SIMPLIFIED MAXIMUM POWER POINT CONTROL UTILIZING THE PV ARRAY VOLTAGE AT THE MAXIMUM POWER POINT

• US 20090189574A1
• Filed: 01/23/2009
• Published: 07/30/2009
• Est. Priority Date: 01/23/2008
• Status: Abandoned Application

• Current Assignee: Alpha Technologies Incorporated (EnerSys)
• Original Assignee: Alpha Technologies Incorporated (EnerSys)
• Inventors: LE, THANH, YAN, SIMON TSZ SUI, SHI, WEN
• Application Number:
  US12/358,496
• Publication Number:
  US 20090189574A1
• Time in Patent Office: Days
• US Class Current: 323/234
• CPC Class Codes: G05F 1/67 to the maximum power available from a generator, e.g. from solar cell
• CPC Class Codes: Y02E 10/56 Power conversion systems, e.g. maximum power point trackers

Abstract

A converter system adapted to be connected between a photovoltaic power source and a load comprises a converter circuit, a control circuit, and a PWM generator circuit. The converter circuit is operatively connected to transfer energy from the photovoltaic power source to the load. The control circuit generates a raw control signal based on at least a voltage generated by the photovoltaic power source. The PWM generator circuit is operatively connected to the converter circuit and generates a PWM switch signal based on the raw control signal. The converter circuit transfers energy from the photovoltaic power source to the load based on the PWM switch signal.

Claims

1. A converter system adapted to be connected between a photovoltaic power source and a load, comprising:

a converter circuit operatively connected to transfer energy from the photovoltaic power source to the load;

a control circuit that generates a raw control signal based on at least a voltage generated by the photovoltaic power source; and

a PWM generator circuit operatively connected to the converter circuit, where the PWM generator circuit generates a PWM switch signal based on the raw control signal;

whereby

the converter circuit transfers energy from the photovoltaic power source to the load based on the PWM switch signal.

2. A converter system as recited in claim 1, in which:

the control circuit is operatively connected to the PWM generator circuit;

the raw control signal is a PWM control signal; and

the PWM generator circuit generates the PWM switch signal based on the PWM control signal.

3. A converter system as recited in claim 1, further comprising:

an error amplifier; and

a reference generator circuit operatively connected to the error amplifier, where the reference generator generates a reference voltage signal;

whereby

the error amplifier generates a PWM control signal based on the raw control signal generated by the control circuit and the reference voltage signal generated by the reference generator; and

the PWM generator circuit generates the PWM switch signal based on the PWM control signal.

4. A converter system as recited in claim 3, in which the reference generator circuit comprises:

an output voltage sense circuit that generates an output voltage signal based on an output of the converter circuit; and

a processor operatively connected to the output voltage sense circuit, where the processor generates the reference voltage signal based on the output voltage signal.

5. A converter system as recited in claim 3, in which the reference generator circuit comprises:

an output current sense circuit that generates an output current signal based on an output of the converter circuit; and

a processor operatively connected to the output voltage sense circuit, where the processor generates the reference voltage signal based on the output current signal.

6. A converter system as recited in claim 3, in which the reference generator circuit comprises:

an output voltage sense circuit that generates an output voltage signal based on an output of the converter circuit;

an output current sense circuit that generates an output current signal based on the output of the converter circuit; and

a processor operatively connected to the output voltage sense circuit, where the processor generates the reference voltage signal based on at least one of the output voltage signal and the output current signal.

7. A converter system as recited in claim 3, in which the reference generator circuit comprises:

an input voltage sense circuit that generates an input voltage signal based on an output of the photovoltaic power source; and

a processor operatively connected to the output voltage sense circuit, where the processor generates the reference voltage signal based on the input voltage signal.

8. A converter system as recited in claim 3, in which the reference generator circuit comprises:

an input voltage sense circuit that generates an input voltage signal based on an output of the photovoltaic power source;

an output voltage sense circuit that generates an output voltage signal based on an output of the converter circuit;

an output current sense circuit that generates an output current signal based on the output of the converter circuit; and

a processor operatively connected to the output voltage sense circuit, where the processor generates the reference voltage signal based on at least one of the input voltage signal, the output voltage signal, and the output current signal.

9. A converter system as recited in claim 1, further comprising:

an input EMC filter and an input power filter operatively connected between the photovoltaic power source and the converter circuit; and

an output EMC filter and an output power filter operatively connected between the converter circuit and the load.

10. A converter system as recited in claim 1, further comprising a system controller for generating a communications signal based on at least one of an input to or an output of the converter circuit.

11. A converter system as recited in claim 8, in which the processor further generates a communications signal based on at least one the input voltage signal, the output voltage signal, and the output current signal.

19. A converter system as recited in claim 1, further comprising:

an input EMC filter and an input power filter operatively connected between the photovoltaic power source and the converter circuit; and

an output EMC filter and an output power filter operatively connected between the converter circuit and the load.

12. A method of connecting a photovoltaic power source to a load, comprising:

arranging a converter circuit to transfer energy from the photovoltaic power source to the load;

generating a raw control signal based on at least a voltage generated by the photovoltaic power source; and

generating a PWM switch signal based on the raw control signal;

operating the converter circuit based on the PWM switch signal to transfer energy from the photovoltaic power source to the load.

13. A method as recited in claim 12, further comprising the steps of:

generating the raw control signal as a PWM control signal; and

generating the PWM switch signal based on the PWM control signal.

14. A method as recited in claim 12, further comprising the steps of:

generating a PWM control signal based on the raw control signal and a reference voltage signal; and

generating the PWM switch signal based on the PWM control signal.

15. A method as recited in claim 14, further comprising the steps of generating the reference voltage signal based on at least one of an input to the converter circuit and an output of the converter circuit.

16. A method as recited in claim 12, further comprising the step of generating a communications signal based on at least one of an input to the converter circuit or an output of the converter circuit.

17. A converter system adapted to be connected between a photovoltaic power source and a load, comprising:

a converter circuit operatively connected to transfer energy from the photovoltaic power source to the load;

a control circuit that generates a raw control signal based on at least a voltage generated by the photovoltaic power source;

an error amplifier;

a reference generator circuit operatively connected to the error amplifier, where the reference generator generates a reference voltage signal; and

a PWM generator circuit operatively connected to the converter circuit, where the PWM generator circuit generates a PWM switch signal based on the raw control signal;

whereby

the converter circuit transfers energy from the photovoltaic power source to the load based on the PWM switch signal;

the error amplifier generates a PWM control signal based on the raw control signal generated by the control circuit and the reference voltage signal generated by the reference generator; and

the PWM generator circuit generates the PWM switch signal based on the PWM control signal.

18. A converter system as recited in claim 17, in which the reference generator circuit comprises:

an input voltage sense circuit that generates an input voltage signal based on an output of the photovoltaic power source;

an output voltage sense circuit that generates an output voltage signal based on an output of the converter circuit;

an output current sense circuit that generates an output current signal based on the output of the converter circuit; and

a processor operatively connected to the output voltage sense circuit, where the processor generates the reference voltage signal based on at least one of the input voltage signal, the output voltage signal, and the output current signal.

20. A converter system as recited in claim 18, in which the processor further generates a communications signal based on at least one the input voltage signal, the output voltage signal, and the output current signal.