Method and system for improving voltage regulator accuracy in vehicle alternators
View Patent ↗A method for implementing voltage regulation for an electrical generator device includes comparing an output voltage of the electrical generator device to a desired set point voltage thereof, and generating an output control signal configured to regulate a field current of the generating device. The output control signal is generated in accordance with a linear mode of operation during of one of an overvoltage condition and an undervoltage condition with respect to the desired set point voltage, and wherein the output control signal is automatically set to a predetermined value in a non-linear mode of operation during the other of the overvoltage condition and the undervoltage condition.
1. A method for implementing voltage regulation for an electrical generator device, the method comprising:
comparing an output voltage of the electrical generator device to a desired set point voltage thereof;
generating an output control signal configured to regulate a field current of the generating device, the output control signal comprising a pulse with modulation signal configured to control the duty cycle of a switching device selectively activating and deactivating the field current;
wherein the output control signal is generated in accordance with a linear mode of operation during an undervoltage condition with respect to the desired set point voltage, and wherein the output control signal is automatically set to a predetermined value in a non-linear mode of operation during an overvoltage condition;
linearly incrementing the value of a duty cycle step variable during the undervoltage condition, so long as the value of the duty cycle step variable is not already at a predetermined maximum value thereof;
linearly decrementing the value of a duty cycle step variable during the overvoltage condition, so long as the value of the duty cycle step variable is not already at a predetermined minimum value thereof;
setting the output control signal to correspond to the present value of the duty cycle step variable during the linear mode of operation; and
setting the output control signal to correspond to the predetermined minimum value of the duty cycle step variable during the non-linear mode of operation, regardless of the present value of the duty cycle step variable.
2. The method of claim 1 , further comprising setting the duty cycle of the switching device to a predetermined minimum value during the overvoltage condition.
3. A storage medium, comprising:
a computer readable computer program code for implementing voltage regulation for an electrical generator device; and
instructions for causing a computer to implement a method, the method further comprising:
comparing an output voltage of the electrical generator device to a desired set point voltage thereof;
generating an output control signal configured to regulate a field current of the generating device, the output control signal comprising a pulse with modulation signal configured to control the duty cycle of a switching device selectively activating and deactivating the field current;
wherein the output control signal is generated in accordance with a linear mode of operation during an undervoltage condition with respect to the desired set point voltage, and wherein the output control signal is automatically set to a predetermined value in a non-linear mode of operation during an overvoltage condition;
linearly incrementing the value of a duty cycle step variable during the undervoltage condition, so long as the value of the duty cycle step variable is not already at a predetermined maximum value thereof;
linearly decrementing the value of a duty cycle step variable during the overvoltage condition, so long as the value of the duty cycle step variable is not already at a predetermined minimum value thereof;
setting the output control signal to correspond to the present value of the duty cycle step variable during the linear mode of operation; and
setting the output control signal to correspond to the predetermined minimum value of the duty cycle step variable during the non-linear mode of operation, regardless of the present value of the duty cycle step variable.
4. The storage medium of claim 1 , wherein the method further comprises setting the duty cycle of the switching device to a predetermined minimum value during the overvoltage condition.
5. A voltage regulator for an electrical generator, comprising:
an electronic device configured to compare an output voltage of the generator to a desired set point voltage thereof;
the electronic device further configured to generate an output control signal for regulating a field current of the generator;
a switching device in communication with the output control signal, the output control signal comprising a pulse with modulation signal configured to control the duty cycle of the switching device so as activate and deactivate the field current of the generator;
wherein the output control signal is generated in accordance with a linear mode of operation during an undervoltage condition with respect to the desired set point voltage, and wherein the output control signal is automatically set to a predetermined value in a non-linear mode of operation during an overvoltage condition;
wherein the electronic device is configured to:
linearly increment the value of a duty cycle step variable during the undervoltage condition, so long as the value of the duty cycle step variable is not already at a predetermined maximum value thereof;
linearly decrement the value of a duty cycle step variable during the overvoltage condition, so long as the value of the duty cycle step variable is not already at a predetermined minimum value thereof;
set the output control signal to correspond to the present value of the duty cycle step variable during the linear mode of operation; and
set the output control signal to correspond to the predetermined minimum value of the duty cycle step variable during the nonlinear mode of operation, regardless of the present value of the duty cycle step variable.
6. The voltage regulator of claim 5 , wherein the electronic device further comprises a microcontroller.
7. The voltage regulator of claim 5 , wherein the electronic device is configured to set the duty cycle of the switching device to a predetermined minimum value during the overvoltage condition.
8. A vehicle charging system, comprising:
an alternator having one or more stator windings on a stationary portion thereof and a field coil on a rotatable portion thereof;
a voltage regulator configured to regulate an output voltage of the alternator through control of a field current through the field coil, the voltage regulator further comprising:
an electronic device configured to compare the output voltage of the alternator to a desired set point voltage thereof; and
the electronic device further configured to generate an output control signal for regulating the field current of the generator;
a switching device in communication with the output control signal, the output control signal comprising a pulse with modulation signal configured to control the duty cycle of the switching device so as activate and deactivate the field current of the generator;
wherein the output control signal is generated in accordance with a linear mode of operation during an undervoltage condition with respect to the desired set point voltage, and wherein the output control signal is automatically set to a predetermined value in a non-linear mode of operation during an overvoltage condition;
wherein the electronic device is configured to:
linearly increment the value of a duty cycle step variable during the undervoltage condition, so long as the value of the duty cycle step variable is not already at a predetermined maximum value thereof:
linearly decrement the value of a duty cycle step variable during the overvoltage condition, so long as the value of the duty cycle step variable is not already at a predetermined minimum value thereof;
set the output control signal to correspond to the present value of the duty cycle step variable during the linear mode of operation; and
set the output control signal to correspond to the predetermined minimum value of the duty cycle step variable during the non-linear mode of operation, regardless of the present value of the duty cycle step variable.
9. The vehicle charging system of claim 8 , wherein the electronic device further comprises a microcontroller.
10. The vehicle charging system of claim 8 , wherein the electronic device is configured to set the duty cycle of the switching device to a predetermined minimum value during the overvoltage condition.