SE1600151A1 - Indication of load distribution of power generation units - Google Patents

Abstract

There is provided mechanisms for indicating a load distribution of power generation units. A method is performed by a controller. The method comprises obtaining a power demand for at least one of the power generation units. The method comprises obtaining a set of load distributions between the different power generation units available for the needed power demand. The method comprises determining a respective cost for each obtained load distribution. The method comprises indicating to a user interface the load distribution having lowest cost.(Fig. 4)

Description

1 INDICATION OF LOAD DISTRIBUTION OF POWER GENERATION UNITS TECHNICAL FIELD Embodiments presented herein relate to a method, a controller, a computer 5 program, and a computer program product for indicating load distribution of power generation units.

BACKGROUND Electrical propulsion, of for example vessels, is well-known in the art of electrical propulsion. Power generation for such electrical propulsion is 10 provided using an engine that drives a generator. Large vessels may have several power generation units (PGUs), each comprising a diesel engine and a generator. Depending on the desired load, only a selected subset of the power generation units can be momentarily used. The required load should then be distributed over the power generation units. To do this optimally the specific 15 fuel consumption (in terms of fuel mass (such as in kilograms, kg) divided by the produced energy (such as per Watt hour, kWh)) for each individual power generation unit should be known.

Known mechanisms for determining the specific fuel consumption for an individual power generation unit are based on printed, or otherwise available, data sheets of fuel consumption curves provided by the manufacturer of the power generation unit. A typical fuel consumption curve would resemble a second degree polynomial curve and thus have one global minimum where the fuel consumption is optimal (i.e., the lowest).

However, real-life performance of power generation units do not follow 25 second degree polynomial curves. Further, even if the average performance of an ensemble of power generation units follows a second degree polynomial curves, there may be individual discrepancies from this average performance for an individual power generation unit. Further, real-life performance of power generation units is not constant over time. Generally, fuel 30 consumption can be regarded as increasing over time, inter alia because of 2 degeneration (such as wear and tear) of the power generation units. Hence, the load distribution being regarded as optimal for a certain distribution of power generation units at a certain point of time may not be optimal at another point in time. 5 Further, there is a need for an improved mechanism for indicating the load distribution of the power generation units.

SUMMARY An object of embodiments herein is to provide efficient indicating load distribution of power generation units. 10 According to a first aspect there is presented a method for indicating a load distribution of power generation units. The method is performed by a controller. The method comprises obtaining a power demand for at least one of the power generation units. The method comprises obtaining a set of load distributions between the different power generation units available for the 15 needed power demand. The method comprises determining a respective cost for each obtained load distribution. The method comprises indicating to a user interface the load distribution having lowest cost.

Advantageously this enables the load distribution of the power generation units to be efficiently indicated.

Advantageously this enables the fuel consumption to be reduced.

Advantageously this enables efficient power management of power generation units on vessels or in individual power grids.

Advantageously this gives human operators of the power generation units to more time to focus on other less automated tasks. 25 According to a second aspect there is presented a controller for indicating a load distribution of power generation units. The controller comprises processing circuitry. The processing circuitry is configured to cause the controller to obtain a power demand for at least one of the power generation 3 units. The processing circuitry is configured to cause the controller to determine a set of load distributions between the different power generation units available for the needed power demand. The processing circuitry is configured to cause the controller to determine a respective cost for each 5 obtained load distribution. The processing circuitry is configured to cause the controller to indicate to a user interface the load distribution having lowest cost.

According to a third aspect there is presented a computer program for indicating a load distribution of power generation units, the computer 10 program comprising computer program code which, when run on a controller, causes the controller to perform a method according to the first aspect.

According to a fourth aspect there is presented a computer program product comprising a computer program according to the third aspect and a 15 computer readable storage medium on which the computer program is stored.

It is to be noted that any feature of the first, second, third and fourth aspects may be applied to any other aspect, wherever appropriate. Likewise, any advantage of the first aspect may equally apply to the second, third, and/or fourth aspect, respectively, and vice versa. Other objectives, features and advantages of the enclosed embodiments will be apparent from the following detailed disclosure, from the attached dependent claims as well as from the drawings.

Generally, all terms used in the claims are to be interpreted according to their 25 ordinary meaning in the technical field, unless explicitly defined otherwise herein. All references to "a/an/the element, apparatus, component, means, step, etc." are to be interpreted openly as referring to at least one instance of the element, apparatus, component, means, step, etc., unless explicitly stated otherwise. The steps of any method disclosed herein do not have to be 30 performed in the exact order disclosed, unless explicitly stated. 4 BRIEF DESCRIPTION OF THE DRAWINGS The inventive concept is now described, by way of example, with reference to the accompanying drawings, in which: Fig. 1 is a schematic diagram illustrating a control system according to 5 embodiments; Fig. 2 is a schematic diagram showing functional units of a controller according to an embodiment; Fig. 3 shows one example of a computer program product comprising computer readable storage medium according to an embodiment; 10 Fig. 4 is a flowchart of methods according to embodiments; and Fig. 5 schematically illustrates a user interface according to an embodiment. DETAILED DESCRIPTION The inventive concept will now be described more fully hereinafter with reference to the accompanying drawings, in which certain embodiments of 15 the inventive concept are shown. This inventive concept may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided by way of example so that this disclosure will be thorough and complete, and will fully convey the scope of the inventive concept to those skilled in the art.

Like numbers refer to like elements throughout the description. Any step or feature illustrated by dashed lines should be regarded as optional.

Fig. 1 is a schematic diagram illustrating a control system loo where embodiments presented herein can be applied. The control system 100 comprises at least one power generation unit noa, nob, ..., lion. Each power 25 generation unit noa, nob, ..., lion comprises an engine and a generator. The engine can be a diesel engine, a heavy fuel oil engine, or liquefied natural gas engine. The at least one power generation unit noa, nob, ..., non can be part of a vessel 12oa or an isolated electrical grid i2ob.

The control system loo further comprises a controller 200. The controller 200 is operatively connected to the at least one power generation unit noa, nob, ..., lion and thereby configured to obtain measured values of fuel flow and values of produced power from the at least one power generation unit noa, nob, ..., non. Further operations and features of the controller 200 will be disclosed below.

Once in operation, the at least one power generation unit noa, nob, ..., non supplies power to a load. Load balancing can be used to distribute the load between two or more power generation units noa, nob, ..., non. Assuming 10 that the control system 100 comprises more than one power generation unit noa, nob, ..., non, as noted above, it can be difficult to determine the best distribution of the load between different power generation units noa, nob, ..., non, and hence to perform efficient load balancing. The embodiments disclosed herein therefore relate to indicating the load distribution of the 15 power generation units noa, nob, ..., non. In order to obtain such estimation there is provided a controller 200, a method performed by the controller 200, a computer program product comprising code, for example in the form of a computer program, that when run on a controller 200, causes the controller 200 to perform the method.

Fig. 2a schematically illustrates, in terms of a number of functional units, the components of a controller 200 according to an embodiment. Processing circuitry 2is provided using any combination of one or more of a suitable central processing unit (CPU), multiprocessor, microcontroller, digital signal processor (DSP), etc., capable of executing software instructions stored in a 25 computer program product 3(as in Fig. 3), e.g. in the form of a storage medium 230. The processing circuitry 2may further be provided as at least one application specific integrated circuit (ASIC), or field programmable gate array (FPGA).

Particularly, the processing circuitry 2is configured to cause the controller 200 to perform a set of operations, or steps, Sio2-Sio8. These operations, or steps, Si02-S108 will be disclosed below. For example, the storage medium 6 230 may store the set of operations, and the processing circuitry 2may be configured to retrieve the set of operations from the storage medium 2to cause the controller 200 to perform the set of operations. The set of operations may be provided as a set of executable instructions.

Thus the processing circuitry 2is thereby arranged to execute methods as herein disclosed. The storage medium 230 may also comprise persistent storage, which, for example, can be any single one or combination of magnetic memory, optical memory, solid state memory or even remotely mounted memory. The controller 200 may further comprise a 10 communications interface 2for communications at least with at least one power generation unit noa, nob, ..., non and to provide information to a user interface and to obtain information from the user interface. As such the communications interface 2may comprise one or more transmitters and receivers, comprising analogue and digital components. The processing 15 circuitry 2controls the general operation of the controller 200 e.g. by sending data and control signals to the communications interface 2and the storage medium 230, by receiving data and reports from the communications interface 220, and by retrieving data and instructions from the storage medium 230. Other components, as well as the related functionality, of the controller 200 are omitted in order not to obscure the concepts presented herein.

Fig. 3 shows one example of a computer program product 3comprising computer readable storage medium 330. On this computer readable storage medium 330, a computer program 320 can be stored, which computer 25 program 3can cause the processing circuitry 2and thereto operatively coupled entities and devices, such as the communications interface 2and the storage medium 230, to execute methods according to embodiments described herein. The computer program 320 and/or computer program product 310 may thus provide means for performing any steps as herein 30 disclosed. 7 In the example of Fig. 3, the computer program product 310 is illustrated as an optical disc, such as a CD (compact disc) or a DVD (digital versatile disc) or a Blu-Ray disc. The computer program product 310 could also be embodied as a memory, such as a random access memory (RAM), a read-only 5 memory (ROM), an erasable programmable read-only memory (EPROM), or an electrically erasable programmable read-only memory (EEPROM) and more particularly as a non-volatile storage medium of a device in an external memory such as a USB (Universal Serial Bus) memory or a Flash memory, such as a compact Flash memory. Thus, while the computer program 320 is 10 here schematically shown as a track on the depicted optical disk, the computer program 320 can be stored in any way which is suitable for the computer program product 310.

Fig. 4 is a flow chart illustrating embodiments of methods for indicating a load distribution of power generation units noa, nob, ..., non. The methods 15 are performed by the controller 200. The methods are advantageously provided as computer programs 320.

S102: The controller 200 obtains a power demand for at least one of the power generation units noa, nob, ..., lion.

S1o4: The controller 200 obtains a set of load distributions between the different power generation units noa, nob, ..., lion available for the needed power demand. Hence each load distribution in the set of load distributions represents one way of distributing the load between the load power generation units noa, nob, ..., non such that the power demand can be met.

S106: The controller 200 determines a respective cost for each obtained load 25 distribution. That is, each of the load distributions has an associated cost.

S1o8: The controller 200 indicates to a user interface the load distribution having lowest cost. 8 A new indication of a new load distribution for which the cost is lowest can be provided to the user interface each time one occurrence of steps S102-8108 is performed.

Embodiments relating to further details of indicating a load distribution of 5 power generation units noa, nob, ..., non as performed by the controller 200 will now be disclosed.

There can be different ways for the controller 200 obtain the set of load distributions. According to an embodiment the controller 200 is configured to selectively operate in automated mode or manual mode. Hence, according 10 to an embodiment the controller 200 is configured to perform step Sio4a: S104a: The controller 200 obtains an indication of engine prioritization of the load distribution being in automated mode or manual mode.

There can be different ways for the controller 200 to act depending on if the controller 200 is in automated mode or in manual mode. 15 According to a first embodiment the engine prioritization in step Sio4a is indicated to be in automated mode. The controller 200 is thus enabled to determine an optimal load distribution. According to this first embodiment the controller 200 is configured to perform step Slo8a: Sio8a: The controller 200 indicates to the user interface any energy saving from determining the load distribution having lowest cost.

According to a second embodiment the engine prioritization in step Sio4a is indicated to be in manual mode. The controller 200 may thus not be enabled to determine an optimal load distribution. According to this second embodiment the controller 200 is configured to perform step Sion: 25 Sio8b: The controller 200 indicates to the user interface any fuel consumption losses from using a load distribution not having lowest cost. 9 Regardless of automated mode or manual mode the controller 200 can indicate which engine or engines are used and hence be configured to perform step Si°8c: Sio8c: The controller 200 indicates to the user interface which of the power 5 generation units noa, nob, ..., non are used for the load distribution.

Further, the controller 200 can be configured to indicate other properties of the load distribution of the power generation units noa, nob, ..., non to the user interface. Examples of such properties include, but are no limited to, the power of each engine (or other power source), the fuel consumption of each 10 engine, the fuel consumption of the all engines, the start order of not started engines, the fuel consumption deviation from the optimal load distribution (in manual mode), and standard procedure settings e.g. equal load sharing.

A human operation could be able to select which engines to use in the optimization and even put power constraints on individual engines. Thus the 15 controller 200 can be configured to obtain an indication from the user interface regarding which of the power generation units noa, nob, ..., non are to be used for the load distribution and any constraints applicable to the power generation units noa, nob, ..., non In the case where not all engine are needed/used the controller 200 can be configured to indicate to the user interface the most beneficial start order of the remaining engines.

When a given engine of the engines is indicated as being under maintenance, this given engine is removed from being included in the best load balancing such that the best load balancing not including this engine(s) should be 25 chosen.

Prediction views of the system could also be used such that only one single, some, or even all, load balancing combinations could be displayed in comparison, since this could be used to predict when to perform maintenance based on future power demands.

Fig. 5, is a schematic illustration of a user interface 500 according to an embodiment. The user interface 500 comprises a first portion 510a, a second portion 510b, and a third portion 510c. The first portion 5ioa is configured to receive user input (as in step Sio4a) in any way suitable. Hence the first 5 portion can comprise any of a touch pad, a joystick, a keyboard, a mouse, a touch sensitive screen, and so on. The second portion 510b is configured to provide indications (as in any of steps Sio8, Sio8a, Sio8b, Sio8c) in any way suitable to a human operator of the user interface 500. The third portion 510c is configured to communicate with the controller 200 (for example by 10 forwarding information obtained from the first portion 510a and by displaying information received from the controller 200).

There may be different examples of power demands. According to an embodiment the power demand is in step S102 obtained from the user interface, from a voyage planning system, or from an electrical grid power 15 planning system.

There may be different examples of power generation units noa, nob, ..., non. According to an embodiment the power generation unit noa, nob, ..., non is part of a vessel i2oa, such as a marine vessel. The vessel can be powered by one or more power generation units noa, nob, ..., non.

According to an alternative embodiment the power generation unit noa, nob, ..., non is part of an isolated electrical grid i20b. The isolated electrical grid can be powered with one or more combustion engine drive generators and hence by one or more power generation units noa, nob, ..., non.

There may be different examples of type of fuel of the fuel consumption. For 25 example, the fuel of the fuel consumption can be diesel, heavy fuel oil, or liquefied natural gas (LNG), depending on the type of engine of the power generation unit noa, nob, ..., non.

The inventive concept has mainly been described above with reference to a few embodiments. However, as is readily appreciated by a person skilled in 30 the art, other embodiments than the ones disclosed above are equally ncept, as defined by the

Claims (11)

12 CLAIMS

1. A method for indicating a load distribution of power generation units (noa, nob, ..., non), the method being performed by a controller (200), the method comprising: obtaining (Sio2) a power demand for at least one of the power generation units (110a, nob, ..., non); obtaining (S104) a set of load distributions between the different power generation units (ma, nob, ..., non) available for the needed power demand; determining (Slob) a respective cost for each obtained load distribution; and indicating (S108) to a user interface (500) the load distribution having lowest cost.

2. The method according to claim 1, further comprising: obtaining (Sio4a) an indication of engine prioritization of the load distribution being in automated mode or manual mode.

3. The method according to claim 1, wherein the engine prioritization is indicated to be in automated mode, the method further comprising: indicating (Sio8a) to the user interface (500 any energy saving from determining the load distribution having lowest cost.

4. The method according to claim 1, wherein the engine prioritization is indicated to be in manual mode, the method further comprising: indicating (Slab) to the user interface (500) any fuel consumption losses from using a load distribution not having lowest cost.

5. The method according to claim 1, further comprising: indicating (Sio8c) to the user interface (500) which of the power generation units (um, nob, ..., non) are used for the load distribution. 13

6. The method according to claim 1, wherein the power demand is obtained from the user interface (500), from a voyage planning system, or from an electrical grid power planning system.

7. The method according to claim 1, wherein the power generation unit (ma, nob, ..., non) is part of a vessel (120a) or of an isolated electrical grid (12013).

8. The method according to claim 1, wherein the fuel of the fuel consumption is diesel, heavy fuel oil, or liquefied natural gas.

9. A controller (200) for indicating a load distribution of power generation 10 units (ma, nob, ..., non), the controller (200) comprising processing circuitry (210), the processing circuitry being configured to cause the controller (200) to: obtain a power demand for at least one of the power generation units (ma, nob, ..., non); determine a set of load distributions between the different power generation units (noa, nob, ..., non) available for the needed power demand; determine a respective cost for each obtained load distribution; and indicate to a user interface (500) the load distribution having lowest Cost. io. A computer program (320) for indicating a load distribution of power generation units (ma, nob, ..., non), the computer program comprising computer code which, when run on processing circuitry (210) of a controller (200, causes the controller (200) to: obtain (8102) a power demand for at least one of the power generation units (noa, nob, ..., non); determine (8104) a set of load distributions between the different power generation units (ma, nob, ..., non) available for the needed power demand; determine (S106) a respective cost for each obtained load distribution; 14 and indicate (Sio8) to a user interface (500) the load distribution having lowest cost. ii. A computer program product (310) comprising a computer program (320) according to claim 10, and a computer readable storage medium (330) on which the computer program is stored. 1/3 110a PGU 110b PGU 200 Controller 120a, 120b r--/ 110n PGU amow .■ ■■ ■ ■I100