초록 ▼

An alternator system having an alternating current (ac) voltage source includes a switched-mode rectifier (SMR) coupled to the ac voltage source and having an output port coupled to an output of the alternator system, and a controller coupled to said switched-mode rectifier so as to provide a contro

An alternator system having an alternating current (ac) voltage source includes a switched-mode rectifier (SMR) coupled to the ac voltage source and having an output port coupled to an output of the alternator system, and a controller coupled to said switched-mode rectifier so as to provide a controlled pulse sequence synchronized with an angular rotor position of the (ac) voltage source to activate and deactivate the switched-mode rectifier. The controller further includes a PWM generator having a first input to receive a total duty ratio signal synchronized with an angular rotor position of the (ac) voltage source. The switched mode rectifiers are controlled to increase power output levels at lower speeds near idle. The controller combines improved idle speed power output levels with load matching improvements from PWM control for more efficient operation when compared to circuits using conventional control or PWM load matching control alone.

대표청구항 ▼

1. An alternator system, having an alternating current (ac) voltage source having at least one rotor, said ac voltage source having an output voltage controllable by a field current thereof and an output, said alternator system comprising:a switched-mode rectifier (SMR) coupled to the ac voltage sou

1. An alternator system, having an alternating current (ac) voltage source having at least one rotor, said ac voltage source having an output voltage controllable by a field current thereof and an output, said alternator system comprising:a switched-mode rectifier (SMR) coupled to the ac voltage source and having an output port coupled to an output of the alternator system; and a controller coupled to said switched-mode rectifier so as to provide a controlled pulse sequence synchronized with an angular rotor position of the ac voltage source to activate and deactivate said switched-mode rectifier. 2. The system of claim 1 wherein the controller comprises a PWM generator having a first input adapted to receive a total duty ratio signal synchronized with an angular rotor position of the ac voltage source.3. An aternator system, having an alternating current voltage source having at least one rotor, said ac voltage source having an output voltage controllable by a field current thereof and an output, said alternator system comprising:a switched-mode rectifier (SMR) coupled to the ac voltage source and having an output port coupled to an out put of the alternator system; and a controller coupled to said switched-mode rectifier so as to provide a controlled pulse sequence synchronized with an angular rotor position of the ac voltage source to activate and deactivate said switched-mode rectifier wherein the controller comprises: a PWM generator having a first input adapted to receive a total duty ratio signal synchronized with an angular rotor position of the ac voltage source, a bounded summation circuit having a first input, a second input, and an output coupled to the first input of the PWM generator; a base duty ratio generator coupled to the first input of the bounded summation circuit; and a timing duty ratio generator coupled to the second input of the bounded summation circuit. 4. The system of claim 3 wherein the timing duty ratio generator comprises a first input coupled to an output of a timing reference circuit adapted to receive a timing reference event signal synchronized with the angular rotor position of the ac voltage source.5. The system of claim 4 wherein the timing reference event signal is provided by one of:a detection of a polarity change in a phase current of said voltage source; a given count from a position encoder coupled to a shaft of the rotor of said voltage source; and a polarity of the voltage across the switched-mode rectifier. 6. An alternator system having an alternating current (ac) voltage source having at least one rotor, said ac voltage source having an output voltage controllable by a field current thereof and an output, said alternator system comprising:a switched-mode rectifier (SMR) coupled to the ac voltage source and having an output port coupled to an output of the alternator system; and a controller coupled to said switched-mode rectifier so as to provide a controlled pulse sequence synchronized with an angular rotor position of the ac voltage source to activate and deactivate said switched-mode rectifier wherein the controlled pulse sequence comprises a plurality of intervals, the plurality of intervals repeating at a fundamental electrical frequency of said voltage source, each such interval having an adjustable duration and comprising a pulse width modulation (PWM) signal provided by a PWM generator having an input coupled to a summation of a base duty ratio signal having a duty cycle adjustable from zero to unity and a timing duty ratio signal synchronized with the angular rotor position of the ac voltage source. 7. The system of claim 1 wherein a timing reference pulse of the controlled pulse sequence is triggered by an adjustable delay initiated by an event related to a fundamental electrical frequency of said voltage source.8. An alternator system having an alternating current (ac) voltage source having at least one rotor, said ac voltage source having an output voltage controllably by a field current thereof and an output, said alternator system comprising:a switched-mode rectifier (SMR) coupled to the ac voltage source and having an output port coupled to an output of the alternator system; and a controller coupled to said switched-mode rectifier so as to provide a controlled pulse sequence synchronized with an angular rotor position of the ac voltage source to activate and deactivate said switched-mode rectifier wherein the controlled pulse sequence comprises a plurality of intervals, the plurality of intervals repeating at a fundamental electrical frequency of said voltage source, each such interval having an adjustable duration and comprising the logical combination of a pulse width modulation (PWM) signal having a duty cycle adjustable from zero to unity and a timing reference pulse signal having a predetermined pulse duration interval less than a fundamental electrical period of said voltage source. 9. The system of claim 8 wherein an initial one of the plurality of intervals is aligned with a timing reference event signal, the pulse signal duration of the initial interval has a zero duration, such that the initial interval provides a pulse delay interval having a predetermined duration, such that a first timing reference pulse signal of the plurality of intervals occurs after the pulse delay interval following the reference signal timing event signal.10. The system of claim 9 wherein the timing reference event signal is provided by one of:a detection of a polarity change in a phase current of said voltage source; a given count from a position encoder coupled to a shaft of the rotor of said voltage source; and a polarity of the voltage across the switched-mode rectifier. 11. An alternator system having an alternating current (ac) voltage source having at least one rotor, said ac voltage source having an output voltage controllably by a field current thereof and an an output, said alternator system comprising:a switched-mode rectifier (SMR) coupled to the ac voltage source and having an output port coupled to an output of the alternator system; and a controller coupled to said switched-mode rectifier so as to provide a controlled pulse sequence synchronized with an angular rot or position of the ac voltage source to activate and deactivate said switched-mode rectifier wherein said controller comprises a microprocessor. 12. The system of claim 11 wherein said microprocessor is a programmable microprocessor operable in response to stored program instructions; and said alternator system further comprises a lookup table which can be interrogated by said programmable microprocessor, to provide information in response to said event, for selectively generating said controlled pulse sequence.13. An alternator system having an alternating current (ac) voltage source having at least one rotor, said ac voltage source having an output voltage controllable by a field current thereof and an output, said alternator system comprising:a switched-mode rectifier (SMR) coupled to the ac voltage source and having an output port coupled to an output of the alternator system; and a controller coupled to said switched-mode rectifier so as to provide a controlled pulse sequence synchronized with an angular rotor position of the ac voltage source to activate and deactivate said switched-mode rectifier wherein said controller comprises: a pulse timing reference circuit; a timing reference pulse generator coupled to said pulse timing reference circuit; and a logic element having a first input coupled to an output of said timing reference pulse generator, and having an output coupled to said switched-mode rectifier. 14. The system of claim 13 wherein said controller further comprises a base duty ratio pulse width modulation (PWM) generator having an output coupled to a second input of said logic element.15. The system of claim 14 wherein the pulse sequence further comprises a plurality of adjustable time periods, wherein each of the plurality of adjustable time periods comprises the output of the base duty ratio PWM generator operating at a predetermined duty ratio for the respective period.16. The system of claim 14 wherein said base duty ratio PWM generator has an input coupled to a sensor which senses a parameter of a first one of said ac voltage source and an engine and in response thereto said sensor provides a signal representative of the parameter to said base duty ratio PWM generator.17. The system of claim 16 wherein in response to signal information provided thereto, said base duty ratio PWM generator provides a base duty ratio PWM signal to said logic element which causes the switched-mode rectifier to operate with a particular duty cycle selected to provide a controlled transformation of voltage and current between terminals of the ac voltage source and output terminals of the alternator system and to convert an ac voltage from the ac voltage source to a direct current (dc) voltage.18. The system of claim 16 wherein said sensor senses at least one of an ac voltage source speed, an ac voltage source fundamental electrical frequency, and an ac voltage source back emf.19. The system of claim 18 wherein said sensor comprises:a sense winding electromagnetically coupled to the alternating current ac voltage source; and a back emf detection circuit. 20. The system of claim 16 wherein said sensor is coupled to an engine and said sensor senses at least one of an engine speed, and an engine frequency.21. The system of claim 1 further comprising a field controller comprising:an input port coupled to an output of the controller; and an output port coupled to an input port of a field current regulator to provide the field current to said ac voltage source. 22. The system of claim 16 wherein in response to the sensor sensing an output voltage having a value which is less than a reference value, the controller provides a first output signal to increase the field current to said ac voltage source.23. The system of claim 21 wherein said controller senses an output voltage level at the output of said alternator system, and compares the sensed output voltage level to a reference value and provides control signals to said field controller in response to the comparison.24. The system of claim 23 wherein in response to the sensed output voltage being less than the reference value the controller provides a first output signal to increase the field current to said ac voltage source.25. The system of claim 1 further comprising a fault protection controller having an input port coupled to an output of the alternator system and having an output port coupled to an input of said controller.26. The system of claim 1 further comprising a thermal sensor disposed on the ac voltage source and having an output port coupled to a thermal sensor input port of said controller.27. A method for controlling an alternator having an alternating current (ac) voltage source, an output voltage controllable by a field current thereof and having a rectifying circuit including a switched mode rectifier, the method comprising:sensing an event synchronized with an angular rotor position of the ac voltage source; generating a controlled pulse sequence in response to sensing the event; and providing said controlled pulse sequence to control the switched mode rectifier. 28. A method for controlling an alternator having an alternating current (ac) voltage source, an output voltage controllable by a field current thereof and having a rectifying circuit including a switched mode rectifier, the method comprising:sensing an event synchronized with an angular rotor position of the ac voltage source; generating a controlled pulse sequence in response to sensing the event; and providing said controlled pulse sequence to control the switched mode rectifier wherein generating a controlled pulse sequence comprises: providing a base duty ratio signal; providing a timing duty ratio signal; summing the base duty ratio signal and timing duty ratio signal to provide a total duty ratio signal; and generating a PWM signal having the total duty ratio. 29. The method of claim 28 wherein said event is a timing mark derived from at least one of engine speed, engine frequency, an alternating current (ac) voltage source speed, an ac voltage source frequency and an ac voltage source back emf.30. The system of claim 1 wherein:said AC voltage source comprises a plurality of phase winding outputs; and said SMR comprises: a plurality of SMR connections each of said SMR connections coupled to at least one of said plurality of phase winding outputs; a rectifier having a positive terminal and a negative terminal, coupled to said ac voltage source; a controller so as to provide a controlled pulse sequence: a first switch having a first terminal coupled to a neutral leg, a second terminal coupled to a first reference potential and wherein said first switch is coupled to said controller, such that the controller activates and deactivates said first switch. 31. The system of claim 30 wherein the first switch is provided as field effect transistor.32. The system of claim 30 wherein the first reference potential comprises at least one of:a ground reference potential; the negative output terminal; and the positive output terminal. 33. The system of claim 30 further comprising a second switch coupled to the neutral leg and having an output port coupled to a second reference potential such second reference potential being different from the first reference potential and wherein said second switch is coupled to said controller, such that the controller activates and deactivates said first and second switches.34. The system of claim 33 wherein the first and second reference potentials comprise at least one of:the negative output terminal; and the positive output terminal. 35. The system of claim 33 wherein the first switch comprises a metal oxide semiconductor field effect transistor (MOSFET) and the second switch comprises a MOSFET.36. The system of claim 30 wherein the first switch comprises a diode.37. The system of claim 33 wherein the second switch comprises a diode.38. The system of claim 1 further comprising a sensor coupled to sense at least one parameter of at least one of said AC voltage source; and said engine and wherein in response to sensing a parameter, said sensor provides a sensor signal at an output thereof; andwherein said SMR comprises: a plurality of connections for receiving at least one phase winding output; a rectifier having an output voltage port, at least one first diode and at least one second diode, a cathode of the at least one first diode coupled to an anode of a respective at least one second diode; a circuit coupled to the output voltage port, said circuit comprising: at least one reactive device having a first port and a second port coupled to an anode of the respective at least one second diode; at least one switch having a control terminal, a first terminal coupled to the first port of a respective at least one reactive device and a second terminal coupled to a reference potential; and wherein said controller is provided having an input terminal coupled to the output of the sensor, and wherein the controller is adapted to control said at least one switch such that a respective at least one reactive element can be selectively coupled between each of a respective phase winding output and the reference potential when said ac voltage source reaches a predetermined rotational speed, such that conduction times for the plurality of first and second diodes are modified resulting in increased output power. 39. The system of claim 38 wherein said reactive device comprises a capacitor.40. The system of claim 38 wherein said sensor senses at least one of:an ac voltage source speed; an ac voltage source fundamental electrical frequency; an ac voltage source back emf; and a rectifier output voltage. 41. The system of claim 38 wherein the reference potential comprises at least one of:the negative output terminal; and the positive output terminal.