Control in an island network

Abstract

The invention relates to an electrical island network (1) comprising a bus (2) and a plurality of electrical units (3) that can be coupled to the bus (2), wherein the electrical units (3) can be energy sources (4), energy consumers (5), or also couplings (6), the electrical island network (1) also comprising electrical lines (7) for electrically connecting energy sources (4) and energy consumers (5), communication interfaces for transferring data between the electrical units (3), and an energy management system, wherein the electrical units (3) each have the same control algorithm associated with the energy management system, and the prioritisation of the utilisation of the energy sources (3) is dynamically adjustable. The invention also relates to a method for controlling the utilisation in an electrical island network (1).

Description

[0001] Description

[0002] Control in the island grid

[0003] The invention relates to an electrical island network and a method for controlling the load in an island network.

[0004] The use of more efficient energy generators makes regulating the utilization of energy generators in island grids more complex and demanding. These electrical units sometimes require dynamic control during operation to accommodate their functionality. An example is a combination of wave generators, steam turbines, batteries, and diesel generators. These must be coordinated and ensure the supply in an island grid.

[0005] A power management system (PMS) is a system responsible for monitoring, controlling, and optimizing energy consumption and distribution in electrical installations or networks. Its purpose is to ensure that the electrical system is safe and efficient. It can be used to analyze energy demand, optimize energy supply, and achieve energy savings. Other functions could include automatically switching loads (e.g., diesel generators) on and off when load fluctuates, or, if, for example, electricity consumption exceeds electricity generation capacity, load shedding could be performed to avoid a power outage.

[0006] A marine energy management system is a complete switchgear and generator control system for synchronizing ships' auxiliary engines through automatic load balancing and optimizing the efficiency of the power generators. The marine energy management system can control various configurations of generators driven by diesel engines, steam turbines, and main engines, in combination with switchboards of varying complexity.

[0007] The electrical energy in any combination of power generators is used according to the calculations of the energy management system. The PMS decides which combination of power generators is best based on energy demand. The capacity of the power generators is designed so that, in the event of a failure of one of the units, all the power required for normal operating conditions for propulsion and safety can still be provided.

[0008] In existing PMSs, special algorithms are used for each type of electrical unit. A control algorithm is a mathematical algorithm that is used to control and regulate the electrical units. The algorithm accepts input variables (measured variables or sensor data) and generates corresponding output variables (control variables or actuator data) in order to bring the electrical units of the stand-alone grid into a desired state or to maintain this state. The control algorithm continuously analyses the input data and compares it with the desired setpoints or setpoint curves. On the basis of the deviations determined, the algorithms calculate the necessary adjustments to the control variables in order to steer the stand-alone grid towards the setpoints. The integration of new or modified electrical units is correspondingly complex.

[0009] For example, the power and torque of a steam turbine depend on the steam supplied to it. This in turn varies in pressure and temperature and therefore in its energy depending on the parameters of the exhaust gas used to generate steam. Since operation at a fixed operating point is not possible, the steam turbine as an electrical unit can typically be operated in an operating range of 500kW to 5MW. The power of a shaft generator / motor also depends on the speed of the shaft on which it is mounted. The speed of the rotor influences the motor voltage and therefore the available torque that can be taken from the shaft generator in generator mode. Here, too, operation is not tied to an operating point but to an operating range.For this reason, in island networks, state-of-the-art technology includes, in addition to a standard calculation, an additional calculation for setpoints and, based on this, an adjustment of the setpoints.

[0010] Specifically, in addition to the standard calculation for the diesel generators, a calculation for the steam turbine and another calculation for the shaft generator were performed. These calculations were then combined, and only then could the setpoints be transferred to the controllers. This solution, again, was only suitable for a limited system configuration and had to be revised for each project.

[0011] The object of the invention is to provide an electrical island network with high flexibility regarding expansion (or reduction) of the network or failure of electrical units. A further object of the invention is to provide a method for regulating the load in an island network.

[0012] The invention solves the problem directed at an electrical island network by providing that in such an electrical island network, comprising a bus and a plurality of electrical units which can be coupled to the bus, wherein the electrical units can be energy sources, energy consumers or also couplings, the electrical island network further comprises electrical lines for connecting energy sources and energy consumers, communication interfaces for data transfer between the electrical units and an energy management system, the electrical units each have the same control algorithm belonging to the energy management system and that a prioritization of the utilization of the energy sources is dynamically adaptable.

[0013] Based on the total available and consumed power, each individual electrical unit calculates its setpoint. Priorities can be changed dynamically during operation and can also be grouped. This allows, for example, a battery to be switched from discharging to charging without the need for centralized, complex calculations.

[0014] The term "dynamically adaptable" refers to the ability of the island electrical grid to adapt automatically or in real time to changing conditions or requirements. It implies a degree of flexibility and responsiveness that goes beyond simple adaptability. This differs significantly from "adaptable," which generally refers to something that can be changed or adjusted to meet specific needs or requirements. However, this adjustment may be manual or static and not necessarily automatic or dynamic.

[0015] Special additional setpoints can also be easily added and taken into account without having to consider this in a complicated way elsewhere.

[0016] Depending on their use in the island grid, energy storage systems can be seen as energy sources or as energy consumers (when storing surplus energy from energy sources).

[0017] Advantageously, the bus can be separated into sections and then reconnected using the couplings. It is also advantageous if individual electrical units can be connected to or separated from the bus using switches. Advantageously, the electrical units announce their minimum and maximum power as well as their minimum and maximum power for continuous operation. This allows load distribution in the island grid to be optimized. The power of the electrical units can be adjusted accordingly to achieve even utilization and avoid overloads or bottlenecks. This ensures efficient use of the available energy sources and a more stable power supply. Knowing the minimum and maximum power for continuous operation helps to optimize the operation of the electrical units in the island grid.The controller can adjust the electrical units to operate at their most efficient level, minimizing energy losses and maximizing equipment lifespan. This leads to improved energy efficiency and cost savings. Finally, deviations from these values ​​can be identified as potential problems. If a unit exceeds its normal power limit or falls below its minimum power, it may indicate a defect or malfunction. This enables early fault detection and rectification to ensure the smooth operation of the island grid.

[0018] All electrical units in the island grid can calculate their setpoints and maintain their limits based on their own parameters and the parameters reported back from the other electrical units. Since the data from the other electrical units also detects the section in which each electrical unit is located, independence from the configuration of the entire island grid is ensured, as the same algorithm is always applied.

[0019] It is useful if the electrical unit is a diesel generator, a steam turbine, a shaft generator / motor and / or a battery. Diesel generators and batteries are very reliable energy sources. They can supply power continuously and be started quickly when needed. This ensures a stable power supply in an island grid. Steam turbines can use waste heat and thus increase efficiency and reduce energy losses. Batteries can also help to optimise energy consumption by storing excess energy and releasing it when needed. The combination of different energy sources in an island grid offers a high level of flexibility, reliability and efficiency in the power supply.

[0020] It is also useful if the control of the off-grid grid is based on at least one of the following: weather data, geographical data, operating conditions, operating hours, predicted energy demand in the off-grid grid and preferences entered by the user. The control of the off-grid grid can react to changing operating conditions. It can control the energy sources accordingly to ensure operation within optimal parameters. This ensures a stable power supply and protects the equipment from overload or damage. Control based on operating hours and predicted energy demand enables efficient use of the available resources. It can optimize the use of energy sources to extend their service life and minimize wear and tear. Taking into account the preferences entered by the user enables personalized control of the off-grid grid.This can include, for example, prioritizing certain energy sources, the timing of energy drops, or setting operating parameters. User preferences can also be the basis for intelligent load management to optimize energy consumption and save costs. Combining these different factors when controlling an island grid enables a customized and efficient energy supply. It takes into account the specific conditions of the island grid, the available resources, the energy demands, and the users' preferences to ensure a reliable, sustainable, and adaptable power supply. Finally, it is advantageous if electrical units can be grouped together, so that prioritization can be done for the group rather than for individual electrical units.Grouping electrical units into a group simplifies control and management. Instead of monitoring and controlling each unit individually, the group can be viewed as a whole, reducing administration overhead. Grouping electrical units also allows for more flexible use of the island grid. Depending on requirements and priorities, units can be organized into different groups. This facilitates adaptation to changing conditions and requirements, e.g., during peak loads or specific operating modes.

[0021] The problem, which is directed to a method for controlling the load in an island network, is solved by a method in which the island network comprises a bus and a plurality of electrical units which can be coupled to the bus, wherein the electrical units can be energy sources, energy consumers or couplings, wherein the same control algorithm is executed in each of the electrical units and a prioritization of the electrical units is dynamically adapted.

[0022] It is advantageous if electrical units are grouped together and prioritized for the group.

[0023] Furthermore, it is advantageous if the bus is divided into sections by means of the couplings or at least two sections are connected to one another via the couplings.

[0024] Advantageously, the control algorithm processes information on the minimum power, maximum power, minimum power during continuous operation, and maximum power during continuous operation of the electrical units. It is also advantageous if a prioritization of the electrical units is specified by selecting a driving profile. For example, in a profile with maximum energy efficiency for a ship, corresponding energy sources could be given priority. The situation is different in maneuvering mode. There, a reliable and stable energy source is necessary, even if this comes at the expense of the environment or the economy.

[0025] It is advisable to define the prioritization of the electrical units using a priority list. This priority list can be advantageously adjusted based on an evaluation of the electrical units' operating hours. Finally, it is also advantageous to re-sort the priority list based on an evaluation of the consumed and available power and the nominal values ​​of the diesel generators.

[0026] Furthermore, it is advisable for the island grid's energy management system to take into account relevant regulations that must be observed and that can vary depending on the country and region. Regulations concern, for example, grid security. This includes protection against power outages, surges, and other electrical disturbances. Regulations also concern grid reliability, or grid stability, with the goal of minimizing or, if necessary, compensating for interruptions and voltage fluctuations in order to generally ensure a stable power supply.

[0027] Advantageously, communication between the electrical units is wireless. Wireless communication, also known as wireless communication, offers a number of advantages over traditional wired connections. Compared to wired connections, setting up wireless communication requires less effort and time. There is no need to lay or connect physical cables, which simplifies installation and configuration. Wireless networks are relatively easy to expand and adapt. New devices can be easily integrated into the network without the need for additional cabling. This allows for easy scalability and flexibility when expanding the network. At the same time, it can facilitate the exchange of data, sharing of resources, and collaboration between different devices.

[0028] According to the present invention, the constellation of the island electrical network is continuously monitored and, by means of an identical control algorithm installed on all electrical units, energy production and energy consumption can be brought into balance or differences can be compensated.

[0029] With the use of diesel engines, wave generators, steam turbines, batteries, supercapacitors, fuel cells, etc., it is becoming increasingly difficult to control the isolated grid using external logic. Especially with a comparatively large number of energy generators, the mix of efficiency, dynamics, and safety functions can no longer be effectively controlled centrally.

[0030] For example, thanks to the flexible prioritization according to the invention, an e-diesel, i.e., a diesel generator intended exclusively for generating electrical energy, can be assigned a priority. This priority can be changed based on its condition or operating status or by calculating the grid configuration, so that it either remains in the grid in all cases, maintains its minimum load in all cases, or deregisters its generated power from the grid and then disconnects from the grid.

[0031] For example, during operation, as soon as a ship picks up speed and the power output of the main diesel engine increases, the associated shaft generator can absorb more power. The steam turbine can be started as a supplement. If the priority were fixed, the steam turbine would have top priority, followed by the shaft generator and the diesel generator. This would make perfect sense for static operation. However, if the ship enters shallow waters and the need for torque increases, meaning the shaft generator has to reduce its power, the priority of the shaft generator falls behind that of the diesel generator, so that the steam turbine and diesel generator take over and the shaft generator only supplies the remainder, as far as possible.If the requirements of the energy suppliers change further, so that the shaft generator is no longer supposed to supply energy but an additional torque to the shaft, its priority will decrease further, since it will now only be available as a generator in an emergency.

[0032] The invention is explained in more detail by way of example with reference to the drawings. They show schematically and not to scale:

[0033] Figure 1 shows a simplified representation of an electrical energy distribution network with several power sources and consumers for a first operation,

[0034] Figure 2 shows a simplified representation of an electrical energy distribution network with several power sources and consumers for a second operation and

[0035] Figure 3 shows a simplified representation for the grouping of electrical units.

[0036] Figure 1 shows a schematic and exemplary representation of an electrical island network 1 according to the invention, comprising a bus 2 and a plurality of different electrical units 3 which can be coupled to the bus 2 via electrical lines 7 and switches 9, wherein the electrical units 3 can be energy sources 4, energy consumers 5 or also couplings 6, wherein the bus 2 can be separated into sections 8 and reconnected by means of the couplings 6. In the exemplary embodiment in Figure 1, the island network 1 comprises a diesel generator 10, a steam turbine 11, a shaft generator 12 and a battery 13 as energy sources 4, wherein the battery 13 can also act as a load in the island network 1, depending on whether it is being discharged or charged. Likewise, the shaft generator 12 can be used as a motor and would then act as a load in the island network 1.The island electrical grid 1 further comprises an energy management system, and the electrical units 3 each have the same control algorithm. According to the invention, the prioritization of the utilization of the energy sources 4 is dynamically adaptable.

[0037] Figures 1 and 2 show how the electrical units 3 , or more precisely the energy sources 4 , are prioritized by selecting a driving profile .

[0038] Figure 1 can be used as an example of so-called sea operation of a naval vessel: In the embodiment according to Figure 1, the energy from the steam turbine 11 is available free of charge, as this energy is obtained from exhaust gas generated on site and not further used. This available power should therefore be used up in the island grid 1, and the steam turbine 11 is therefore given priority 1. The electrical energy from the shaft generator 12 is the next most economical energy, as it represents only a fraction of the energy of the main engine (not shown in Figure 1) and at the same time increases the available power from the steam turbine 11. The priority of the shaft generator 12 is therefore indicated in Figure 1 as "2". The battery 13 then supplies the remainder of the power required in the island grid 1 or absorbs the shocks in the island grid 1. The diesel generator 10 should remain switched off as much as possible in the embodiment of Figure 1.

[0039] The situation is different in maneuvering mode. The exemplary embodiment in Figure 2 shows the corresponding prioritization of the energy sources 4. In maneuvering mode, reliable and stable energy sources 4 are required and because the steam turbine 9 and shaft generator 10 are very limited in their output, they are declared unimportant, so that the diesel generator 10 and the battery 13 take over the supply in the island network 1. Figure 3 shows two configurations a) and b) possible combinations of individual electrical units 3 into groups 14. In configuration a) all electrical units 3 remain as the smallest possible units, whereas in configuration b) electrical units 3 are combined into groups 14. The combination into groups 14 does not necessarily have to be in pairs, as indicated in Figure 2. Other combinations are also possible.

[0040] Figures 1 to 3 are merely exemplary embodiments of the present invention and are provided for purposes of illustration and description. Those skilled in the art will recognize that various changes, modifications, and variations are possible without departing from the spirit and scope of the present disclosure as defined in the following claims. For example, such an island grid 1 need not always be without direct electrical connection to other power grids. Thus, the possibility of a shore connection would also be possible.

Claims

Patent claims 1. An electrical island network (1), comprising a bus (2) and a plurality of electrical units (3) which can be coupled to the bus (2), wherein the electrical units (3) can be energy sources (4), energy consumers (5) or also couplings (6), the electrical island network (1) further comprising electrical lines (7) for electrically connecting energy sources (4) and energy consumers (5), communication interfaces for data transfer between the electrical units (3) and an energy management system, characterized in that the electrical units (3) each have the same control algorithm belonging to the energy management system and that a prioritization of the utilization of the energy sources (3) can be dynamically adapted.

2. The electrical island network (1) according to claim 1, wherein the bus (2) can be separated into sections (8) or reconnected by means of the couplings (6) and individual electrical units (3) can be connected to or separated from the bus (2) by means of switches (9).

3. The electrical island network (1) according to one of claims 1 or 2, wherein the energy management system is based on information on the minimum power, the maximum power, the minimum power in continuous operation and the maximum power in continuous operation of the electrical units (3).

4. The electrical island network (1) according to one of the preceding claims, wherein the electrical unit (3) is a diesel generator (10), a steam turbine (11), a shaft generator / motor (12) and / or a battery (13).

5. The electrical island network (1) according to one of the preceding claims, wherein the energy management system is based on at least one of the following: weather data, geographical data, operating conditions, operating hours, predicted energy demand in the island grid (1) and user-entered preferences.

6. The electrical island network (1) according to one of the preceding claims, wherein electrical units (3) can be combined to form a group (14) and the prioritization can be carried out for the group (14) instead of for individual electrical units (3).

7. Method for controlling the load in an electrical island network (1), the island network (1) comprising a bus (2) and a plurality of electrical units (3) which can be coupled to the bus (2), wherein the electrical units (3) can be energy sources (4), energy consumers (4) or also couplings (6), characterized in that the same control algorithm is carried out in each of the electrical units (3) and a prioritization of the electrical units (3) is dynamically adapted.

8. The method according to claim 7, wherein electrical units (3) are grouped together into a group (14) and prioritized for the group (14).

9. Method according to one of claims 7 or 8, wherein the bus (2) is divided into sections (7) by means of the couplings (6) or at least two sections (7) are connected to one another via the couplings (6).

10. Method according to one of claims 7 to 9, wherein information on the minimum power, the maximum power, the minimum power in continuous operation and the maximum power in continuous operation of the electrical units is processed in the control algorithm.

11. Method according to one of claims 7 to 10, wherein a prioritization is specified by selecting a driving profile.

12. Method according to one of claims 7 to 10, wherein the prioritization is defined by means of a priority list.

13. The method according to claim 12, wherein the priority list is adjusted based on an evaluation of the operating hours of the electrical units (3).

14. Method according to one of claims 7 to 13, wherein regulations concerning the electrical island network (1) are taken into account.

15. Method according to one of the preceding claims, wherein the communication between the electrical units is wireless.

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