OPTIMAL LOAD DISTRIBUTING SYSTEM

• US 20090276103A1
• Filed: 04/30/2008
• Published: 11/05/2009
• Est. Priority Date: 04/30/2008
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: IWAMOTO, Tetsuya, Watanabe, Tsuneo
• Granted Patent: US 7,853,365 B2
• Time in Patent Office: Days
• US Class Current: 700/291
• CPC Class Codes: H02J 2203/20 Simulating, e g planning, reliability check, modelling or computer assisted design [CAD]
• CPC Class Codes: H02J 3/00 Circuit arrangements for ac mains or ac distribution networks
• CPC Class Codes: Y02B 70/3225 Demand response systems, e.g. load shedding, peak shaving
• CPC Class Codes: Y02E 60/00 Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
• 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

To provide an operation schedule that minimizes the fuel cost that involves a minimum number of input parameters, is calculated offline, and is arranged taking into account the output distribution among a plurality of units that minimizes the fuel cost.

An optimal load distributing system for managing an optimal load distribution of a total output of a power plant composed of a plurality of units among the plurality of units has: a data inputting part 1 that is used for inputting plant specifications of each unit required for optimal load distribution; an optimal load distribution input file 2 that stores data input via the data inputting part; an optimal load distribution calculating part 3 that carries out an optimal load distribution calculation based on data stored in the optimal load distribution input file; an optimal load distribution output file 4 that stores the result of the calculation carried out by the optimal load distribution calculating part; an optimal load distribution pattern displaying part 5 that displays a sending-end characteristic curve for each unit, a fuel cost curve for each unit, a curve of the load optimally distributed to each unit versus the total output, a fuel cost curve for the total output, and fuel cost curves for comparison between a conventional load distribution and the optimal load distribution based on data stored in the optimal load distribution output file and the optimal load distribution input file; and an optimal load distribution schedule displaying part 6 that displays a power transmission time schedule table, a power transmission time schedule curve, and a fuel cost comparison table for different operating schemes.

Claims

1. An optimal load distributing system that manages an optimal load distribution of a total output of a power plant composed of a plurality of units among the plurality of units, comprising:

data inputting means that is used for inputting plant specifications of each unit required for optimal load distribution;

an optimal load distribution input file that stores data input via said data inputting means;

optimal load distribution calculating means that carries out an optimal load distribution calculation based on data stored in said optimal load distribution input file;

an optimal load distribution output file that stores the result of the calculation carried out by said optimal load distribution calculating means;

optimal load distribution pattern displaying means that displays a sending-end characteristic curve for each unit, a fuel cost curve for each unit, a curve of the load optimally distributed to each unit versus the total output, a fuel cost curve for the total output, and fuel cost curves for comparison between a conventional load distribution and the optimal load distribution based on data stored in said optimal load distribution output file and said optimal load distribution input file; and

optimal load distribution schedule displaying means that displays a power transmission time schedule table, a power transmission time schedule curve, and a fuel cost comparison table for different operating schemes.

2. The optimal load distributing system according to claim 1, further comprising means capable of carrying out an optimal load distribution calculation for three or more units by grouping the three or more units into two virtual units and applying an optimal load distribution calculation for two units to the two virtual units.

3. The optimal load distributing system according to claim 1, wherein said optimal load distribution pattern displaying means visually displays the calculated load distributed to each unit versus the total output and a total fuel cost.

4. The optimal load distributing system according to claim 1, wherein the optimal load distribution calculation is carried out based on an input desired transmission power output value for each time zone, and an operation schedule table and an operation schedule curve that describe an optimal load distribution among the units are displayed.

5. The optimal load distributing system according to claim 4, wherein when an operation schedule is to be displayed, the operation schedule is designed to minimize the number of activations and stops of an auxiliary machine based on a transmission power in a case where an auxiliary machine changeover occurs and a minimum auxiliary machine operating time input via said data inputting means.

6. The optimal load distributing system according to claim 5, wherein, in a case where a large load change in a short time that exceeds the processing capacity of the system occurs, an operational inconsistency in which the load has to be increased before the load is completely decreased is calculated, and the inconsistent status is visually displayed.

7. The optimal load distributing system according to claim 1, wherein the total fuel cost is compared among three cases including a case where the load is conventionally (equally) distributed among the units, a case where the load is distributed among the units by taking into account activations and stops of an auxiliary machine, and a case where the load is optimally distributed by giving priority to cost reduction.

8. The optimal load distributing system according to claim 4, wherein desired total output values (time of day and output) are previously input, the load starts to be gradually increased before a desired time according to the rate of change of load for each unit so that a desired output is achieved at a desired time in a case of increasing the load, the load starts to be decreased after a desired time and a desired load achievement time is calculated in a case of decreasing the load, and the optimal load distribution schedule displaying means displays the result.

9. An optimal load distributing method for managing an optimal load distribution of a total output of a power plant composed of a plurality of units among the plurality of units, comprising:

inputting plant specifications of each unit required for optimal load distribution and storing input data;

carrying out an optimal load distribution calculation based on said data and storing the result of the calculation;

displaying a sending-end characteristic curve for each of said plurality of units, a fuel cost curve for each of said plurality of units, a curve of the load optimally distributed to each of said plurality of units versus the total output, a fuel cost curve for the total output, and fuel cost curves for comparison between a conventional load distribution and the optimal load distribution based on said data and the result of said calculation; and

displaying a power transmission time schedule table, a power transmission time schedule curve, and a fuel cost comparison table for different operating schemes.