Solar-Powered LED Street Light

• US 20090303703A1
• Filed: 01/27/2009
• Published: 12/10/2009
• Est. Priority Date: 06/06/2008
• Status: Active Grant

• Current Assignee: Acbel Polytech Incorporated
• Original Assignee: Acbel Polytech Incorporated
• Inventors: Lin, Wei-Liang, Kao, Ching-Shang
• Granted Patent: US 8,040,102 B2
• Time in Patent Office: Days
• US Class Current: 362/183
• CPC Class Codes: F21S 8/086 with lighting device attached sideways of the standard, e.g. for roads and highways
• CPC Class Codes: F21S 9/035 the solar unit being integrated within the support for the lighting unit, e.g. within or on a pole
• CPC Class Codes: F21W 2131/103 of streets or roads
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: H05B 47/185 via power line carrier transmission
• CPC Class Codes: Y02B 20/72 in street lighting
• CPC Class Codes: Y10S 136/291 Applications
• CPC Class Codes: Y10S 362/80 Light emitting diode

Abstract

A solar-powered LED street light that can immediately report its power data. The disclosed LED street light has a solar cell, a switch power supply unit, and a power cable data communicating unit. The mains power cable of the LED street light connects to the switch power supply unit for providing it with DC power. The solar cell has a solar board, a battery and a charge controller. The charge controller can also provide the LED street light with DC power. The charge controller has a power data digital output interface for connecting with the power cable data communicating unit, outputting the power data of the solar cell to the power cable data communicating unit. Through the mains power cable, the status of solar cell of each LED lamp is monitored.

Claims

1. A solar-powered LED street light comprising:

an LED lamp mounted on a lamp post;

a solar cell comprising a solar board, a charge controller and a battery, wherein the charge controller is electrically connected between the solar board and the battery and electrically connected to the LED lamp for converting power in the battery and outputting to the LED lamp, and the charge controller has a power data digital output interface;

a switch power supply unit connected to an mains power cable for converting AC power into DC power and outputting the DC power to the LED lamp; and

a power cable digital communicating unit coupled to the AC power cable and electrically connected to the power data digital output interface of the charge controller to obtain power data of the solar cell, the power data being modulated and coupled to the mains power cable for transmission.

2. The solar-powered LED street light as claimed in claim 1, wherein the solar cell comprises:

a solar board mounted on the lamp post to absorb solar optical energy and convert the solar optical energy into DC power for output;

a battery mounted on the lamp post;

a charge controller fixed on the lamp post and electrically connected among the solar board, the LED lamp, and the battery to control whether to convert the DC power for charging the battery or to output the power of the battery to the LED lamp.

3. The solar-powered LED street light as claimed in claim 2, wherein the power cable data communicating unit comprises:

an analog front transceiving unit coupled to the mains power cable;

a digital processing unit electrically connected to the analog front transceiving unit to receive external data signals from the mains power cable via the analog front transceiving unit or to process and modulate data and couple the data to the mains power cable via the analog front transceiving unit for sending them outward; and

a digital communicating interface electrically connected with the power data digital output interface of the charge controller to obtain the power data of the battery and to output the power data to the digital processing unit.

4. The solar-powered LED street light as claimed in claim 3, wherein the switch power supply unit comprises:

a full wave rectifying filter circuit, a power factor correction controller, a transformer having a primary side and a secondary side, an active switch connected to the primary side of the transformer in series, a digital pulse width (PWM) modulator and a photo coupler;

wherein the digital PWM modulator has

a digital interface connected to an output terminal of the digital processing unit through an electric isolator;

a reference voltage modulating unit connected to the digital interface to and adjusting an internal reference voltage based on a command from the digital processing unit;

a voltage feedback terminal connected to the voltage output terminal of the switch power supply unit via the photo coupler, thereby obtaining a feedback voltage;

a gain adjusting unit connected to the reference voltage modulating unit and the voltage feedback terminal via an operating amplifier, thereby comparing the internal reference voltage with the feedback voltage and adjusting a gain of the compared result;

a driver connected to the gain adjusting unit for adjusting a pulse width modulation driving signal according to the compared result; and

a driving output terminal connected to the output terminal of the driver and the active switch for controlling a conduction time of the active switch.

5. The solar-powered LED street light as claimed in claim 4 further comprising:

a DC to DC converter whose input terminal connected to a DC voltage output terminal of the switch power supply unit and reducing the output voltage of the switch power supply unit for outputting to the power cable communicating unit.

6. The solar-powered LED street light as claimed in claim 4, wherein the switch power supply unit is a flyback power circuit, a forward power circuit or a buck power circuit.

7. The solar-powered LED street light as claimed in claim 5, wherein the switch power supply unit is a flyback power circuit, a forward power circuit or a buck power circuit.

8. The solar-powered LED street light as claimed in claim 4, wherein the digital interface of the digital PWM modulator and the output terminal of the digital processing unit are I²C interfaces and the electric isolator is a transformer.

9. The solar-powered LED street light as claimed in claim 1 further comprising:

a video camera for capturing road images having an image data output terminal connected with the power cable data communicating unit so that the power data communicating unit loads the road images into the mains power cable and sends them out.

10. The solar-powered LED street light as claimed in claim 9, wherein the solar cell comprises:

a solar board mounted on the lamp post to absorb solar optical energy and convert the solar optical energy into DC power for output;

a battery mounted on the lamp post;

a charge controller fixed on the lamp post and electrically connected among the solar board, the LED lamp, and the battery to control whether to convert the DC power for charging the battery or to output the power of the battery to the LED lamp.

11. The solar-powered LED street light as claimed in claim 10, wherein the power cable data communicating unit includes:

an analog front transceiving unit coupled to the mains power cable;

a digital processing unit electrically connected to the analog front transceiving unit to receive external data signals from the mains power cable via the analog front transceiving unit or to process and modulate data and couple the data to the mains power cable via the analog front transceiving unit for sending them outward; and

a digital communicating interface electrically connected with the power data digital output interface of the charge controller to obtain the power data of the battery and to output the power data to the digital processing unit.

12. The solar-powered LED street light as claimed in claim 10, wherein the switch power supply unit comprises:

a full wave rectifying filter circuit, a power factor correction controller, a transformer having a primary side and a secondary side, an active switch connected to the primary side of the transformer in series, a digital pulse width modulator (PWM) and a photo coupler;

wherein the digital PWM has

a digital interface connected to an output terminal of the digital processing unit through an electric isolator;

a reference voltage modulating unit connected to the digital interface to and adjusting an internal reference voltage based on a command from the digital

processing unit;

a voltage feedback terminal connected to the voltage output terminal of the switch power supply unit via the photo coupler, thereby obtaining a feedback voltage;

a gain adjusting unit connected to the reference voltage modulating unit and the voltage feedback terminal via an operating amplifier, thereby comparing the internal reference voltage with the feedback voltage and adjusting a gain of the compared result;

a driver connected to the gain adjusting unit for adjusting a pulse width modulation driving signal according to the compared result; and

a driving output terminal connected to the output terminal of the driver and the active switch for controlling a conduction time of the active switch.

13. The solar-powered LED street light as claimed in claim 12, further comprising:

a DC to DC converter whose input terminal connected to a DC voltage output terminal of the switch power supply unit and reducing the output voltage of the switch power supply unit for outputting to the power cable communicating unit.

14. The solar-powered LED street light as claimed in claim 13, wherein the switch power supply unit is a flyback power circuit, a forward power circuit, or a buck power circuit.

15. The solar-powered LED street light as claimed in claim 13, wherein the digital interface of the digital PWM modulator and the output terminal of the digital processing unit are I²C interfaces and the electric isolator is a transformer.