Method for coupling a hydroelectric power plant to the grid comprising at least two hydroelectric units

Patent metadata

Field	Value
Publication number	US-12092067-B2
Application number	US-202017783347-A
Country	US
Kind code	B2
Filing date	Dec 11, 2020
Priority date	Dec 12, 2019
Publication date	Sep 17, 2024
Grant date	Sep 17, 2024

Abstract

The invention concerns a method for coupling a hydroelectric power plant in a turbine mode to a grid, in order to generate power for a grid, said hydroelectric power plant comprising at least a first hydroelectric unit (10) and a second hydroelectric unit (100), each provided with a runner (6) mechanically coupled to a shaft line (8) and to a generator, a distributor (4) comprising guide vanes to control a flow of water to said runner, said hydroelectric power plant further comprising a variable frequency drive (20), the method comprising:a) starting the rotation of at least said first hydroelectric unit (10) and said second hydroelectric unit (100);b) connecting the variable frequency drive (20) to the generator of the first hydroelectric unit (10) and to the grid and stabilizing the speed of the first hydroelectric unitc) connecting the first hydroelectric unit (10) to the grid and disconnecting the generator of the first hydroelectric unit from the variable frequency drive (20);d) connecting said variable frequency drive (20) to the generator of the second hydroelectric unit (100) and to the grid and stabilizing the speed of the second hydroelectric unit;e) connecting the second hydroelectric unit (100) to the grid and disconnecting the generator of the second hydroelectric unit from said variable frequency drive (20).

First claim

The invention claimed is:

1. A method for coupling a hydroelectric power plant in a turbine mode to a grid in order to generate power for the grid, wherein the hydroelectric power plant includes:
a first hydroelectric unit and a second hydroelectric unit;
each of the first and second hydroelectric units having a runner mechanically coupled to a shaft line and to a generator, and a distributor comprising guide vanes to control a flow of water to the runner; and
a variable frequency drive;

the method comprising:
a) starting rotation of the first hydroelectric unit and the second hydroelectric unit;
b) after the first and the second hydraulic units are rotating, connecting the variable frequency drive to the generator of the first hydroelectric unit and to the grid, and stabilizing a speed of the first hydroelectric unit;
c) connecting the first hydroelectric unit to the grid and then disconnecting the generator of the first hydroelectric unit from the variable frequency drive;
d) connecting the variable frequency drive to the generator of the second hydroelectric unit and to the grid and stabilizing a speed of the second hydroelectric unit; and
e) connecting the second hydroelectric unit to the grid and then disconnecting the generator of the second hydroelectric unit from said variable frequency drive;
wherein steps (a) through (e) are performed in recited order.

2. The method according to claim 1 , wherein step a) includes partially opening the guide vanes of the first hydroelectric unit and of the second hydroelectric unit.

3. The method according to claim 2 , wherein the guide vanes of the first hydroelectric unit are further opened after step c).

4. The method according to claim 2 , wherein the guide vanes of the second hydroelectric unit are further opened after step e).

5. The method according to claim 1 , wherein the guide vanes of the first hydroelectric unit are more open than the guide vanes of the second hydroelectric unit during part of a time span between the beginning of step a), and the beginning of step c).

6. The method according to claim 1 , wherein the generator of the second hydroelectric unit is connected to the variable frequency drive less than 20 seconds after connecting the first hydroelectric unit to the grid.

7. The method according to claim 1 , wherein:
the generator of the first hydroelectric unit and the generator of the second hydroelectric unit are connectable to the variable frequency drive through a first and a second connection, respectively;
the generator of the first hydroelectric unit and the generator of the second hydroelectric unit are connectable to the grid through a third and a fourth connection, respectively; and
the variable frequency drive is connectable to the grid through a fifth connection.

8. The method according to claim 1 , wherein:
an opening of the guide vanes of each of the first hydroelectric unit and the second hydroelectric unit is controlled through a first control loop; and
the variable frequency drive is controlled during each of steps b) and e) through a second control loop.

9. The method according to claim 1 , wherein the hydroelectric power plant includes a third hydroelectric unit having a runner mechanically coupled to a shaft line and to a generator and a distributor having guide vanes to control a flow of water to the runner of the third hydroelectric unit, the method further comprising:
a′) starting rotation of the third hydroelectric unit with the first hydroelectric unit and the second hydroelectric unit;
b′) after step e), connecting the variable frequency drive to the generator of the third hydroelectric unit and to the grid and stabilizing a speed of the third hydroelectric unit; and
c′) connecting the third hydroelectric unit to the grid and then disconnecting the generator of the third hydroelectric unit from the variable frequency drive.

10. The method according to claim 9 , wherein the guide vanes of the third hydroelectric unit are further opened after step c′).

11. A hydroelectric power plant, comprising;
a first hydroelectric unit and a second hydroelectric unit, each of the first and second hydraulic units comprising a runner mechanically coupled to a shaft line and to a generator, and a distributor comprising guide vanes to control a flow of water to the runner;
a variable frequency drive common to the first and second hydraulic units; and
a controller configured to start the hydroelectric power plant according to the method of claim 1 .

12. The hydroelectric power plant according to claim 11 , wherein each of the first and second said hydroelectric units comprises a turbine configured as one of: a Francis, a Kaplan, a bulb, a Pelton, or reversible Francis or pump turbine type.

13. The hydroelectric power plant according to claim 11 , wherein each of the first and second hydroelectric units comprises:
a first control loop to control the opening of the guide vanes; and
a second control loop to control the variable frequency drive.

14. The hydroelectric power plant according to claim 11 , further comprising a third one of the hydroelectric units, the variable frequency drive common to the first, second, and third hydroelectric drives, the controller further configured to couple the hydroelectric power plant to the grid by:
starting rotation of the third hydroelectric unit with the first hydroelectric unit and the second hydroelectric unit;
after the second hydroelectric unit is connected to the grid and the generator of the second hydroelectric unit is disconnected from said variable frequency drive, connect the variable frequency drive to the generator of the third hydroelectric unit and to the grid and stabilizing a speed of the third hydroelectric unit; and
connect the third hydroelectric unit to the grid and disconnect the generator of the third hydroelectric unit from the variable frequency drive.

Assignees

• Ge Renewable Tech

Inventors

• Alloin Quentin
• Guillaume Renaud

Classifications

• Y10T74/19014

  Plural prime movers selectively coupled to common output · CPC title

• F02K1/15

  Control or regulation · CPC title

• F01D13/003

  with at least two independent shafts, i.e. cross-compound · CPC title

• F01D13/00

  Combinations of two or more machines or engines (F01D15/00 takes precedence; combinations of two or more pumps F04; fluid gearing F16H) · CPC title

• H02J3/381

  Dispersed generators · CPC title