switch elements to supply a torque to said engine when said rotational speed is smaller than said time average value.

2. An apparatus according to claim 1, wherein said control unit has a learning function of computing a rotational speed variation obtained as a difference between an actual rotational speed in terms of degrees of crankshaft rotation of said engine and an average rotational speed obtained by averaging said rotational speed during one rotation of said engine, and controlling in accordance with rotational speed variation information over at least one previous rotation of said engine to switch said ac generator to operate as a generator or a motor.

3. An apparatus according to claim 1, wherein said power storing means includes a plurality of capacitors, and a booster circuit adapted to be connected in parallel on charge and connected in series on discharge.

4. An apparatus according to claim 2, wherein said power storing means includes a plurality of capacitors, and a booster circuit adapted to be connected in parallel on charge and connected in series on discharge.

5. A power generation control apparatus for an internal combustion engine comprising:

an ac generator including a plurality of armature windings and driven by said engine;

power storage means for storing power supplied from said ac generator;

a selector circuit for detecting an electromotive force difference generated by said plurality of armature windings to select one of said windings to be energized;

a plurality of rectifiers for respectively rectifying outputs of said plurality of armature windings;

a plurality of switch elements connected in parallel with said plurality of rectifiers to apply the power stored in said power storage means to said selected armature winding in response to a signal from said selector circuit;

rotational speed detecting means for detecting a rotational speed of said engine and outputting a rotational speed signal; and

a control unit responsive to said rotational speed signal outputted from said rotational speed detecting means to control in such a manner that a generated output from said armature windings is supplied to said power storage means through said plurality of rectifiers to apply a rotational load to said engine when said rotational speed is greater than a predetermined value thereof and the power from said power storage means is selectively supplied to said armature windings through said plurality of switch elements to supply a torque to said engine when said rotational speed is smaller than said predetermined value.

6. An apparatus according to claim 5, wherein said control unit has a learning function of computing a rotational speed variation obtained as a difference between an actual rotational speed in terms of degrees of crankshaft rotation of said engine and an average rotational speed obtained by averaging said rotational speed during one rotation of said engine, and controlling in accordance with rotational speed variation information over at least one previous rotation of said engine to switch said ac generator to operate as a generator or a motor.

7. An apparatus according to claim 6, wherein said power storing means includes a plurality of capacitors, and a booster circuit adapted to be connected in parallel on charge and connected in series on discharge.

8. An apparatus according to claim 5, wherein said power storing means includes a plurality of capacitors, and a booster circuit adapted to be connected in parallel on charge and connected in series on discharge.

9. The apparatus according to claim 5, further comprising:

an idling detecting means for detecting an idling operation of said engine;

wherein said apparatus is operated only when said idling detecting means detects that said engine is idling.