Electrical power distribution system for street lighting

• US 20020062180A1
• Filed: 07/05/2001
• Published: 05/23/2002
• Est. Priority Date: 06/19/2000
• Status: Active Grant

• Current Assignee: Strategic Design Federation W, LLC
• Original Assignee: Lime Energy Co. (Willdan Group, Inc.)
• Inventors: Enberg, Denis
• Granted Patent: US 7,136,724 B2
• Time in Patent Office: Days
• US Class Current: 700/286
• CPC Class Codes: G06Q 50/06 Energy or water supply
• CPC Class Codes: H05B 47/16 by timing means
• CPC Class Codes: Y02B 20/40 Control techniques providing energy savings, e.g. smart controller or presence detection
• CPC Class Codes: Y02E 40/70 Smart grids as climate change mitigation technology in the energy generation sector
• CPC Class Codes: Y04S 10/50 Systems or methods supporting the power network operation or management, involving a certain degree of interaction with the load-side end user applications

Abstract

The present invention comprises an electric power distribution system for providing power to a plurality of loads. An energy reduction device receives high voltage electrical power from a utility. A processor controls three variable transformer windings to produce electrical power at three phases at three independent reduced voltages. The energy reduction device thereby controls the output voltage on each phase to provide an individualized regulated voltage for each phase. The regulated voltage provided includes a sufficient voltage required to power the loads connected to that phase, plus an additional voltage which compensates for the voltage drop caused by the length of wire run in that phase. The electrical distribution system of the present invention eliminates the need for low voltage step-down transformers at the point of the load. The energy reduction device can also regulate the voltage provided to lighting loads as a function of the time of day or the ambient light levels (as sensed by a light sensor near the lamps). A starting voltage can be applied to the lighting loads for a warmup period of predetermined length. The voltage supplied to the loads can also be reduced during periods of low public usage in order to save energy.

Claims

1. An electrical power distribution system, comprising:

an electrical power input breaker receiving three-phase high voltage electrical power from a high voltage system;

a processor; and

three variable output windings controlled by the processor, each variable output windings providing electrical power to an associated load,

wherein the processor controls each variable output winding to produce an independent regulated voltage from each output winding, wherein each independent regulated voltage is selected by the processor based on a voltage required by the associated load coupled to the winding and a voltage drop between the variable output winding and the load.

2. The system of claim 1, wherein the regulated voltage produced from each output winding includes a voltage required to power the associated load plus a voltage drop over the length of a wiring run from the output winding to the load.

3. The system of claim 1, wherein the load is a lighting load.

4. The system of claim 1, wherein the processor controls a variable output winding to produce a starting voltage for the load.

5. The system of claim 4, wherein the starting voltage is applied to the load for a predetermined period of time.

6. The system of claim 5, wherein the voltage is reduced following the predetermined period of time.

7. The system of claim 1, wherein the processor controls the voltage produced by an output winding as a function of an ambient light level at the load.

8. The system of claim 1, wherein the processor controls the voltage produced by an output winding as a function of a scheduling function.

9. The system of claim 1, processor controls the voltage produced by an output winding as a function of public usage.

10. The system of claim 1, wherein the processor controls the voltage produce by an output winding by use of a plurality of relays.

12. The apparatus of claim 9, wherein the load is a lighting load.

13. The apparatus of claim 9, wherein the processor controls a variable output winding to produce a starting voltage for the load.

16. The apparatus of claim 9, wherein the processor controls the voltage produced by an output winding as a function of an ambient light level at the load.

17. The apparatus of claim 9, wherein the processor controls the voltage produced by an output winding as a function of a scheduling function.

18. The apparatus of claim 9, processor controls the voltage produced by an output winding as a function of public usage.

19. The system of claim 9, wherein the processor controls the voltage produce by an output winding by use of a plurality of relays.

11. A voltage reduction apparatus, comprising:

a plurality of variable output windings receiving high voltage electrical power from a high voltage system, each variable output winding providing electrical power to an associated load; and

a processor controlling the plurality of variable output windings to produce an independent regulated voltage from each of the plurlality of output windings, wherein each independent regulated voltage is selected by the processor based on a voltage required by the load coupled to the winding and a voltage drop between the variable output winding and the load.

14. The apparatus of claim 11, wherein the starting voltage is applied to the load for a predetermined period of time.

15. The apparatus of claim 12, wherein the voltage is reduced following the predetermined period of time.

20. A method of distributing electrical power to plurality of loads, comprising:

receiving high voltage electrical power from a high voltage system;

reducing the high voltage to a three reduced voltages corresponding to three phases; and

distributing the electrical power over three phases to at least one load associated with each phase, wherein each reduced voltage comprises a voltage required by the associated load plus a voltage drop caused by a length of wire run.