Energy storage systems

Abstract

The invention relates to an energy storage system (100) for at least one electrical consumer (106) in an electrical system (142) of a vessel (108), the energy storage system (100) comprising at least one converter (140) connected to the electrical system (142) for supplying the consumer (106). According to the invention, an energy storage device (160) is associated to the at least one converter (140). Even consumers (106) which cause high electrical peak loads, such as stabilization devices (120), steering systems (128), etc., can be operated without problems on the electrical system (142) of the vessel (108).

Description

Technical Field

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[0001] The present invention relates to an energy storage system for at least one electrical consumer device in a ship's electrical system, the energy storage system including at least one converter connected to the electrical system for supplying the consumer device.

Background Art

[0002] From the prior art, fin stabilizers and steering gears such as passenger ships, large yachts, floating pontoons, etc. are known in a wide variety of variations. Fin stabilizers and steering gears function periodically, and the reason that a temporarily high peak load occurs is that rapid movement continues and then there is often a stage of resting or waiting with minimal energy intake. In many cases, due to the high peak load, it is often necessary to overdesign the power trains of the electrical systems supplying the fin stabilizers, steering gears, and these consumer devices.

[0003] Fin stabilizers and steering gears usually operate electrohydraulically. In the case of an electrohydraulic power train, energy storage is only possible when a hydrostatic transmission is used as a so-called open hydraulic circuit with nitrogen storage support. The main drawback of this storage technology is that the efficiency of the open hydraulic circuit is relatively low because unnecessary energy is dissipated as heat in the form of resistance control. In comparison, whether it is a speed control system or a displacement control system, the closed hydraulic circuit is highly efficient, but in principle, energy accumulation cannot be achieved.

[0004] A drillship supply system is known from Patent Document 1. Further technical background is disclosed in Patent Documents 2, 3, 4, and 5.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

[0006] Book The objective of the invention is to identify an energy storage system for the electrical systems of ships and other vessels, so that consuming equipment that generates high electrical peak loads can operate without compromising the stability of the electrical system. [Means for solving the problem]

[0007] The above objective is, This is achieved by the energy storage system according to claim 1. In particular, here, at least one consuming device is a ship's stabilization device or steering system that affects the ship's movement, i.e., an electrical consuming device that generates a high peak load, and the energy storage device is Associated with at least one converter ru Energy storage allows for virtually instantaneous extraction of the electrical energy required for maximum load operation of consumer equipment, and simultaneously provides the option to recharge the storage unit during the standby or dormant phase of consumer equipment, when it places little to no load on the ship's electrical system. Furthermore, the storage capacity of the energy storage device can be made large enough to ensure that the emergency functions of connected electrical consumer equipment are still guaranteed for a minimum period of at least a few minutes, even in the event of a complete electrical system failure (a so-called "black ship"). Thus, for example, the fins of a fin stabilizer may remain mechanically locked even after moving to a stationary position. In addition, the steering position of the ship's rudder, driven by the steering gear, can be moved to a neutral position, or the rudder can be "engaged" again. The transducer can be embodied in both block and disassembled structures. In particular, it allows for the isolation of large, power-hungry equipment on ships that cause high, individual peak loads from the electrical system.

[0008] The energy storage device is preferably connected to the DC intermediate circuit of the converter. From the viewpoint of control technology, a simple connection for energy storage is provided in this way.

[0009] In one technically advantageous design, the energy storage device includes at least one energy converter and at least one associated storage unit. Thus, a modular and easily expandable structure for the energy storage system is provided. The energy converter is preferably configured to allow bidirectional energy flow. As a result, reversal of the energy flow becomes possible, enabling the recovery of excess electrical energy to the ship's electrical system with low loss.

[0010] In the case of further technologically advantageous developments, at least one storage unit is formed with at least one high-capacitance capacitor. This allows for a high energy density in the storage unit with low maintenance intensity. In addition, the capacitor has high cycle stability, short response time, and long lifespan. For example, so-called ultracapacitors, supercapacitors, and double-layer capacitors are considered high-capacitance capacitors. As an alternative or addition, coils with the highest possible inductance can also be used.

[0011] In one advantageous design, at least one storage unit is formed by at least one centrifugal mass system, particularly a flywheel. Such storage units with centrifugal mass systems achieve short response times, exhibit minimal self-discharge in the short term, and are unaffected by repeated deep discharges. Furthermore, high energy density can be achieved with centrifugal mass systems, for example, in the form of a high net mass flywheel rotating at high rotational speeds of up to 100,000 revolutions per minute. In addition, the gyroscopic effect can optionally provide a stabilization effect on the onboard vessel.

[0012] The vessel is preferably a ship. This makes the present invention applicable to the most frequently encountered type of vessel, which has a compact, elongated hull. Alternatively, the vessel may be a floating platform, pontoon, pontoon arrangement, etc.

[0013] Hereinafter, preferred exemplary embodiments of the present invention will be described in more detail with reference to schematic diagrams. [Brief explanation of the drawing]

[0014] [Figure 1] This shows a schematic block circuit image of the energy storage system of the present invention for use in ships. [Modes for carrying out the invention]

[0015] Figure 1 shows a schematic block diagram of the energy storage system of the present invention for ships such as vessels. The energy storage system 100 functions to supply a (large) consuming device 106 that causes a high electrical peak load on a vessel 108, such as ship 110. The electrical consuming device 106 is hereby embodied, in mere example, as a stabilization device 120 having at least one associated electric drive unit 122 for pivoting drive of stabilization fins 126 for stabilizing ship 110, about at least one spatial axis not further shown (indicated by black double arrows). Furthermore, the electrical consuming device 106 may also be configured as a steering system 128 having at least one steering gear 130 for driving at least one associated rudder 132 to influence the course of ship 110.

[0016] The energy storage system 100 includes, among other things, a converter 140 supplied from the electrical system 142 of the ship 110. The electrical system 142 is preferably a three-phase power system having a neutral wire and a protective conductor or earth. Here, the converter 140 is configured as a classic conductor having a passive diode bridge 146 for rectifying the three-phase current 144 supplied by the electrical system 142, a DC intermediate circuit 148 for stabilization, and an output inverter 152, just as an example. The output inverter 152 can be realized with multiple circuit breakers, and here only one circuit breaker 150 is shown, representing all the other circuit breakers. The output inverter 152 is operational. Circuit breakers are, for example, power bipolar transistors, power MOSFETs, IGBTs, thyristors, triacs, etc. Through the supply line 154, the converter 140 supplies the electrical energy necessary for operation to the (large) power-consuming equipment 106. The detailed technical circuit structure of the converter is well known to those skilled in the art working in the field of electrical energy technology; therefore, for the sake of brevity, a detailed explanation can be omitted here. Instead of the three-phase current 144, the electrical system 142 may also provide DC, and instead of the (frequency) converter 140, a voltage converter or so-called DC-DC converter, not shown, may be required.

[0017] The energy storage system 100 further comprises an energy storage device 160, which includes an energy converter 162 electrically connected to a converter 140 by a connecting line 164. Furthermore, the energy storage device 160 includes at least one associated storage unit 170 for storing different forms of energy, such as electrical energy, kinetic energy, chemical energy, or potential energy. Preferably, the energy storage device 160 is intended for low-loss storage of electrical energy.

[0018] The storage unit 170, not shown in more detail, can for example be a plurality of high-capacity (single) capacitors interconnected with a capacitor battery. Only one capacitor, representative of all the other capacitors of the capacitor battery, is shown by reference numeral 172.

[0019] To enable the energy stored in the storage unit 170 to be recovered losslessly into the DC intermediate circuit 148 of the converter 140, the energy converter 162 is configured to implement a bidirectional energy flow. For this purpose, for example, the energy converter 162 can include at least one electrical converter or one inverter not shown. If a capacitor 172 is used to store electrical energy in the storage unit 170, the energy converter 162 is preferably implemented by a DC / DC converter. Conversely, if a centrifugal high-capacity storage or a flywheel 174 is used inside the storage unit 170, the energy converter 162 is composed of an inverter. These circuit variations of the energy converter 162 enable the above-described bidirectional electrical energy flow.

[0020] In contrast to a passive diode bridge, an active front-end module enables a low-loss bidirectional flow of electrical energy in an electrical converter in four-quadrant operation and can be implemented with actively switchable electronic switches such as, for example, IGBTs, power bipolar transistors, or power MOSFETs. A heating resistor for dissipating the reverse-flowing electrical energy is still essential in an electrical converter or inverter equipped with a diode bridge but is omitted. For this reason, the control of the active front-end module is relatively complex. If energy recovery from the inverter 140 to the electrical system 142 is possible, the diode bridge 146 in the inverter 140 must also be replaced by such an active front-end module. Since the detailed structure of such a converter equipped with an active front-end module is well known to those skilled in the art active in the field of energy electronics, for the sake of brevity of the description, at this point, a detailed description of the details of the technical circuit can be omitted.

[0021] Alternatively or additionally, the storage unit 170 can include at least one centrifugal mass system such as, for example, a flywheel 174 rotating at a high rotational speed. In addition, the storage unit 170 can include a chemical battery having the highest possible energy density, such as, for example, a lithium battery or a lithium polymer battery. Optionally, the energy converter 162 can additionally or alternatively include at least one electrolytic cell and at least one fuel cell for converting electrical energy into chemical energy and vice versa. In this case, the storage unit 170 can be configured to include a low-pressure metal hydride storage or a high-pressure hydrogen pressure storage so that it can permanently store at least the hydrogen released from the electrolytic cell.

[0022] Energy can be supplied to the storage unit 170 of the energy storage device 160 using the energy converter 162. This energy can be obtained by converting electrical energy, which can be extracted via the connection line 164 in the DC intermediate circuit 148, into an energy form suitable for the storage unit 170. Conversely, energy can be drawn from the storage unit 170 and supplied again in the form of electrical energy to the DC intermediate circuit 148 of the converter 140 via the connection line 164 through reverse conversion by the energy converter 162. This bidirectional process is indicated by the charging arrow 180 and the opposing discharge arrow 182. Charging the storage unit 170 into an energy form suitable for it is generally continued until a full charge of the storage unit 170 is achieved.

[0023] For example, when energy is stored in the storage unit 170 using the flywheel 174, the kinetic energy stored in the storage unit 170 can be converted back into electrical energy using the energy converter 162 and supplied again to the DC intermediate circuit 148 of the converter 140 via the connection line 164. This can be done, for example, with the help of an electric motor or generator in generator mode, in which case each is preferably incorporated into the energy converter 162 and mechanically rotated by the flywheel 174. Conversely, electrical energy from the DC intermediate circuit 148 of the converter 140 can be converted into kinetic energy by the energy converter 162 via the flywheel 174, and is rotated by an electric motor until the flywheel 174 reaches a predetermined maximum rotational speed.

[0024] In contrast, when a large-capacity capacitor is used in the storage unit 170, the energy converter 162 adjusts only the electrical energy supplied or removed with respect to current intensity and / or voltage level. Furthermore, the energy converter 162 can be used to model the time course of current and / or voltage. Moreover, if necessary, the energy converter 162 can be used not only for DC-DC conversion but also for AC-DC conversion or vice versa.

[0025] In the normal, idle, or standby state of the (large) power-consuming appliance 106, which is available but not currently needed, electrical energy is preferably transferred or stored from the DC intermediate circuit 148 to the energy storage device 160 via the connection line 164. This is indicated by the storage arrow 190. This storage process is usually continued until a full charge of the energy storage unit 170 is achieved. In addition, the released brake energy of the (large) power-consuming appliance 106 can be stored (regenerated) in the energy storage device 160.

[0026] In contrast, if the electrical appliance 106 generates a peak electrical load or a high continuous load in the DC intermediate circuit 148 that cannot be fully or temporarily covered by the electrical system 142, the energy storage device 160 and connecting line 164 can be used to immediately feed back the lost electrical energy to the DC voltage intermediate circuit 148 of the converter 140 of the energy storage system 100. This is represented by the storage return arrow 192. Depending on the capacity of the storage unit 170 of the energy storage device 160, this process may last up to several minutes. As a result, short-term and long-term electrical overload conditions caused by the (large) electrical appliance 106 in the area of ​​the DC intermediate circuit 148 can be compensated using the energy storage device 160.

[0027] Furthermore, the energy storage system 100 of the present invention eliminates the need to design the electrical system 142 of the ship 108 based on the possibility of a maximum electrical load peak of the power-consuming equipment 106, which rarely occurs.

[0028] Furthermore, in the event of a complete failure of the electrical system 142 ("black ship"), at least emergency operation of the power consumption device 106 is possible. For example, in this configuration, the electric drive unit 122, which is supplied with emergency power by the energy storage device 160, can move the fins 126 of the stabilizer 120 to a resting position and optionally mechanically lock them. The same applies to the electric steering gear 130 of the steering device 128 that drives the rudder 132.

[0029] All processes within the energy storage system 100, in particular the storage and recovery of electrical energy to and from the storage unit 160 via the energy converter 162, as well as the charging and discharging of the storage unit 170 of the energy storage device 160 by the energy converter 162 in different forms of energy, particularly in the form of electrical energy, kinetic energy, potential energy, and / or chemical energy, are controlled by an efficient control and adjustment unit 200.

[0030] The present invention relates to an energy storage system 100 for at least one electrical consuming device 106 in the electrical system 142 of a ship 108, wherein the energy storage system 100 includes at least one converter 140 connected to the electrical system 142 to supply power to the consuming device 106. According to the present invention, an energy storage device 160 is associated with at least one converter 140. Even consuming devices 106 that cause high electrical peak loads, such as a stabilizer 120 and a steering system 128, can be operated without problems on the electrical system 142 of the ship 108. [Explanation of symbols]

[0031] 100 Energy Storage Systems 106 Electrical appliances 108 Ship 110 Ship 120 Stabilizer 122 Electric drive unit 124 Black double arrow 126 stabilizing fins 128 Steering System 130 Electric steering gear 132 Ladder 140 Converters 142 Electrical Systems 144 Three-phase current 146 Diode Bridge 148 DC intermediate circuit 150 Circuit breakers 152 Output Inverter 154 supply lines 160 Energy storage devices 162 Energy Converter 164 connection lines 170 storage units 172 Capacitors 174 Flywheel 180 Charging Arrow 182 Discharge arrow 190 Storage Arrows 192nd regeneration arrow 200 Control and / or adjustment units

Claims

1. An energy storage system (100) for at least one electrical consuming device (106) in the electrical system (142) of a ship (108), wherein the energy storage system (100) includes at least one converter (140) connected to the electrical system (142) for supplying power to the consuming device (106), and the energy storage device (160) is associated with the at least one converter (140), wherein the at least one consuming device (106) is a stabilization device (120) of the ship (108) or a steering system (128) that affects the course of the ship (108), The energy storage device (160) is connected to the DC intermediate circuit (148) of the converter (140) via a connection line (164). An energy storage system (100) characterized in that, when at least one consumer device (106) generates a high peak load, the energy storage device (160) feeds back electrical energy to the DC intermediate circuit (148) via the connection line (164).

2. The energy storage system (100) according to claim 1, characterized in that the energy storage device (160) includes at least one energy converter (162) and at least one storage unit (170) associated with the at least one energy converter (162).

3. The energy storage system (100) according to claim 2, characterized in that the energy converter (162) is configured to enable bidirectional energy flow.

4. The energy storage system (100) according to any one of claims 2 to 3, characterized in that the at least one storage unit (170) is formed of at least one large-capacity capacitor (172).

5. The energy storage system (100) according to any one of claims 2 to 3, characterized in that the at least one storage unit (170) is formed of at least one centrifugal mass system, in particular a flywheel (174).

6. The energy storage system (100) according to any one of claims 1 to 5, characterized in that the vessel (108) is a ship (110).

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