Generator load response control

• US 4,459,489 A
• Filed: 09/30/1982
• Issued: 07/10/1984
• Est. Priority Date: 09/30/1982
• Status: Expired due to Term

• Current Assignee: Delphi Technologies, Inc. (BorgWarner Incorporated)
• Original Assignee: General Motors Corporation (General Motors Company)
• Inventors: Kirk, Thomas E., Sheldrake, Leonard J., Munden, Curtis D.
• Primary Examiner(s): Truhe, J. V.
• Assistant Examiner(s): Flower, Terry
• Application Number:
  US06/429,269
• Time in Patent Office: 649 Days
• Field of Search: 290/7, 290/11, 290/12, 290/13, 290/51, 361/18, 361/21, 361/88, 361/165, 322/28, 322/36, 322/8, 320/64, 323/22, 317/36, 317/13 B, 219/202
• US Class Current: 290/13
• CPC Class Codes: H02J 7/24 using discharge tubes or semiconductor devices
• CPC Class Codes: H02P 2101/45 for motor vehicles, e.g. car alternators
• CPC Class Codes: H02P 9/102 for limiting effects of transients
• CPC Class Codes: H02P 9/305 controlling voltage H02P9/302 takes precedence

Abstract

A voltage regulating system for a generator that supplies the battery and electrical loads on a motor vehicle. The system includes a load response control for detecting whenever a substantial electrical load is applied to the generator tending to cause a drop in generator output voltage and when such a condition is detected field current is controlled to gradually increase field current from some value. The load response control includes means for storing an electrical signal that corresponds to generator field current and for utilizing this stored value to set generator field current at a value corresponding to a field current that occurred just prior to the detected drop in voltage and then increasing field current slowly from this value. The system includes means for preventing a subsequent drop in detected load voltage from actuating the load response control for the time duration that field current is being slowly increased by the load response control once it has been triggered by an initial drop in voltage.

Claims

1. A voltage regulating system for an electrical generator having a field winding that is operative to control field current to maintain a regulated generator output voltage and to control the rate of increase of field current when an electrical load of at least a predetermined magnitude is applied to the generator comprising, field current control means connected to said field winding for varying field current, voltage responsive means connected to sense generator output voltage and to said field current control means for varying field current as a function of the output voltage of the generator to thereby maintain the generator output voltage at a desired regulated value, means for developing and storing a control signal the magnitude of which is a function of the current being supplied to the field winding during control by said voltage responsive means, and means responsive to a decrease in output voltage of said generator of at least a predetermined magnitude for varying field current in such a manner as to gradually increase field current and thereby increase generator output voltage toward said regulated value, said last-named means including means operative to initially set field current to a value substantially corresponding to a magnitude represented by said stored control signal and gradually increasing field current from that value.

2. A voltage regulating system for a generator having an output winding and a field winding comprising, voltage responsive means connected to said output winding and coupled to field current control means for controlling field current to maintain a desired regulated generator output voltage, storage means coupled to said field current control means for developing and storing an electrical signal the magnitude of which is indicative of the magnitude of field current supplied to said field winding, voltage detector means coupled to said output winding of said generator for detecting a drop in generator output voltage, and load response control means responsive to detection of said drop in voltage for setting field current to a value corresponding to said stored electrical signal and gradually increasing field current from that value for a predetermined time period, said load response control means including means for decrementing the stored electrical signal at a predetermined rate, the field current gradually increasing as said stored electrical signal is decrementing and said system returning to control by said voltage responsive means when said electrical signal has been completely decremented.

3. A voltage regulating system for a generator having an output winding and a field winding comprising, means for detecting the magnitude of the output voltage of said generator, field current control means coupled to said last-named means for controlling field current as a function of the output voltage of the generator to thereby maintain a desired regulated voltage, said field current control means comprising switching means connected in series with said field winding, a capacitor, means coupled to said switching means for charging the capacitor to a voltage which is a function of the average current supplied to said field winding, voltage detecting means coupled to the output winding of said generator for detecting a drop in generator output voltage indicative of the application of an electrical load to the generator, and means responsive to the detection of said drop in voltage operative to permit said capacitor to discharge at a predetermined rate and for setting field current to a value that is a function of the voltage attained by the capacitor when the drop in voltage occurred, said last-named means gradually increasing field current in response to discharge of said capacitor.

4. A voltage regulating system for a generator having an output winding and a field winding comprising, voltage responsive means coupled to output winding of the generator and to field current control means for varying field current as a function of generator output voltage to thereby maintain the output voltage at a desired regulated value, means connected to said generator for detecting a drop in generator output voltage indicative of the application of an electrical load to the generator, control means responsive to the detection of said drop in voltage for setting field current to a predetermined value and then gradually increasing field current from that value for a time period, and means for preventing operation of said control means by a subsequent drop in generator voltage while field current is being slowly increased for said time period.

5. A voltage regulating system for a generator having an output winding and a field winding comprising, voltage responsive means coupled to the output winding of said generator and to field current control means for varying field current as a function of generator output voltage to thereby maintain the output voltage at a desired regulated value, voltage detector means for detecting a drop in generator output voltage indicative of the application of an electrical load to the generator, means responsive to the detection of said drop in voltage for setting field current to a predetermined value and then gradually increasing field current from that value for a time period, and means for disabling said voltage detector means when field current is being slowly increased for said time period.

6. An electrical system for controlling the output voltage of a generator having an output winding and a field winding comprising, voltage regulating means including transistor switching means connected to said field winding for controlling average field current, said transistor switching means being coupled to means responsive to the output voltage of the generator so as to control the transistor switching means in accordance with the voltage sensed, voltage drop detecting means coupled to the output winding of the generator for detecting a drop in generator output voltage, and pulse width modulator control means operative to control average field current as a function of pulse width when said voltage drop detecting means detects a drop in voltage of a predetermined magnitude, said pulse width modulator control means including means for setting pulse width initially to a value that provides a predetermined average field current and is then operative to gradually increase pulse width to thereby gradually increase average generator field current.

7. A voltage regulating system for a diode-rectified alternating current generator which supplies the electrical loads on a motor vehicle comprising, an alternating current generator having an output winding and a field winding, rectifier means connected to said output winding and to power supply conductors for feeding the electrical loads on the motor vehicle including the vehicle battery, a voltage regulator sensing the voltage across said power supply conductors and including transistor switching means connected in series with said field winding for controlling field current so as to maintain a substantially constant desired regulated voltage across the power supply conductors, voltage detector means connected across said power supply conductors for detecting a drop in voltage, a pulse width modulating control means, means responsive to the detection of said drop in voltage for setting said pulse width modulating control means into operation, means coupling said pulse width modulating control means to said transistor switching means such that said transistor switching means is switched in accordance with a pulse width produced by said pulse width modulating means, and means for causing the pulse width of said pulse width control means to gradually increase for a predetermined time period once it is set into operation to thereby gradually increase average generator field current.

8. A motor vehicle electrical system comprising, a generator driven by the engine of the vehicle having an output winding and a field winding, power supply conductors connected with said generator for feeding the electrical loads on the motor vehicle including the vehicle battery, voltage regulating means sensing the output voltage across said power supply conductors and coupled to said field winding for controlling field current so as to maintain a voltage of a desired regulated value across said power supply conductors, means for detecting a drop in voltage across said power supply conductors indicative of the application of an electrical load to said power supply conductors, and means responsive to the detection of said voltage drop for setting field current to a predetermined value and then slowly increasing field current from that value whereby a sharply increasing torque load is not applied to the engine.

9. An electrical system for controlling the output voltage of a generator having an output winding and a field winding comprising, a field circuit for energizing said field winding from said generator output winding comprising a semiconductor switching means connected in series with said field winding, voltage responsive means coupled to said output winding and to said semiconductor switching means for causing said semiconductor means to switch on and off in accordance with generator output voltage to thereby control average field current, a capacitor, a first switching means operative to connect said capacitor across said semiconductor switching means such that the capacitor can charge during time periods when the semiconductor switching means is nonconductive whereby the capacitor attains a charge that is a function of average field current, a second switching means, load response control means connected to said semiconductor switching means for at times controlling the duration of the time period that the semiconductor switching means is biased conductive as a function of capacitor voltage, said time period during inversely related to capacitor voltage, a resistor, and means responsive to a drop in generator output voltage of a predetermined magnitude for opening said first switching means and for actuating said second switching means to connect said capacitor to said load response control means and to said resistor to discharge the capacitor through the resistor.

10. An electrical system for controlling the output voltage of a generator having an output winding and a field winding comprising, a field circuit for energizing said field winding from said generator output winding comprising semiconductor switching means connected in series with said field winding, voltage responsive means coupled to said output winding and to said semiconductor switching means for causing said semiconductor switching means to switch on and off in accordance with generator output voltage to thereby control average field current, first and second capacitors, means connecting said first capacitor across said semiconductor switching means such that said first capacitor can charge during time periods when the semiconductor switching means is nonconductive whereby said first capacitor attains a charge that is a function of average field current, load response control means connected to said semiconductor switching means for at times controlling the duration of the time period that the semiconductor switching means is biased conductive as a function of the voltage on said second capacitor, said time period being inversely related to the voltage of said second capacitor, a resistor, means connecting said resistor across said second capacitor, and means responsive to a drop in generator output voltage of a predetermined magnitude for discharging said first capacitor into said second capacitor whereby said load response control means is controlled by the voltage on said second capacitor and said second capacitor discharges through said resistor.

11. An electrical system for controlling the output voltage of a generator having an output winding and a field winding comprising, voltage regulating means having output transistor switching means connected in series with said field winding and having driver transistor switching means coupled to respond to the output voltage of said generator, a switching device so connected between said driver transistor switching means and said output transistor switching means that said output transistor switching means is controlled by said driver transistor switching means when said switching device is conductive and said output transistor switching means is biased non-conductive whenever said switching device is non-conductive, pulse width modulating control means coupled to said switching device for at times controlling the operation of said switching device, means responsive to a drop in output voltage of said generator of a predetermined magnitude for causing said pulse width modulating control means to switch said switching device on and off, said last-named means operative when said voltage drop occurs to control the switching of said switching device such that said output transistor switching means is switched in a manner to gradually increase average field current from a predetermined value.

12. An electrical system for controlling the output voltage of a generator having an output winding and a field winding comprising, voltage regulating means coupled to said output winding and field winding for controlling field current as a function of generator output voltage, said regulating means including switching means connected in series with said field winding that is actuated conductive when generator output voltage is below a desired regulated value and nonconductive when generator output voltage is above the desired regulated value, means coupled to said voltage regulating means for developing and storing an electrical control signal the magnitude of which is a function of average field current, said last-named means including means to increment said control signal when said switching means is in one state and decrement said control signal when said switching means is in an opposite state, and means responsive to a drop in generator voltage to a value below said desired regulated value for setting field current to a value corresponding to said stored control signal and then gradually increasing field current from that value to thereby raise the generator output voltage toward said desired regulated value.

13. A motor vehicle electrical system for supplying electrical loads on the vehicle wherein the vehicle engine drives a generator having a field winding an an output winding and wherein the system is arranged to prevent a sharply increasing torque load from being applied to the engine by the generator when an electrical load is applied to the output winding of the generator comprising, voltage regulating means coupled to said output winding and to said field winding for controlling field current as a function of generator output voltage to thereby maintain the output voltage at a desired regulated value, and load control means coupled to said field winding and responsive to a decrease in generator output voltage indicative of the application of an electrical load of at least a predetermined magnitude to the generator output winding for gradually increasing field current from substantially a value that existed when said drop in voltage occurred whereby generator output voltage is increased toward said desired regulated value and the torque load applied to the engine by the generator is gradually increased.