PHOTOVOLTAIC SYSTEM AND BOOST CONVERTER THEREOF

• US 20110139213A1
• Filed: 12/07/2010
• Published: 06/16/2011
• Est. Priority Date: 12/11/2009
• Status: Abandoned Application

• Current Assignee: Du Pont Taiwan Limited (Corteva, Inc.)
• Original Assignee: Du Pont Taiwan Limited (Corteva, Inc.)
• Inventors: LEE, Chun-Hsien
• Application Number:
  US12/961,499
• Publication Number:
  US 20110139213A1
• Time in Patent Office: Days
• US Class Current: 136/244
• CPC Class Codes: G05F 1/67 to the maximum power available from a generator, e.g. from solar cell
• CPC Class Codes: Y02B 10/10 Photovoltaic [PV]
• CPC Class Codes: Y02E 10/56 Power conversion systems, e.g. maximum power point trackers

Abstract

A photovoltaic system is disclosed herein, which includes a blocking diode, a string of photovoltaic modules, a boost converter and a controller. The photovoltaic modules are connected in series with the blocking diode. A voltage input terminal of the boost converter is connected to an anode of the blocking diode, and a voltage output terminal of the boost converter is connected to a cathode of the blocking diode. In use, the controller can drive the boost converter when the blocking diode is cut off.

Claims

1. A photovoltaic system comprising:

a blocking diode;

a plurality of photovoltaic modules connected in series with the blocking diode; and

a boost converter having a voltage input terminal connected to an anode of the blocking diode and a voltage output terminal connected to a cathode of the blocking diode; and

a controller for driving the boost converter when the blocking diode is cut off.

2. The photovoltaic system of claim 1, wherein the boost converter comprises:

a controlled switch;

a diode having an anode connected to the controlled switch and a cathode configured to serve as the voltage output terminal; and

an inductor having one end connected to the anode of the diode and another end configured to serve as the voltage input terminal.

3. The photovoltaic system of claim 2, wherein the inductor is an inductance coil.

4. The photovoltaic system of claim 2, wherein the controlled switch is a metal oxide semiconductor or a bipolar junction transistor.

5. The photovoltaic system of claim 1, wherein the controller comprises:

a voltage detector for detecting a forward voltage across the blocking diode potential difference between the anode and the cathode of the blocking diode; and

a maximum power point tracker configured to send a pulse width modulation signal to the controlled switch for maximizing power at the voltage output terminal when the forward voltage the potential difference is lower than a cut-in voltage of the blocking diode.

6. The photovoltaic system of claim 1, wherein the controller comprises:

a current detector for detecting electric current through the blocking diode; and

a maximum power point tracker configured to send a pulse width modulation signal to the controlled switch for maximizing power at the voltage output terminal when the electric current is lower than a predetermined current.

7. The photovoltaic system of claim 1, further comprising:

a power conditioner connected in parallel to the blocking diode and the photovoltaic modules.

8. The photovoltaic system of claim 1, further comprising:

a plurality of bypass diodes, wherein each of the bypass diodes is connected with each of the photovoltaic modules in parallel.

10. The photovoltaic system of claim 1, wherein the boost converter comprises:

a controlled switch;

a diode having an anode connected to the controlled switch and a cathode configured to serve as the voltage output terminal; and

an inductor having one end connected to the anode of the diode and another end configured to serve as the voltage input terminal.

11. The photovoltaic system of claim 10, wherein the inductor is an inductance coil.

12. The photovoltaic system of claim 10, wherein the controlled switch is a metal oxide semiconductor or a bipolar junction transistor.

9. A photovoltaic system comprising:

a blocking diode;

a plurality of photovoltaic modules connected in series with the blocking diode; and

a boost converter having a voltage input terminal connected to an anode of the blocking diode and a voltage output terminal connected to a cathode of the blocking diode; and

means for driving the boost converter when the blocking diode is cut off.

13. The photovoltaic system of claim 9, wherein the means for driving the boost converter comprises:

means for detecting a forward voltage across the blocking diodepotential difference between the anode and the cathode of the blocking diode; and

means for maximizing power at the voltage output terminal when the forward voltage potential difference is lower than a cut-in voltage of the blocking diode.

14. The photovoltaic system of claim 9, wherein the controller comprises:

means for detecting electric current through the blocking diode; and

means for maximizing power at the voltage output terminal when the electric current is lower than a predetermined current.

15. The photovoltaic system of claim 9, further comprising:

a power conditioner connected in parallel to the blocking diode and the photovoltaic modules.

16. The photovoltaic system of claim 9, further comprising:

a plurality of bypass diodes, wherein each of the bypass diodes is connected with each of the photovoltaic modules in parallel.

17. A boost converter comprising:

a controlled switch;

a diode having an anode connected to the controlled switch and a cathode configured to serve as a voltage output terminal connected to a cathode of a blocking diode, wherein the blocking diode is connected in series with a string of photovoltaic modules;

a inductor having one end connected to the anode of the diode and another end configured to serve as a voltage input terminal connected to a cathode of the blocking diode; and

a controller for providing a pulse width modulation signal to control the controlled switch when the blocking diode is cut off.

18. The boost converter of claim 17, wherein the controller comprises:

a voltage detector for detecting a forward voltage across the blocking diode potential difference between the anode and the cathode of the blocking diode; and

a maximum power point tracker configured to send a pulse width modulation signal to the controlled switch for maximizing power at the voltage output terminal when the forward voltage potential difference is lower than a cut-in voltage of the blocking diode.

19. The boost converter of claim 17, wherein the controller comprises:

a current detector for detecting electric current through the blocking diode; and

a maximum power point tracker configured to send a pulse width modulation signal to the controlled switch for maximizing power at the voltage output terminal when the electric current is lower than a predetermined current.

20. The boost converter of claim 17, wherein the inductor is an inductance coil, and the controlled switch is a metal oxide semiconductor or a bipolar junction transistor.