KR20190142703A - Ship applied with low-voltage distribution - Google Patents

Abstract

Embodiments of the present invention relate to a ship which comprises a first power system related to an essential load and a second power system related to a service load. The first power system includes a first load part including a first power generation part, a first distribution panel, and an essential load. The second power system includes a second load part including a second power generation part, a second distribution panel, and a service load. The first load part further comprises: a step-up transformer configured to output voltage higher than input voltage; a thruster motor located remote from the first distribution panel; and a cable configured to electrically connect the thruster motor from a first main bus via the step-up transformer.

Description

SHIP APPLIED WITH LOW-VOLTAGE DISTRIBUTION}

The present invention relates to a vessel to which low-voltage distribution is applied, and more specifically, it is divided into different power systems according to the characteristics of the ship power load divided into essential load (Essential, Important Load) and service load (for example, A ship having a power supply system for ships capable of low voltage distribution (such as 440V) and capable of powering a large load (such as a thruster motor), such as a thruster motor, by means of a boost transformer, can be provided.

Onboard power loads may include essential loads associated with the operation (eg Essential & Important Load-Fuel oil supply pump, fuel valve cooling pump, etc.) and service loads not associated with the operation (eg Service Load-Reefer container load). Can be. A representative example of the required load in a ship is a Thruster Motor. The thruster motor is a large-capacity load (approximately 2 MW class) used for the docking / berthing of a large ship. In the case of a normal container ship, two thruster motors are installed in the bow part.

In addition, the essential loads and service loads of these vessels are variable loads whose power consumption varies depending on the driving characteristics such as continuous loads that consume constant power during operation, variable frequency drive (VFD) loads, and refrigerated container loads. It may include. Typically, ships are powered by an AC power supply system and are linked to a single power system with a mixture of continuous and variable loads.

Typically, for large vessels, the single power system capacity is very large, more than 10 MW. Powering all the loads of a large vessel in a single system will lead to a surge in power supply cables. In addition, since the main load of the vessel is a low voltage of 690V or less, when the power system is designed to supply power at a low pressure of 690V or less, a very high current flows in the switchboard due to the low distribution voltage relative to the system capacity. Therefore, expensive blocking equipment is needed to protect the system accident due to the high current in the system. If the rated rectification is more than 4000 ~ 5000A, there is no commercial shutdown facility, so the single power system has a limitation in the low voltage-based power supply due to the capacity limitation.

Therefore, in the case of a ship to which a power system of a certain size or more is applied, a power supply system that generates power at a high pressure and converts it to a low pressure to supply power to a load in order to solve the cable capacity and system capacity limitation due to the high current of a low voltage system. Has

1 is a diagram illustrating a system structure of a power supply system for a ship configured as a single system by mixing a continuous load and a variable load according to a conventional embodiment.

Referring to FIG. 1, a ship power supply system in which a continuous load and a variable load are mixed in a single power system includes a high pressure power generation unit 10; High pressure switchboard 20; Low pressure switchboard 30; One or more transformers 40 for reducing the voltage of the high-voltage switchboard 20; A load unit 50 in which a continuous load and a variable load are mixed; And emergency switchboard 60.

As shown in FIG. 1, when a single grid ship power supply system is applied to a large vessel, when the scale of the grid is larger than a certain size, even if the rated voltage of the load is low, the main distribution is branched to a sub-grid to which the load is applied and the high voltage is applied. When supplying power through the high-voltage / voltage transformer 40 to transform the high pressure to low pressure.

If the 6.6kV high voltage is applied to the switchboard 20 of Figure 1, the power supply process to the load is as follows. 6.6kV generator-> 6.6kV high voltage main switchboard-> 6.6kV / 440V transformer-> 440V low voltage sub-switchboard. That is, the ship power supply system of FIG. 1 generates power at high pressure, transforms it to low pressure, and supplies power to the load.

FIG. 2 is a view for explaining the internal structure of a conventional ship having the ship power supply system of FIG.

Referring to FIG. 2, the vessel 1000 includes an engine room 1030. The engine room 1030 includes various engine facilities such as generators, and other facilities connected to the engine facility, and the ECR switchboard room 1005, which is a space in which an engine control room (ECR) and / or a switchboard for controlling the engine is disposed. And a transformer room 1007, which is a space in which the high / low voltage transformer 40 is disposed.

As described above, the power system of FIG. 1 to which the high voltage distribution is partially applied requires a large capacity high voltage / low voltage transformer 40 to supply power to the load. Since high pressure distribution is performed in a ship with a large load, the size of the transformer chamber 1007 in which the high / low voltage transformer 40 is disposed is considerable.

For example, in the case of Figure 1, the high voltage / low voltage transformer 40 is 6600/440 VAC, 3400 kVA, 3ph specifications, each transformer size is horizontal (2.6m) x vertical (2.65m) x height (1.6m) When eight high / low voltage transformers 40 are installed in a ship, considerable space is utilized for the transformer compartment. For example, two inboard (engine room) spaces with dimensions of width (13-15 m) Х length (6-8 m) Х height (6-8 m) (for example, 13.25 m Х6.06 m Х 6.62 m) It is used as two transformer rooms. As a result, the available space on board is reduced by the size corresponding to the transformer room.

In addition, the high-voltage distribution-based single power system of Figure 1 has a low performance in terms of power generation efficiency. In the case of AC systems, the load efficiency should reach 70 ~ 80% for optimum power generation efficiency. Therefore, the power supply system of FIG. 1 uses a fixed RPM generator that generates power at 70-80% of the load rate. The generation capacity of the fixed RPM generator included in the power generation unit 10 is calculated based on the maximum load power of the continuous load, variable load. Therefore, when the required power is lowered compared to the maximum load power in the driving characteristics such as the variable load, the load ratio of the generator is lowered and the power generation efficiency is lowered.

For example, when the power supply system of FIG. 1 is applied to a container ship, the container ship may include a refrigerated container which is a typical variable load. Large container ships carry approximately 1000 FEU refrigerated containers, with a maximum power consumption of 4.5 to 5 MW. The power consumption of the refrigeration container varies depending on the outside temperature and the type of shipment. The load rate of the refrigeration container is about 30-40% of the load stage in the system. The low average load ratio of such a refrigerated container leads to a decrease in the overall load ratio of the system in a single power system, thereby lowering the power generation efficiency of the entire single power system. That is, in the system of FIG. 1, the larger the ratio of the variable load to the total load, the lower the power generation efficiency.

In order to overcome the problem of high-voltage distribution, when inventing a low-voltage power supply system capable of distribution, the following additional problems occur.

Power to thruster motor loads located in the bow is carried out via generators and switchboards located in the engine room. In a typical container ship, the engine room is located at the stern and the generator and switchboard are also located at the stern. The straight line distance from the generator and switchboard to the forward thruster motor is approximately 300m.

As such, the thruster motor is a remote large load remote from the engine room and requires a power supply line (such as a cable) to be powered. If a power supply line is to be connected from the engine room and / or switchboard room to the bow thruster, a power supply line of approximately 300-350 m in length is laid. Since the voltage drop occurs in proportion to the length of the power supply and the magnitude of the current, the voltage drop occurs in the case of a large load thruster motor.

The main factor is the length and current magnitude of the power supply line at the corresponding voltage drop. Since the thrust motor cannot be changed in function, the method of reducing the current size can improve the voltage drop. Higher voltage distribution is more advantageous in terms of voltage drop than low voltage distribution because the voltage must be increased to reduce the current size. However, when the low voltage distribution is performed, the cross-sectional area of the power supply line is larger than that of the high voltage distribution due to the increase of the current magnitude. For example, when delivering power to a thruster motor with 440V low-voltage distribution, 8-10 strands of cable (acceptable current 270A) with a cross section of 150 SQMM must be installed from the bow to the stern and the cable weight is also significantly increased.

As a result, low-voltage distribution in ships is limited in terms of power supply to the thruster motor.

Patent Publication No. 10-2017-0118285

According to an aspect of the present invention, low voltage distribution (eg, 440V) is possible by separating into different power systems according to the characteristics of the ship power load divided into essential load and essential load and service load. In addition, a large load (eg, a thruster motor) located remotely from a low voltage switchboard may be provided with a vessel having a marine power supply system capable of supplying power using a boost transformer.

The ship having the essential load and the service load according to an aspect of the present invention, the first power system associated with the essential load; And a second power system associated with the service load. Here, the first power system includes a thruster motor.

In one embodiment, the first power system may include a first load unit including a first power generation unit, a first switchboard, and an essential load required for the operation of the ship.

In one embodiment, the first load unit further comprises a set-up transformer for outputting a voltage higher than the input voltage, and a cable for electrically connecting the thruster motor from the first switchboard through the boost transformer. It may include.

In one embodiment, the output voltage of the boost transformer may be a voltage of 1500V or less.

In one embodiment, the cross-sectional area of the cable connecting between the first switchboard and the thruster motor may be less than 180SQMM.

In one embodiment, the boost transformer and the thruster motor may be connected by less than eight strands of cable.

In one embodiment, the thruster motor may have a load capacity of 2MW or more.

According to an aspect of the present invention, the low-voltage power distribution-based power system having a vessel is divided into an essential load power system, and a service load power system according to the load characteristics. Required loads The power system contains the essential loads necessary for the operation of the ship (eg thruster motors, engine lubricating oil pump motors, etc.), and most of the required loads are continuous loads. Service load The power system is not essential to the operation of the ship, but includes the loads associated with providing service by the ship (eg loads for storing cargo such as refrigerated containers, etc.), and most of the service loads are variable loads. .

This load separation reduces the capacity of each power grid compared to a single single grid, so that only low-voltage distribution can supply power to each load in the power grid. As a result, the high voltage distribution is not necessary, and the existing high voltage distribution panel and the large capacity high voltage / low voltage transformer are not required.

As such, by not using a plurality of high voltage / voltage transformers, a cost reduction of approximately 250 million / chuck can be achieved in terms of CAPEX (Capital expenditures).

In addition, the space previously provided for high / low voltage transformers (ie, transformer rooms) can be used for a variety of other purposes. Generally, the high and low voltage transformers are located in the engine room with high equipment density, which greatly affects the utilization of space on board.

In addition, by separating the essential load power system and the service load power system to increase the stability of each system. In the conventional case, if a system accident occurs at the service load end, the system is composed of a single system, which affects the required load. If the system is separated, the accident of the service load stage spreads only in the service load power system, and thus does not affect the essential load power system. Likewise, the accident does not spread to the service load stage even in the event of an essential load stage disconnection.

In addition, because the power systems are isolated, each power system can configure and operate a generator optimized for the type of load involved.

For example, a fixed RPM generator is installed in a power system mainly including a continuous load, and a variable speed RPM generator is installed in a power system mainly including a variable load to supply power.

In one embodiment, in the case of container ships, a variable load power generation efficiency in which a generator having a power generation capacity showing an optimum efficiency for continuous load power supply is installed in a mandatory load power system and operated at a fixed RPM, and the load ratio is changed in the service load power system. Install a variable speed RPM generator to optimize the performance.

In the case of refrigerated containers, which are typical service loads in containers, the average load rate is 30-40% of the total load stage in the system. Compared with the power system of FIG. 1, which uses a fixed RPM generator to power service loads, the amount of fuel consumed to generate 1 km / h of power based on a 35% load rate is reduced from approximately 216 g to approximately 190 g. That is, the container ship according to the present invention can improve fuel consumption of approximately 13%.

As a result, OPEX USD 2,4000 / year (= USD 9,636 / day × improvement efficiency) is calculated by simplifying 10% improvement in fuel consumption for container ships using $ 640 / ton Marine Gas Oil (MGO) as fuel. (10%) × number of days of operation (typically 250 days) of fuel costs.

In addition, the ship power supply system is configured in such a low-voltage distribution system to obtain the effect of the above-described low-voltage distribution, power to a large load (for example, a thruster motor of about 2MW) located far away from the generator and switchboard. If you want to supply the voltage, the transformer can supply power to large remote loads while minimizing voltage drop and power supply. As a result, the cross-sectional area and the number of strands of the power supply line (e.g., cable) which electrically connects from the generator and the switchboard to the remotely located large load reduce the weight of the power supply line. This makes it easier to install the power supply line.

The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.

BRIEF DESCRIPTION OF DRAWINGS To describe the technical solutions in the embodiments of the present invention or in the prior art more clearly, the drawings required in the description of the embodiments are briefly introduced below. It is to be understood that the drawings below are for the purpose of describing the embodiments herein and are not intended to be limiting. In addition, some elements to which various modifications, such as exaggeration and omission, may be shown in the following drawings for clarity of explanation.
1 is a diagram illustrating a system structure of a power supply system for a ship configured as a single system by mixing a continuous load and a variable load according to a conventional embodiment.
2 is a view for explaining the internal structure of a conventional vessel having a high-voltage power distribution-based single power system of FIG.
3 is a schematic system structural diagram of a marine power supply system including a separate power system according to an embodiment of the present invention.
4 is a view showing a relationship between the load ratio of the load stage in the power system and the fuel consumption of the generator to power the load stage.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, terms such as "comprise" or "have" are intended to embody the described features, regions, numbers, steps, actions, components, and / or components, and include one or more other features, regions, numbers, It is not intended to exclude the presence or addition of steps, actions, components, and / or components.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms such as those defined in the commonly used dictionaries should be construed as meanings consistent with the meanings in the context of the related art, and shall not be construed in ideal or excessively formal sense unless clearly defined herein. .

In the present specification, a vessel is a vessel including essential loads essential for the operation of the vessel and a service load additionally used for functions other than the operation, and refers to various vessels such as container carriers, fuel carriers, passenger ships, and the like.

In this specification, the division of the load system into the essential load system and the service load system means that the essential load and the service load are not mixed in the same system, but are included in different systems and configured to be powered by different main distribution boards. . Separation of the load grid is not permanent, and different load grids can be connected by any component that can be electrically connected between the power supply components (e.g., an SPDT switch, or a bus-tie breaker, etc.). have.

Embodiments herein relate to the power system of a ship. In the case of ships, the range of low pressure is set to 1500V or less in the international regulations, and unless otherwise specified, the term "low pressure" herein refers to a voltage corresponding to 1500V or less.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

3 is a schematic system structural diagram of a marine power supply system including a separate power system according to an embodiment of the present invention.

Referring to FIG. 3, the marine power supply system 1 includes one or more power systems 100, 200, and the like. The power system 100 includes a power generation unit 110, a distribution panel 130 including a main distribution panel, and an essential load unit 150 including an essential load. The power system 200 includes a power generation unit 210, a distribution board 230 including a main distribution board, and a service load unit 250 including a service load.

In addition, the ship power supply system 1 may further include a controller (not shown) for monitoring the state of the power system and controlling the power supply. The controller may include one or more of a power management system (PMS), an energy management system (EMS), and an energy power management system (EPMS).

Hereinafter, for clarity of description, the ship power supply system 1 is described as including two power systems 100 and 200, but is not to be construed as limited thereto. In addition, in some cases, a detailed description of the two components is represented by representing a detailed description of the one component.

As shown in FIG. 3, the ship power supply system 1 is configured in a state in which a power system is separated for each of an essential load and a service load.

The power generation unit 110 supplies power to the essential load unit 150 through the switchboard 130 so that the load of the essential load unit 150 consumes and drives power.

The generator 110 outputs an alternating current electrical signal, and includes a plurality of generators (eg, generators 111 and 112 in Fig. 3. The properties and power generation capacity of the generators 111 and 112 depend on the load. For example, an alternator can be used when the motor load for the ship's operation is a constant output load, and when the capacity of the generator is 85% and the load capacity is 1MW, the generator's generating capacity is about 1.2MW. Can be.

The generators 111 and 112 may include, but are not limited to, a diesel generator, a combined fuel generator, a gas fuel generator, a gas turbine, and the like.

In addition, the power generation unit 110 may further include one or more switches, and / or disconnectors for power supply control according to a situation. For example, as shown in FIG. 3, the ship power supply system 1 may further include two switches 113A and 113B when the two generators 111 and 112 are included.

In the switchboard 130, power is supplied to the AC. In one embodiment, the switchboard 130 may include a main switchboard of the power system 100. The main switchboard is composed of a bus cable, in which case the bus cable may be referred to as a main bus.

Also, in some embodiments, switchboard 130 may include a plurality of bus cables. For example, the switchboard 130 may include a plurality of bus cables, such as a main bus 131 electrically connected to the generator 111 and a main bus 132 electrically connected to the generator 112. In this case, the switchboard 130 is electrically connected to the plurality of main buses 131 and 132 as usual, but further includes a bus tie breaker 133 that is electrically disconnected in case of emergency and / or accident. can do.

Low voltage can be applied to the switchboard 130, the power system 100 is capable of low voltage distribution. For example, an AC voltage of 440V may be applied to the main bus 131 and the main bus 132 of FIG. 3 to supply power to the load.

Components of the power system 100 may be electrically connected to interact. For example, the ship power supply system 1 may supply power to the essential load using a power supply line that electrically connects the power generation unit 110 to the essential load unit 150 through the switchboard 130.

As shown in FIG. 3, the essential load 150 of the electric power system 100 includes essential loads (eg, thruster motors, lubricant pumps, engine fuel supply pumps, cooling pumps, etc.) used for the operation of the ship. It may include. Most of the essential load included in the essential load unit 150 corresponds to a continuous load in which the load rate does not change.

In some embodiments, the mandatory load unit 150 may further include a variable frequency drive (VFD) based load. A variable frequency control-based load is an essential load that optimizes the power consumption of the load stage according to the operating characteristics, such as a central cooling system.For example, a VFD load is a cooling pump configured to control the temperature of the cooling water. Essential loads configured to control temperature, pressure, and the like.

As described above, the switchboard 130 is configured to perform low voltage distribution. Thus, as shown in FIG. 3, at least some of the required loads can be electrically connected directly and powered without the need for a separate transformer.

The thruster motor 152 is a motor used for the teeth of the ship. The thruster motor 152 is a large load that consumes a large amount of power compared to other continuous loads. For example, the thruster motors 152A and 152B of FIG. 3 have a load capacity of about 2 MW. For this reason, when power is supplied by the low voltage switchgear 130 to which a low voltage such as 440 V is applied, 8 to 10 strands of cable 270A having a cross section of 150 SQMM should be laid, and the installation of the power supply line in the vessel 1000 may not be easy. Can be.

In one embodiment, the required load 150 may be a power supply line (not shown) for electrically connecting the thruster motor 152 from the switchboard 130, and to supply the power to the thruster motor 152 more efficiently. A booster transformer 153 may be further included.

The power supply line is a component that electrically connects the switchboard 130 to the thruster motor 152. In one example, the power supply line may be a cable.

The boost transformer 153 is a transformer for boosting the low voltage supplied from the switchboard 130, and the output voltage of the boost transformer 153 is configured to correspond to the driving voltage of the thruster motor 152. The boost transformer 153 is a different transformer from the high voltage / low voltage transformer 40 of FIG. 1, and the output voltage of the boost transformer 153 has a voltage higher than that of the switchboard 130, but still has a low voltage of 1500 V or less. Is configured to output.

The voltage is increased from low voltage to high voltage by the boost transformer 153, and the current magnitude in the corresponding power supply line is reduced by the boost transformer 153. As a result, the voltage drop is improved to reduce the cross-sectional area of the cable and / or the number of strands. In one embodiment, the cross-sectional area of the cable may be 50SQMM, and in another embodiment, the cross-sectional area of the cable may be 50SQMM to 75SQMM. In addition, the ship power supply system 1 may supply power to the thruster motor 152 using one strand of cable.

As a result, in the case where the boost transformer 153 is not included in FIG. 3, 8 to 10 strands are required for a cable having a cross-sectional area of 150 SQMM. However, when the boost transformer 153 is used as shown in FIG. The strands also provide power to the 2MW thruster motor 152 with a load capacity.

Further, in some embodiments, the mandatory load 150 may include one or more lower switchboards 154 (154A, 154B in FIG. 3) that supply power to a voltage lower than the voltage of the switchboard 130 (eg, 220V). It may further include. In this case, the essential load unit 150 may further include a transformer 155 (155A and 155B of FIG. 3) disposed between the switchboard 130 and the lower switchboard 154 to reduce the voltage. The transformer 155 is a small transformer having a small capacity.

In addition, the power system 100 may further include an emergency switchboard 160 including an emergency generator for supplying power in an emergency situation such as black out and a load operating at this time. The emergency switchboard 160 may include shore power, emergency load, and the like.

Since components and operations of the power system 200 are substantially similar to those of the power system 100, the following description will focus on differences.

On the other hand, the service load unit 250 of the power system 200 includes a service load additionally used in addition to the operation of the ship. The service load includes the load for storing the shipment used to store the shipment and the load for the user's convenience used for the convenience of the passenger of the ship. If the vessel is a container ship, the service load 250 is a vessel cargo is stored and the storage temperature changes over time. It may include a refrigerated container. Most of the service loads correspond to variable loads with varying load rates.

In addition, the variable load unit 250 may further include one or more lower switchboards (not shown) for supplying power at a lower voltage than the switchboard 230.

Since the power supply system for ships (1) is composed of a separate power system according to the required load and service load, each power system (100, 200) is mainly configured and operated efficiently by configuring and operating the type of generator optimized for the included load type Can supply power

In one embodiment, the required load power system 100 may include a fixed RPM generator, and the service load power system 200 may include a variable speed RPM generator. For example, in FIG. 3, the generators 111 and 112 of the essential load power system may be fixed RPM generators, and the generators 211 and 212 of the service load power system 200 may be variable speed RPM generators.

In the case of continuous load, there is no load variation due to the constant output characteristics, so that there is almost no change in the load ratio, while the variable load is characterized by a change in the load ratio.

Since most of the load of the required load power system 100 corresponds to a continuous load in which the load rate does not change, the fixed RPM generator is operated to operate in the optimum efficiency section. On the other hand, since most of the load of the service load power system 200 is a variable load whose load rate is changed, the variable speed RPM generator capable of variable speed operation is operated in accordance with the load rate variation.

As such, when the generator rotational speed is controlled by the RPM having the optimum power generation efficiency for each load section through the variable speed RPM generator of the service load power system 200, the variable load is variable compared to the case where the continuous load and the variable load are mixed in a single system. It is possible to improve the fuel efficiency of the generator that powers the load.

4 is a view showing a relationship between the load ratio of the load stage in the power system and the fuel consumption of the generator to power the load stage.

As described above, the conventional single power system uses a fixed RPM generator to power a variable load (eg, a refrigerated container). The load factor of the entire refrigerated container averages 30-40% of the maximum power requirements. When power is supplied to the entire refrigeration container using a fixed RPM generator as in the prior art, it consumes approximately 216 g / kwh of fuel based on a 35% load rate (point P _F of FIG. 4). On the other hand, according to an embodiment of the present invention it is possible to supply power to the variable load by using a variable speed RPM generator. When power is supplied using a variable speed RPM generator as in one embodiment of the present invention, it consumes approximately 190 g / kwh of fuel based on the same 35% load rate (point P _V of FIG. 4).

As a result, the power supply system 1 of FIG. 3 has an effect of improving fuel consumption by approximately 13% in generating the same power.

As a result, OPEX USD 2,4000 / year (= USD 9,636 / day × improvement efficiency) is calculated by simplifying 10% improvement in fuel consumption for container ships using $ 640 / ton Marine Gas Oil (MGO) as fuel. (10%) × number of days of operation (typically 250 days) of fuel costs.

In addition, when the service load is configured to have a load section in which the load ratio fluctuates with time, the power generation efficiency may be further improved by controlling the generator rotation speed with RPM having an optimal power generation efficiency for each load section.

In ship load, the low load section L1 is a section having a load rate of 10 to 40% and has a fuel consumption of approximately 285 to 210 g / kwh. The heavy load section L2 is a section with a load ratio of 40 to 60% and has a fuel consumption of approximately 210 to 194 g / kwh. The high load section L3 represents a section having a load ratio of 80 to 100%, and has a fuel consumption of approximately 185 to 190 g / kwh. The power supply system 1 of FIG. 3 has a fuel consumption similar to that of the power supply system of FIG. 1 in the high load section L3. However, in the low load section L1, the fuel consumption rate per kwh is improved by about 6 to 10%, and in the heavy load section L2, the fuel consumption per kwh is improved by about 10 to 35%.

As such, the variable speed RPM generator of the service power system 200 of FIG. 3 may control the RPM based on the load ratio of each load section, thereby improving power generation efficiency of the power generation unit 210.

The fuel improvement effect described with reference to FIG. 4 has been described with respect to the service load power system 200, but is not limited thereto.

As described above, the essential load unit 150 may include a variable frequency drive (VFD) based load that controls temperature, pressure, cooling water, and the like in relation to the operation of the ship. The load rate of the variable frequency control-based load may be changed to control the temperature, the pressure coolant, and the like. For this reason, the variable frequency control-based load has various load sections according to the operating characteristics of the ship.

In another embodiment, where the vessel is other than a container vessel (eg, an LNG vessel), a variable speed RPM generator may also be included in the mandatory power system 100. When the vessel to which the ship power supply system 1 is applied is not a container vessel, the proportion of the variable load in the service load may be relatively reduced. In addition, when a plurality of variable frequency control based loads are installed in such a vessel, the essential load power system 100 may be treated as a variable load power system by a relative relationship.

When the power supply is performed by the variable speed RPM generator in the required load power system 100, the variable speed RPM generator is associated with a variable frequency drive (VFD) based load of the required load unit 150.

As such, when the generator rotation speed is controlled by the RPM having the optimum power generation efficiency for each load section through the variable speed RPM generator of the essential load power system 100, the variable load is variable as compared to the case where the continuous load and the variable load are mixed in a single system. It is possible to improve the fuel efficiency of the generator that powers the load. As it is similar to the embodiment of the service load power system 200 described above, a detailed description thereof will be omitted.

In addition, in the ship power supply system 1 according to the embodiments of the present invention, as described above, the power system is separated into the power system for the essential load and the service load power system according to the characteristics of the ship power load.

As a result, the stability of each system also increases. In the conventional case, if a system accident occurs at the service load end, the system is composed of a single system, which affects the required load. If the system is separated, the accident of the service load stage spreads only in the service load power system, and thus does not affect the essential load power system. Likewise, the accident does not spread to the service load stage even in the event of an essential load stage disconnection.

In addition, the size of individual power systems is reduced compared to a single power system. For example, when a single power system having a power capacity of 14 MW is separated into a mandatory load power system 100 at 9 MW and a service load power system 200 at 5 MW as shown in FIG. 3, the size of the individual power system is 14 MW. To 9MW and 14MW to 5MW respectively.

And, instead of the high voltage of 6.6kV or more, a low voltage (eg, 440V) is applied to the power supply through the main switchboard. This no longer requires the large capacity high pressure / low voltage transformer 40 of FIG. 1. Thus, in terms of capital expenditures (CAPEX), cost savings of approximately 250 million / chuck can be achieved.

Furthermore, the space occupied by the high / low voltage transformer 40 of FIG. 2 (that is, the existing transformer chamber) 1007 can be more efficiently utilized.

Referring again to FIG. 2, when the power supply system 1 of FIG. 3 is applied to a container ship, the space of the transformer compartment 1007 in which eight high / low voltage transformers 40 may be placed may be used for the shipment of silver containers. Can be further utilized.

A commonly used container standard is a TEU container with a size of 6.058m × 2.591m × 2.438m. Using the TEU container as a reference, the number of containers that can be shipped in two spaces of a transformer room of 13.25m × 6.06m × 6.62m is calculated. In the conventional transformer room 1007, a maximum of 26 TEU containers (= 13Х2) Can be shipped. That is, a ship having the marine power supply system 1 of FIG. 3 can ship up to 26 TEU containers more than the conventional container ship having the marine power supply system of FIG. 1. In some embodiments, approximately 20 (= 10 Х2) containers may be additionally shipped, considering that the space should be more relaxed in consideration of loading and unloading containers.

Also, if no high pressure / low pressure transformer is used, the container may be further shipped in the space associated with the utilization of the conventional high pressure / low pressure transformer. For example, certain structures may have been installed due to the presence of transformer 40 on the deck surface located vertically in conventional transformer room 1007. However, the transformer 40 may not be necessary and some structures may also not be needed, so that additional containers may be vertically loaded onto the deck surface. In this case, 100 more containers may be loaded if 5 more horizontally and 10 more vertically are loaded onto the deck surface.

Thus, the high pressure / low pressure transformer 40 is not used, allowing up to about 120 more containers to be shipped on the vessel 1000. In addition, the number of containers shipped in the space of the existing transformer chamber 1007 is merely exemplary, and 120 or more containers may be further loaded according to the shape of the container, the transformer, and the size of the transformer chamber.

In addition, due to the application of the ship power supply system 1 of FIG. 3, it is possible to move an object previously placed in a space other than the existing transformer chamber 1007 into the space of the transformer chamber 1007. In this case, the space originally located due to the movement of the prearranged object becomes an empty space. The container may additionally be placed in the additionally generated empty space instead of being shipped directly to the space of the transformer chamber 1007.

Alternatively, space in existing transformer rooms may be utilized for a variety of purposes other than shipping containers.

In this specification, the structure of the power supply system 1 with reference to FIG. 3 may differ depending on the ship environment, such as the load capacity included in the ship. For example, three generators may be included in the power system 100. In addition, the generating capacity of the three generators may be the same or not all the same.

In addition, 440V applied to the switchboard 130 of FIG. 3 is merely an exemplary voltage indicating a lower voltage than the 6.6kV of FIG. 1, and the switchboards 130 and 230 may supply power at different voltages in some cases. For example, 450V may be applied to the switchboard 130 depending on the rated voltage of the different loads, or 690V may be applied to the switchboard 230 by an alternating current (AC) / direct current (DC) inverter.

In addition, the power supply system 1 may control the operation of the generator according to the time zone (or the operation mode) and adjust the amount of power supplied to the load unit. For example, if the required load 150 of the power system 100 does not require the generating capacity of two generators 111 and 112, the marine power supply system 1 may be at least one generator (eg, The generator 111 may be set as a standby generator to stop operation, and if necessary, the standby generator may be used to supply power to the essential load unit 150 and other purposes.

Although the present invention described above has been described with reference to the embodiments shown in the drawings, this is merely exemplary, and it will be understood by those skilled in the art that various modifications and variations may be made therefrom. However, such modifications should be considered to be within the technical protection scope of the present invention. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

Claims (7)

In ships with required and service loads,
A first power system associated with the required load; And
Including a second power system associated with the service load,
And the first power system comprises a thruster motor.
The method of claim 1,
The first power system is a ship, characterized in that it comprises a first load unit including the essential load required for the operation of the first power generation unit, the first switchboard and the ship.
The method of claim 2,
The first load unit further includes a set-up transformer for outputting a voltage higher than an input voltage, and a cable for electrically connecting the thruster motor from the first switchboard through the boost transformer. Ship.
The method of claim 2,
The output voltage of the boost transformer is a ship, characterized in that the voltage of less than 1500V.
The method of claim 2,
The cross-sectional area of the cable connecting the first switchboard and the thruster motor is less than 180SQMM.
The method of claim 2,
The boost transformer and the thruster motor is characterized in that connected by less than eight cables.
The method of claim 1,
The thruster motor is characterized in that the load capacity is more than 2MW.

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