Method and Apparatus for Determining Actual Reactive Capability Curves

• US 20070162189A1
• Filed: 03/13/2007
• Published: 07/12/2007
• Est. Priority Date: 06/25/2004
• Status: Active Grant

• Current Assignee: Emerson Process Management Power & Water Solutions Incorporated (Emerson Electric Company)
• Original Assignee: Emerson Process Management Power & Water Solutions Incorporated (Emerson Electric Company)
• Inventors: Cheng, Xu, Francino, Peter, Huff, Frederick
• Granted Patent: US 7,385,300 B2
• Time in Patent Office: Days
• US Class Current: 700/287
• CPC Class Codes: G06Q 10/04 Forecasting or optimisation specially adapted for administrative or management purposes, e.g. linear programming or "cutting stock problem" market predictions or forecasting for commercial activities G06Q30/0202
• CPC Class Codes: G06Q 10/06 Resources, workflows, human or project management; Enterprise or organisation planning; Enterprise or organisation modelling
• CPC Class Codes: G06Q 50/06 Energy or water supply
• CPC Class Codes: H02J 3/0075 for providing alternative feeding paths between load and source according to economic or energy efficiency considerations, e.g. economic dispatch
• CPC Class Codes: H02J 3/46 Controlling of the sharing of output between the generators, converters, or transformers
• CPC Class Codes: H02J 3/50 Controlling the sharing of the out-of-phase component
• CPC Class Codes: H02P 9/105 for increasing the stability
• CPC Class Codes: Y02B 70/3225 Demand response systems, e.g. load shedding, peak shaving
• CPC Class Codes: Y02E 10/72 Wind turbines with rotation axis in wind direction
• CPC Class Codes: Y04S 20/222 Demand response systems, e.g. load shedding, peak shaving

Abstract

A system for generating updated reactive capability curves of a generator operates the genarator at a number of operating load levels and at a number of different power factors to collect data regarding the real and reactive power generated at each of the various operating load levels and power factors. Subsequently, the system analyzes the collected data to determine an actual reactive capability curve of the generator. The system also provides generator health monitoring and identifies changes and trends in the capability curves of the generator. The updated reactive capability curves may be used by an economic dispatch program in determining optimum MW and MVAR setpoints for the generator.

Claims

1. A method of determining a transitional operating point of a generator, the transitional operating point corresponding to a particular load level, the method comprising:

setting the operating point of the generator to the particular load level;

setting the operating power factor of the generator close to one;

measuring total power of the generator;

incrementally decreasing the operating power factor of the generator and measuring incremental change in the total power of the generator;

comparing the incremental change in the total power of the generator to a threshold; and

if the incremental change is greater than the threshold, storing the operating power factor as the transitional operating power factor at the particular load level.

2. A method of claim 1, further comprising at least one of:

(1) allowing a user of the generator to determine the threshold value and (2) determining the threshold based on historical values of the transitional operating point.

3. A method of claim 1, wherein decreasing the operating power factor comprises decreasing the operating power factor in a manner such that the resulting operating power factor is a lagging power factor.

4. A method of claim 1, further comprising setting the operational load point to a plurality of operating levels, wherein each of the plurality of operating levels is below a maximum load capacity of the generator and determining a plurality of transitional operating points of the generator at each of the plurality of operating load levels.

5. A method of claim 4, further comprising:

storing each of the plurality of transitional operating points;

representing the plurality of transitional operating points by a neural network; and

using the neural network in an economic dispatch program used to allocate a power demand to the generator.