APPARATUS AND METHOD FOR CONTROLLING AND SIMULATING ELECTRIC POWER SYSTEM

• US 20120303170A1
• Filed: 12/12/2011
• Published: 11/29/2012
• Est. Priority Date: 06/15/2010
• Status: Abandoned Application

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: TOMITA, Taminori, TOMITA, Yasushi
• Application Number:
  US13/316,732
• Publication Number:
  US 20120303170A1
• Time in Patent Office: Days
• US Class Current: 700/286
• CPC Class Codes: H02J 13/00002 characterised by monitoring
• CPC Class Codes: H02J 13/00016 using a wired telecommunication network or a data transmission bus
• CPC Class Codes: H02J 13/00034 the elements or equipment being or involving an electric power substation
• CPC Class Codes: H02J 2203/20 Simulating, e g planning, reliability check, modelling or computer assisted design [CAD]
• CPC Class Codes: H02J 2310/58 The condition being electrical
• CPC Class Codes: H02J 3/144 Demand-response operation of the power transmission or distribution network
• 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 60/00 Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
• CPC Class Codes: Y04S 10/30 State monitoring, e.g. fault, temperature monitoring, insulator monitoring, corona discharge
• CPC Class Codes: Y04S 20/222 Demand response systems, e.g. load shedding, peak shaving
• CPC Class Codes: Y04S 40/124 using wired telecommunication networks or data transmission busses
• CPC Class Codes: Y04S 40/20 Information technology specific aspects, e.g. CAD, simulation, modelling, system security

Abstract

A power system power flow simulator includes a power system power flow calculator using load power in local voltage transformers to calculate power flow in power system extending from a transformer substation to local power transformers, customer load imitators which calculate time change of load power used by customers, dispersed power source imitators which calculate time change of power generated by dispersed power sources and a system status manager which manages operation procedure. The system status manager advances processing while supplying a load power request message with time information attached thereto to the customer load imitators and the dispersed power source imitators, and decides time intervals of supply of the load power request message in accordance with the power load temporal change rate calculated by the customer load imitators and the dispersed power source imitators.

Claims

1. A system status operation device comprising:

an information obtaining part to obtain information of power amounts of power flow or reverse power flow in plural customers on service lines branched at plural local power transformers from power line at frequency according to change amount of the power amounts and

an operation part to calculate voltage condition at predetermined points on the power line on the basis of the information of the obtained plural power amounts.

2. The system status operation device according to claim 1, wherein

information of the power amount is transmitted as power amount at time indicated by time information in response to a power amount request message containing the time information.

3. The system status operation device according to claim 2, wherein

interval for the obtainment corresponding the frequency is prescribed and the information of power amount contains information concerning the interval for obtainment.

4. The system status operation device according to claim 3, wherein

the information of power amount contains time information concerning transmission of next information of power amount as the information concerning the interval for obtainment.

5. The system status operation device according to claim 4, wherein

when the time information concerning transmission of the next information of power amount is transmitted from plural points, shortest time interval of the time is selected.

6. The system status operation device according to claim 4, wherein

the change amount is calculated as power amount change rate prescribed by power amount at time indicated by the time information and power amount at predetermined time in the past before the time indicated by the time information and when the power amount change rate is larger than predetermined value, the frequency is set to be increased.

7. The system status operation device according to claim 5, wherein

when the power amount change rate is smaller than predetermined value, the frequency is decided to correspond to predetermined maximum interval.

8. A system status operation system including a power distribution status operation part and plural transmission parts, wherein

the power distribution status operation part transmits a power amount request message containing time information to the transmission parts and

each of the plural transmission parts transmits information of power amount of power flow or reverse power flow in customers on service lines branched at plural power transformers from power line at frequency according to change amount of power amount as power amount message in response to the power amount request message,

the power distribution status operation part receiving the power amount message and calculating voltage condition at predetermined points on the power line on the basis of power amount indicated by the received power amount message.

9. The system status operation system according to claim 8, wherein

the change amount is calculated in the transmission parts.

10. The system status operation system according to claim 9, wherein

the change amount is calculated each time the power amount request message is received.

11. The system status operation system according to claim 10, wherein

the change amount is calculated by the power distribution status operation part.

12. A system controller comprising:

an information obtaining part to obtain information of power amounts of power flow or reverse power flow in plural customers on service lines branched at plural local power transformers from power line at frequency according to change amount of the power amounts;

an operation part to calculate voltage condition at predetermined points on the power line on the basis of the information of the obtained plural power amounts; and

a control part to control voltage of the system on the basis of operation result.

13. A power distribution system power flow simulator which simulates power flow in power distribution system extending from a transformer substation through local power transformers to customer loads, comprising:

a power distribution system power flow calculator using load power in the local power transformers to calculate power flow of power in power distribution system part extending from the transformer substation to the local power transformers;

plural customer load imitators to imitate time change of load power of forward power flow which is power used by plural customers individually;

plural dispersed power source imitators to imitate time change of load power of reverse power flow which is power generated by plural dispersed power sources individually; and

a system status manager which supplies a load power request message containing time information to the customer load imitators and the dispersed power source imitators and obtains information containing load power at time indicated by the time information from the customer load imitators and the dispersed power source imitators as response information thereto, the system status manager using the obtained load power to calculate load power at plural local power transformers disposed in the power distribution system, the system status manager supplying the calculated load power at local power transformers to the power distribution system power flow calculator to make the power distribution system power flow calculator execute power flow calculation;

the customer load imitators and the dispersed power source imitators transmitting information deciding time intervals of supply of the load power request message after next time to the system status manager as response information to the load power request message;

the system status manager deciding the time intervals of supply after next time on the basis of information deciding the time intervals of supply.

14. The power distribution system power flow simulator according to claim 13, wherein

the customer load imitators and the dispersed power source imitators calculate load power temporal change rates in the customer load imitators and the dispersed power source imitators on the basis of load power at time indicated by the time information and load power at time before the time indicated by the time information and

transmit the calculated load power temporal change rates to the system status manager as information deciding the time intervals of supply.

15. The power distribution system power flow simulator according to claim 13, wherein

the customer load imitators and the dispersed power source imitators make the information deciding the time intervals of supply be contained into response information to the load power request message to be transmitted to the system status manager.

16. The power distribution system power flow simulation according to claim 13, wherein

when maximum load power temporal change rate is smaller than predetermined value, the customer load imitators and the dispersed power source imitators stop transmission of the information deciding the time intervals of supply of the load power request message or transmit information deciding predetermined maximum time intervals to the system status manager and

the system status manager changes the time intervals of supply after next time to the predetermined maximum time intervals when the system status manager confirms that all of the customer load imitators and the dispersed power source imitators stop transmission of the information deciding the time intervals of supply or the information deciding the predetermined maximum time intervals is transmitted.

17. The power distribution system power flow simulator according to claim 13, wherein

the system status manager obtains time constants of time change of load power of the customer load imitators and the dispersed power source imitators from among the response information responded by the customer load imitators and the dispersed power source imitators and

decides time intervals of supply of the load power request message after next time in accordance with minimum time constant of the obtained time constants of time change of load power.

18. A system control method comprising:

obtaining information of power amounts of power flow or reverse power flow in plural customers on service lines branched at plural local power transformers from power line at frequency according to change amount of the power amounts and

calculating voltage condition at predetermined points on the power line on the basis of the information of the obtained plural power amounts.

19. A power distribution system power flow simulation method of simulating power flow in power distribution system extending from a transformer substation through local power transformers to customer loads by computer, wherein

the computer comprises:

a power distribution system power flow calculator using load power in the local power transformers to calculate power flow of power in power distribution system part extending from the transformer substation to the local power transformers;

plural customer load imitators to imitate time change of load power of forward power flow which is power used by plural customers individually;

plural dispersed power source imitators to imitate time change of load power of reverse power flow which is power generated by plural dispersed power sources individually; and

a system status manager to manage processing in the power distribution system power flow calculator, the customer load imitators and the dispersed power source imitators; and

the computer executes, as processing in the system status manager, the following;

processing of supplying a load power request message containing time information to the customer load imitators and the dispersed power source imitators;

processing of obtaining information containing load power at time indicated by the time information from the customer load imitators and the dispersed power source imitators as response information to the load power request message;

processing of calculating load power in plural local power transformers disposed in the power distribution system using the obtained load power;

processing of supplying the calculated load power in the local power transformers to the power distribution system power flow calculator; and

processing of deciding time intervals of supply of the load power request message after next time on the basis of response information to the load power request message from the customer load imitators and the dispersed power source imitators.

20. The power distribution system power flow simulation method according to claim 19, wherein

the computer executes, as processing in the customer load imitators and the dispersed power source imitators, the following:

processing of calculating load power temporal change rates in the customer load imitators and the dispersed power source imitators on the basis of load power at time indicated by the time information and load power at time before the time indicated by the time information; and

processing of transmitting information deciding time intervals of supply of the load power request message after next time in accordance with maximum load power temporal change rate of the calculated load power temporal change rates to the system status manager; and

the computer executes, as processing in the system status manager, the following;

processing of deciding time intervals of supply after next time on the basis of information deciding the supply time intervals transmitted from the customer load imitators and the dispersed power source imitators.

21. The power distribution system power flow simulation method according to claim 20, wherein

the computer executes, as processing of deciding the supply time intervals after next time, the following:

processing of producing information deciding time intervals of supply of the load power request message after next time to be predetermined maximum time intervals when the maximum load power temporal change rate is smaller than predetermined value.

22. The power distribution system power flow simulation method according to claim 19, wherein

the computer executes, as processing of deciding supply time intervals after next time, the following:

processing of obtaining time constants of time change of load power from among the response information responded by the customer load imitators and the dispersed power source imitators and

processing of deciding time intervals of supply of the load power request message after next time in accordance with minimum time constant of the obtained time constants of time change of load power.