Active load management system

• US 8,415,830 B2
• Filed: 06/03/2010
• Issued: 04/09/2013
• Est. Priority Date: 06/03/2010
• Status: Active Grant

• Current Assignee: Briggs & Stratton LLC (Briggs & Stratton Corporation)
• Original Assignee: Briggs & Stratton Corporation
• Inventors: Lim, Sie Teong, Batzler, Brandon M., Stair, Kenny J.
• Primary Examiner(s): Fureman, Jared
• Assistant Examiner(s): PEREZ BORROTO, ALFONSO
• Application Number:
  US12/792,937
• Publication Number:
  US 20110298285A1
• Time in Patent Office: 1,041 Days
• Field of Search: 307 39- 41, 361/90, 363/95
• US Class Current: 307/41
• 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: H02J 9/08 requiring starting of a prime-mover
• 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 20/20 End-user application control systems
• CPC Class Codes: Y04S 20/222 Demand response systems, e.g. load shedding, peak shaving
• CPC Class Codes: Y04S 20/248 UPS systems or standby or emergency generators

Abstract

A method and system for managing loads powered by a standby generator. The method includes utilizing a transfer switch control unit to selectively shed loads each associated with one of a series of priority circuits. The loads are shed in a sequential order based upon the priority circuit to which the load is applied. Once a required load has been shed, the control unit determines whether any of the lower priority loads can be reconnected to the generator without exceeding the rating of the generator while one of the higher priority circuits remains open.

Claims

1. A method for managing a plurality of electric loads powered by a standby generator, the method comprising the steps of:

interconnecting each of the plurality of electric loads to the generator through an interconnect device that is operable to selectively connect and disconnect the electric load from the generator;

assigning a priority value to each of the electric loads from a lowest priority value to a highest priority value;

providing a control unit in communication with each of the interconnect devices to control the connection of each of the electric loads to the generator;

monitoring a combined load on the generator in the control unit;

selectively disconnecting the electric loads from the generator in a sequential order based on the priority value assigned to each load, wherein the loads having the lowest priority value are sequentially disconnected from the generator by the control unit until the combined load on the generator falls below a rated value for the generator;

predicting the additional load on the generator for each of the electric loads disconnected from the generator; and

selectively reconnecting one or more of the electric loads having priority values lower than the electric load having the highest priority value that is disconnected from the generator when the combination of the predicted additional load and the combined load remains below the rated value of the generator.

2. The method of claim 1 wherein the control unit is contained within a transfer switch positioned between the generator and a main breaker panel.

3. The method of claim 2 wherein the interconnect devices are contained within the transfer switch.

4. The method of claim 2 wherein the interconnect devices are positioned external to the transfer switch.

5. The method of claim 1 wherein the rated value for the generator is a predetermined percentage of the maximum generator output.

6. The method of claim 1 further comprising the step of monitoring the power drawn by each of the electric loads during operation and storing a power draw value for each of the electric loads in the control unit.

7. The method of claim 1 wherein the control unit monitors the load on the generator.

13. The load management system of claim 1 wherein the control unit monitors the power drawn by each of the electric loads and stores a power draw value for each electric load.

8. A load management system for managing one or more electric loads powered by a standby generator, the system comprising:

a transfer switch coupled to the standby generator;

a plurality of interconnect devices each positioned between one of the loads and the generator, wherein each interconnect device is operable to selectively connect and disconnect the electric load from the generator;

a control unit in communication with each of the interconnect devices to selectively control the interconnect devices, the control unit being configured to;

assign a priority value to each of the electric loads from a lowest priority value to a highest priority value;

monitor a combined load on the generator;

selectively disconnect the electric loads from the generator in a sequential order based on the priority value assigned to each load, wherein the loads having the lowest priority values are sequentially disconnected until the combined load on the generator falls below a rated value for the generator;

predicting the additional load on the generator for each of the electric loads disconnected from the generator; and

;

selectively re-connecting one or more of the electric loads having a priority value lower than the electric load having the highest priority value that is disconnected from the generator when the combination of the predicted additional load and the combined load remains below the rated value of the generator.

9. The load management system of claim 8 wherein the control unit is contained within the transfer switch and the transfer switch is positioned between the generator and a main breaker panel.

10. The load management system of claim 9 wherein the interconnect devices are each contained within the transfer switch.

11. The load management system of claim 9 wherein the interconnect devices are positioned external to the transfer switch.

12. The load management of claim 8 wherein the rated value for the generator is a predetermined percentage of a maximum generator output.

14. A method of managing a plurality of electric loads powered by a standby generator, the method comprising the steps of:

assigning a priority value to each of the electric loads from a lowest priority value to a highest priority value;

monitoring a combined load on the generator in a control unit;

selectively disconnecting the electric loads from the generator in a sequential order based on the priority value assigned to each load, wherein the electric loads having the lowest priority value are sequentially disconnected until the combined load on the generator falls below a rated value for the generator;

predicting the additional load on the generator for each of the electric loads disconnected from the generator; and

selectively reconnecting one or more of the electric loads having a priority value lower than the highest priority value of the electric load that is disconnected from the generator when the combination of the predicted additional load and the combined load remains below the rated value of the generator.

15. The method of claim 14 further comprising the step of monitoring the power drawn by each of the loads and storing a power draw for each of the loads in the control unit.

16. The method of claim 14 wherein each of the electric loads is connected to a priority output of the transfer switch, wherein each of the priority outputs are assigned a priority value.

17. The method of claim 16 wherein the control units selectively controls each of the priority outputs.

18. The method of claim 14 wherein the control unit is contained within a transfer switch positioned between the generator and a main breaker panel.