Energy supply system for an isolated network

Abstract

An energy supply system (1) which comprises an energy management system (2), a first power generating device (7), and a second power generating device (8) has a first operating state (17) and a second operating state which are temporally different. In the first operating state, a first operating mode (19) is assigned to the first power generating device (7), and a second operating mode (20) is assigned to the second power generating device (8). In the second operating state (18), the first operating mode (19) is assigned to the second power generating device (8), and the second operating mode (20) or a different operating mode (26) is assigned to the first power generating device (7). By virtue of the assignment of different modes, the energy supply system (1) is optimized.

Description

Description Energy supply system for an island grid. The invention relates to an energy supply system for an island grid. The energy supply system has at least two generators for generating electrical energy. Island power grids are known, for example, from ships, but also from pipeline compressor stations. An island power grid can be a DC grid, an AC grid, or a mixed grid. For example, DE 10 2010 040 613 AI is an island ¬ A network with a frequency greater than 60 Hz is known, which is used particularly for pipeline compressor stations. ¬This island grid has at least one gas turbine directly coupled to a dynamo-electric machine. The dynamo-electric machine is connected to a public or interconnected grid via a busbar with a decoupling device. Other electrical equipment, such as compressors, are also electrically connected to the busbar. For example, an island grid for a ship is known from DE 10 2009 017 023 AI. In ship propulsion systems with a converter and a DC link, the energy released during regenerative braking can be fed back into the grid via a converter. An energy supply system for island grids is known from DE 102 20 738 AI. This energy supply system for island grids is understood to be a holistic energy system, i.e., an energy system in which electrical energy is generated, transmitted, and ultimately converted back into other forms of energy, whereby the system is spatially limited in its scope and not comparable to a nationwide energy supply. Such systems are found particularly in fixed and / or mobile installations at sea. For example, on ships and other seagoing vessels, drilling platforms, or other isolated, preferably sea-based, technical installations with energy requirements. One object of the invention is to provide an efficient energy supply. ¬ to provide a supply system, especially in an island network. A solution to the problem is found in an energy supply system according to claim 1, or in a method for operating an island grid according to claim 16. Embodiments are found in dependent claims 2 to 15 and 17 to 21, respectively. An energy supply system, with an energy management system, comprises a first power generation unit and a second power generation unit. Power supply units are, for example, sets consisting of a diesel engine and a... ¬ A generator, a gas turbine and a generator, a rechargeable battery, supercapacitors, etc. The energy management ¬A mentsystem is, for example, a central or distributed control device that performs control and / or regulation functions. ¬ The system fulfills its tasks. For example, the energy supply system is located on a ship, a platform such as an oil platform or gas platform, or it is an island grid for a pipeline pumping station, a mobile fracking station, etc. The energy supply system has a first operating state and a second operating state, with the first operating state differing from the second operating state in terms of time. The first operating state follows the second operating state either immediately or with an interruption. ¬and vice versa. In the first operating state, the first power generating unit is assigned a first operating mode, and the second power generating unit is assigned a second operating mode. In the second operating state, the second power generating unit is assigned the first operating mode. The operating mode is a way in which the power ¬ is operated as a generating facility. Examples of this are: Voltage regulation, frequency regulation, power optimization, optimization of response speed to load fluctuations, etc. In one embodiment, at least one operating mode involves an ISO mode or a DROOP mode. The energy supply system has one or more loads. Depending on their power requirements, power fluctuations, required reactive power, and other boundary conditions, it may be necessary to assign specific operating modes to certain power generation facilities, in which they can then be operated, or are operated, to improve system efficiency. Energy-efficient systems and an electrical island grid stabilizing energy management control system for island grids with their own energy supply. ¬ Power generation from turbines and generators (gas and steam turbines, diesel engines and the associated generators) is becoming increasingly important as energy costs rise and environmental requirements grow. In the design of an energy supply system, the assignment of an operating mode depends on the prioritization of power generation facilities. Does the energy management system indicate... ¬For example, if 10 available power generation units of the same or different output are available, a different number of power generation units can be activated, depending on the required power, which in turn depends on the load requirements. Both the activation sequence and the assignment of the different operating modes can be prioritized. In one configuration of the energy supply system, the second operating mode or a further operating mode is to be used in the second operating state of the first power generation unit. ¬ organized. The energy management system is particularly overarching and regulates the energy supply system, especially that of an island. ¬network, the active power distribution and / or the reactive power distribution between the generating power plants, such as a set consisting of a turbine and a generator. A generator is, for example, a synchronous machine ¬ rail or an asynchronous machine. The higher-level energy ¬ In one configuration, the energy management system does not regulate the turbines and generators to their optimal efficiency and optimize energy efficiency locally, but rather distributes the load between the power generation facilities proportionally, either in equal parts or in different parts. The energy supply system can be designed such that the first power generation unit regulates the frequency and voltage in the grid with priority 1. This can represent the first operating mode. A second or subsequent power generation unit operates at its respective optimal operating point (e.g., depending on rotational speed, active power, reactive power, steam pressure, exhaust gas temperature, etc.). This can represent the second operating mode. An additional power generation unit, in addition to the second or subsequent power generation unit, can be provided to supply the reactive power required in the grid or the remaining active power. This can represent a third operating mode. In one configuration of the energy supply system, the first power generation unit can be operated with priority 1 at a regulated voltage for the generator and at a regulated frequency for a gas turbine or diesel engine. This is an operating mode for the first power supply unit. ¬ The second power supply unit has priority 2. If, for example, the first power supply unit fails due to a defect... ¬ If the first power supply unit switches off, the second power supply unit takes over the operating mode of the first power supply unit. direction. After the failure of the first power supply unit with priority 1, the second power supply unit with priority 2 then operates in a mode in which a regulated voltage for the generator and a regulated frequency for a gas turbine or diesel engine are used. In one configuration of the energy supply system, the first operating mode is an ISO mode. In ISO mode, the turbine is regulated according to its frequency. This is an isochronous operating mode. This allows the control of the ISO machine, i.e., the power generator, to ensure that... ¬The generating unit, which is operated in ISO mode, is set to, for example, 50% of the maximum possible active power and a cos φ of, for example, 0.9, so that the reactive power of this machine is large enough that, when loads are switched on or off, or in the event of unforeseen events in the electrical network, the generating unit has the possibility of reserves to remain within the permissible range of the generator stability curve and to react accordingly without reaching the physical limits of the turbine and the generator. In one configuration of the power supply system, the second operating mode is a droop mode. In droop mode, a turbine in the power supply unit is controlled according to a droop characteristic. Frequency deviations are permitted. Therefore, the second operating mode can be a droop mode. In another configuration of the power supply system, the first operating mode has a power function. By calculating how much active and reactive power is required in an islanded electrical network and by calculating how much power the existing power generation units in operation, e.g., sets of turbines and generators, can provide, the load is distributed among the turbines in such a way that as many turbine-generator sets as possible operate in optimal conditions. ¬ painting (most energy-efficient) operating point. In one configuration of the energy supply system, the first operating mode features a coscop function. This allows the offset between voltage and current to be regulated. In one configuration of the energy supply system, the most efficient operating point for one or more turbines is determined. ¬ The rator set is individually and dynamically calculated. The optimal arrangement ¬ The operating point is defined by the turbine and generator manufacturer and determined by certain environmental parameters (e.g., ambient temperature, steam temperature, steam pressure, cooling water temperature, etc.). To simultaneously achieve the highest possible electrical efficiency... ¬ grid stability with regard to island grid frequency and island ¬ To achieve grid voltage, the ISO machine (turbine), i.e., the power generating unit with a turbine operating in ISO mode, is reduced to, for example, 50% of its capacity. ¬The turbine's output is regulated (through active power distribution from the other turbines in the island grid), but it is in frequency control mode. This stabilizes the island grid frequency at the nominal grid frequency. The associated generator of the ISO turbine is in voltage control mode and is regulated by the power management system to, for example, coscp=0.9 (through reactive power distribution from the other turbines in the island grid). This stabilizes the island grid voltage at the nominal grid voltage. In one configuration of the energy supply system, the power generating unit operating in the first mode has a rated output of at least 200% of the rated output of the highest load. This provides a sufficient power reserve. In one configuration of the energy supply system, the second operating mode has a power optimization function. This allows a power supply device to be operated in a particularly energy-efficient manner. In one configuration of the energy supply system, this includes a third power generation facility, wherein in The third operating mode is assigned to the first operating state of the third power generation unit. ¬ The drive mode serves, for example, the reactive power compensation. ¬ tion in the grid and not primarily an efficient operation of the power generation facility. In one configuration of the energy supply system, a third power generation unit is assigned a second operating mode or another operating mode in the second operating state. This can occur, for example, when the first power generation unit has failed, the second power generation unit switches to the first operating mode, and the third power generation unit switches to the second operating mode. Modes can also be combined. For instance, the first operating mode can also include radio communication. ¬The reactive power compensation is not present when no third power generation unit is active, which operates in the third operating mode. In one embodiment of the energy supply system, this includes a fourth power generation unit, wherein the second operating mode is assigned to the fourth power generation unit in the first operating state, and wherein in the second operating state ¬ The operating state of the fourth power generation unit is also assigned to the second operating mode. In a design of the energy supply system with a ¬In a third power generating unit and a fourth power generating unit, the second operating mode is assigned to the third power generating unit in the first operating state, and the second operating mode is also assigned to the third power generating unit in the second operating state, wherein the second operating mode is a DROOP mode and has a power supplement function, and a third operating mode is assigned to the fourth power generating unit in the first operating state, and the third operating mode is also assigned to the fourth power generating unit in the second operating state. Through the under- Different allocation of modes in known optimizations of the existing active and inactive power generation facilities can affect the overall system, i.e., the energy supply system. ¬The system can be optimized. Depending on the power output and the optimal operating points, an optimal prioritization of the assigned modes can be achieved for a customized energy supply system, particularly in island grid operation. In one configuration of the energy supply system, at least one of the power generation units comprises an internal combustion engine and an electric generator. The generator is, for example, a separately excited synchronous generator. ¬ rator. In this type of generator, reactive power can be controlled via the excitation voltage. Self-excited synchronous machines can also be used as generators. In one configuration of the power supply system, only the regulated rator is used. ¬ te Reactive power generator externally excited. In one configuration of the energy supply system, the power generation facilities supply an island grid, with each power generation facility in the island grid having a capacity of less than 100 MW. This allows for high redundancy and efficiency, for example, for large ships such as cruise ships, container ships, etc. In a method for operating an island grid, which is in particular a power supply system in a ship or an oil or gas platform, the active and reactive power required in the island grid is calculated, and the load is distributed among a multitude of power generation units in such a way as to optimize the operation of the power generation units. Power generation units are, for example, sets consisting of a diesel engine and a generator or of a gas turbine and a generator. The goal is to control as many sets as possible at their optimal operating point. This is achieved by calculating the amount of active and reactive power required in an electrical island network. The load on the turbines is to be determined by calculating how much power can be provided by the existing turbines and generators in operation. ¬ The turbines are distributed in such a way that as many turbine generator sets as possible are operated at their optimal and most energy-efficient operating point. Each set can have its own optimal operating point. In one embodiment of the method, to optimize the operation of the power generation facilities, the majority of the power generation facilities are operated at an optimal operating point. At least one of the sets is operated at an optimized and / or optimal response point and / or range in order to react more quickly to load changes than when operating at the most energy-efficient operating point. Thus, one set can operate in an improved ¬ The reaction point is operated and a maximum white ¬The number of additional sets at an optimal operating point with regard to energy efficiency is determined. The most efficient operating point, in terms of energy efficiency, is calculated individually and, in particular, dynamically for each turbine-generator set. The optimal operating point is defined, for example, by the turbine and / or generator manufacturer and is determined or influenced by certain environmental parameters such as ambient temperature, steam temperature, steam pressure, and cooling water temperature. To simultaneously achieve the highest possible electrical grid stability ¬To achieve the desired effect with regard to island grid frequency and voltage, in one embodiment the ISO-mode operated machine (turbine) is regulated to, for example, approximately 50% of its capacity. This is achieved by distributing the active power among the other turbines in the island grid, but it operates in frequency control mode. This stabilizes the island grid frequency at the nominal grid frequency. The associated generator of the ISO turbine operates in voltage control mode and is regulated by the power management system to, for example, a power factor (cos φ) of approximately 0.9. This is made possible by the energy management system's active reactive power distribution from the other turbines in the island grid. This stabilizes the island grid voltage at the nominal grid voltage. In one embodiment of the procedure, the value of the generated energy is used to optimize the operation of the island grid. ¬The power generated by power generation facilities operating at their optimal operating point is maximized. In this case, the focus is not on optimizing the number of active sets operating at the most energy-efficient operating point, but rather on optimizing the total power generated by active sets operating at the most energy-efficient operating point. By operating the power generation facilities that are not needed, for example, for reactive power compensation or for a rapid load reserve, i.e., for the remaining turbine-generator sets in the electrical network at their most energy-efficient operating point, si ¬ It is ensured that the highest possible overall efficiency is achieved for electricity / voltage generation in turbines and generators, regardless of whether they use steam, gas, or oil. This contributes to reducing overall energy demand. In one embodiment of the method, an energy supply system of the type described is used, which is particularly suitable for use at sea. The invention is subsequently described with reference to embodiments. ¬ Playing is explained. It shows: FIG 1 a power supply system in a first operating state; FIG 2 shows the power supply system in a second operating state, and FIG 3 shows a power generation facility. The diagram in FIG. 1 shows a power supply system 1, comprising an energy management system 2, a first power generating unit 7, a second power generating unit 8, a third power generating unit 9, and a fourth power generating unit 10. The energy management system 2 is connected to the first power generating unit 7 via a communication link 3. The energy management system 2 is connected to the second power generating unit 8 via a communication link 4. The energy management system 2 is connected to the third power generating unit 9 via a communication link 5. The energy management system 2 is connected to the fourth power generating unit 10 via a communication link 6. Through the energy management system 2, the Power generating units 7, 8, 9, and 10 are assigned different modes 19, 20, and 21. A first operating mode, I 19, is assigned to the first power generating unit 7. The first power generating unit 7 is therefore operated in operating mode I 19. A second operating mode, II 20, is assigned to the second power generating unit 8. The second power generating unit 8 is therefore operated in operating mode II 20. A third operating mode, III 21, is assigned to the third power generating unit 9. The third power generating unit 9 is therefore operated in operating mode II 21. ¬ driven. The second operating mode I 20 is the power generation ¬ assigned to power generation unit 10. The fourth power generation unit. ¬ Device 10 is therefore operated in operating mode II 20. The modes 19, 20, 21 assigned to the different power generation devices 7, 8, 9, 10 constitute a first operating state 17. The different power generation devices¬ Facilities 7, 8, 9, and 10 feed a distribution network 12, to which a first load 13, a second load 14, a third load 15, a fourth load 16, and further loads are connected. All of this together forms an island grid 11. The first load ¬ Operating state 17 differs from a second operating state. ¬ Driving state 18, which is shown by way of example in FIG. 2 It is the same island network 11, but with different operating times. The diagram in FIG. 2 shows the power supply system 1, with the energy management system 2 and the power generating units 7, 8, 9, and 10. The energy management system 2 assigns different modes 19, 20, and 21 to the power generating units 7, 8, 9, and 10. According to FIG. 2, a fault 27 is assumed in power generating unit 7. Power generating unit 7 is therefore inactive and without an operating mode. The second power generating unit ¬Setup 8 is now assigned to the first operating mode I 19. ¬ net. The third power generation unit 9 is assigned the second operating mode II 20. The fourth power generation unit ¬ Device 10 is assigned to the third operating mode III 21. ¬ net. By switching modes, the island grid can continue to operate efficiently, even though the initial power generation ¬ Device 7 has failed. Figure two shows a second operating state 18, which corresponds to the first operating state. ¬ the situation occurs at different times and, for example, through a ¬ a fault, maintenance work on power generation equipment, or different loads from connected loads 13, 14, 15, 16 can cause this. The second power supply unit 8 has a higher Prioritization compared to the others, so that the first mode I 19 is assigned to it. The first operating mode 19 is, for example, an ISO mode with frequency control and voltage control. An average power utilization of 50% can be provided, for example, with a cos φ of 0.9. The second operating mode II 20 is at ¬ For example, a DROOP mode with control for optimal energy efficiency of reactive and active power. The third operating mode III 21 is also a DROOP mode, where the remaining required reactive and active power is generated. The illustration in FIG. 3 shows the power generation device 7, in which an internal combustion engine 22, such as a diesel engine or a turbine, is connected via a shaft 23 to an electric generator 24. The generator 24 produces three-phase alternating current for an island grid, which is connected via a distribution network connection 25.

Claims

1.  An Energy supply system for an island grid (1), having a first electricity generating device (7), having a second electricity generating device (8), having a third electricity generating device (9), having a fourth electricity generating device (10), having a load (13, 14, 15, 16), having an energy management system (2), having a first operating state (17) and a second operating state (18) which differs therefrom, wherein a first operating mode (19) is assigned to the first electricity generating device (7) and a second operating mode (20) is assigned to the second electricity generating device (8) in the first operating state, wherein the first operating mode (19) is assigned to the second electricity generating device (8) in the second operating state (18), wherein the second operating mode (21) is assigned to the third electricity generating device (9) in the first operating state (17), wherein the second operating mode (20) is also assigned to the third electricity generating device (9) in the second operating state (18), characterized in that the second operating mode (20) is a droop mode and has a power addition function, wherein a third operating mode (20) is allocated to the fourth electricity generating device (10) in the first operating state (17), wherein the third operating mode (20) is also assigned to the fourth electricity generating device (10) in the second operating state (18), and  in that  the assignment of an operating mode (18, 19, 20) depends on a prioritization of the electricity generating devices (7, 8, 9, 10), wherein the electricity generating device (7, 8, 9, 10) that is in the first operating mode (19) has a rated power of at least 200% of the rated power of the greatest load (13, 14, 15, 16). 2.  The energy supply system (1) according to Claim 1, wherein the first operating mode (19) has a power function. 3.  The energy supply system (1) according to either of Claims 1 and 2, wherein the first operating mode (19) has a cos φ function. 4.  The energy supply system (1) according to claim 1, wherein at least one of the electricity generating devices (7, 8, 9, 10) has an internal combustion engine (22) and an electric generator (24). 5.  The energy supply system (1) according to claim 1, wherein the electricity generating devices (7, 8, 9, 10) form an island grid (11), wherein the electricity generating devices (7, 8, 9, 10) in the island grid (11) each have a power of less than 100 MW. 6.  A Method for operating an island grid (11), wherein an active power and a reactive power required in the island grid (11) are calculated, and wherein the load is distributed among a plurality of electricity generating devices (7, 8, 9, 10) in such a way that operation of the electricity generating devices (7, 8, 9, 10) is optimized,  characterized in that  an energy supply system (1) according to claim 1 is used. 7.  The Method according to Claim 6, wherein, to optimize operation of the electricity generating devices (7, 8, 9, 10), the majority of the electricity generating devices (7, 8, 9, 10) are operated at an optimum operating point, wherein the optimum operating point is defined by the manufacturer of the electricity generating device and is determined by ambient parameters, wherein the the ambient parameters are ambient temperature, steam temperature, steam pressure, cooling water temperature. 8.  The Method according to Claim 7, wherein, to optimize operation of the island grid (11), the value of the generated power that is generated using electricity generating devices (7, 8, 9, 10) at the optimum operating point is maximized. 9.  The Method according to  Claim 7wherein the island grid (11) is used on a ship. 10.  The Method according to Claim 7, wherein the island grid (11) is used on a platform that is suitable for use at sea.

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