KR102155422B1 - Ship applied with low-voltage distribution - Google Patents

Abstract

The embodiments include a first power system related to an essential load used in the operation of the ship and a second power system related to a service load additionally used other than the operation of the ship, wherein the first power system is a first power generation system. The second power system includes: a second power generation unit and a second switchgear; and a first load unit including a sub, a first switchboard, and an essential load; And it relates to a ship to which a power supply system for a ship including a second load including a service load is applied.

Description

Vessels with low voltage distribution applied {SHIP APPLIED WITH LOW-VOLTAGE DISTRIBUTION}

The present invention relates to a ship to which low-voltage distribution is applied, and more particularly, by separating into different power systems according to the characteristics of the ship power load divided into essential loads and service loads (e.g., For ships with a power system capable of supplying power to the load through alternating current and/or direct current distribution that is capable of low-voltage distribution (such as 440V) and is optimized for the power required for the load within the essential load system and/or service load system. Related.

The ship's power load includes essential loads related to operation (e.g., Essential & Important Load-Fuel oil supply pump, fuel valve cooling pump, etc.) and service loads not related to operation (e.g. Service Load-Reefer container load). I can. A typical example of an essential load in a ship is a thruster motor. The thruster motor is a large-capacity load (approximately 2MW class) used for berthing/berthing of large ships, and in the case of a normal container ship, two thruster motors are installed on the bow part.

In addition, these essential loads and service loads are variable loads in which power consumption varies according to operating characteristics, such as continuous loads, variable frequency drive (VFD) loads, and reefer container loads that consume constant power during operation. Can include. Typically, a ship is connected to a single power system by using an AC power supply system and a mixture of continuous and variable loads.

Typically, large ships have a very large single power system capacity of 10MW or more. If power is supplied to all loads of large ships in a single system, the quantity of power supply cables will increase rapidly. In addition, since the main load of the ship is a low voltage of 690V or less, if the power system is designed to supply power at a low voltage of 690V or less, the distribution voltage is low compared to the system capacity, so very high current flows through the switchboard. Therefore, in order to protect a system accident due to the high current in the system, an expensive cut-off facility is required. If the rated rectification is 4000~5000A or more, there is no commercial shut-off facility, so a single power system has a limitation in supplying low-voltage-based power due to its capacity limitation.

Therefore, in the case of a ship to which a power system of a certain size or higher is applied, a power supply system that inevitably generates high-voltage power and transforms it into low-voltage to supply power to the load in order to solve the cable quantity and system capacity limitations due to high current of the low-voltage system. Have.

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

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

As shown in Fig. 1, when the power supply system for a single system ship is applied to a large ship, when the system size is more than a certain size, the main distribution applies high-voltage distribution and branches to the sub-system to which the load is connected, even if the rated voltage of the load is low. In this case, power is supplied through a high-voltage/voltage transformer 40 that converts high-voltage to low-pressure.

When a 6.6kV high voltage is applied to the switchboard 20 of FIG. 1, the process of supplying power 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 and transforms it to low pressure to supply power to the load.

FIG. 2 is a view for explaining an internal structure of a conventional ship having the ship power supply system of FIG. 1.

Referring to FIG. 2, the ship 1000 includes an engine room 1030. The inside of the engine room 1030 includes various engine facilities such as a generator, and other facilities connected to the engine facilities, and an ECR (Engine Control Room) that controls the engine and/or an ECR-distribution panel room 1005, which is a space in which a switchboard is placed. ), 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 high-voltage distribution is partially applied requires a high-capacity high-voltage/low-voltage transformer 40 to supply power to a load. Since high-voltage distribution is performed in a ship having a large load, the size of the transformer chamber 1007 in which the high-voltage/low-voltage transformer 40 is disposed is considerable.

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

In addition, the high-voltage distribution-based single power system of FIG. 1 has low performance in terms of power generation efficiency. In the case of an AC system, the power generation efficiency is optimal when the load ratio reaches 70~80%. Accordingly, the power supply system of FIG. 1 uses a fixed RPM generator that generates power according to 70 to 80% of the load factor. The power generation capacity of the fixed RPM generator included in the power generation unit 10 is calculated based on the continuous load and the maximum load power of the variable load. Accordingly, when there is a case in which the required power is lowered compared to the maximum load power in the operation characteristics such as a variable load, the load ratio of the generator is lowered, resulting in a decrease in power generation efficiency.

For example, when the power supply system of FIG. 1 is applied to a container ship, the container ship may include a reefer container that is a representative variable load. Large container ships transport approximately 1000 FEU reefer containers, and the maximum power consumption of these reefer containers is about 4.5 to 5 MW. The power consumption of a reefer container fluctuates according to the outside temperature and the type of shipment, and the load ratio of the reefer container is, on average, around 30 to 40% of the load end in the system. Such a low average load factor of the reefer container leads to a decrease in the overall system load factor in a single power system, thereby reducing the power generation efficiency of the entire single power system. That is, in the system of FIG. 1, as the ratio of the variable load to the total load increases, the generation efficiency is significantly lowered.

In addition, there is a trend of increasing loads based on Variable Frequency Drive (VFD) that optimizes the power consumption of the load stage according to the characteristics of operation, including the Central Cooling System. This trend also affects the reduction of the overall load ratio, resulting in a problem of lowering power generation efficiency.

Unexamined Patent Publication No. 10-2017-0118285

In one aspect of the present invention, low voltage distribution (e.g., 440V) is possible by separating into different power systems according to the characteristics of the ship's power load divided into essential loads and service loads, In addition, a ship to which a power supply system capable of supplying power to a load through alternating current and/or direct current distribution may be applied according to the configuration of a continuous load and a variable load within the essential load system and/or service load system.

A ship having an essential load and a service load according to an aspect of the present invention includes a first power system associated with the essential load; And a second power system associated with a service load, and at least one of the first power system and the second power system may be configured to enable direct current distribution.

In one embodiment, the second power system may include a second power generation unit, a second switchboard, and a second load unit including a service load.

In one embodiment, the second power generation unit may include a variable speed RPM generator.

In one embodiment, the second power generation unit further comprises an alternating current (AC) / direct current (DC) inverter for receiving an alternating current (AC) electrical signal and converting it into a direct current (DC) electrical signal,

The second load unit may further include a direct current (DC)/alternating current (AC) inverter that receives a direct current (DC) electrical signal and converts it into an alternating current (AC) electrical signal.

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

In one embodiment, the first power generation unit may include a fixed RPM generator.

In one embodiment, the essential load may include at least one of a thruster motor, an engine fuel supply pump, a lubricating oil pump, and a cooling pump.

In one embodiment, when the ship is a container ship, the service load may include a refrigerated container.

According to an aspect of the present invention, a low-voltage distribution-based power system of a ship is divided into an essential load power system and a service load power system according to load characteristics. Essential load The power system includes essential loads (eg, thruster motors, engine lubricant pump motors, etc.) essential for the operation of a ship, and most of the essential loads correspond to continuous loads. Service load The power system is not essential to the operation of the ship, but includes loads related to providing services by the ship (e.g., load for storing shipments such as refrigerated containers, etc.), and most of the service load corresponds to variable load. .

Due to this load separation, the capacity of each power system is reduced compared to the existing single system, and power can be supplied to the load in each power system only by low voltage distribution. As a result, high-voltage distribution is not required, and conventional high-voltage switchgear and large-capacity high-voltage/low-voltage transformers are not required.

As described above, by not using a plurality of high-voltage/voltage transformers, it is possible to achieve a cost reduction effect of approximately 250 million/unit in terms of capital expenditures (CAPEX).

In addition, a space (ie, a transformer room) previously provided for a high/low voltage transformer can be utilized for various other purposes. In general, the high-voltage/low-voltage transformer is located in an engine room with high equipment density, so it has a great effect on improving the space utilization on board.

In addition, by separating the power system for the essential load and the power system for the service load, the stability of each system is also increased. In the existing case, when a system accident occurs at the service load stage, it is composed of a single system, which affects the essential load. In the case of separating the system, when an accident occurs at the service load stage, the system accident does not affect the power system for the essential load because it spreads only within the power system for the service load. Likewise, in case of an accident at the essential load stage when the system is separated, the accident does not spread to the service load stage.

In addition, since the power system is separate, each power system can configure and operate a generator optimized for the type of load it contains.

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 a container ship, a generator having a power generation capacity that exhibits optimum efficiency for continuous load power supply is installed in the essential load power system and is operated at a fixed RPM, and the variable load power generation efficiency in which the load ratio changes in the service load power system. Install a variable speed RPM generator that can optimize

In the case of a refrigerated container, which is a typical service load in the container, the average load rate is 30 to 40% of the total load in the system. Compared with the power system of FIG. 1 that supplies power to a service load using a fixed RPM generator, the amount of fuel consumed for generating 1 kmh of power is reduced from about 216 g to about 190 g based on a 35% load factor. That is, in the case of the container ship according to the present invention, fuel consumption of about 13% can be improved.

For this reason, if the improvement in fuel consumption is simplified to 10% for a container ship using MGO (Marin Gas Oil) of $640/ton as fuel, OPEX USD 2,4000/year (=USD 9,636/day × improvement efficiency) (10%) × number of operating days (typically 250 days)) fuel cost savings can be obtained.

In addition, by installing a variable speed RPM generator in the essential load power system, a variable frequency control (VFD, Variable Frequency Drive) based load may be linked to the variable speed RPM generator and the essential load stage. As a result, when the load ratio of the load based on variable frequency control is reduced according to the operation characteristics of the ship, the problem of lowering the power generation efficiency when the load ratio is lowered due to a decrease in power consumption is improved.

Furthermore, the distribution method in each power system may be configured to enable low voltage DC distribution and/or low voltage AC distribution. That is, unlike a conventional power supply system in which DC power distribution is difficult, the distribution mode can be freely set, and thus flexible power supply may be possible.

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

In order to more clearly describe the technical solutions of the embodiments of the present invention or prior art, the drawings necessary in the description of the embodiments are briefly introduced below. It is to be understood that the following drawings are for the purpose of describing the embodiments of the present specification and not for the purpose of limitation. In addition, some elements to which various modifications such as exaggeration and omission are applied may be shown in the drawings below for clarity of description.
1 is a diagram showing a system structure diagram of a power supply system for a ship configured as a single system in which continuous load and variable load are mixed according to a conventional embodiment.
FIG. 2 is a diagram illustrating an internal structure of a conventional ship having a single power system based on high-voltage distribution of FIG. 1.
3 is a schematic system structure diagram of a power supply system for a ship including a separate power system according to an embodiment of the present invention.
FIG. 4 is a diagram showing a relationship between a load ratio of a load end in a power system and a fuel consumption amount of a generator with power to the load end.
5 is a schematic system structure diagram of a power supply system for a ship in which an essential load power system is AC distribution and a service load power system is DC distribution according to an embodiment of the present invention.
6 is a schematic system structure diagram of a power supply system for a ship in which the essential load power system is DC distribution and the service load power system is AC distribution according to another embodiment of the present invention.
7 is a schematic system structure diagram of a power supply system for a ship in which an essential load power system and a service load power system are configured with DC distribution according to another embodiment of the present invention.

The terms used in this specification are used only to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In the present specification, terms such as "comprise" or "have" are intended to specify the described features, regions, numbers, steps, actions, components, and/or components, and one or more other features, regions, numbers, It does not exclude the presence or addition of steps, actions, components, and/or components.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. Terms as defined in a commonly used dictionary should be interpreted as having a meaning consistent with the meaning in the context of the related technology, and should not be interpreted as an ideal or excessively formal meaning unless explicitly defined in the present specification. .

In the present specification, a ship is a ship including an essential load essential for the operation of the ship and a service load additionally used for functions other than the operation, and refers to various ships such as a container carrier, a fuel carrier, and a passenger ship.

In this specification, the fact that the load system is divided into an essential load system and a service load system refers to that the essential load and the service load are not mixed in the same system, but are included in different systems and are configured to receive power by different main switchboards. . The separation of the load grid is not permanent, and the different load grids may be connected by any component (e.g., SPDT switch, or bus-tie breaker) that can be electrically connected between the power supply components. have.

In this specification, embodiments relate to a power system of a ship. In the case of ships, since the range of low voltage is prescribed as 1500V or less in international regulations, the term "low voltage" in the present specification refers to a voltage corresponding to 1500V or less unless there is any particular limitation.

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

3 is a schematic system structure diagram of a power supply system for a ship 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, etc. The power system 100 includes a power generation unit 110, a switchboard 130 including a main switchboard, and an essential load unit 150 including an essential load. The power system 200 includes a power generation unit 210, a switchboard 230 including a main switchboard, and a service load unit 250 including a service load.

In addition, the marine power supply system 1 may further include a control unit (not shown) that monitors the state of the power system and controls power supply. The control unit 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 marine power supply system 1 is described as including two power systems 100 and 200, but is not construed as being limited thereto. In addition, in some cases, a detailed description of two components is represented by a detailed description of one component.

As shown in Fig. 3, the power supply system 1 for ships is configured in a state in which the power system is separated for each essential load and 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 power and drives it.

The power generation unit 110 outputs an alternating current electric 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, when the motor load for the operation of the ship is a constant output load, an alternator can be used In addition, when the capacity of the generator is 85% and the load capacity is 1MW, the power generation capacity of the generator is about 1.2MW Can be

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

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

In the switchboard 130, power is supplied by 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, and in this case, the bus cable may be referred to as a main bus.

Further, in some embodiments, the 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 further includes a bus tie breaker 133 that connects the plurality of main buses 131 and 132 electrically, but the electrical connection is cut off in case of an emergency and/or accident. can do.

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

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

The essential load unit 150 of the power system 100 includes essential loads (eg, thruster motors, lubricating oil pumps, engine fuel supply pumps, cooling pumps, etc.) used for operation of the ship, as shown in FIG. 3. Can include. Most of the essential loads included in the essential load unit 150 correspond to a continuous load whose load factor does not change.

In some embodiments, the essential load unit 150 may further include a variable frequency control (VFD, Variable Frequency Drive) based load. A load based on variable frequency control is an essential load that optimizes the power consumption of the load stage according to operational characteristics, such as a cooling system (Central Cooling System), for example, a VFD load is a cooling pump configured to control the temperature of the cooling water. Includes essential loads configured to control temperature, pressure, etc.

As described above, the switchboard 130 is configured to perform low-voltage distribution. Accordingly, as shown in FIG. 3, at least some essential loads may be electrically connected directly without the need for a separate transformer to receive power.

The thruster motor 152 is a motor used in the berth/berth of a 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 2MW. For this reason, when power is supplied by the low-voltage switchboard 130 to which a low voltage such as 440V is applied, 8-10 cables of 270A with a cross-sectional area of 150SQMM must be laid, and the installation of the power supply line in the ship 1000 is not easy. I can.

In one embodiment, the essential load unit 150 may supply a power supply line (not shown) electrically connecting the thruster motor 152 from the switchboard 130, and power to the thruster motor 152 more efficiently. It may further include a step-up transformer 153.

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

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

The voltage is increased from low to high voltage by the boosting transformer 153, and the magnitude of the current in the power supply line is reduced by the boosting transformer 153. As a result, the voltage drop is improved and the cross-sectional area of the cable and/or the number of strands is reduced. 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 marine power supply system 1 may supply power to the thruster motor 152 using a single cable.

As a result, if the step-up transformer 153 is not included in FIG. 3, 8 to 10 cables with a cross-sectional area of 150SQMM are required, but when the step-up transformer 153 is used as shown in FIG. 3, a cable of 50SQMM Even a strand can supply power to the 2MW thruster motor 152 with a load capacity.

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

In addition, the power system 100 may further include an emergency generator that supplies power in an emergency situation such as blackout, and an emergency switchboard 160 including a load operating at this time. The emergency switchboard 160 may include shore power and an emergency load.

Since the components and operations of the power system 200 are substantially similar to those of the power system 100, the differences will be mainly described.

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 a load for storage of shipments used to store shipments, a load for user convenience used for the convenience of occupants of a ship, and the like. When the ship is a container ship, the service load unit 250 stores the ship cargo and the storage temperature changes with 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) that supply power at a lower voltage than the switchboard 230.

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

In one embodiment, the essential 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 a fixed RPM generator, and the generators 211 and 212 of the service load power system 200 may be a variable speed RPM generator.

In the case of a continuous load, there is no change in the load due to the constant output characteristic, so there is little change in the load factor, whereas the variable load is characterized by a change in the load factor.

Essential load Since most of the load of the power system 100 corresponds to a continuous load in which the load factor does not change, a fixed RPM generator is operated to operate in an optimum efficiency section. On the other hand, most of the loads of the service load power system 200 are variable loads in which the load ratio changes, and thus a variable speed RPM generator capable of variable speed operation according to the load ratio change is operated.

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

FIG. 4 is a diagram showing a relationship between a load ratio of a load end in a power system and a fuel consumption amount of a generator that supplies power to the load end.

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

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

For this reason, if the improvement in fuel consumption is simplified to 10% for a container ship using MGO (Marin Gas Oil) of $640/ton as fuel, OPEX USD 2,4000/year (=USD 9,636/day × improvement efficiency) (10%) × number of operating days (typically 250 days)) fuel cost savings can be obtained.

Furthermore, when the service load is configured to have a load section in which the load rate varies by time slot, power generation efficiency can be further improved by controlling the rotational speed of the generator with RPM having an optimum power generation efficiency for each load section.

In the ship load, the low load section L1 is a section in which the load factor is 10 to 40% and has a fuel consumption of approximately 285 to 210 g/kwh. The heavy load section (L2) is a section in which the load factor is 40 to 60%, and has a fuel consumption of approximately 210 to 194 g/kwh. The high load section L3 represents a section in which the load factor is 80-100%, and has a fuel consumption of approximately 185-190g/kwh. The power supply system 1 of FIG. 3 has substantially the same fuel consumption as 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 approximately 6-10% compared to FIG. 1, and in the heavy-load section (L2), the fuel consumption rate per kwh is improved by approximately 10-35% compared to FIG.

In this way, the variable speed RPM generator of the service power system 200 of FIG. 3 controls 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 for the service load power system 200, but is not limited thereto.

As described above, the essential load unit 150 may include a variable frequency control (VFD, Variable Frequency Drive) based load that controls temperature, pressure, coolant, etc. in relation to the operation of the ship. In order to control the temperature and pressure of the coolant, the load ratio of the load based on the variable frequency control may be changed. For this reason, the variable frequency control-based load has various load sections according to the operating characteristics of the ship.

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

When power is supplied by a variable speed RPM generator in the essential load power system 100, the variable speed RPM generator is linked to a variable frequency control (VFD, Variable Frequency Drive) based load of the essential load unit 150.

In this way, when the rotational speed of the generator is controlled by RPM having the optimum power generation efficiency for each load section through the variable speed RPM generator of the essential load power system 100, compared to the case where continuous load and variable load are mixed in a single system, it is variable. The fuel efficiency of the generator that supplies power to the load can be improved. This is similar to the embodiment of the service load power system 200 described above, and a detailed description thereof will be omitted.

Additionally, since the marine power supply system 1 is capable of low-voltage distribution, the distribution method in each of the power systems 100 and 200 may be configured to enable low-voltage DC distribution and/or low-voltage AC distribution. In one embodiment, when the load inside the ship has an AC voltage as the rated voltage, it is configured as a partial distribution structure in which DC distribution is performed in the switchboard portion. When such DC distribution is performed, power loss due to reactive power can be prevented.

5 is a schematic system structure diagram of a ship's power supply system consisting of a fixed RPM generator-based AC distribution, and a service load power system is a variable RPM generator-based DC or AC distribution according to an embodiment of the present invention. .

Referring to FIG. 5, it is further configured to enable direct current distribution within the service load power system 200. In this case, the generators 111 and 112 may be fixed RPM generators, and the generators 211 and 212 may be variable speed RPM generators.

In one embodiment, the power generation unit 210 further includes an alternating current (AC) / direct current (DC) inverter 216 that receives an alternating current (AC) electrical signal and converts it into a direct current (DC) electrical signal, and the second The load unit may further include a direct current (DC)/alternating current (AC) inverter 256 that receives a direct current (DC) electrical signal and converts it into an alternating current (AC) electrical signal.

As shown in FIG. 5, when the power system 200 includes two generators 211 and 212, two alternating currents (AC) electrically connecting the generators 211 and 212 and the switchboard 230 Includes / DC (DC) inverters (216A, 216B), respectively, and includes a plurality of direct current (DC) / AC (AC) inverters (256A to 256D) electrically connecting between the switchboard 230 and each service load can do. By the alternating current (AC)/direct current (DC) inverter 216 and the direct current (DC)/alternating current (AC) inverter 256, direct current distribution is possible in the switchboard 230 in the power grid 200 .

The voltage applied to the switchboard 230 in the service load power system 200 is set for proper DC distribution, and may be different from the voltage applied to the switchboard 130 in the essential load power system 100. For example, a voltage of 440V is applied to the switchboard 130, but a voltage of 690V may be applied to the switchboard 230 where partial DC distribution is performed.

As such, the power supply system 1 may be configured with a fixed RPM generator-based AC distribution as an essential load power system, and a service load power system as a variable RPM generator-based DC or AC distribution.

6 is a schematic system structure diagram of a ship's power supply system configured with a variable RPM generator-based DC distribution, and a service load power system is a fixed RPM generator-based AC distribution according to another embodiment of the present invention.

6, it is further configured to enable direct current distribution within the essential load power system 100. In this case, the generators 111 and 112 may be variable speed RPM generators, and the generators 211 and 212 may be fixed RPM generators.

In one embodiment, the power generation unit 110 further includes an alternating current (AC) / direct current (DC) inverter 116 that receives an alternating current (AC) electrical signal and converts it into a direct current (DC) electrical signal, and the second The load unit may further include a direct current (DC)/alternating current (AC) inverter 156 that receives a direct current (DC) electrical signal and converts it into an alternating current (AC) electrical signal.

As shown in FIG. 6, when the power system 100 includes two generators 111 and 112, two alternating currents (AC) electrically connecting the generators 111 and 112 and the switchboard 130 Includes a plurality of direct current (DC)/alternating current (AC) inverters 156A to 156M, each including a direct current (DC) inverter 116A, 116B, and electrically connecting the switchboard 130 and each essential load. can do. With the AC/DC inverter 116 and the DC/AC inverter 156, DC distribution is possible in the switchboard 130 in the power system 100 .

In this way, the power supply system 1, the essential load power system 100 may be configured with a variable RPM generator-based alternating current or direct current distribution, and the service load power system 200 may be configured with a fixed RPM generator-based alternating current distribution.

7 is a schematic system structure diagram of a power supply system for a ship in which an essential load power system and a service load power system are configured with DC distribution according to another embodiment of the present invention.

In one embodiment, both the essential load power system 100 and the service load power system 200 may be configured to enable direct current distribution. In this case, the service load power system 200 is similar to the service load power system 200 of FIG. 5, and the essential load power system 100 is similar to the structure of the essential load power system 100 of FIG. Description is omitted.

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

As a result, the stability of each system is also increased. In the existing case, when a system accident occurs at the service load stage, it is composed of a single system, which affects the essential load. In the case of separating the system, when an accident occurs at the service load stage, the system accident does not affect the power system for the essential load because it spreads only within the power system for the service load. Likewise, in case of an accident at the essential load stage when the system is separated, the accident does not spread to the service load stage.

In addition, the scale of individual power systems is reduced compared to a single power system. For example, if a single power system with a power capacity of 14 MW is separated as shown in FIG. 3 as the essential load power system 100 is 9 MW and the service load power system 200 is 5 MW, the size of the individual power system is 14 MW. To 9MW and from 14MW to 5MW respectively.

And, it is possible to supply power through a main switchboard to which a low voltage (eg, 440V) is applied instead of a high voltage of 6.6kV or higher. For this reason, the large-capacity high-voltage/low-voltage transformer 40 of FIG. 1 is no longer required. Accordingly, in terms of capital expenditures (CAPEX), a cost reduction effect of approximately 250 million/ship can be obtained.

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

Referring back to FIG. 2, when the power supply system 1 of FIG. 3 is applied to a container ship, the space of the transformer room 1007 in which eight high-voltage/low-voltage transformers 40 can be disposed is required for shipment of silver containers. It can be further utilized for.

A commonly used container standard is a TEU container with dimensions of 6.058m × 2.591m × 2.438m. When the number of containers that can be shipped in two spaces of 13.25m × 6.06m × 6.62m in size using the TEU container as a reference, the TEU container is at most 26 (= 13Х2) dogs can be shipped. That is, the ship having the power supply system 1 for ships of FIG. 3 can further load up to 26 TEU containers compared to the conventional container ship having the power supply system for ships of FIG. 1. In some embodiments, approximately 20 (= 10 Х2) containers may be additionally loaded, even when taking into account the operation of loading and unloading containers to secure space more freely.

In addition, if the high-voltage/low-voltage transformer is not used, the container may be further shipped in a space associated with the utilization of the conventional high-voltage/low-voltage transformer. For example, a predetermined structure may have been installed due to the presence of the transformer 40 on the deck surface positioned vertically in the conventional transformer room 1007. However, since the transformer 40 is not required and a predetermined structure may not be required, an additional container may be further vertically loaded on the deck surface. In this case, if 5 more containers are loaded horizontally and 10 more vertically on the deck surface, 100 more containers can be loaded.

Therefore, the high/low voltage transformer 40 is not used, and up to about 120 containers can be further loaded on the ship 1000. The number of additionally loaded containers in the space of the existing transformer chamber 1007 is merely exemplary, and 120 or more containers may be further loaded depending on the shape of the container, the transformer, and the size of the transformer chamber.

Additionally, due to the application of the marine power supply system 1 of FIG. 3, an object previously disposed in a space other than the existing transformer room 1007 can be moved to the space of the transformer room 1007. In this case, the space originally located becomes an empty space due to the movement of the pre-arranged object. The container may be additionally disposed in an additionally generated empty space instead of being directly shipped to the space of the transformer room 1007.

Alternatively, the space in the existing transformer room can be used for a variety of purposes other than container shipping.

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

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

Additionally, the power supply system 1 may control the operation of the generator according to the time period (or operation mode), and adjust the amount of power supplied to the load. For example, when the essential load part 150 of the power system 100 does not require the power generation capacity of the two generators 111 and 112, the marine power supply system 1 may have at least one generator (for example, The generator 111 is set as a standby generator to stop the operation, and if necessary, the standby generator can be used to supply power to the essential load unit 150 and use it for other purposes.

The present invention described above has been described with reference to the embodiments shown in the drawings, but these are merely exemplary, and those of ordinary skill in the art will understand that various modifications and variations of the embodiments are possible therefrom. However, such modifications should be considered to be within the technical protection scope of the present invention. Therefore, the true technical scope of the present invention should be determined by the technical spirit of the appended claims.

Claims (8)

In ships with essential and service loads,
A first power system including a first power generation unit including a generator, a first switchboard including a main switchboard for transferring power from the first power generation unit to an essential load, and a first load unit including an essential load required for operation of the ship; And
Including a second power system including a second power generation unit including a generator, a second switchboard including a main switchboard for transferring the power of the second power generation unit to a service load, and a second load unit including a service load different from the essential load But,
The first load unit includes at least one of a thruster motor, an engine fuel supply pump, a lubricating oil pump, and a cooling pump as a continuous load, and the second load unit includes a refrigeration container as a variable load,
At least one of the first power system and the second power system is configured to enable direct current distribution,
Each of the main switchboards connected to the power generation units of the first and second power systems is a low-voltage switchboard, and in the case of AC distribution, a voltage of 1000V or less is applied to the low-voltage switchboard,
A ship, characterized in that the power generation unit of the second power system comprises a variable speed RPM generator.
delete delete The method of claim 1,
The second power generation unit further includes an alternating current (AC) / direct current (DC) inverter for receiving an alternating current (AC) electrical signal and converting it into a direct current (DC) electrical signal,
The second load unit further comprises a direct current (DC) / alternating current (AC) inverter for receiving a direct current (DC) electrical signal and converting it into an alternating current (AC) electrical signal.
delete The method of claim 1,
A ship, characterized in that the first power generation unit comprises a fixed RPM generator.
delete delete

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