ELECTRIC POWER CONTROL SYSTEM

• US 20160056630A1
• Filed: 04/07/2014
• Published: 02/25/2016
• Est. Priority Date: 04/09/2013
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: MARUHASHI, Kenichi, HARADA, Takashi
• Granted Patent: US 10,074,984 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G05B 15/02 electric
• CPC Class Codes: H02J 3/28 Arrangements for balancing of the load in a network by storage of energy
• CPC Class Codes: H02J 7/34 Parallel operation in networks using both storage and other dc sources, e.g. providing buffering H02J7/14 takes precedence

Abstract

An electric power control system of the present invention includes an electric power supplying means, a load means, and an energy storing means. The electric power control system includes: an energy storage controlling means for controlling the energy storing means so as to decrease charge or discharge electric power over a response time corresponding to a set time constant for energy storing means; and a supplied energy controlling means for executing control to change electric power supplied by the electric power supplying means over a response time corresponding to a set time constant for electric power supplying means so that the electric power supply and demand difference is kept within the preset given range. The time constant for energy storing means is set to be longer than the time constant for electric power supplying means.

Claims

1. An electric power control system comprising:

an electric power supplying unit supplying electric power;

a load unit receiving supply of electric power and consuming the electric power;

an energy storing unit being charged with electric power supplied by the electric power supplying unit or discharging electric power to be supplied to the load unit;

a total supplied energy acquiring unit acquiring a total supplied energy, the total supplied energy being a total of electric power supplied by the electric power supplying unit and electric power discharged by the energy storing unit;

a total consumed energy acquiring unit acquiring a total consumed energy, the total consumed energy being a total of electric power consumed by the load unit and electric power with which the energy storing unit is charged;

an energy storage controlling unit, when an electric power supply and demand difference representing a difference between the total supplied energy and the total consumed energy exceeds a preset given range, making the energy storing unit charged with electric power or discharge electric power, and executing control to keep the electric power supply and demand difference within the given range, and also controlling the energy storing unit so as to decrease the charge or discharge electric power over a response time corresponding to a set time constant for energy storing unit; and

a supplied energy controlling unit executing control to change electric power supplied by the electric power supplying unit over a response time corresponding to a set time constant for electric power supplying unit so that the electric power supply and demand difference is kept within the preset given range,

wherein the time constant for energy storing unit is set to be longer than the time constant for electric power supplying unit.

2. The electric power control system according to claim 1, wherein:

when the electric power supply and demand difference exceeds the preset given range, the energy storage controlling unit sets an energy equivalent to the electric power supply and demand difference as an initial energy, and executes control to make the energy storing unit charged with the initial energy of electric power or discharge the initial energy of electric power, and also controls the energy storing unit so as to gradually decrease the charge or discharge electric power over the response time corresponding to the time constant for energy storing unit so that the electric power changes from the initial energy to a given value; and

the supplied energy controlling unit executes control changing electric power supplied by the electric power supplying unit over the response time corresponding to the time constant for electric power supplying unit so that the electric power supply and demand difference is kept within the given range, the electric power supply and demand difference being made as a result that the energy storage controlling unit gradually decreases a charge or discharge energy of the energy storing unit.

3. The electric power control system according to claim 1, wherein:

the electric power supplying unit includes at least one generator; and

the supplied energy controlling unit executes control changing a supplied energy over the response time corresponding to the time constant for electric power supplying unit set for the generator so that the electric power supply and demand difference is kept within the preset given range, the supplied energy being an amount of electric power generated by the generator.

4. The electric power control system according to claim 3, wherein:

the electric power supplying unit includes a plurality of generators, and time constants for electric power supplying unit are set for the respective generators; and

the time constant for energy storing unit is set to be longer than the time constant for electric power supplying unit set for at least one of the generators.

5. The electric power control system according to claim 4, wherein:

the electric power supplying unit includes N generators; and

the time constant for energy storing unit is set to be longer than a (N−

1)^th in increasing order of the time constants for electric power supplying unit set for the generators.

6. The electric power control system according to claim 4, wherein the time constant for electric power supplying unit set for the generator is set so as to be shorter as a change amount of an amount of electric power generated by the generator, the change amount being a set characteristic, and the amount of electric power being controlled by the supplied energy controlling unit is larger.

7. The electric power control system according to claim 4, comprising an electric power supplying unit time constant setting unit for setting the time constant for electric power supplying unit for each of the generators.

8. The electric power control system according to claim 1, comprising a plurality of load units,

the electric power control system comprising a supply and demand condition controlling unit for controlling to stop electric power supply to some load units among the load units when the electric power supply and demand difference exceeds the preset given range,

wherein the energy storage controlling unit and the supplied energy controlling unit operate on a basis of the electric power supply and demand difference after stoppage of electric power supply to the some load units by the supply and demand condition controlling unit.

9. The electric power control system according to claim 8, wherein:

the electric power supplying unit includes an electric power system supplying a given energy of electric power and at least one generator;

the supply and demand condition controlling unit stops electric power supply to the some load units other than one or more load units among the load units when the electric power supply and demand difference exceeds the preset given range due to stoppage of electric power supply from the electric power system, the one or more load units being capable of operating with a total of amounts of electric power which can be generated by all the generators; and

the energy storage controlling unit executes control to make the energy storing unit charged with or discharge an initial energy of electric power, the initial energy being an energy keeping the electric power supply and demand difference within the given range, and the electric power supply and demand difference being that after stoppage of electric power supply to the some load units by the supply and demand condition controlling unit.

10. The electric power control system according to claim 9, wherein:

the some load units to which the supply and demand condition controlling unit stops electric power supply are preset on a basis of a total of amounts of electric power which can be generated, the amounts being preset for the respective generators; and

an initial energy is preset on a basis of a difference between a total of amounts of electric power generated by the generators and a total of consumed energies of the load units to which the supply and demand condition controlling unit does not stop electric power supply, the initial energy being an amount of electric power which the energy storing unit is charged with or discharges under control of the energy storage controlling unit.

11. An electric power control device connected to an electric power supplying unit supplying electric power, a load unit receiving supply of electric power and consuming the electric power, and an energy storing unit being charged with electric power supplied by the electric power supplying unit or discharging electric power to be supplied to the load unit, the electric power control device comprising:

a total supplied energy acquiring unit acquiring a total supplied energy, the total supplied energy being a total of electric power supplied by the electric power supplying unit and electric power discharged by the energy storing unit;

a total consumed energy acquiring unit acquiring a total consumed energy, the total consumed energy being a total of electric power consumed by the load unit and electric power with which the energy storing unit is charged; and

an energy storage controlling unit, when an electric power supply and demand difference representing a difference between the total supplied energy and the total consumed energy exceeds a preset given range, making the energy storing unit charged with electric power or discharge electric power, and executing control to keep the electric power supply and demand difference within the given range, and also controlling the energy storing unit so as to decrease the charge or discharge electric power over a response time corresponding to a set time constant for energy storing unit,

wherein in a case where the electric power supplying unit includes a supplied energy controlling unit, the time constant for energy storing unit is set to be longer than a set time constant for electric power supplying unit, the supplied energy controlling unit being for executing control to change electric power supplied by the electric power supplying unit over a response time corresponding to the set time constant for electric power supplying unit so that the electric power supply and demand difference is kept within the preset given range.

12. The electric power control device according to claim 11, wherein:

when the electric power supply and demand difference exceeds the preset given range, the energy storage controlling unit sets an energy equivalent to the electric power supply and demand difference as an initial energy, and executes control to make the energy storing unit charged with the initial energy of electric power or discharge the initial energy of electric power, and also controls the energy storing unit so as to gradually decrease the charge or discharge electric power over the response time corresponding to the time constant for energy storing unit so that the electric power changes from the initial energy to a given value.

13. A non-transitory computer-readable medium storing a program comprising instructions for causing an electric power control device, which is connected to an electric power supplying unit supplying electric power, a load unit receiving supply of electric power and consuming the electric power, and an energy storing unit being charged with electric power supplied by the electric power supplying unit or discharging electric power to be supplied to the load unit, to realize:

a total supplied energy acquiring unit acquiring a total supplied energy, the total supplied energy being a total of electric power supplied by the electric power supplying unit and electric power discharged by the energy storing unit;

a total consumed energy acquiring unit acquiring a total consumed energy, the total consumed energy being a total of electric power consumed by the load unit and electric power with which the energy storing unit is charged; and

an energy storage controlling unit, when an electric power supply and demand difference representing a difference between the total supplied energy and the total consumed energy exceeds a preset given range, making the energy storing unit charged with electric power or discharge electric power, and executing control to keep the electric power supply and demand difference within the given range, and also controlling the energy storing unit so as to decrease the charge or discharge electric power over a response time corresponding to a set time constant for energy storing unit,

wherein in a case where the electric power supplying unit includes a supplied energy controlling unit, the time constant for energy storing unit is set to be longer than a set time constant for electric power supplying unit, the supplied energy controlling unit being for executing control to change electric power supplied by the electric power supplying unit over a response time corresponding to the set time constant for electric power supplying unit so that the electric power supply and demand difference is kept within the preset given range.

14. The non-transitory computer-readable medium storing the program according to claim 13, wherein:

when the electric power supply and demand difference exceeds the preset given range, the energy storage controlling unit sets an energy equivalent to the electric power supply and demand difference as an initial energy, and executes control to make the energy storing unit charged with the initial energy of electric power or discharge the initial energy of electric power, and also controls the energy storing unit so as to gradually decrease the charge or discharge electric power over the response time corresponding to the time constant for energy storing unit so that the electric power changes from the initial energy to a given value.

15. An electric power control method for controlling electric power of an electric power supplying unit supplying electric power, a load unit receiving supply of electric power and consuming the electric power, and an energy storing unit being charged with electric power supplied by the electric power supplying unit or discharging electric power to be supplied to the load unit, the electric power control method comprising:

acquiring a total supplied energy which is a total of electric power supplied by the electric power supplying unit and electric power discharged by the energy storing unit, and a total consumed energy which is a total of electric power consumed by the load unit and electric power with which the energy storing unit is charged;

when an electric power supply and demand difference representing a difference between the total supplied energy and the total consumed energy exceeds a preset given range, making the energy storing unit charged with electric power or discharge electric power, and executing control to keep the electric power supply and demand difference within the given range, and also controlling the energy storing unit so as to decrease the charge or discharge electric power over a response time corresponding to a set time constant for energy storing unit; and

executing control to change electric power supplied by the electric power supplying unit over a response time corresponding to the set time constant for electric power supplying unit so that the electric power supply and demand difference is kept within the preset given range,

wherein the time constant for energy storing unit is set to be longer than a set time constant for electric power supplying unit.

16. The electric power control method according to claim 15, comprising:

when the electric power supply and demand difference exceeds the preset given range, setting an energy equivalent to the electric power supply and demand difference as an initial energy, and executing control to make the energy storing unit charged with the initial energy of electric power or discharge the initial energy of electric power, and also controlling the energy storing unit so as to gradually decrease the charge or discharge electric power over the response time corresponding to the time constant for energy storing unit so that the electric power changes from the initial energy to a given value; and

executing control changing electric power supplied by the electric power supplying unit over the response time corresponding to the time constant for electric power supplying unit so that the electric power supply and demand difference is kept within the given range, the electric power supply and demand difference being made as a result that a charge or discharge energy of the energy storing unit gradually decreases.