TRANSFER SWITCH CONTROLLER EMPLOYING ACTIVE INDUCTIVE LOAD CONTROL AND TRANSFER SWITCH INCLUDING THE SAME

• US 20100013308A1
• Filed: 07/21/2008
• Published: 01/21/2010
• Est. Priority Date: 07/21/2008
• Status: Active Grant

• Current Assignee: Eaton Intelligent Power Limited (Eaton Corporation PLC.)
• Original Assignee: Eaton Corp. (Wisconsin) (Eaton Corporation PLC.)
• Inventors: LATHROP, TODD M., HJEMVICK, JACOB A., POPOVICH, BERT, FAYLO, SAMUEL E.
• Granted Patent: US 7,948,117 B2
• Time in Patent Office: Days
• US Class Current: 307/64
• 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 3/14 by switching loads on to, or off from, network, e.g. progressively balanced loading
• 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 20/242 Home appliances
• CPC Class Codes: Y04S 20/244 the home appliances being or involving heating ventilating and air conditioning [HVAC] units

Abstract

A transfer switch controller is for a transfer switch, which cooperates with a plurality of loads including an air conditioner. The transfer switch controller includes a first input structured to input a thermostat start request signal for the air conditioner, a second input structured to determine power consumed by the loads, an output structured to output a start signal to the air conditioner, and a circuit. The circuit cooperates with the first input, the second input and the output. The circuit causes the start signal to be output by the output responsive to the thermostat start request signal of the first input if the determined power consumed by the loads is less than the difference between a predetermined maximum power output of a generator and a previous maximum peak start up power consumed by the air conditioner.

Claims

1. A transfer switch controller for a transfer switch, said transfer switch cooperating with a plurality of loads, said transfer switch controller comprising:

a first input structured to input a start request signal for one of said loads;

a second input structured to determine power consumed by said loads;

an output structured to output a start signal to said one of said loads; and

a circuit cooperating with said first input, said second input and said output, said circuit being structured to cause the start signal to be output by said output responsive to the start request signal of said first input if the determined power consumed by said loads is less than the difference between a predetermined value and a previous start up power consumed by said one of said loads.

2. The transfer switch controller of claim 1 wherein said one of said loads is an air conditioner;

and wherein said start request signal is a thermostat signal, which requests that said air conditioner be started.

3. The transfer switch controller of claim 2 wherein said circuit comprises a processor;

and wherein said processor is structured to sense said thermostat signal and to cause the start signal to be output by said output.

4. The transfer switch controller of claim 1 wherein said circuit is structured to store as the previous start up power consumed by said one of said loads the difference between:

(a) the determined power consumed by said loads after the start signal is output by said output, and (b) the determined power consumed by said loads before the start signal is output by said output.

5. The transfer switch controller of claim 4 wherein said circuit comprises a processor and a non-volatile memory;

and wherein said processor is structured to store said difference in said non-volatile memory after the start signal is output by said output.

6. The transfer switch controller of claim 1 wherein said circuit is structured to store as the previous start up power consumed by said one of said loads a predetermined value times the difference between:

(a) the determined power consumed by said loads after the start signal is output by said output, and (b) the determined power consumed by said loads before the start signal is output by said output.

7. The transfer switch controller of claim 1 wherein said predetermined value is maximum power output of a generator.

8. The transfer switch controller of claim 1 wherein said start request signal is a closed contact.

9. The transfer switch controller of claim 8 wherein said one of said loads is an air conditioner;

and wherein said closed contact requests that said air conditioner be started.

10. The transfer switch controller of claim 1 wherein said circuit is structured to determine and store as the previous start up power consumed by said one of said loads a peak start up power consumed by said one of said loads based upon the difference between:

(a) the determined power consumed by said loads a predetermined time after the start signal is output by said output, and (b) the determined power consumed by said loads before the start signal is output by said output.

11. A transfer switch for a plurality of loads, said transfer switch comprising:

a first input structured to input a first voltage from a first power source;

a second input structured to input a second voltage from a second power source;

a third input structured to input a start request signal for one of said loads;

a fourth input structured to determine power consumed by said loads;

a first output structured to output a start signal to said one of said loads;

a second output structured to output power to said loads;

a transfer mechanism structured to selectively electrically connect one of said first input and said second input to said second output; and

a circuit cooperating with said third input, said fourth input and said first output, said circuit being structured to cause the start signal to be output by said first output responsive to the start request signal of said third input if the determined power consumed by said loads is less than the difference between a predetermined value and a previous start up power consumed by said one of said loads, said circuit also being structured to cooperate with said first input, said second input and said transfer mechanism to cause said transfer mechanism to electrically connect one of said first input and said second input to said second output.

12. The transfer switch of claim 11 wherein said first input is structured to input from a utility power source;

wherein said second input is structured to input from a generator power source including a generator having a maximum power output; and

wherein when the generator is powering said loads, the first time that the start request signal is input by said third input, said circuit does not cause the start signal to be output by said output unless the determined power consumed by said loads is below a predetermined percentage of the maximum power output of the generator.

13. The transfer switch of claim 12 wherein said predetermined percentage is about 80%.

14. The transfer switch of claim 11 wherein said first input is structured to input from a utility power source;

wherein when said transfer mechanism electrically connects said first input to said second output, said circuit unconditionally causes the start signal to be output by said output responsive to the start request signal; and

wherein said circuit is further structured to store as the previous start up power consumed by said one of said loads the difference between;

(a) the determined power consumed by said loads after the start signal is output by said output, and (b) the determined power consumed by said loads before the start signal is output by said output.

15. The transfer switch of claim 11 wherein said circuit is structured to store as the previous start up power consumed by said one of said loads a predetermined value times the difference between:

(a) the determined power consumed by said loads after the start signal is output by said output, and (b) the determined power consumed by said loads before the start signal is output by said output.

16. The transfer switch of claim 15 wherein the last said predetermined value is one plus a predetermined percentage.

17. The transfer switch of claim 11 wherein said previous start up power consumed by said one of said loads is peak start up power consumed by said one of said loads during the time that said one of said loads is started.

18. The transfer switch of claim 11 wherein said circuit comprises a processor and a non-volatile memory;

wherein said processor is structured to store said difference in said non-volatile memory after the start signal is output by said output; and

wherein said difference is a maximum peak start up power consumed by said one of said loads.

19. The transfer switch of claim 18 wherein said circuit determines steady state power of said one of said loads after the start signal is output by said output and stores the steady state power in said non-volatile memory for use by a load shedding function.

20. The transfer switch of claim 11 wherein said second output has a voltage;

and wherein said circuit comprises a current transformer disposed about said second output and a processor, said current transformer being structured to sense current flowing to said second output and output a sensed current value to said processor, said processor being structured to calculate the determined power consumed by said loads from the sensed current value times the voltage of said second output.

21. The transfer switch of claim 11 wherein said one of said loads is an air conditioner;

and wherein said start request signal is a thermostat signal, which requests that said air conditioner be started.

22. The transfer switch of claim 21 wherein upon start up of the air conditioner, said circuit stores as the previous start up power consumed by said one of said loads the amount of power consumed by start up of the air conditioner.

23. The transfer switch of claim 11 wherein said circuit is further structured to shed a number of said loads, other than said one of said loads, if the determined power consumed by said loads is greater than or equal to the difference between the predetermined value and the previous start up power consumed by said one of said loads.