Power system of MVDC electric propulsion ship, and power control method of power system

Abstract

Disclosed in one embodiment of the present invention is a power system for an MVDC electric propulsion ship, comprising: a power source for generating power; a power-source-corresponding rectifier correspondingly associated with the power source; an MVDC distribution unit for receiving the power through the power-source-corresponding rectifier; and a load terminal for receiving the power generated from the power source without passing through the MVDC distribution unit.

Description

Power system of an MVDC electric propulsion vessel and power control method of the power system

[0001] The present invention relates to a method for controlling power in a power system within a ship, and more specifically, to a method for implementing and controlling a power system of an MVDC electric propulsion ship.

[0002] MVDC (Medium-Voltage Direct Current) refers to a power supply method that transmits and distributes medium-voltage electricity between 1.5 and 35 kV as direct current. For carbon reduction, energy efficiency is just as important as increasing capacity to utilize eco-friendly / renewable energy with direct current characteristics, and MVDC transmission / distribution systems are a necessary technology to increase the efficiency of eco-friendly / renewable energy with direct current characteristics.

[0003] Meanwhile, a fuel cell is an energy conversion device that directly converts the chemical energy of fuel into electrical energy through an electrochemical reaction. Unlike batteries, it can continuously produce electrical energy without recharging as long as fuel is supplied. In particular, hydrogen fuel cells have the advantage of being pollution- and noise-free, making them essential for realizing MVDC electric ships.

[0004] Fuel cells are LVDC outputs due to their characteristics, and when implementing an MVDC electric propulsion vessel, the distribution section inside the vessel is generally configured as an MVDC system. Among the technologies for connecting the MVDC (system) and the LVDC (fuel cell), the most basic conventional technology is a method as shown in Fig. 1, which uses several insulating modules to connect the LVDC lines in parallel and the MVDC lines in series.

[0005] Figure 1 is a diagram illustrating a conventional method in which a fuel cell and an MVDC system are connected.

[0006] Referring to FIG. 1, Fuel Cell 1 (10) is V corresponding to LVDC L (11) outputs, and the output V L Through a converter composed of a total of (n+1) modules, the MVDC output V M It can be seen that it is converted to (12). At this time, the MVDC output V M (12) is the output of each module, V m,0 (12a) to V m,n It becomes the sum of (12n).

[0007] The technical problem that the present invention aims to solve is to provide a power system of an MVDC electric propulsion vessel and a method for controlling the power of said power system.

[0008] A power system according to an embodiment of the present invention for solving the above technical problem comprises: a power source that generates power; a power source corresponding rectifier connected in correspondence with the power source; an MVDC distribution unit that receives power through the power source corresponding rectifier; and a load unit that receives power generated from the power source without passing through the MVDC distribution unit.

[0009] A method according to another embodiment of the present invention for solving the above technical problem is a power control method for a power system of an MVDC electric propulsion vessel, comprising: a step of determining a power source that supplies power to a load end of the power system; a step of controlling power generation based on the determined power source; and a step of controlling power generated from the determined power source to be supplied to the load end without passing through an MVDC distribution unit.

[0010] One embodiment of the present invention may provide a computer-readable recording medium storing a program for executing the method.

[0011] When implementing an MVDC power system using existing technology, efficiency is reduced during the process of converting AC, DC, and AC in sequence at the converter, and the devices required to implement this process occupy a significant volume, making it difficult to utilize space inside the ship. However, according to the present invention, the devices that convert power in the sequence of AC, DC, and AC are omitted, thereby significantly reducing the volume of the entire power system.

[0012] In addition, not only can power efficiency be increased by using a transformer, but even if a fault occurs in the main distribution unit, power can be continuously supplied to the load as long as the generator is operational, thereby enabling the overall stable operation of the MVDC electric propulsion vessel.

[0013] Figure 1 is a diagram illustrating a conventional method in which a fuel cell and an MVDC system are connected.

[0014] FIG. 2 is a schematic diagram for explaining, module by module, the components included in an MVDC electric propulsion vessel to which the method according to the present invention is applied.

[0015] FIG. 3 is a schematic diagram showing a power system of an MVDC electric propulsion vessel according to another embodiment of the present invention.

[0016] FIGS. 4 to 6 are schematic diagrams showing various different embodiments of the power system of the MVDC electric propulsion vessel described in FIG. 3.

[0017] FIG. 7 is a block diagram showing an example of a power control device according to the present invention.

[0018] FIG. 8 is a diagram illustrating a submodule included in the processor of FIG. 7.

[0019] FIG. 9 is a flowchart illustrating an example of a power control method according to the present invention.

[0020] A power system according to an embodiment of the present invention for solving the above technical problem comprises: a power source that generates power; a power source corresponding rectifier connected in correspondence with the power source; an MVDC distribution unit that receives power through the power source corresponding rectifier; and a load unit that receives power generated from the power source without passing through the MVDC distribution unit.

[0021] The above power system can be implemented in a structure in which two or more of the power source, the corresponding rectifier, the MVDC distribution unit, and the load end are connected using a bus-tie breaker.

[0022] In the above power system, the bus-tie breaker may be one of a first type implemented as a mechanical switch, a second type implemented as a semiconductor, or a third type implemented as a hybrid circuit breaker.

[0023] In the above power system, the MVDC distribution unit may be the main switchboard of the MVDC electric propulsion vessel.

[0024] In the above power system, the load terminal may be an AC load terminal in which an AC load is connected together with a step-down transformer.

[0025] In the above power system, the power source may be at least one of an engine generator, a solid oxide fuel cell, and an energy storage system (ESS).

[0026] In the above power system, the load unit can receive power generated from the engine generator.

[0027] A method according to another embodiment of the present invention for solving the above technical problem is a power control method for a power system of an MVDC electric propulsion vessel, comprising: a step of determining a power source that supplies power to a load end of the power system; a step of controlling power generation based on the determined power source; and a step of controlling power generated from the determined power source to be supplied to the load end without passing through an MVDC distribution unit.

[0028] In the above method, the power system may be implemented in a structure in which two or more of the power source, the MVDC distribution unit, and the load end are connected using a bus-tie breaker.

[0029] In the above method, the bus-tie breaker may be one of a first type implemented as a mechanical switch, a second type implemented as a semiconductor, or a third type implemented as a hybrid circuit breaker.

[0030] In the above method, the MVDC distribution unit may be the main switchboard of the MVDC electric propulsion vessel.

[0031] In the above method, the load terminal may be an AC load terminal to which an AC load is connected together with a step-down transformer.

[0032] In the above method, the power source may be at least one of an engine generator, a solid oxide fuel cell, and an energy storage system (ESS).

[0033] In the above method, the load unit can receive power generated from the engine generator.

[0034] One embodiment of the present invention may provide a computer-readable recording medium storing a program for executing the method.

[0035] The present invention is capable of various modifications and may have various embodiments; specific embodiments are illustrated in the drawings and described in detail in the detailed description. The effects and features of the present invention, and the methods for achieving them, will become clear by referring to the embodiments described below in detail together with the drawings. However, the present invention is not limited to the embodiments disclosed below but can be implemented in various forms.

[0036] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. When describing with reference to the drawings, identical or corresponding components are given the same reference numerals, and redundant descriptions thereof will be omitted.

[0037] In the following embodiments, terms such as first, second, etc. are used not in a limiting sense, but for the purpose of distinguishing one component from another component.

[0038] In the following embodiments, singular expressions include plural expressions unless the context clearly indicates otherwise.

[0039] In the following embodiments, terms such as "include" or "have" mean that the features or components described in the specification are present, and do not preclude the possibility that one or more other features or components may be added.

[0040] Where an embodiment can be implemented differently, a specific process sequence may be performed differently from the order described. For example, two processes described consecutively may be performed substantially simultaneously or proceed in the reverse order of the description.

[0041] FIG. 2 is a schematic diagram for explaining, module by module, the components included in an MVDC electric propulsion vessel to which the method according to the present invention is applied.

[0042] FIG. 2 illustrates an exemplary power system (20) of an MVDC electric propulsion vessel operating based on MVDC power. Referring to FIG. 2, it can be seen that the power system (20) of the MVDC electric propulsion vessel includes a fuel cell (21), a generator (22), a fuel cell-compatible converter (23), a generator-compatible rectifier (24), an MVDC distribution unit (25), a DC propulsion drive (26), a propulsion motor (27), a propeller (28), and an AC load unit (29).

[0043] The fuel cell (21) of FIG. 2 is a device capable of directly producing and supplying electricity to the outside through a chemical reaction between fuel and an oxidant. It is similar to a battery in that it is a module that supplies electricity, but it differs from a conventional battery in that it can continuously generate electricity when fuel is continuously supplied. In particular, the fuel cell is an essential energy source for realizing low-carbon and carbon-free electric propulsion vessels, as it can use LNG, ammonia, and hydrogen fuels in compliance with carbon regulations. In one embodiment of the present invention, the fuel cell (21) may be a solid oxide fuel cell (SOFC) or a polymer electrolyte membrane fuel cell (PEMFC). When implementing an MVDC electric propulsion vessel, the power distribution section inside the vessel is generally configured as an MVDC system, whereas the fuel cell (21) has low-voltage direct current (LVDC) output characteristics, so a fuel cell compatible converter (23) that includes a transformer is essential to connect the MVDC (system) and the LVDC (fuel cell).

[0044] The generator (22) of FIG. 2 is a device that generates power independently of the fuel cell (21). In the present invention, the generator (22) may be a 6-phase engine generator. The power output from the generator (22) may be transmitted to the MVDC distribution unit (25) via a generator-corresponding rectifier (24) connected through a switch. In one embodiment of the present invention, the generator (22) may be an engine generator.

[0045] The fuel cell-compatible converter (23) of FIG. 2 can boost the output of the fuel cell (21), which is an LVDC output, and rectify it with diode-based rectification characteristics to transmit the output of the fuel cell (21) to the MVDC distribution unit (25). In one embodiment, the fuel cell-compatible converter (23) may be one of a SAB (Single Active Bridge), DAB (Dual Active Bridge), MMC (Modular Multi Level), or Boost converter.

[0046] The generator corresponding rectifier (24) of Fig. 2 can be implemented as any one of DFE (Diode Front End), TFE (Thyristor Front End), or AFE (Active Front End).

[0047] The MVDC distribution unit (25) of FIG. 2 is a distribution unit that supplies MVDC-class power to the entire MVDC electric propulsion vessel and is essential for implementing the MVDC power system. The MVDC distribution unit (25) can be connected to the power system of the MVDC electric propulsion vessel arranged symmetrically and identically to FIG. 2 through a bus-tie breaker, and this will be described later in FIG. 3.

[0048] The DC propulsion drive (26) of FIG. 2 is a device that operates by receiving MVDC power through a connection to an MVDC distribution unit (25), and is connected to a propulsion motor (27) to control and manage power so that the propulsion motor (27) can propel the ship. The DC propulsion drive (26) can play a key role in controlling the speed of an MVDC electric propulsion ship by adjusting the amount and quality of power delivered to the propulsion motor (27).

[0049] The propulsion motor (27) of FIG. 2 is a device that converts electrical energy supplied from the DC propulsion drive (26) into mechanical rotational energy. The propulsion motor (27) may be a permanent magnet motor that physically contains a permanent magnet to rotate when power is supplied, and depending on the embodiment, it may be implemented as an induction motor or a superconducting motor. The propeller (28) of FIG. 2 is directly connected to the propulsion motor (27) and rotates at a speed proportional to the rotation of the propulsion motor (27) to generate thrust for the MVDC electric propulsion vessel.

[0050] The AC load section (29) of FIG. 2 is a part that includes an AC load for receiving AC power, and includes a plurality of modules or devices including a step-down transformer, etc. The AC load section (29) will be explained in FIG. 3.

[0051] The power system (20) of the MVDC electric propulsion vessel illustrated in FIG. 2 includes the following improved features. First, the AC output from the generator (22) is transmitted to the generator-corresponding rectifier (24) through a switch, converted into an MVDC output, and then transmitted to the MVDC distribution unit (25). However, as illustrated in FIG. 2, the power from the generator (22) can be transmitted directly to the AC load (29) without passing through the MVDC distribution unit (25) via additional wires before reaching the generator-corresponding rectifier (24). Although not shown in FIG. 2, the power control device (700) precisely controls the operation of a switch installed between the generator (22) and the generator corresponding rectifier (24) so ​​that at least a portion of the AC output generated by the generator (22) is transmitted directly to the AC load terminal (29) without passing through the MVDC distribution unit (25), and the control characteristics of the power control device (700) will be described later in FIG. 7 to FIG. 9.

[0052] The power from the generator (22) delivered to the AC load section (29) not only enables the AC load included in the AC load section (29) to operate stably, but also allows the generator (22) to continuously supply power to the AC load even if there is a problem with the MVDC distribution section (25), which is the main switchboard, as long as the generator (22) does not stop.

[0053] In addition, in order for the AC load section (29) to receive AC power from the MVDC distribution section (25), which is the main distribution board, the AC power of the generator (22) must be converted into DC power corresponding to the MVDC distribution section (25) and then converted back into AC power. Therefore, energy loss occurs during the two conversion processes, and the volume and weight of the module for each conversion may act as a burden on the entire MVDC electric propulsion vessel. However, according to the present invention, since the AC power of the generator (22) is delivered to the AC load section (29) without passing through the MVDC distribution section (25), energy loss can be minimized. In particular, considering that most of the equipment operated when the vessel is docked at a port and performing tasks such as unloading is supplied with AC power, the configuration according to the present invention can minimize loss compared to delivery to the AC load section through the MVDC distribution section.

[0054] FIG. 3 is a schematic diagram showing a power system of an MVDC electric propulsion vessel according to another embodiment of the present invention.

[0055] The power system of the MVDC electric propulsion vessel illustrated in FIG. 3 is an embodiment that further extends the power system (20) of the MVDC electric propulsion vessel described in FIG. 2, and has the characteristic of being able to selectively connect two MVDC distribution units (25) of the power system (20) of the MVDC electric propulsion vessel through the bus-tie breaker of FIG. 2. That is, the power system (30) of the MVDC electric propulsion vessel illustrated in FIG. 3 is characterized by being implemented symmetrically with respect to the bus-tie breaker. In FIG. 3, two power sources, MVDC distribution units, and load terminals are connected using the bus-tie breaker, but according to the embodiment, the power system according to the present invention can be implemented in a manner in which three or more power sources, MVDC distribution units, and load terminals are connected using the bus-tie breaker.

[0056] In FIG. 3, the fuel cell (21), generator (22), fuel cell corresponding converter (23), generator corresponding rectifier (24), MVDC distribution unit (25), DC propulsion drive (26), propulsion motor (27), propeller (28), and AC load unit (29) included in the power system (20) on the left may be referred to as the first fuel cell, the first generator, the first fuel cell corresponding converter, the first generator corresponding rectifier, the first MVDC distribution unit, the first DC propulsion drive, the first propulsion motor, the first propeller, and the first AC load unit in order to distinguish them from the sub-components included in the power system on the right. Meanwhile, the sub-components included in the power system on the right in FIG. 3 can be respectively referred to as the second fuel cell (31), the second generator (32), the second fuel cell corresponding converter (33), the second generator corresponding rectifier (34), the second MVDC distribution unit (35), the second DC propulsion drive (36), the second propulsion motor (37), the second propeller (38), and the second AC load unit (29).

[0057] Hereinafter, the power system on the left side of FIG. 3 will be abbreviated as the first power system, and the power system on the right side of FIG. 3 will be abbreviated as the second power system.

[0058] FIGS. 4 to 6 are schematic diagrams showing various different embodiments of the power system of the MVDC electric propulsion vessel described in FIG. 3.

[0059] First, FIG. 4 is a schematic diagram showing a first type of power system in which a bus-tie breaker that selectively connects the first power system and the second power system is implemented as a mechanical switch. The power system shown in FIG. 4 consists of a power generation unit (410), a main distribution unit (430), and a sub-distribution unit (450).

[0060] The power generation unit (410) includes multiple power sources that generate power. As illustrated in FIG. 4, the power generation unit (410) may include an engine generator, a solid oxide fuel cell, and an energy storage system (ESS). The engine generator and the solid oxide fuel cell can perform the same functions as the fuel cell (21) and generator (22) described in FIG. 2. In FIG. 4, the ESS refers to a large-scale energy storage device that stores power and allows it to be used when needed. In the power generation unit (410), the ESS can play an important role in mitigating the variability of renewable energy from the fuel cell and increasing power grid stability. As illustrated in FIG. 4, depending on the embodiment, the ESS may be implemented in a form that supplies power to the main distribution unit (430) by being included in the sub-distribution unit (450) rather than the power generation unit (410).

[0061] The power control device (700) described later in FIG. 7 can appropriately change the power supplied from the power generation unit (410) to the main distribution unit (430) and the sub-distribution unit (450). More specifically, the power control device (700) can improve the overall stability of the power system of the MVDC electric propulsion vessel by controlling the output and output ratio of the fuel cell, generator, and ESS included in the power generation unit (410). In particular, as described in FIG. 2, the power control device (700) can stably supply power from the generator to various loads of the MVDC electric propulsion vessel even if the main distribution unit (430) fails, by transmitting the power generated from the generator to the AC load terminal without passing through the main distribution unit (430) through an additional power line including a switch between the generator and the generator-corresponding rectifier among the power sources. As an example, the output ratio of the fuel cell and the engine / generator is controlled by a power control device (700) by considering the load fluctuation characteristics in ship operation according to the ship operation mode and speed and the marine environment conditions. When the load fluctuation is low, the fuel cell output ratio is increased to maximize energy efficiency, and when the load fluctuation is high, the engine / generator output ratio is increased to increase the stability of the onboard power supply.

[0062] In FIG. 4, the main distribution unit (430) can perform power distribution based on MVDC to minimize the loss of DC output of the fuel cell, which is the main power source, and includes a bus-tie breaker (431) in the form of a mechanical switch that opens at an appropriate time so that when a fault occurs in either the first power system or the second power system, the fault current does not shock the other system.

[0063] In FIG. 4, the sub-distribution unit (450) includes various loads including the AC load section (29) of FIG. 2 and includes an AC-based sub-distribution board. As an example, the sub-distribution unit (450) may include at least one of a fixed pitch propeller (FPP), a controllable pitch propeller (CPP), a contra-rotating propeller (CRP), and a pod propeller.

[0064] In particular, in FIG. 4, the AC load section is illustrated as the AC output from the generator of the power generation unit (410) being converted into a DC output through a converter (AC -> DC), then converted back into an AC output through an inverter (DC -> AC), and then transmitted to the LVAC SWBD (Low Voltage AC Switchboard) via a transformer. However, this describes another embodiment, and as described in FIG. 2, the AC output from the generator (DG) of the power generation unit (410) may be transmitted directly to the LVAC SWBD without passing through the main distribution unit (430). The AC load connected to the LVAC SWBD can receive stable AC power supply while the generator of the power generation unit (410) is operating. The power system of the MVDC electric propulsion vessel illustrated in FIG. 4 includes an ESS, a fuel cell, and a generator in the power generation unit (410), so a more stable system configuration is possible than that of a conventional electric propulsion vessel's power circuit. In particular, in the present invention, high power supply efficiency can be ensured by configuring the fuel cell to be connected to a DC system rather than an AC system.

[0065] In addition, when the power ratio of the generator (22) is lowered and the fuel cell (21) is used as the main power source to reduce exhaust gas in consideration of environmental issues in an electric propulsion vessel, the response speed to output fluctuations is slower than when the generator (22) is used as the main power source, so if the load changes rapidly or changes frequently, there is a problem in that stable power supply to the entire circuit becomes impossible. However, according to the present invention, the power generation ratio of the ESS, fuel cell, and generator is appropriately controlled by a power control device through a switch, and at the same time, AC power can be stably supplied to the sub-distribution unit (450) without passing through the main distribution unit (430), so that a stable system configuration can be achieved overall.

[0066] Next, FIG. 5 is a diagram schematically illustrating a second type of power system in which a bus-tie breaker that selectively connects the first power system and the second power system is implemented as a semiconductor. In FIG. 5, the main power distribution unit (430) can perform power distribution based on MVDC to minimize the loss of DC output of the fuel cell, which is the main power source, and includes an SSCB (433) that opens at an appropriate time so that if a fault occurs in either the first power system or the second power system, the fault current does not shock the other system.

[0067] Meanwhile, FIG. 6 is a schematic diagram illustrating a third type of power system in which a bus-tie breaker that selectively connects the first power system and the second power system is implemented in a form that includes both mechanical and semiconductor types. In FIG. 6, the main distribution unit (430) includes a Hybrid CB (435) that opens at an appropriate time so that when a fault occurs in either the first power system or the second power system, the fault current does not shock the other system. The Hybrid CB (435) of FIG. 6 is a circuit breaker designed for fast and efficient interruption in high-voltage and high-current circuits, and can significantly improve the performance and reliability of the breaker in the power system. The Hybrid CB (435) of FIG. 6 may be composed of energy-absorbing elements such as a traditional mechanical breaker, an IGBT (Insulated Gate Bipolar Transistor) or GTO (Gate Turn-Off Thyristor)-based semiconductor switch, and a Snubber circuit. The Hybrid CB (435) of Fig. 6 can perform a circuit breaker function in such a way that current flows through a mechanical circuit breaker in a normal state, but when a fault is detected by a power control device, the semiconductor switch performs an immediate interruption, and the mechanical circuit breaker operates in succession to achieve a complete physical isolation state.

[0068] FIG. 7 is a block diagram showing an example of a power control device according to the present invention.

[0069] Referring to FIG. 7, it can be seen that the power control device (700) includes a communication unit (710), a processor (730), and a memory (750). The power control device (700) illustrated in FIG. 7 is omitted from FIG. 2 through FIG. 6 for convenience of explanation and can be positioned in a location where it can appropriately control the operation of all switches included in the power system.

[0070] The communication unit (710) may include one or more components that enable wired / wireless communication with an external device. For example, the communication unit (710) may include at least one piece of hardware necessary to implement short-range communication such as Wi-Fi or Bluetooth in a network provided by a communication network, or to implement various communications including the Internet when a LAN cable is connected. Additionally, the communication unit (710) may include hardware for power line communication.

[0071] Memory (750) is hardware that stores various data processed within the power control device (700) and can store programs for processing and controlling the processor (730). Memory (750) may include RAM (random access memory) such as DRAM (dynamic random access memory) and SRAM (static random access memory), ROM (read-only memory), EEPROM (electrically erasable programmable read-only memory), CD-ROM, Blu-ray or other optical disc storage, HDD (hard disk drive), SSD (solid state drive), or flash memory.

[0072] The processor (730) can control the overall operation of the power control device (700). For example, the processor (730) can control the operation of the input unit (not shown), display (not shown), communication unit (710), memory (750), etc. included in the power control device (700) by executing programs stored in memory (750).

[0073] In one embodiment, the processor (730) of the power control device (700) can determine a power source that supplies power to the load end of the power system of an MVDC electric propulsion vessel, control power generation based on the determined power source, and control power generated from the determined power source to be supplied to the load end without passing through the MVDC distribution unit.

[0074] In one embodiment, the power system controlled by the power control device (700) may have the power source, MVDC distribution unit, and load end symmetrically implemented with respect to the bus-tie breaker.

[0075] In one embodiment, in a method performed by a power control device (700), the bus-tie breaker may be one of a first type implemented as a mechanical switch, a second type implemented as a semiconductor, or a third type implemented as a hybrid circuit breaker.

[0076] In one embodiment, the MVDC distribution unit controlled by the power control device (700) may be the main switchboard of an MVDC electric propulsion vessel.

[0077] In one embodiment, the load terminal controlled by the power control device (700) may be an AC load terminal in which an AC load is connected together with a step-down transformer.

[0078] As one embodiment, the power source in the power system controlled by the power control device (700) may be at least one of an engine generator, a solid oxide fuel cell, and an energy storage system (ESS).

[0079] In one embodiment, the load section controlled by the power control device (700) can receive power generated from an engine generator.

[0080] When the power control device (700) is implemented as a physical device, the processor (730) may be implemented using at least one of ASICs (application specific integrated circuits), DSPs (digital signal processors), DSPDs (digital signal processing devices), PLDs (programmable logic devices), FPGAs (field programmable gate arrays), controllers, micro-controllers, microprocessors, and other electrical units for performing functions.

[0081] In addition, when the power control device (700) in the present invention is implemented in the form of an application (program) that runs on an integrated data processing device such as a server, the processor (730) and memory (750) included in the power control device (700) may be implemented in the form of a virtual machine that implements hardware such as DSPs, microcontrollers, RAM, ROM, HDD, etc., as software (command script).

[0082] FIG. 8 is a diagram illustrating a submodule included in the processor of FIG. 7.

[0083] Referring to FIG. 8, it can be seen that the processor (730) includes a power source determination unit (731), a power generation control unit (733), and a power transfer control unit (735). Since the power source determination unit (731), the power generation control unit (733), and the power transfer control unit (735) shown in FIG. 8 are logically and conceptually separated modules to explain the process performed by the processor (730) in the process of implementing the method according to the present invention, FIG. 8 shows three sub-modules, but depending on the embodiment, the processor (730) may include fewer than three or more than three sub-modules. In addition, since the power source determination unit (731), power generation control unit (733), and power transfer control unit (735) of FIG. 8 are sub-modules of the processor (730), they can be implemented using at least one of ASICs (application specific integrated circuits), DSPs (digital signal processors), DSPDs (digital signal processing devices), PLDs (programmable logic devices), FPGAs (field programmable gate arrays), controllers, micro-controllers, microprocessors, and other electrical units for performing functions, just like the processor (730).

[0084] The power source determination unit (731) can determine the power source that supplies power to the load end of the power system of the MVDC electric propulsion vessel.

[0085] The power generation control unit (733) can control power generation based on a determined power source.

[0086] The power transfer control unit (735) can control the power generated from the power source determined by the power source determination unit (731) to be supplied to the load without passing through the MVDC distribution unit.

[0087] FIG. 9 is a flowchart illustrating an example of a power control method according to the present invention.

[0088] Since the method according to FIG. 9 can be implemented by the power control device and sub-modules included in the device described in FIG. 7, the following description will be made with reference to FIG. 2 to FIG. 8, and descriptions that overlap with previously explained content will be omitted.

[0089] The power control device (700) can determine the power source that supplies power to the load end of the power system of the MVDC electric propulsion vessel (S910).

[0090] The power control device (700) can control power generation based on a determined power source (S930).

[0091] The power control device (700) can control and monitor the power generated from the power source determined by the power source determination unit (731) so that it is delivered to the load side without passing through the MVDC distribution unit (S950).

[0092] When implementing an MVDC power system using existing technology, efficiency is reduced during the process of converting AC, DC, and AC in sequence at the converter, and the devices required to implement this process occupy a significant volume, making it difficult to utilize space inside the ship. However, according to the present invention, the devices that convert power in the sequence of AC, DC, and AC are omitted, thereby significantly reducing the volume of the entire power system.

[0093] In addition, not only can power efficiency be increased by using a transformer, but even if a fault occurs in the main distribution unit, power can be continuously supplied to the load as long as the generator is operational, thereby enabling the overall stable operation of the MVDC electric propulsion vessel.

[0094] The embodiments according to the present invention described above may be implemented in the form of a computer program that can be executed through various components on a computer, and such a computer program may be recorded on a computer-readable medium. In this case, the medium may include a magnetic medium such as a hard disk, a floppy disk, and a magnetic tape, an optical recording medium such as a CD-ROM and a DVD, a magneto-optical medium such as a floptical disk, and a hardware device specifically configured to store and execute program instructions, such as a ROM, RAM, or flash memory.

[0095] Meanwhile, the above-mentioned computer program may be one specifically designed and configured for the present invention, or one known and available to those skilled in the art of computer software. Examples of computer programs may include machine code, such as that generated by a compiler, as well as high-level language code that can be executed by a computer using an interpreter, etc.

[0096] The specific embodiments described in this invention are examples and do not limit the scope of the invention in any way. For the sake of brevity of the specification, descriptions of prior electronic configurations, control systems, software, and other functional aspects of said systems may be omitted. Additionally, the connections of lines or connecting members between components shown in the drawings are illustrative of functional connections and / or physical or circuit connections, and may be replaced or additionally represented as various functional connections, physical connections, or circuit connections in actual devices. Furthermore, unless specifically stated as “essential,” “importantly,” etc., a component may not be strictly necessary for the application of the invention.

[0097] In the specification of the present invention (particularly in the claims), the use of the term “above” and similar descriptive terms may be in both singular and plural. Furthermore, where a range is described in the present invention, it is to include the invention to which individual values ​​belonging to said range are applied (unless otherwise stated), and is equivalent to describing each individual value constituting said range in the detailed description of the invention. Finally, regarding the steps constituting the method according to the present invention, unless explicitly stated in order or otherwise stated, said steps may be performed in a suitable order. The present invention is not necessarily limited by the order in which said steps are described. The use of all examples or exemplary terms (e.g., etc.) in the present invention is merely for the purpose of describing the present invention in detail, and the scope of the present invention is not limited by said examples or exemplary terms unless limited by the claims. Furthermore, those skilled in the art will understand that various modifications, combinations, and changes may be made according to design conditions and factors within the scope of the claims or equivalents to which they are added.

Claims

1. A power source that generates power; A power source corresponding rectifier connected in correspondence with the above power source; An MVDC distribution unit that receives power through the above-mentioned power source corresponding rectifier; and A power system of an MVDC electric propulsion vessel including a load section that receives power generated from the above power source without passing through the above MVDC distribution section.

2. In Paragraph 1, The above power system is, A power system of an MVDC electric propulsion vessel, implemented in a structure in which two or more of the above power source, the above corresponding rectifier, the above MVDC distribution unit, and the above load terminal are connected using a bus-tie breaker.

3. In Paragraph 2, The above bus-tie breaker is, A power system of an MVDC electric propulsion vessel, which is one of a first form implemented with a mechanical switch, a second form implemented with a semiconductor, and a third form implemented with a hybrid circuit breaker.

4. In Paragraph 1, The above MVDC distribution unit is, The power system of the MVDC electric propulsion vessel, which is the main switchboard of the above MVDC electric propulsion vessel.

5. In Paragraph 1, The above load unit is, A power system of an MVDC electric propulsion vessel, which is an AC load stage connected to an AC load along with a step-down transformer.

6. In Paragraph 1, The above power source is, A power system of an MVDC electric propulsion vessel, comprising at least one of an engine generator, a solid oxide fuel cell, and an energy storage system (ESS).

7. In Paragraph 6, The above load unit is, A power system of an MVDC electric propulsion vessel that receives power generated from the above-mentioned engine generator.

8. As a power control method for the power system of an MVDC electric propulsion vessel, A step of determining a power source that supplies power to the load end of the above power system; A step of controlling power generation based on a determined power source; and A power control method for a power system of an MVDC electric propulsion vessel, comprising the step of controlling the supply of power generated from the above-determined power source to the load terminal without passing through the MVDC distribution unit.

9. In Paragraph 8, The above power system is, A power control method for a power system of an MVDC electric propulsion vessel, implemented in a structure in which two or more of the above power source, the above MVDC distribution unit, and the above load end are connected using a bus-tie breaker.

10. In Paragraph 9, The above bus-tie breaker is, A power control method for a power system of an MVDC electric propulsion vessel, which is one of a first form implemented with a mechanical switch, a second form implemented with a semiconductor, and a third form implemented with a hybrid circuit breaker.

11. In Paragraph 8, The above MVDC distribution unit is, A method for controlling power of the power system of an MVDC electric propulsion vessel, which is the main switchboard of the MVDC electric propulsion vessel.

12. In Paragraph 8, The above load unit is, Power control method for the power system of an MVDC electric propulsion vessel, which is an AC load stage where an AC load is connected together with a step-down transformer.

13. In Paragraph 8, The above power source is, A power control method for a power system of an MVDC electric propulsion vessel, comprising at least one of an engine generator, a solid oxide fuel cell, and an energy storage system.

14. In Paragraph 13, The above load unit is, A power control method for the power system of an MVDC electric propulsion vessel that receives power generated from the above-mentioned engine generator.

15. A computer-readable recording medium storing a program for executing the method according to paragraph 8.

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