Integrated distribution system optimization

• US 8,886,362 B2
• Filed: 03/30/2012
• Issued: 11/11/2014
• Est. Priority Date: 03/30/2012
• Status: Active Grant

• Current Assignee: GE Infrastructure Technology, LLC (GE Vernova, Inc.)
• Original Assignee: General Electric Company
• Inventors: Krok, Michael Joseph, Black, Jason Wayne, Genc, Sahika, Baggu Data Venkata Satya, Murali Mohan, Tyagi, Rajesh
• Primary Examiner(s): JARRETT, RYAN A
• Application Number:
  US13/435,940
• Publication Number:
  US 20130261823A1
• Time in Patent Office: 956 Days
• Field of Search: None
• US Class Current: 700/291
• CPC Class Codes: G05F 5/00 Systems for regulating electric variables by detecting deviations in the electric input to the system and thereby controlling a device within the system to obtain a regulated output
• CPC Class Codes: H02J 2203/20 Simulating, e g planning, reliability check, modelling or computer assisted design [CAD]
• CPC Class Codes: H02J 3/003 Load forecast, e.g. methods or systems for forecasting future load demand
• CPC Class Codes: H02J 3/16 by adjustment of reactive power
• CPC Class Codes: H02J 3/28 Arrangements for balancing of the load in a network by storage of energy
• CPC Class Codes: H02J 3/381 Dispersed generators
• CPC Class Codes: Y02B 70/3225 Demand response systems, e.g. load shedding, peak shaving
• CPC Class Codes: Y02E 40/30 Reactive power compensation
• CPC Class Codes: Y02E 40/70 Smart grids as climate change mitigation technology in the energy generation sector
• CPC Class Codes: Y02E 60/00 Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
• 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
• CPC Class Codes: Y04S 20/222 Demand response systems, e.g. load shedding, peak shaving
• CPC Class Codes: Y04S 40/20 Information technology specific aspects, e.g. CAD, simulation, modelling, system security

Abstract

A power forecasting module determines a load forecast of a distribution system (DS) and a power generation forecast of distributed energy resources (DERs) A demand response (DR) module estimates an available DR based on the load and the power generation forecast and modifies the load forecast by dispatching an optimal DR. An energy storage commitment module determines a charging/discharging schedule of energy storage devices in the system based on the modified load profile and generates a second load profile by incorporating the charging/discharging schedule of energy storage devices. An unit commitment (UC) module determines a DER schedule of supplying electrical power to the loads in the second load profile based on a first objective function. An economic dispatch (ED) module determines an optimum operating point for each DER and an Integrated Volt-VAR Control (IVVC) module controls distribution assets to maintain a voltage profile in the system.

Claims

1. A system comprising:

a power forecasting module for forecasting a load profile of a distribution system and a power generation forecast of distributed energy resources (DERs) in the distribution system for a period of interest;

a demand response module for estimating an available demand response on the distribution system for the period of interest based on the load profile and the power generation forecast and modifying the load profile by dispatching an optimal demand response;

an energy storage commitment module to determine a charging and discharging schedule of energy storage devices in the distribution system for the period of interest based on the modified load profile and generate a second load profile by incorporating the charging and discharging schedule of energy storage devices in the modified load profile;

an unit commitment module to determine a DER schedule of supplying electrical power to the loads in the second load profile based on a first objective function;

an economic dispatch module to determine an optimum operating point for each DER in the DER schedule; and

an Integrated Volt-VAR Control (IVVC) module having software and hardware elements to control distribution assets to maintain a voltage profile for the period of interest in the distribution system based on information from the economic dispatch module.

2. The distribution system of claim 1, wherein the load forecast is determined based on time, weather conditions, customer types, distribution system conditions and historical data.

3. The distribution system of claim 1, wherein the modified load profile is obtained by shifting a peak load above a threshold value to a time where the load is below the threshold value.

4. The distribution system of claim 1, wherein the charging and discharging schedule of energy storage devices include charging the energy storage devices during off peak hours and discharging during peak hours.

5. The distribution system of claim 1, wherein the energy storage commitment module determines the charging and discharging schedule based on factors including load for each time step, generation cost for each time step, initial status of the energy storage device, the energy storage device capacity, charging efficiency of the energy storage device, minimum reserve of the energy storage device and charge and discharge rate of the energy storage device.

6. The distribution system of claim 1, wherein the second load profile is generated by adding or subtracting a total amount of energy storage device discharge or charge respectively from the modified load profile.

7. The distribution system of claim 1, wherein the DER schedule includes a schedule for utilizing power from DERs and a power grid.

8. The distribution system of claim 7, wherein the first objective function includes minimizing operating costs of supplying power to loads from DERs and the power grid with system constraints.

9. The distribution system of claim 8, wherein the system constraints include voltage limits or reactive power limits.

10. The distribution system of claim 1, wherein the optimum operating point for each DER is determined based on constraints including lower and upper bounds on power amplitudes, power per time step and penalties on operating at the lower bound.

11. The distribution system of claim 1, wherein the IVVC module includes a load flow algorithm to determine voltage information at various nodes in the distribution system.

12. The distribution system of claim 1, wherein the distribution assets include capacitance banks, voltage regulators and transformers.

13. A method of controlling electrical power in a distribution system comprising:

forecasting a load profile of the distribution system and a power generation profile of distributed energy resources (DERs) in the distribution system for a period of interest;

estimating an available demand response on the distribution system for the period of interest and modifying the load profile by dispatching an optimal demand response;

determining a charging and discharging schedule of energy storage devices in the distribution system for the period of interest based on the modified load profile and generating a second load profile by incorporating the charging and discharging schedule of energy storage devices in the modified load profile;

determining a DER schedule of supplying electrical power to the loads in the second load profile based on a first objective function;

determining an optimum operating point for each DERs in the DER schedule; and

controlling distribution assets in the distribution system to maintain a voltage profile for the period of interest.

14. The method of claim 13, wherein the load profile is forecasted based on time, weather conditions, customer types, distribution system conditions and historical data.

15. The method of claim 13, wherein the charging and discharging schedule of energy storage devices include charging the energy storage devices during off peak hours and discharging during peak hours.

16. The method of claim 13, wherein charging and discharging schedule is determined based on factors including load for each time step, generation cost for each time step, initial status of the energy storage device, the energy storage device capacity, charging efficiency of the energy storage device, minimum reserve of the energy storage device and charge and discharge rate of the energy storage device.

17. The method of claim 13, wherein the second load profile is generated by adding or subtracting a total amount of energy storage device discharge or charge respectively from the modified load profile.

18. The method of claim 13, wherein DER schedule includes a schedule for utilizing energy from DERs and a power grid.

19. The method of claim 18, wherein the first objective function includes minimizing operating costs of supplying energy to loads from DERs and the power grid power with system constraints.

20. The method of claim 13, wherein the optimum operating point for each DER is determined based on constraints including lower and upper bounds on power amplitudes, power per time step and penalties on operating at the lower bound.

21. A system comprising:

a power forecasting module for forecasting a load profile of the distribution system and a power generation forecast of distributed energy resources (DERs) in the distribution system for a period of interest;

an energy storage commitment module to determine a charging and discharging schedule of energy storage devices in the distribution system for the period of interest based on the load profile and the power generation forecast and modify the load profile based on the charging and discharging schedule of energy storage devices;

a demand response module for estimating an available demand response on the distribution system for the period of interest based on a modified load profile and generating a second load profile by dispatching an optimal demand response;

an unit commitment module to determine a DER schedule of supplying electrical power to the loads in the second load profile based on a first objective function;

an economic dispatch module to determine an optimum operating point for each DERs in the DER schedule; and

an IVVC module having software and hardware elements to control distribution assets to maintain a voltage profile for the period of interest in the distribution system based on information from the economic dispatch module.