ES2608527B2 - Hydraulically hybridized photovoltaic pumping system with the power grid or with diesel groups for irrigation applications - Google Patents

Abstract

Photovoltaic pumping system hydraulically hybridized with the power grid or with diesel groups for irrigation applications. # Photovoltaic pumping system (1) hydraulically hybridized with the power grid or with diesel groups for irrigation applications, comprising at least one irradiance sensor and temperature (6), a plurality of water pumps (2), frequency inverters (3), photovoltaic generators (4a), connections to the power grid or diesel groups (4b), and contactors (5) to select the type of water pump power (2). All water pumps (2) pour into the same pipe (8), hybridizing to the hydraulic part. The system also comprises a control unit (7) configured to establish, from the number of photovoltaic water pumps (2) that can be fed, a mode of operation of the pumping system (1) selected from photovoltaic mode, hybrid mode , and network / diesel mode.

Description

Hydraulically hybridized photovoltaic pumping system with the power grid or with diesel groups for irrigation applications.

Technical sector The invention falls within the technical field of folovoltaic technologies and in the technical sector of agriculture, and in particular in the sector of photovoltaic irrigation techniques for different agricultural crops.

The object of the present invention is to provide a hydraulically hybridized folovoltatic pumping system with the power grid or with diesel groups for irrigation applications capable of offering maximum utilization and greater penetration of photovoltaic solar energy, both in pressure irrigation and constant flow as at variable pressure and flow.

BACKGROUND OF THE INVENTION Today, hydraulic hybridizations of photovoltaic pumping systems with power grid or diesel groups consist of feeding only a limited number of pumps in a pumping station with photovoltaic.

This number of pumps fed with photovoltaic solar energy is even more reduced in constant pressure and flow irrigation, in which the pressure control is entrusted to pumps connected to the electricity grid or diesel groups.

This type of systems limits the penetration of photovoltaic solar energy and forces a greater consumption of electricity from the electricity grid or from diesel groups.

It is therefore necessary in this technical sector to have a photovoltaic pumping system hydraulically hybridized with the power grid or with diesel groups capable of maximizing the use and penetration of photovoltaic solar energy.

Description of the invention In this way, the photovoltaic pumping system hydraulically hybridized with the power grid or with diesel groups for irrigation applications that the present invention proposes, is presented as an improvement over what is known in the state of the art since manages to successfully achieve the aforementioned objectives as suitable for the technique.

The pumping system for irrigation applications of the invention comprises at least one solar and temperature irradiance sensor, a plurality of water pumps, a plurality of frequency inverters, a plurality of photovoltaic generators, a plurality of connections to the mains or diesel groups, and a plurality of contactors that allow the pumps to be connected to the frequency inverters. All the pumps pour into the same water pipe, so that the hybridization of the system is carried out in the hydraulic part.

According to the invention, a first subgroup of water pumps are exclusively connected to a first subgroup of frequency inverters powered by photovoltaic generators, a second subgroup of water pumps are exclusively connected to a second subgroup of frequency inverters powered by the electrical network or by diesel groups, and a third subgroup of water pumps are connected, through contactors, to a third subgroup of frequency inverters powered by photovoltaic generators and to a fourth subgroup of frequency inverters powered by the electrical network or by diesel groups These contactors are adapted to allow the connection of the water pumps of the third subgroup with the third or fourth subgroup of frequency inverters.

The sum of the number of water pumps of the first and third subgroups of water pumps, and the sum of the number of pumps of the second and third subgroups of water pumps, satisfy the demand for the necessary flow for irrigation.

In addition, the pumping system comprises a control unit configured to receive the flow demand necessary for irrigation; determine the number of water pumps that need to be fed to meet the flow demand; evaluate potency

Folovoltaic available from the irradiance and temperature sensor; determine the number of water pumps that can be fed from the available photovoltaic power; Y establish a mode of operation of the pumping system, from the number of water pumps that need to be fed and that can be fed with power photovoltaic available, and where the established operating mode is selected between: photovoltaic mode, hybrid mode, and network / diesel mode.

The control unit configured to set: -The folovoltaic mode if the number of water pumps that can be fed with the available photovoltaic power is greater than or equal to the number of water pumps that is necessary to feed to meet the flow demand; -The hybrid mode if the number of water pumps that can be fed with the power Available photovoltaic is greater than the number of pumps in the first subgroup but less than number of water pumps that need to be fed to meet the demand of flow; -y, the control unit sets the network / diesel mode if the number of water pumps that it is possible to feed with the available photovoltaic power is less than the number of pumps of the first subgroup.

If the control unit sets the photovoltaic mode, said control unit is also configured for: - stop the second and fourth subgroups of frequency inverters, -order the contacts their connection with the third subgroup of frequency inverters, - start the first subgroup of frequency inverters and a number of variable frequency drives frequency of the third subgroup, where the sum of frequency inverters started matches the number of water pumps that need to be fed to meet the flow demand.

If the control unit sets the hybrid mode, said control unit is also configured for: - enable the connection to the mains or start the diesel generator, - order the contactors their connection with a number of frequency inverters of the third subgroup, where said number of drives matches the number of pumps

water of the third subgroup that is possible to feed with the available folovoltaic power, and start said number of frequency variators, - order the contactors their connection with a number of frequency inverters of the fourth subgroup, where said number of inverters coincides with the number of water pumps that need to be fed to meet the flow demand less the number of water pumps of the third subgroup that can be fed with the available photovoltaic power and less the number of water pumps of the first and second subgroup, and start said number of frequency variators, start the frequency inverters of the first and second subgroups.

If the control unit sets the network / diesel mode, said control unit is also configured for: - stop the first and third subgroups of frequency inverters, - enable the connection to the mains or start the diesel generator, -order all contactors their connection with the fourth subgroup of inverters frequency, - start the second subgroup of frequency inverters and a number of variable frequency drives frequency of the fourth subgroup, where the sum of frequency inverters started matches the number of water pumps that need to be fed to meet the flow demand.

In this way, the pumping system of the invention allows three modes of operation: photovoltaic mode (photovoltaic only), hybrid mode, and network / diesel mode (only network / diesel) that maximize the use of photovoltaic solar energy and minimize consumption from the power grid or diesel groups, both in pumping to raft with pressure and flow variables, such as in direct irrigation at constant pressure and flow. Thus, the invention allows maximum photovoltaic utilization at all possible irradiance levels.

According to a preferred embodiment, the control unit is configured to establish a first mode of operation (F1) with variable pressure and flow pumping, and a second operating mode (F2) with constant pressure and flow pumping, and incorporate a control algorithm for monitoring the maximum power point of the generator photovoltaic

If the control unit establishes the first mode of operation (F1), said control unit is also configured to: - establish as a working point of the first and third subgroup of frequency inverters the monitoring of the maximum power point of the photovoltaic generator by means of the monitoring control algorithm of the control unit, -and establish its nominal power as the working point of the second and fourth frequency inverter subgroups.

If the control unit sets the second mode of operation (F2), said unit of control is also configured to: -control the second and third sub-group of frequency inverters by pressure, - establish as the working point of the first subgroup of frequency inverters the monitoring of the maximum power point of the photovoltaic generator using the algorithm monitoring control unit control, - establish as the working point of the fourth subgroup of frequency inverters its rated power

Preferably, the second and fourth subgroup of frequency inverters Prepared to work at nominal power, they can be replaced by starters soft.

Description of the drawings To complement the description that is being made and in order to help a better understanding of the features of the invention, according to a preferred example of practical realization thereof, is accompanied as an integral part of said description, A drawing where, for illustrative and non-limiting purposes, the following has been represented:

Figure 1.- Shows a schematic view of a pumping system for applications of irrigation, according to a preferred embodiment of the invention.

Preferred Embodiment of the Invention Figure 1 shows a pumping system (1) for constant pressure and flow irrigation composed of three water pumps (2), four frequency inverters (3), a contact (5),

a pipe (8), a control unit (7), a photovoltaic generator (4a), connections to a diesel group (4b), and an irradiance and temperature sensor (6) connected to the control unit (7).

According to the invention, the pumping system (1) comprises a first subgroup of water pumps (2a) connected to a first subgroup of frequency inverters (3a) fed only by folovoltaic generators (4a), a second subgroup of pumps of water (2b) connected to a second subgroup of frequency inverters (3b) fed only by diesel generators (4b), and a third subgroup of water pumps (2c) connected, via contactors (5), to a third subgroup of frequency inverters (3c) fed by photovoltaic generators (4a) and to a fourth subgroup of frequency inverters (3d) fed by the diesel group (4b).

In the system of Figure 1, the first (2a), the second (2b) and the third subgroup of water pumps (2c) are each formed by a single water pump (2).

According to a preferred embodiment, the first (2a) and the second subgroup of water pumps (2b) will be formed by a single water pump (2), and the third subgroup (2c) will be formed by a plurality of water pumps ( 2), the rest of the water pumps that integrate the pumping system (1) until the necessary demand is reached. In this case, the pumping system (1) will require one more water pump (n + 1 water pumps) than the water pumps that would be required in the state of the art (n water pumps) to reach the pressure and the workflow required. Likewise, the system will require 2n frequency inverters (3).

As seen in Figure 1, the pumping system (1) comprises a single pipe (8) to which all water pumps (2) are connected. In this way, the hybridization of the pumping system (1) is carried out in the hydraulic part, and not in the electrical part.

In an embodiment of the invention with constant pressure and flow pumping (second mode of operation (F2 '), the control unit (7) receives the required flow demand and determines that it is necessary to feed two water pumps (2) to satisfy said demand Subsequently, the control unit (7) evaluates the signal it receives from the irradiance and temperature sensor (6) and determines that there is enough photovoltaic power to power two water pumps (2). control unit (7) sets the photovoltaic mode Under this photovoltaic mode, the control unit (7) commands: stop the second (3b) and the fourth subgroup of frequency inverters (3d) (powered by diesel groups (4b » , to the contactor (5) that is connected to the third subgroup of frequency inverters (3c) (powered by the photovoltaic generator (4a »), and to the two frequency inverters (3) powered by the photovoltaic generator (4a) (of the first and of the third subgroup of var frequency indicators) that are put into operation. The frequency converter of the first subgroup (3a) will work at the maximum power point by means of an algorithm for monitoring the maximum power point of the photovoltaic generator (4a) of the control unit (7), and the frequency inverter (3) of the Third subgroup (3c) will be controlled by pressure. In the example of Figure 1, under this photovoltaic mode, the two water pumps (2) of the first (2a) and the third subgroup (2c) will operate.

In another embodiment of the invention with constant pressure and flow pumping (second mode of operation (F2 '), the control unit (7) receives the required flow demand and determines that it is necessary to feed two water pumps (2) to satisfy said demand Subsequently, the control unit (7) evaluates the signal it receives from the irradiance and temperature sensor (6), and determines that there is not enough photovoltaic power to power two water pumps (2). the control unit (7) establishes the hybrid mode Under this hybrid mode, the control unit (7) orders: stop the frequency inverters (3) of the third (3c) and the fourth subgroup (3d), start the group diesel (4b), and start the frequency inverters (3) of the first (3a) and the second subgroup (3b) The frequency inverter of the first subgroup (3a) will work at the maximum power point using a tracking algorithm maximum power point of the photovoltaic generator ico (4a) of the control unit (7), and the variator of the second subgroup (3b) will be controlled by pressure. In the example of Figure 1, under this hybrid mode, the two water pumps (2) of the first (2a) and the second subgroup (2b) will operate.

In another embodiment of the invention with constant pressure and flow pumping (second mode of operation (F2 '), the control unit (7) receives the required flow demand and determines that it is necessary to feed two water pumps (2) to satisfy said demand Subsequently, the control unit (7) evaluates the signal it receives from the

irradiance and temperature sensor (6), and determines that there is not enough photovoltaic power to power even a water pump (2). Based on this, the control unit (2) establishes the network / diesel mode. Under this network / diesel mode, the control unit (7) commands: stop the frequency inverters (3) of the first (3a) and the third subgroup (3c), 5 start the diesel group (4b), order the contactor ( 5) connect to the frequency inverter (3) of the fourth subgroup (3d) and start it, and start the frequency inverter (3) of the second subgroup (3b). The frequency converter of the second subgroup (3b) will work under pressure control and the inverter of the fourth subgroup (3d) will work at its nominal power. In the example of Figure 1, under this network / diesel mode, both will work

10 water pumps (2) of the second (2b) and the third subgroup (2c).

According to one preferred embodiment, the frequency inverters (3) fed by diesel groups (4b) that always work at nominal power (second (3b) and fourth subgroup of frequency inverters (3d ') will be soft starters.

Finally, in view of this description and figures, the person skilled in the art will be able to understand that the invention has been described according to some preferred embodiments thereof, but that multiple variations can be introduced in said preferred embodiments, without leaving the object of the invention as claimed.

Claims (2)

1.-Photovoltaic pumping system (1) hydraulically hybridized with the power grid or with diesel groups for irrigation applications, comprising at least one irradiance and temperature sensor (6), a plurality of water pumps (2), a plurality of frequency inverters (3), a plurality of photovoltaic generators (4a), a plurality of connection points to the power grid or diesel groups (4b), where each water pump (2) is connected to a frequency inverter (3), and where each frequency inverter (3) is powered by a generator (4a) or by the power grid or diesel groups (4b), characterized in that - a first subgroup of water pumps (2a) are connected to a first subgroup of frequency inverters (3a) powered by photovoltaic generators (4a), -a second subgroup of water pumps (2b) are connected to a second subgroup of frequency inverters (3b) powered by the power grid or by diesel groups (4b), -y, a third r subgroup of water pumps (2c) are connected, through contactors (5), to a third subgroup of frequency inverters (3c) powered by photovoltaic generators (4a) and to a fourth subgroup of frequency inverters (3d) powered by the power grid or by diesel groups (4b), where said contactors (5) are adapted to allow the connection of the water pumps (2) of the third subgroup (2c) with the third (3c) or the fourth subgroup of inverters frequency (3d), - and where both the sum of the number of water pumps (2) of the first (2a) and the third subgroup of water pumps (2c), and the sum of the number of pumps of the second (2b) and of the third subgroup of water pumps (2c), they satisfy the demand of necessary flow for the irrigation, and also that it includes a control unit (7) configured to: -receive the demand of necessary flow for the irrigation, -determine the number of water pumps (2) that need to be fed to meet the demand d e flow rate, - obtain the available photovoltaic power from the irradiance and temperature sensor (6), - determine the number of water pumps (2) that can be fed from the available photovoltaic power, - and, establish a mode of operation of the pumping system (1), from the number of water pumps (2) that it is necessary to feed and that it is possible to feed with the available photovoltaic power, where the established operating mode is selected from: photovoltaic mode, hybrid mode, and network / diesel mode, and where,

-

The control unit (7) establishes the photovoltaic mode if the number of water pumps (2) that can be fed with the available photovoltaic power is greater than or equal to the number of water pumps (2) that need to be supplied to satisfy the flow demand,

-

the control unit (7) sets the hybrid mode if the number of water pumps

(2) that it is possible to feed with the available folovoltaic power is greater than the number of pumps of the first subgroup (2a) but less than the number of water pumps (2) that it is necessary to feed to meet the flow demand,

-

and, the control unit (7) establishes the network / diesel mode if the number of water pumps (2) that can be fed with the available photovoltaic power is less than the number of pumps of the first subgroup (2a),

-

and where, if the control unit (7) sets the photovoltaic mode, said control unit (7) is also configured to:

•

stop the second (3b) and the fourth subgroup of frequency inverters (3d),

• order the contactors (5) to connect with the third subgroup of frequency inverters (3c),

•

start the first subgroup of frequency inverters (3a) and a number of frequency inverters (3) of the third subgroup (3c), where the sum of frequency inverters (3) started matches the number of water pumps (2) that it is necessary to feed to meet the flow demand,

-

and where, if the control unit (7) establishes the hybrid mode, said control unit (7) is further configured to:

• enable connection to the mains or start the diesel generator (4b), • order the contactors (5) to connect with a number of frequency inverters of the third subgroup (3c), where said number of inverters matches the number of water pumps (2) of the third subgroup (2c) that can be fed with the available photovoltaic power, and starting said number of frequency inverters (3c), • order the contactors (5) their connection with a number of frequency inverters of the fourth subgroup (3d), where said number of inverters coincides with the number of water pumps (2) that it is necessary to feed to meet the flow demand less the number of water pumps (2) of the third subgroup (2c) that can be fed with the available photovoltaic power and less the number of water pumps (2) of the first (2a) and second subgroup (2b), and starting said number of frequency inverters (3d), • start the frequency inverters of the first (3a) and the second subgroup (3b),

-

And where, if the control unit (7) sets the network / diesel mode, said control unit (7) is further configured to:

•

stop the first (3a) and the third subgroup of frequency inverters (3c),

•

enable connection to the mains or start the diesel generator (4b),

• order all contactors (5) to connect to the fourth sub-group of frequency inverters (3d),

•

start the second subgroup of frequency inverters (3b) and a number of frequency inverters (3) of the fourth subgroup (3d), where the sum of frequency inverters (3) started matches the number of water pumps (2) that it is necessary to feed to meet the flow demand,

and because it also comprises a pipe (8) connected to all the water pumps (2) of the pumping system (1). 2.-Photovoltaic pumping system (1) hydraulically hybridized with the power grid or with diesel groups for irrigation applications, according to claim 1, characterized in that the control unit (7) is configured to: - establish a first mode of operation (F1) with variable pressure and flow pumping, and a second mode of operation (F2) with constant pressure and flow pumping, -e, incorporate a monitoring algorithm for monitoring the maximum power point of the photovoltaic generator (4a) ,

-

where, if the control unit (7) establishes the first mode of operation (F1), said control unit (7) is further configured to:

• establish as a working point of the first (3a) and the third subgroup of frequency inverters (3c) the monitoring of the maximum power point of the photovoltaic generator (4a) by means of the tracking control algorithm of the control unit (7) , • establish the nominal power as the working point of the second (3b) and the fourth subgroup of frequency inverters (3d),

-

and where, if the control unit (7) establishes the second mode of operation 5 (F2), said control unit (7) is further configured to:

•

pressure control the second (3b) and the third subgroup of frequency inverters (3c),

•

establish as a working point of the first subgroup of frequency inverters (3a) the monitoring of the maximum power point of the generator

10 photovoltaic (4a) by means of the tracking control algorithm of the control unit (7), • establish the nominal power as the working point of the fourth subgroup of frequency inverters (3d).