Control device for hydraulic turbines

Abstract

Control device for hydraulic turbines configured to adjust the resistant torque provided by the generator to the movement of the impeller of an hydraulic turbine so that a stable pressure is set at the inlet (Pi) and at the outlet (Po) regardless of the circulating flow rate (Q), and to adjust the electrical energy produced by the turbine to achieve the desired hydraulic behavior, the device comprising a controller and a power device; wherein said controller is connected to a pressure detector at the inlet (Pi) and at the outlet (Po) and to a flow-meter for obtaining the circulating flow rate (Q), as well as to a power sensor for measuring the power of the turbine; all this, in such a way that the controller acts on the power device for causing the application of the braking torque necessary to maintain a stable set-point value on the turbine.

Claims

1. A control device for hydraulic turbines configured to adjust the resistant torque provided by the generator to the movement of the impeller of a hydraulic turbine so that a stable pressure is set at the inlet or at the outlet regardless of the circulating flow rate, and to adjust the electrical energy produced by the turbine to achieve the desired hydraulic behavior, the control device comprising a controller and a power device, wherein said controller is connected to a pressure detector that detects the pressure at the inlet and at the outlet and to a flow-meter for obtaining the circulating flow rate, as well as to a power sensor that measures the power of the turbine, so that the controller acts on the power device for causing the application of the braking torque necessary to maintain a stable set-point value on the turbine; and, wherein, based on the received signals, the controller is configured to operate in one of the following modes: a) a first mode, wherein the turbine regulates the pressure; wherein the controller is configured to calculate the braking torque necessary to maintain the pressure set-point at the outlet or at the inlet of the turbine regardless of the demanded flow rate, having a hydraulic behavior equal to a pressure regulating valve; b) a second mode with the turbine at maximum power, wherein the controller is configured to calculate the braking torque with the maximum generated power without ensuring a constant pressure, since it will depend on the demanded flow rate; c) a third mode with the turbine at maximum performance, wherein the controller is configured to determine the braking torque necessary for the yield to be maximum, without ensuring a constant pressure value, maximizing the ratio between the generated electric power and the available hydraulic power; and, d) a fourth mode with the turbine regulating the flow rate, wherein the controller is configured to set the braking torque necessary to maintain a constant flow rate set-point regardless of the pressure upstream or downstream of the turbine.

2. The device of claim 1, wherein the power device is configured to excite the windings of the stator of the generator according to the order of the controller, so that the resistant torque therein is adequate to maintain the set-point.

3. The device of claim 2, wherein the power device comprises a driver based on a bridge of thyristors or antiparallel IGBT configured and synchronized as a result of the signals received by the controller, allowing a controlled passage of current generated by the generator, and so regulating the braking torque exerted by it on the impeller of the turbine.

4. The device of claim 1, wherein the power device comprises a driver based on a bridge of thyristors or antiparallel IGBT configured and synchronized as a result of the signals received by the controller, allowing a controlled passage of current generated by the generator itself, and so regulating the braking torque exerted by it on the impeller of the turbine.

5. The device of any of claim 1, wherein the power device is connected to an energy receiving system, which is selected from an inverter for injection of electricity into the network, an equipment of battery charging, a particular facility for self-consumption, or any other system which is able to exploit electrical energy.

6. A control device for a hydraulic turbine coupled to an electric generator, comprising a driver for the generator and a controller for the driver, so that the generator is able to apply to the turbine the braking torque necessary to maintain a stable set-point value, the controller being connected to pressure sensors at the inlet and outlet of the turbine, to a flow-meter for measuring the flow rate in the turbine and to a network analyzer for determining the power generated by the generator, the controller being configured to calculate the braking torque necessary for the generated electric power to be maximum; and, wherein, based on the received signals, the controller is configured to operate in one of the following modes: a) a first mode, wherein the turbine regulates the pressure; wherein the controller is configured to calculate the braking torque necessary to maintain the pressure set-point at the outlet or at the inlet of the turbine regardless of the demanded flow rate, having a hydraulic behavior equal to a pressure regulating valve; b) a second mode with the turbine at maximum power, wherein the controller is configured to calculate the braking torque with the maximum generated power without ensuring a constant pressure, since it will depend on the demanded flow rate; c) a third mode with the turbine at maximum performance, wherein the controller is configured to determine the braking torque necessary for the yield to be maximum, without ensuring a constant pressure value, maximizing the ratio between the generated electric power and the available hydraulic power; and, d) a fourth mode with the turbine regulating the flow rate, wherein the controller is configured to set the braking torque necessary to maintain a constant flow rate set-point regardless of the pressure upstream or downstream of the turbine.

7. The device of claim 6, wherein the driver is configured to excite the windings of the stator of the generator according to the order of the controller, so that the resistant torque therein is adequate to maintain the set-point.

8. The device of claim 6, wherein the driver comprises a bridge of thyristors or antiparallel IGBT configured and synchronized as a result of the signals received by the controller, allowing a controlled passage of current generated by the generator, and so regulating the braking torque exerted by it on the impeller of the turbine.

9. The device of claim 6, wherein the driver is connected to an energy receiving system, which is selected from an inverter for injection of electricity into the network, an equipment of battery charging, a particular facility for self-consumption, or any other system which is able to exploit electrical energy.

10. A control device for a hydraulic turbine coupled to an electric generator, comprising a driver for the generator and a controller for the driver, so that the generator is able to apply to the turbine the braking torque necessary to maintain a stable set-point value, the controller being connected to pressure sensors at the inlet and outlet of the turbine, to a flow-meter for measuring the flow rate in the turbine and to a network analyzer for determining the power generated by the generator, the controller being configured to calculate the braking torque necessary for the electric yield to be maximum; and, wherein, based on the received signals, the controller is configured to operate in one of the following modes: a) a first mode, wherein the turbine regulates the pressure; wherein the controller is configured to calculate the braking torque necessary to maintain the pressure set-point at the outlet or at the inlet of the turbine regardless of the demanded flow rate, having a hydraulic behavior equal to a pressure regulating valve; b) a second mode with the turbine at maximum power, wherein the controller is configured to calculate the braking torque with the maximum generated power without ensuring a constant pressure, since it will depend on the demanded flow rate; c) a third mode with the turbine at maximum performance, wherein the controller is configured to determine the braking torque necessary for the yield to be maximum, without ensuring a constant pressure value, maximizing the ratio between the generated electric power and the available hydraulic power; and, d) a fourth mode with the turbine regulating the flow rate, wherein the controller is configured to set the braking torque necessary to maintain a constant flow rate set-point regardless of the pressure upstream or downstream of the turbine.

11. The device of claim 10, wherein the driver is configured to excite the windings of the stator of the generator according to the order of the controller, so that the resistant torque therein is adequate to maintain the set-point.

12. The device of claim 10, wherein the driver comprises a bridge of thyristors or antiparallel IGBT configured and synchronized as a result of the signals received by the controller, allowing a controlled passage of current generated by the generator, and so regulating the braking torque exerted by it on the impeller of the turbine.

13. The device of claim 10, wherein the driver is connected to an energy receiving system, which is selected from an inverter for injection of electricity into the network, an equipment of battery charging, a particular facility for self-consumption, or any other system which is able to exploit electrical energy.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) In the following, a series of drawings is described very briefly which help to better understand the invention and which are expressly related to an embodiment of said invention which is presented as a non-limiting example thereof.

(2) FIG. 1 shows a schematic view of a typical example of assembly of the control device for hydraulic turbines.

DETAILED EXAMPLE

(3) As previously explained, the device hereof allows a new control strategy based on which the turbine exploits at any time the maximum hydraulic energy available in the network, further ensuring a stable hydraulic behavior despite the flow rate variations that occur in supply networks, since it depends on the needs of users.

(4) The use of a regenerative braking system in hydraulic turbines permits adjusting the resistant torque provided by the generator to the movement of the impeller, so that a stable pressure level can be ensured at the inlet or outlet of the turbine regardless of the flow rate circulating through it and, therefore, adjusting the generated electrical energy to the available hydraulic energy.

(5) As shown in the attached FIGURE, the device hereof comprises a first controller (100) and a second power device (200).

(6) The first controller (100), in a first embodiment, comprises a PLC that receives signals of pressure at the inlet (Pi), pressure at the outlet (Po), circulating flow rate (Q) obtained through a flow-meter (1) and generated electric power, which is obtained via a network analyzer (2) connected directly to the power signal of the turbine (3).

(7) The first controller (100) presents a PID structure.

(8) Appropriate orders can be sent through the controller (100) to the second power device (200) to apply the braking torque necessary to maintain a stable set-point value. Therefore, it is configured to adjust the electrical energy produced by the turbine (3) to achieve the desired hydraulic behavior.

(9) Based on the received signals, the first controller (100) is configured to operate in one of the following operation modes:

(10) a) a first mode, wherein the turbine (3) regulates the pressure; wherein the first controller (100) is configured to calculate the braking torque necessary to maintain the pressure set-point at the outlet or at the inlet of the turbine (3) regardless of the demanded flow rate, having a hydraulic behavior equal than a pressure regulating valve.

(11) b) a second mode with the turbine (3) at maximum power, wherein the first controller (100) is configured to calculate the braking torque with the maximum generated power without ensuring a constant pressure, since it will depend on the demanded flow rate (Q).

(12) c) a third mode with the turbine (3) at maximum performance, wherein the first controller (100) is configured to determine the braking torque necessary for the yield to be maximum, without ensuring a constant pressure value, maximizing the ratio between the generated electric power and the available hydraulic power; and,

(13) d) a fourth mode with the turbine (3) regulating the flow rate (Q), wherein the controller (100) is configured to set the braking torque necessary to maintain a constant flow rate set-point regardless of the pressure upstream (Pi) or downstream (Po) of the turbine (3).

(14) The second power device (200), which is directly connected to the generator of the turbine (3), is responsible for adjusting the generated electrical energy to charge a battery or for injection into the grid. Likewise, is are responsible for exciting the windings of the stator of the generator according to the order of the first controller (100), so that the resistant torque therein is adequate to maintain the set-point.

(15) On a practical level, the second power device (200) can be implemented by a driver (201) based on a bridge of thyristors or IGBT antiparallel configured and synchronized by the signals received by the first controller (100), allowing a controlled passage of current generated by the generator itself, which could be of the brushless type, and so regulate the braking torque exerted by it on the impeller of the turbine.

(16) In the attached FIGURE, it can be seen how the generating turbine (3) is installed in the duct (4), and is placed in an underground chamber or a valves room along with the measuring equipment [pressure sensors (Po, Pi) and flow-meter (1)]. Thus, a pressure sensor is placed at the inlet (Pi) and another at the outlet (Po) of the turbine (3), while the flow-meter (1) can be placed at the inlet or outlet thereof.

(17) The wiring of signals from the measuring equipment [the network analyzer (2)], as well as the wiring of power from the generator of the turbine (3), conduct it to the control device (100, 200), which may be located in the same enclosure or in a separate enclosure.

(18) The power output of the control device (100, 200), which can be monitored with a network analyzer (2), is connected to the energy receiving system (5), which may be an inverter for injection of electricity into the network, an equipment of battery charging, a particular facility for self-consumption, or any other system which can exploit electrical energy.

(19) By controlling the regenerative braking, the turbine (3) can operate at different rotation rates depending on the conditions of flow rate (Q) and available hydraulic jump.