Dynamic load shedding system for a standby generator

• US 8,410,633 B2
• Filed: 06/03/2010
• Issued: 04/02/2013
• Est. Priority Date: 06/03/2010
• Status: Active Grant

• Current Assignee: Briggs & Stratton LLC (Briggs & Stratton Corporation)
• Original Assignee: Briggs & Stratton Corporation
• Inventors: Batzler, Brandon M., Stair, Kenny J., Lim, Sie Teong
• Primary Examiner(s): Fureman, Jared
• Assistant Examiner(s): PEREZ BORROTO, ALFONSO
• Application Number:
  US12/792,938
• Publication Number:
  US 20110298286A1
• Time in Patent Office: 1,034 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 electrical loads on a standby generator. The method includes utilizing a transfer switch control to selectively shed loads each associated with one of a series of priority circuits. Priority values are initially assigned to each of the electric loads based upon the initial hard-wired connection of the electric loads to a main breaker panel during set up. The control unit of a transfer switch allows the user to reassign priority values to each of the electric loads based upon a user preference. The control unit includes one or more predefined priority assignment programs that can be selected to modify the priority values assigned to the electric loads.

Claims

1. A method of 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 one of a plurality of outputs such that the electric loads receive power through the outputs;

providing a plurality of predefined priority assignment programs in a control unit;

assigning a priority value to each of the electric loads between a highest priority value and a lowest priority value for each of the priority assignment programs, wherein the initial priority values assigned to the electric loads vary among the plurality of priority assignment programs;

receiving a selection of one the predefined priority assignment programs from a user;

monitoring a combined load on the generator;

selectively disconnecting the electric loads from the generator in a sequential order from the lowest priority value to the highest priority value based on the assigned priority values according to the selected priority assignment program when the combined load on the generator reaches a rated value for the generator, wherein the electric loads having the lowest priority value are sequentially disconnected from the generator until the combined load on the generator falls below the rated value for the generator; and

selectively reassigning the priority values to the electric loads to modify the order the electric loads are disconnected from the generator upon the selection of another priority assignment program by the user.

2. The method of claim 1 wherein the initial priority values for the electric loads are assigned based upon the physical connection of the electric loads to the plurality of outputs.

3. The method of claim 2 wherein the priority values are reassigned based upon user input.

4. The method of claim 3 wherein the user input is received from a user interface device.

5. The method of claim 1 wherein the priority assignment programs are presented on a user interface device such that the user can select one of the priority assignment programs through the user interface device.

6. The method of claim 1 further comprising the step of adjusting the loads connected to the generator based upon the reassigned priority values.

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

interconnecting each of the plurality of electric loads to one of a plurality of outputs;

providing a plurality of predefined priority assignment programs in a control unit;

assigning a priority value to each of the electric loads between a highest priority value and a lowest priority value for each of the priority assignment programs, wherein the initial priority values assigned to the electric loads vary among the plurality of priority assignment programs in a control unit;

receiving a selection of one of the predefined priority assignment programs from a user;

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

selectively disconnecting the electric loads from the generator in a sequential order from the lowest priority value to the highest priority value based on the assigned priority values according to the selected priority assignment program when the combined load on the generator reaches a rated value for the generator, wherein the electric loads having the lowest priority value are sequentially disconnected from the generator until the combined load on the generator falls below the rated value for the generator; and

selectively reassigning priority values to the electric loads to modify the order the electric loads are disconnected from the generator upon the selection of another priority assignment program by the user.

8. The method of claim 7 wherein the initial priority values for the electric loads are assigned based upon the physical connection of the electric loads to the plurality of outputs.

9. The method of claim 8 wherein the priority values are reassigned based upon user input.

10. The method of claim 9 wherein the user input is received from a user interface device.

11. The method of claim 9 wherein the priority assignment programs are presented on a user interface device such that the user can select one of the priority assignment programs through the user interface device.

12. The method of claim 7 further comprising the step of adjusting the loads connected to the generator based upon the reassigned priority values.

13. The method of claim 7 wherein each of the electric loads are connected to an interconnect device, wherein the control unit selectively connects and disconnects each of the electric loads through the interconnect devices.

14. The method of claim 13 wherein the interconnect devices are each contained within a main breaker panel.

15. The method of claim 13 wherein the interconnect devices are positioned external to a main breaker panel.

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

a transfer switch coupled to the standby generator;

a control unit contained within the transfer switch and operable to selectively connect and disconnect each of the electric loads from the generator, the control unit being configured to;

provide a plurality of predefined priority assignment programs;

assign an initial priority value to each of the electric loads between a highest priority value and a lowest priority value for each of the priority assignment programs;

receive a selection of one of the predefined priority assignment programs from a user;

monitor a combined load on the generator;

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

selectively reassign priority values to the electric loads based upon the selection of another priority assignment program through subsequent user input; and

adjust the loads connected to the generator based upon the reassigned priority values from the another selected priority assignment program.

17. The load management system of claim 16 further comprising a user interface device coupled to the control unit of the transfer switch, wherein the user selects the priority assignment programs through the user interface device.

18. The load management system of claim 17 further comprising a plurality of interconnect devices each positioned between one of the electric loads and the transfer switch, wherein each interconnect device is operable to selectively connect and disconnect the electric load from the generator based upon a signal from the control unit.