Streelight monitoring and control

• US 20090066258A1
• Filed: 09/07/2007
• Published: 03/12/2009
• Est. Priority Date: 09/07/2007
• Status: Active Grant

• Current Assignee: LED Roadway Lighting Ltd.
• Original Assignee: Streetlight Intelligence, Inc. (LED Roadway Lighting Ltd.)
• Inventors: Cleland, Donald A., Warrior, Velvet, Lightbody, Simon H., Sharma, Pratibha
• Granted Patent: US 8,290,710 B2
• Time in Patent Office: Days
• US Class Current: 315/158
• CPC Class Codes: H02J 2310/14 The load or loads being home appliances
• CPC Class Codes: H02J 2310/60 Limiting power consumption in the network or in one section of the network, e.g. load shedding or peak shaving
• CPC Class Codes: H02J 3/004 Generation forecast, e.g. methods or systems for forecasting future energy generation
• CPC Class Codes: H02J 3/14 by switching loads on to, or off from, network, e.g. progressively balanced loading
• CPC Class Codes: H05B 41/40 discontinuously
• CPC Class Codes: H05B 47/11 by determining the brightness or colour temperature of ambient light
• CPC Class Codes: H05B 47/14 by determining electrical parameters of the light source
• CPC Class Codes: H05B 47/19 via wireless transmission
• CPC Class Codes: H05B 47/22 with communication between the lamps and a central unit
• CPC Class Codes: Y02B 20/40 Control techniques providing energy savings, e.g. smart controller or presence detection
• CPC Class Codes: Y02B 20/72 in street lighting
• CPC Class Codes: Y02B 70/30 Systems integrating technologies related to power network operation and communication or information technologies for improving the carbon footprint of the management of residential or tertiary loads, i.e. smart grids as climate change mitigation technology in the buildings sector, including also the last stages of power distribution and the control, monitoring or operating management systems at local level
• CPC Class Codes: Y02B 70/3225 Demand response systems, e.g. load shedding, peak shaving
• CPC Class Codes: Y04S 20/222 Demand response systems, e.g. load shedding, peak shaving
• CPC Class Codes: Y04S 20/246 the system involving the remote operation of lamps or lighting equipment

Abstract

Methods and apparatus associated with monitoring and controlling streetlights include monitoring light levels and voltage levels at corresponding streetlights and controlling the streetlights to set or maintain a particular light output at the respective streetlights or providing power consumption estimates for respective streetlights (streetlight specific metering) based on the voltage levels and light levels. A streetlight controller for a streetlight includes a microcontroller; a first sensor to sense a light level from a lamp within the streetlight; a second sensor operative to sense a voltage level on a power supply for the streetlight; and a switching network coupled with the microcontroller and operative to adjust the light level of the lamp. Methods includes monitoring a light level and voltage level and adjusting a light level, estimating power consumption, or facilitating maintenance in accordance with the light level and voltage level. The methods may be performed all or in part at a streetlight, a local gateway or a central controller and database.

Claims

1. A controller for a streetlight comprising:

a microcontroller;

a first sensor coupled with said microcontroller and operative to sense a light level from a lamp within said streetlight;

a second sensor coupled with said microcontroller and operative to sense a voltage level on a power line supplying power to said streetlight;

a switching network coupled with said microcontroller and operative to adjust said light level of said lamp;

wherein said microcontroller is operative to facilitate an estimate of power consumption for said streetlight based on said light level and said voltage level.

2. The controller of claim 1 wherein the switching network further comprises a plurality of switching capacitors that may be selectively used to adjust said light level.

3. The controller of claim 1 wherein the switching network further comprises a triac switching circuit which is controllable by the microcontroller to adjust said light level.

4. The controller of claim 1 wherein the controller is further operable to estimate the power consumption based additionally on ON times of the lamp and voltage levels sensed during the ON times.

5. The controller of claim 1 wherein the controller is further operable to estimate the power consumption based additionally on a volt-hour calculation.

6. The controller of claim 1 wherein the controller is further operable to estimate the power consumption based additionally on at least one of ballast profile characteristics and lamp profile characteristics.

7. The controller of claim 1 wherein the controller maintains a data-log for the streetlight, the data-log comprising ON times and voltage levels sensed during the ON times, the data-log for facilitating the estimate of power consumption.

8. A controller for a streetlight comprising:

a microcontroller;

a first sensor coupled with said microcontroller and operative to sense a light level from a lamp within said streetlight;

a second sensor coupled with said microcontroller and operative to sense a voltage level on a power line supplying power to said streetlight;

a switching network coupled with said microcontroller and a streetlight ballast;

said switching network operative to adjust said light level of said lamp;

wherein said microcontroller is operative to set said light level to a desired level based on the output of said first sensor and said second sensor by selectively adjusting said switching network.

9. The controller of claim 8 wherein the switching network further comprises a plurality of switching capacitors that may be selectively used to adjust said light level.

10. The controller of claim 8 wherein the switching network further comprises a triac switching circuit which is controllable by the microcontroller to adjust said light level.

11. The controller of claim 8 wherein the first sensor is operable to sense ambient light levels and cooperatively with the microcontroller detect night and turn the lamp ON.

12. The controller of claim 8 wherein the microcontroller cooperates with other microcontrollers in other streetlights to determine DAY/NIGHT and responsive thereto turn the lamp ON during NIGHT and OFF during DAY.

13. The controller of claim 8 wherein the microcontroller utilizes a schedule to turn the lamp ON and to turn the lamp OFF, the schedule stored with the microcontroller.

14. The controller of claim 8 wherein the lamp is turned ON and OFF based at least in part on global positioning system (GPS) position.

15. The controller of claim 8 wherein the microcontroller maintains a data-log for the streetlight, the data-log comprising ON times and voltage levels sensed during the ON times, the data-log for facilitating an estimate of power consumption for the streetlight.

16. A method of controlling a streetlight comprising:

monitoring a light level from a lamp within said streetlight with a light sensor;

monitoring a voltage level of a power supply supplying said streetlight;

adjusting an output of a ballast driving said lamp to set said light level to a desired light level based on said monitoring of said light level and said voltage level.

17. The method of claim 16 wherein said adjusting comprises adjusting said output to a higher level when said voltage level is below a nominal level and adjusting said output to a lower level when said voltage level is above a nominal level.

18. The method of claim 16 further comprising:

defining a first light level from said lamp at a first time after installation of said lamp as an absolute light level; and

adjusting an indication of the first light level in accordance with a difference between a first voltage level at the first time and a nominal voltage level to provide an absolute indication of the absolute light level,

wherein the desired light level is relative to the absolute light level.

19. The method of claim 16 further comprising:

monitoring a temperature of said light sensor; and

compensating an output of said light sensor for the temperature of said light sensor.

20. A method of monitoring a streetlight comprising:

monitoring a light level from a lamp within said streetlight with a light sensor;

monitoring a voltage level of a power supply supplying said streetlight;

estimating the power consumption of said streetlight using a known nominal power consumption of said streetlight, said light level and said voltage level.

21. The method of claim 20 wherein the estimating the power consumption is partially based on lamp ON times and voltage levels at the ON times.

22. The method of claim 20 wherein the estimating the power consumption is partially based on volt-hour determinations.

23. The method of claim 20 wherein the estimating power consumption is partially based on streetlight component characterizations.

24. The method of claim 20 wherein the light level and the voltage level are forwarded to a central database where the estimating the power consumption is undertaken.

25. A method of monitoring a plurality of streetlights comprising:

receiving a data-log from each streetlight, the data-log for each streetlight comprising one or more light levels and corresponding voltage levels; and

estimating a power consumption for each streetlight based on the one or more light levels and corresponding voltage levels.

26. The method of claim 25 wherein the estimating the power consumption is further based on component characteristics for each streetlight.

27. The method of claim 25 wherein the estimating the power consumption is further based on lamp ON/OFF times included in the data-log for each streetlight.

28. The method of claim 25 wherein the voltage levels are further used to distinguish between lamp cycling errors due to lamp age and due to voltage sags.