Renewable energy system stabilization system and system stabilization support method

Patent metadata

Field	Value
Publication number	US-11916394-B2
Application number	US-202017781400-A
Country	US
Kind code	B2
Filing date	Sep 1, 2020
Priority date	Dec 20, 2019
Publication date	Feb 27, 2024
Grant date	Feb 27, 2024

Abstract

Provided are an operation limit value management unit managing an operation limit value related to the power flow power of system equipment and a determination unit calculating the power flow state for each set time of the future of a power system based on load dispatching information including a power generation plan value, a predicted output value, and a predicted value of power demand and determining whether or not stable is each power flow state by comparison with the operation limit value. The determination unit sequentially changes the first output power of a first power source defined by the power generation plan value of the first power source and calculates each power flow state based on power including the changed first output power and a predicted value of the output of a second power source.

First claim

The invention claimed is:

1. A renewable energy system stabilization system supporting operation of a power system connecting a load and at least one of a first power source including a thermal power generator generating electricity using at least thermal power as power generation energy and a second power source including a renewable energy apparatus generating electricity with renewable energy, the system comprising:
an operation limit value management unit managing an operation limit value related to power flow power of system equipment; and
a determination unit calculating a power flow state for each set time of future of the power system based on load dispatching information including a power generation plan value of the first power source, a predicted value of output of the second power source, and a predicted value of power demand in the power system and determining whether or not stable is each calculated power flow state by comparing each calculated power flow state with the operation limit value, wherein
the determination unit sequentially changes first output power of the first power source defined by the power generation plan value of the first power source, calculates each of the power flow states based on power including the changed first output power and the predicted value of the output of the second power source, and outputs a result of the calculation to the operation limit value management unit, and
on condition that a positive determination result is obtained from the determination unit, the operation limit value management unit manages the operation limit value at each set time of the future as a sum of the changed first output power and the predicted value of the output of the second power source added to the changed first output power.

2. The renewable energy system stabilization system according to claim 1 , wherein the operation limit value management unit transmits operation limit value information including the operation limit value at each set time of the future to a load dispatching control station system operating the power system.

3. The renewable energy system stabilization system according to claim 1 , further comprising an output adjustment information generation unit generating output adjustment information for adjusting at least one of output power of the first power source and output power of the second power source on condition that a negative determination result is obtained from the determination unit.

4. The renewable energy system stabilization system according to claim 3 , wherein the output adjustment information generation unit transmits the output adjustment information to a load dispatching control station system operating the power system.

5. The renewable energy system stabilization system according to claim 1 , further comprising:
an assumed fault condition setting unit setting an assumed fault condition indicating a condition of a fault assumed to occur in the power system at each set time of the future based on the load dispatching information; and
a control countermeasure information generation unit generating control countermeasure information indicating a control countermeasure in an event of a fault meeting the assumed fault condition based on the load dispatching information.

6. The renewable energy system stabilization system according to claim 5 , wherein the control countermeasure information generation unit transmits the control countermeasure information to at least one of a fault countermeasure execution device managing each of the first power source and the second power source as a control object and a load dispatching control station system operating the power system.

7. The renewable energy system stabilization system according to claim 5 , wherein the control countermeasure information generation unit generates, as the control countermeasure information, power source stop information for stopping at least one of a part of the first power source and the second power source and load shedding information for shedding a load connected to the first power source on condition that a part of the first power source is stopped.

8. The renewable energy system stabilization system according to claim 5 , wherein the control countermeasure information generation unit generates, as the control countermeasure information, overload countermeasure information for eliminating a load of the first power source becoming overload, transient stability countermeasure information for maintaining stability with respect to the power system, voltage maintenance information for maintaining a voltage of the power system within a set voltage range, frequency countermeasure information for maintaining a frequency of the power system within a set frequency range, and restoration countermeasure information for returning the power flow state of the power system to a power flow state before the occurrence of the fault meeting the assumed fault condition.

9. A system stabilization support method in a system supporting operation of a power system connecting a load and at least one of a first power source including a thermal power generator generating electricity using at least thermal power as power generation energy and a second power source including a renewable energy apparatus generating electricity with renewable energy, the method comprising:
an operation limit value management step of managing an operation limit value related to power flow power of system equipment; and
a determination step of calculating a power flow state for each set time of future of the power system based on load dispatching information including a power generation plan value of the first power source, a predicted value of output of the second power source, and a predicted value of power demand in the power system and determining whether or not stable is each calculated power flow state by comparing each calculated power flow state with the operation limit value, wherein
in the determination step, first output power of the first power source defined by the power generation plan value of the first power source is sequentially changed and each of the power flow states is calculated based on power including the changed first output power and the predicted value of the output of the second power source, and
in the operation limit value management step, on condition that a positive determination result is obtained in the determination step, the operation limit value at each set time of the future is managed as a sum of the first output power changed in the determination step and the predicted value of the output of the second power source added to the changed first output power.

10. The system stabilization support method according to claim 9 , wherein, in the operation limit value management step, operation limit value information including the operation limit value at each set time of the future is transmitted to a load dispatching control station system operating the power system.

11. The system stabilization support method according to claim 9 , further comprising an output adjustment information generation step of generating output adjustment information for adjusting at least one of output power of the first power source and output power of the second power source on condition that a negative determination result is obtained in the determination step.

12. The system stabilization support method according to claim 11 , wherein, in the output adjustment information generation step, the output adjustment information is transmitted to a load dispatching control station system operating the power system.

13. The system stabilization support method according to cla

Assignees

• Hitachi Ltd

Inventors

• Kokai Yutaka
• Kuroda Eisuke
• Tsunedomi Kunihiko

Classifications

• H02J2101/20

  Dispersed power generation using renewable energy sources · CPC title

• H02J2101/22

  Solar energy · CPC title

• H02J3/0014

  for preventing or reducing power oscillations in networks · CPC title

• H02J3/381 Primary

  Dispersed generators · CPC title

• H02J3/003

  Load forecast, e.g. methods or systems for forecasting future load demand · CPC title