Power system management device and method

Patent metadata

Field	Value
Publication number	US-9843190-B2
Application number	US-201414461974-A
Country	US
Kind code	B2
Filing date	Aug 18, 2014
Priority date	Sep 20, 2013
Publication date	Dec 12, 2017
Grant date	Dec 12, 2017

Abstract

A power system management device which manages a system state in a power system includes a system state candidate calculation unit for calculating state amounts of the system state based on an objective function from system characteristic information indicating characteristic information of a system structure, an inter-state distance calculation unit for calculating an inter-state distance representing a similarity of values between state amounts of the system state calculated by the system state candidate calculation unit, and a variability evaluation value calculation unit for calculating a variability evaluation value in which a variability of the system state is evaluated, based on an objective function value calculated from the state amount of the system state calculated by the system state candidate calculation unit and the inter-state distance calculated by the inter-state distance calculation unit. The system state is selected based on the calculated variability evaluation value.

First claim

What is claimed is:

1. A power system management device configured to manage a system state in a power system, comprising:
a system state candidate calculation unit configured to calculate a plurality of state amounts of the system state based on a predetermined objective function from system characteristic information indicating characteristic information of a system structure including a load, a device, or a power transmission line connected to the power system;
an inter-state distance calculation unit configured to calculate an inter-state distance, wherein the inter-state distance is a distance value between the system state and a different system state; and
a variability evaluation value calculation unit configured to calculate a variability evaluation value in which a variability of each system state is evaluated, based on an objective function value which is calculated from the state amount of the system state which has been calculated by the system state candidate calculation unit and the inter-state distance which has been calculated by the inter-state distance calculation unit, wherein
the system state is selected based on the variability evaluation value calculated by the variability evaluation value calculation unit.

2. The power system management device according to claim 1 , wherein
the predetermined objective function includes functions relevant to a fuel cost, a transmission loss, a system stability, or the number of times of a control device operation.

3. The power system management device according to claim 1 , wherein
the system state candidate calculation unit weights a plurality of objective functions and calculates the state amount of the system state.

4. The power system management device according to claim 1 , wherein
the inter-state distance is calculated based on the state amount of the system state which has a predetermined number of objective function values in ascending/descending order from the smallest/largest value within the objective function values obtained by the system state candidate calculation unit.

5. The power system management device according to claim 1 , wherein
the system characteristic information includes an expected value and a variation value of a system state amount.

6. The power system management device according to claim 1 , wherein
the variability evaluation value is calculated regarding the system state which has any of a predetermined number of values of the inter-state distance in ascending order from the smallest value or a value of the inter-state distance within a predetermined threshold among the values of the inter-state distance which have been calculated by the inter-state distance calculation unit.

7. The power system management device according to claim 1 , wherein
the variability evaluation value is obtained from an average value of the plurality of objective function values, a difference between the plurality of objective function values, or a value obtained by dividing the value of the inter-state distance by the objective function value.

8. The power system management device according to claim 1 , wherein
the state amount of the system state includes a power generation amount by a power generator, a control amount by a power system control device, a power flow amount in the power system, or a voltage amount in the power system.

9. The power system management device according to claim 1 , further comprising:
a communication unit configured to obtain information including the system state in the power system.

10. The power system management device according to claim 1 , wherein
a control command is transmitted to a control device of the power system based on a determined system state amount of the power system.

11. The power system management device according to claim 1 , wherein
a system state amount in a selected system state is displayed.

12. The power system management device according to claim 1 , wherein
the system state candidate calculation unit obtains a system state amount which minimizes/maximizes the objective function value by using a method which includes linear programming, nonlinear programming, an interior point method, a genetic algorithm, evolutionary programming, a tabu search, a neural network, or PSO.

13. A power system management method for managing a system state in a power system, comprising:
calculating a plurality of state amounts of the system state based on a predetermined objective function from system characteristic information indicating characteristic information of a system structure including a load, a device, or a power transmission line connected to the power system;
calculating an inter-state distance, wherein the inter-state distance is a distance value between the system state and a different system state;
calculating a variability evaluation value in which a variability of each system state is evaluated based on an objective function value which is calculated from the calculated state amount of the system state and the calculated inter-state distance; and
selecting the system state based on the calculated variability evaluation value.

Assignees

• Hitachi Ltd

Inventors

• Yamazaki Jun
• Sato Yasuo
• Sawa Toshiyuki
• Kawahara Taichiro

Classifications

• H02J3/381

  Dispersed generators · CPC title

• H02J2103/30

  Simulating, planning, modelling, reliability check or computer assisted design [CAD] of electric power networks · CPC title

• H02J2101/20

  Dispersed power generation using renewable energy sources · CPC title

• H02J3/0014 Primary

  for preventing or reducing power oscillations in networks · CPC title

• Y02E40/70

  Smart grids as climate change mitigation technology in the energy generation sector · CPC title