Power generation control device, power generation control method, and power generation control program

Abstract

To provide a power generation control device, a power generation control method, and a power generation control program that can respond flexibly to fluctuations in the demand for power on a vessel.SOLUTION: A power generation control device 6 on a ship is provided with a plurality of diesel generators 21, 22, 23 that generate power by combustion of input fuel. The power generation control device 6 on a ship includes a power demand acquiring unit 61 that acquires a power demand, a specified power generation amount deriving unit 62 that derives a specified power generation amount on each of the diesel generators in order to make the total of the specified power generation amounts equal to the power demand acquired by the power demand acquiring unit and to make the total of the fuel consumption of each diesel generator approximately minimum, and a power generation control unit 63 that controls each diesel generator on the basis of the specified power generation amount derived by the specified power generation amount derivation unit.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to power generation control technology. [Background technology]

[0002] Patent Document 1 discloses a supply and demand control method for an electric power system consisting of a large number of generators, such as solar power generators, installed on land. Based on the stored relationship between the output and fuel cost of each generator, the predicted output that will minimize the fuel cost for each generator relative to the predicted power demand is calculated and allocated to each generator. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-90419 Summary of the Invention [Problem to be solved by the invention]

[0004] The present inventor independently studied power generation control for ships equipped with multiple generators, such as diesel generators. Because the amount of fuel available for generators on a ship underway is limited, it is desirable to minimize the fuel consumption of each generator. However, methods such as those described in Patent Document 1, which involve accurate prediction of power demand and complex calculations based on the input / output relationships of multiple generators, are unsuitable for ships. Predicting power demand on a ship is extremely difficult because power demand changes rapidly depending on sea and weather conditions during navigation and the usage status of electric power devices such as side thrusters. Furthermore, performing complex calculations based on the input / output relationships of each generator during navigation, when power demand fluctuates greatly, may result in the amount of power generated being unable to keep up with power demand, potentially leading to a blackout.

[0005] The present invention has been made in view of the above circumstances, and its object is to provide a power generation control device and the like that can flexibly respond to fluctuations in power demand on a ship. [Means for solving the problem]

[0006] In order to solve the above problem, one embodiment of the present invention is a power generation control device for a ship equipped with multiple generators that generate electricity by burning input fuel, and includes a power demand acquisition unit that acquires power demand, a designated power generation amount derivation unit that derives a designated power generation amount for each generator that is equal to the power demand in total and that approximately minimizes the total fuel consumption of each generator, and a power generation control unit that controls the generators based on the designated power generation amount.

[0007] According to this aspect, the designated power generation amount for each generator that substantially minimizes the total fuel consumption of each generator is determined according to the power demand acquired by the power demand acquisition unit. Therefore, the required amount of power can be generated flexibly for each generator without performing complex calculations based on the input / output relationship of each generator as in Patent Document 1.

[0008] Another aspect of the present invention is a power generation control method for a ship equipped with multiple generators that generate electricity by burning fuel, the method including: a power demand acquisition step of acquiring power demand, a designated power generation amount derivation step of deriving designated power generation amounts for each generator that are equal in total to the power demand and that substantially minimize the total fuel consumption of each generator, and a power generation control step of controlling the generators based on the designated power generation amounts.

[0009] Any combination of the above components, and any transformation of the present invention into a method, device, system, recording medium, computer program, etc., are also valid aspects of the present invention. [Effects of the Invention]

[0010] According to the present invention, fluctuations in the power demand on a ship can be flexibly addressed. [Brief explanation of the drawings]

[0011] [Figure 1]1 is a functional block diagram showing the configuration of a power supply system for a marine vessel according to a first embodiment. [Figure 2] An example of the relationship between diesel generator output and fuel efficiency is shown below. [Figure 3] 10 shows an example of a first power generation control by a power generation control unit. [Figure 4] 10 shows an example of a second power generation control by the power generation control unit. [Figure 5] FIG. 10 is a functional block diagram showing the configuration of a power supply system for a marine vessel according to a second embodiment. [Figure 6] Schematic diagram of an example of ocean surface area division on Earth. [Figure 7] 10A and 10B show schematic diagrams of examples of electricity demand maps. [Figure 8] The power generation control process of the power generation control unit will be briefly described below. DETAILED DESCRIPTION OF THE INVENTION

[0012] 1 is a functional block diagram showing the configuration of a marine vessel power supply system 1 according to a first embodiment. The power supply system 1 includes a plurality of diesel generators 21, 22, and 23 (hereinafter collectively referred to as diesel generators 2) that generate AC power by burning input fuel, an AC distribution panel 3 that distributes the AC power generated by the diesel generators 2 to various parts of the vessel (specifically, an onboard load 51 and / or an electric power unit 52, described below), an inverter 4 that converts the AC power from the AC distribution panel 3 into a frequency and / or voltage suitable for distribution to various parts of the vessel, and a power generation control device 6.

[0013] Each diesel generator 2 includes an engine unit (not shown) that outputs rotational power by burning input fuel, and a power generation unit (not shown) that converts the rotational power into AC power. The engine unit of the diesel generator 2 is configured by a diesel engine, but the engine unit of the generator may be configured by another type of engine.

[0014] The AC power generated by multiple (three in the example of FIG. 1 ) diesel generators 2 is collected in an AC distribution panel 3 and supplied to onboard loads 51 and / or electric power plants 52 via inverters 4. In this embodiment, the onboard loads 51 refer to all electrical facilities and electrical equipment onboard, excluding the electric power plants 52 described below, and typically include various electrical facilities such as lighting and air conditioning onboard, and various electrical equipment connected to outlets (plug sockets) provided in cabins, etc.

[0015] The electric power unit 52 is a general term for devices that drive the ship itself and / or ship equipment such as cranes, winches, hydraulic equipment, and pneumatic equipment. A ship that is powered only by the electric power unit 52 is called an electric ship, while a ship that is powered by a combination of the electric power unit 52 and a non-electric power unit such as a diesel engine is called a hybrid ship. The hybrid ship may be a series type in which the engine unit (diesel generator 2), power generation unit (diesel generator 2), motor (electric power unit 52), and propeller (electric power unit 52) ​​are connected in series, or a parallel type in which the engine unit can directly drive the propeller to rotate, and a motor that can drive the propeller to rotate using electric power generated by the power generation unit based on the rotational power of the engine unit is provided in parallel.

[0016] The power generation control device 6, which controls the diesel generator 2 and the inverter 4, includes a power demand acquisition unit 61, a designated power generation amount derivation unit 62, a power generation control unit 63, a recording unit 64, and a designated power generation amount correction unit 65. These functional blocks are realized by the cooperation of hardware resources such as the computer's central processing unit, memory, input devices, output devices, and peripheral devices connected to the computer, and software executed using these. Regardless of the type of computer or its installation location, each of the above functional blocks may be realized by the hardware resources of a single computer or by a combination of hardware resources distributed across multiple computers. In particular, in this embodiment, some or all of the functional blocks of the power generation control device 6 may be realized by a computer on board the ship, or by a computer outside the ship that can communicate with the computer on board the ship.

[0017] The power demand acquisition unit 61 acquires the power demand or total required power of the onboard loads 51 and / or the electric power unit 52, which is the sum of the power generation amounts of the diesel generators 2. The power demand acquisition unit 61 may acquire the power demand directly from the onboard loads 51 and / or the electric power unit 52, or may indirectly acquire a power demand forecast from a power demand map, which will be described later, depending on the area in which the ship is located.

[0018] The designated power generation amount deriving unit 62 derives a designated power generation amount, which is a designated power generation amount of each diesel generator 2 that is uniquely determined according to the power demand acquired by the power demand acquiring unit 61, and whose sum is equal to the power demand acquired by the power demand acquiring unit 61. Specifically, the designated power generation amount deriving unit 62 includes a table that associates the power demand as input with the designated power generation amount of each diesel generator 2 as output, or a function such as a polynomial that calculates the designated power generation amount of each diesel generator 2 as output based on the power demand as input. Here, if the power demand acquired by the power demand acquiring unit 61 is P0, the designated power generation amount of the first diesel generator 21 is P1, the designated power generation amount of the second diesel generator 22 is P2, and the designated power generation amount of the third diesel generator 23 is P3, then the designated power generation amount deriving unit 62 functions as a broad function that gives a unique output (P1, P2, P3) for the input P0. Note that P0 = P1 + P2 + P3 always holds. A detailed example will be described later, but for example, when P0=20, (P1, P2, P3)=(20, 0, 0), etc., the first diesel generator 21 generates all the power demand. When P0=40, (P1, P2, P3)=(20, 20, 0), etc., the first diesel generator 21 and the second diesel generator 22 each generate half of the power demand.

[0019] The designated power generation amount (P1, P2, P3) of each diesel generator 2 is the power generation amount that approximately minimizes the total fuel consumption amount of each diesel generator 2, and is determined based on the relationship between the power generation amount (hereinafter also referred to as output) and fuel consumption amount (hereinafter also referred to as fuel efficiency) of each diesel generator 2.

[0020] Output P represents the power generation of the Nth (N is a natural number) diesel generator 2N N [kW] is the torque of the engine N [Nm] and rotation speed N N It is determined by [rpm], P N =2πT N N N / 60 / 1000×η gen It is expressed as (η gen : Power generation efficiency of diesel generator 2N). Therefore, the torque of the engine T N and rotation speed N N By changing at least one of the following, the power output P of the Nth diesel generator 2N can be calculated according to the above formula: N In other words, the amount of power generation can be changed. In most cases, the onboard loads 51 to which AC power is supplied from the diesel generator 2 can operate only with AC power of a constant frequency (for example, 60 Hz). N It is preferable to keep the rotation speed N of the engine constant so that the generator generates AC power of a constant frequency that meets the requirements of the onboard load 51. N is kept constant, so the engine torque T N With the change in the output P of the Nth diesel generator 2N N In the following, the output P of the Nth diesel generator 2N N [kW] is the rated output or maximum output P of the Nth diesel generator 2N. Nmax Percentage P of [kW] N / P Nmax Expressed in [%].

[0021] Fuel consumption F, which represents the fuel consumption per unit of power generation of the Nth diesel generator 2N N [g / kWh] is also called fuel efficiency and is the measured fuel consumption of the Nth diesel generator 2N. N [g], the measured power generation is E N [kWh](Output P N (proportional to F N =W N / E N The fuel consumption per unit of power generation is expressed as F NThe lower the fuel consumption or fuel efficiency, the lower the fuel consumption per unit of power generation F N The higher the number, the worse the fuel economy or fuel efficiency.

[0022] Figure 2 shows the output P of the Nth diesel generator 2N. N (Power generation amount E N (proportional to) and fuel efficiency F N (Power generation amount E N As shown in Figure 2(A), the output P of the Nth diesel generator 2N is N is the rated output P Nmax In the low output range below about 60% of N It can be seen that the fuel consumption per unit is high and the fuel efficiency is poor. N is the rated output P Nmax In the high output range, which is higher than about 60% of N As shown in Figure 2(B), which is an enlarged view of the high power range, fuel consumption is minimal even within the high power range (F min ) exists (85% in the example of Figure 2). N is minimum when the Nth diesel generator 2N is generating electricity at its optimum output.

[0023] However, when the power demand of the onboard loads 51 and the electric power unit 52 is extremely small, the Nth diesel generator 2N cannot be operated at a relatively large optimum output (85%). Conversely, when the power demand of the onboard loads 51 and the electric power unit 52 is extremely large, the Nth diesel generator 2N must be operated at an output greater than the optimum output (85%). As such, it is not always necessary to operate the Nth diesel generator 2N at the optimum output. Furthermore, when multiple (e.g., three) diesel generators 2 are provided as in this embodiment, the relationship between the amount of power generation and the amount of fuel consumption may differ for each of the diesel generators 21, 22, and 23, and the total fuel consumption (ΣF NIt takes a lot of time to calculate the set of power generation amounts (P1, P2, P3) that approximately minimizes the sum of F1, F2, and F3. On a ship at sea where power demand fluctuates greatly, the power generation amount of each diesel generator 2 needs to quickly keep up with power demand, so there is no time to perform such complex calculations.

[0024] Therefore, in this embodiment, the above-described complex calculations are performed in advance before the ship sets sail, and the resulting tables, polynomials, and other functions are stored in advance in the designated power generation amount deriving unit 62. While the ship is sailing, the total power demand P0 of the onboard loads 51 and / or the electric power plant 52, acquired at any time by the power demand acquisition unit 61, is input into a pre-created table or polynomial by the designated power generation amount deriving unit 62, whereby a set of designated power generation amounts (P1, P2, P3) for each of the diesel generators 21, 22, 23 is instantly obtained. Therefore, the required amount of power can be flexibly generated by each diesel generator 2 without performing complex calculations based on the input / output relationships of each diesel generator 2, as in Patent Document 1.

[0025] The designated power generation amounts P1, P2, P3 (where P0=P1+P2+P3) of the diesel generators 21, 22, 23, which are derived by the designated power generation amount deriving unit 62 by inputting the total power demand P0 into a table or a polynomial, are calculated by subtracting the total fuel consumption amount ΣF N (=F1+F2+F3) is the power generation amount that is approximately minimum. Here, "approximately minimum" means that the total fuel consumption of each diesel generator 21, 22, 23 for a given power demand P0 is ΣF N Find the operational or theoretical minimum or local minimum of F min When the actual fuel consumption of each diesel generator 21, 22, and 23 is set as ΣF N F min More than F min ×1.1 or less (F min ≦ΣF N <F min × 1.1), more preferably F min More than F min ×1.05 or less (F min ≦ΣF N <F min× 1.05).

[0026] The power generation control unit 63 causes at least one of the diesel generators 21, 22, 23 to generate power based on the designated power generation amount (P1, P2, P3) uniquely derived from the power demand P0 by the designated power generation amount derivation unit 62. For example, in the above example where P0=20 and (P1, P2, P3)=(20, 0, 0), the power generation control unit 63 causes one diesel generator 21 to generate power, and in the above example where P0=40 and (P1, P2, P3)=(20, 20, 0), the power generation control unit 63 causes two diesel generators 21, 22 to generate power.

[0027] 3 shows an example of the first power generation control by the power generation control unit 63. The horizontal axis "total power" represents the power demand P0 acquired by the power demand acquisition unit 61 as a percentage of the rated output or maximum output of the power supply system 1. The vertical axis "output of each generator" represents the outputs P1, P2, and P3 of the diesel generators 21, 22, and 23 as a percentage of their respective rated outputs or maximum outputs P 1max , P 2max , P 3max Ratio of P1 / P 1max , P2 / P 2max , P3 / P 3max It is expressed as:

[0028] The following describes the case where the power demand P0 monotonically increases from 0% to 100%. When the power demand P0 starts to increase from 0%, initially, only one diesel generator 21 generates power. At this time, the designated power generation amount deriving unit 62 derives the designated power generation amount (P1, P2, P3) = (P1, 0, 0) in accordance with the power demand P0 (0% to approximately 33%) acquired by the power demand acquisition unit 61, such that only P1 is non-zero among P1, P2, and P3. Since P0 = P1 + P2 + P3, P1 = P0 (however, the unit must be consistent, such as kW, rather than %). When the power demand P0 reaches approximately 33%, the output P1 of the diesel generator 21 reaches 100%, which is the rated power generation amount or the upper limit power generation amount. If the power demand P0 increases further, the power demand P0 cannot be met by just one diesel generator 21, so the power generation control unit 63 starts up a new diesel generator 22.

[0029] When the power demand P0 is about 33 to 35%, the output P1 of the already started diesel generator 21 remains at 100%, and the shortfall is made up by increasing the output P2 of the newly started diesel generator 22 from about 0%. When the power demand P0 reaches about 36%, the output P2 of the newly started diesel generator 22 increases sharply to about 55%, and the output P1 of the already started diesel generator 21 decreases sharply from 100% to about 55%. This is the overall fuel consumption F when the output P1 of the first diesel generator 21 is maintained at 100% and the output P2 of the second diesel generator 22 is gradually increased from 0%. 1(100%) +F 2(0%) Therefore, the total fuel consumption F when the output P1 of the first diesel generator 21 is suddenly reduced to about 55% and the output P2 of the second diesel generator 22 is suddenly increased to about 55% is 1(約55%) +F 2(約55%) When multiple diesel generators 2 with different fuel consumption characteristics are provided, the outputs of the diesel generators 2 for optimizing or minimizing the overall fuel consumption amount are different from each other.

[0030] As described above, when the power demand P0 increases from left to right in FIG. 3 and the power generation control unit 63 activates a new diesel generator 22, the power generation amount E1 or output P1 of the activated diesel generators 21 decreases from 100% to approximately 55%. Conversely, when the power demand P0 decreases from right to left in FIG. 3 and the power generation control unit 63 deactivates some of the activated diesel generators 22, the power generation amount E1 or output P1 of the diesel generators 21 that are not deactivated increases from approximately 55% to 100%. In the example of FIG. 3 , a power demand P0 of approximately 33% serves as the threshold for switching the number of diesel generators 2 to be operated between 1 and 2. When the power demand P0 increases, it becomes the activation threshold. When it exceeds this threshold from left to right, a new diesel generator 22 is activated. When the power demand P0 decreases, it becomes the shutdown threshold. When it exceeds this threshold from right to left, the activated diesel generators 22 are shut down.

[0031] To prevent a blackout caused by a shortage of the total power generation amount (E1 + E2 + E3) relative to the power demand P0, it is preferable to immediately start a new diesel generator 22 when the power demand P0 increases to the start threshold. On the other hand, when the power demand P0 decreases to the shutdown threshold, it is preferable not to immediately shut down the already-started diesel generator 22, but to shut down the already-started diesel generator 22 only if the state where the power demand P0 is below the shutdown threshold continues for a predetermined grace period. By providing such a grace period, if the power demand P0 temporarily falls below the shutdown threshold and then quickly exceeds the shutdown threshold, the two diesel generators 21, 22 can easily meet the power demand P0 without shutting down the already-started diesel generator 22, thereby effectively preventing the occurrence of a blackout.

[0032] Next, when the power demand P0 begins to increase from the first activation threshold of approximately 33%, the two diesel generators 21 and 22 generate power as described above. At this time, the designated power generation amount deriving unit 62 derives the designated power generation amount (P1, P2, P3) = (P1, P2, 0) where P1 and P2 are non-zero among P1, P2, and P3, in accordance with the power demand P0 (approximately 35% to approximately 65%) acquired by the power demand acquisition unit 61. When the power demand P0 reaches approximately 65%, the output P1 of the diesel generator 21 and the output P2 of the diesel generator 22 reach approximately 100%, which is the rated power generation amount or upper limit power generation amount. If the power demand P0 increases further, the two diesel generators 21 and 22 will not be able to cover the power demand P0, so the power generation control unit 63 starts up a new diesel generator 23.

[0033] At this time, the output P3 of the newly started diesel generator 23 increases sharply from approximately 0% to approximately 65%, and the outputs P1 and P2 of the already started diesel generators 21 and 22 decrease sharply from approximately 100% to approximately 65%. This is the overall fuel consumption F when the output P3 of the third diesel generator 23 is gradually increased from 0% while the outputs P1 and P2 of the first and second diesel generators 21 and 22 are maintained at approximately 100%. 1(約100%) +F 2(約100%) +F 3(0%)Therefore, the total fuel consumption F when the outputs P1 and P2 of the first and second diesel generators 21 and 22 are suddenly reduced to about 65% and the output P3 of the third diesel generator 23 is suddenly increased to about 65% is 1(約65%) +F 2(約65%) +F 2(約65%) This is because the difference between the two is smaller, i.e., the fuel efficiency is improved.

[0034] As described above, when the power demand P0 increases from left to right in FIG. 3 and the power generation control unit 63 activates a new diesel generator 23, the power generation amounts E1, E2 or outputs P1, P2 of the activated diesel generators 21, 22 decrease from approximately 100% to approximately 65%. Conversely, when the power demand P0 decreases from right to left in FIG. 3 and the power generation control unit 63 stops some of the activated diesel generators 23, the power generation amounts E1, E2 or outputs P1, P2 of the diesel generators 21, 22 that are not shut down increase from approximately 65% ​​to approximately 100%. In the example of FIG. 3 , the power demand P0 of approximately 65% ​​is the threshold for switching the number of diesel generators 2 to be operated between two and three. When the power demand P0 increases, it becomes the activation threshold. When it exceeds this threshold from left to right, a new diesel generator 23 is activated. When the power demand P0 decreases, it becomes the shutdown threshold. When it exceeds this threshold from right to left, the activated diesel generators 23 are shut down.

[0035] To prevent a blackout caused by a shortage of the total power generation amount (E1 + E2 + E3) relative to the power demand P0, it is preferable to immediately start a new diesel generator 23 when the power demand P0 increases to the start threshold. On the other hand, it is preferable to stop the started diesel generator 23 only if the state where the power demand P0 is below the stop threshold continues for a predetermined grace period, rather than immediately stopping the started diesel generator 23 when the power demand P0 decreases to the stop threshold. By providing such a grace period, if the power demand P0 temporarily falls below the stop threshold and then quickly exceeds the stop threshold, the three diesel generators 21, 22, and 23 can easily meet the power demand P0 without stopping the started diesel generator 23, thereby effectively preventing the occurrence of a blackout.

[0036] Next, when the power demand P0 starts to increase from the second activation threshold of approximately 65%, the three diesel generators 21, 22, 23 generate power as described above. At this time, the designated power generation amount deriving unit 62 derives designated power generation amounts (P1, P2, P3) such that P1, P2, and P3 are all non-zero, in accordance with the power demand P0 (approximately 65% ​​to 100%) acquired by the power demand acquisition unit 61. When the power demand P0 reaches its maximum value of 100%, the output P1 of the diesel generator 21, the output P2 of the diesel generator 22, and the output P3 of the diesel generator 23 reach 100%, which is the rated power generation amount or upper limit power generation amount.

[0037] FIG. 4 shows an example of a second power generation control by the power generation control unit 63. The following describes a case where the power demand P0 monotonically increases from 0% to 100%. When the power demand P0 starts to increase from 0%, initially, only one diesel generator 21 generates power. At this time, the designated power generation amount deriving unit 62 derives the designated power generation amount (P1, P2, P3) = (P1, 0, 0) in accordance with the power demand P0 (0% to approximately 25%) acquired by the power demand acquisition unit 61, such that only P1 is non-zero among P1, P2, and P3. Since P0 = P1 + P2 + P3, P1 = P0 (however, the unit must be consistent, such as kW, rather than %). When the power demand P0 reaches approximately 25%, the output P1 of the diesel generator 21 reaches the activation threshold (70%), which is lower than the rated power generation amount (100%). In principle, the output P1 of the diesel generator 21 is controlled so as not to exceed the start-up threshold (except in the region where the power demand P0 exceeds approximately 70%). Therefore, if the power demand P0 increases further from approximately 25%, the power demand P0 cannot be met by just one diesel generator 21 with an output of 70%, so the power generation control unit 63 starts up a new diesel generator 22.

[0038] The output P2 of the newly started diesel generator 22 increases gradually at first and then increases sharply. In the region where the power demand P0 is between approximately 25% and approximately 30%, the output P2 increases gradually at a predetermined gradient a2 while the output P1 is maintained at 70% of the start-up threshold. Next, when the power demand P0 reaches approximately 30%, the output P2 of the newly started diesel generator 22 increases sharply to 50%, and the output P1 of the already started diesel generator 21 decreases sharply from 70% to 50% of the start-up threshold. This shows the overall fuel consumption F when the output P2 of the second diesel generator 22 continues to increase gradually at a gradient a2 while the output P1 of the first diesel generator 21 is maintained at 70%. 1(70%) +F 2(約25%) Therefore, the total fuel consumption F when the output P1 of the first diesel generator 21 is suddenly reduced to 50% and the output P2 of the second diesel generator 22 is suddenly increased to 50% is 1(50%) +F 2(50%) This is because the difference between the two is smaller, i.e., the fuel efficiency is improved.

[0039] As described above, when the power demand P0 increases from left to right in FIG. 4 and the power generation control unit 63 activates a new diesel generator 22, the power generation amount E1 or output P1 of the activated diesel generators 21 decreases from 70% to 50%. Conversely, when the power demand P0 decreases from right to left in FIG. 4 and the power generation control unit 63 deactivates some of the activated diesel generators 22, the power generation amount E1 or output P1 of the diesel generators 21 that are not deactivated increases from 50% to 70%. In the example of FIG. 4 , a power demand P0 of approximately 25% serves as the threshold for switching the number of diesel generators 2 to be operated between 1 and 2. When the power demand P0 increases, it becomes the activation threshold. When it exceeds this threshold from left to right, a new diesel generator 22 is activated. When the power demand P0 decreases, it becomes the shutdown threshold. When it exceeds this threshold from right to left, the activated diesel generators 22 are shut down.

[0040] To prevent a blackout caused by a shortage of the total power generation amount (E1 + E2 + E3) relative to the power demand P0, it is preferable to immediately start a new diesel generator 22 when the power demand P0 increases to the start threshold. On the other hand, when the power demand P0 decreases to the shutdown threshold, it is preferable not to immediately shut down the already-started diesel generator 22, but to shut down the already-started diesel generator 22 only if the state where the power demand P0 is below the shutdown threshold continues for a predetermined grace period. By providing such a grace period, if the power demand P0 temporarily falls below the shutdown threshold and then quickly exceeds the shutdown threshold, the two diesel generators 21, 22 can easily meet the power demand P0 without shutting down the already-started diesel generator 22, thereby effectively preventing the occurrence of a blackout.

[0041] Furthermore, by setting the startup threshold (70%) for the output P1 of the diesel generator 21 to be lower than the rated power generation capacity (100%), even if a sudden increase in power demand P0 occurs before the newly started diesel generator 22 begins operation, the output P1 of the diesel generator 21 can be increased above the startup threshold in an emergency, thereby effectively preventing the occurrence of blackouts. In other words, a startup threshold lower than the rated power generation capacity creates a margin of error in the output P1 of the diesel generator 21 in case of an emergency.

[0042] Next, when the power demand P0 starts to increase from approximately 25%, the two diesel generators 21 and 22 generate power as described above. At this time, the designated power generation amount deriving unit 62 derives the designated power generation amount (P1, P2, P3) = (P1, P2, 0) where P1 and P2 are non-zero among P1, P2, and P3, in accordance with the power demand P0 (approximately 25% to approximately 45%) acquired by the power demand acquisition unit 61. When the power demand P0 reaches approximately 45%, the output P1 of the diesel generator 21 and the output P2 of the diesel generator 22 reach the startup threshold (70%), which is lower than the rated power generation amount (100%). In principle, the outputs P1 and P2 of the diesel generators 21 and 22 are controlled so as not to exceed the startup threshold (except in the region where the power demand P0 exceeds approximately 70%). Therefore, when the power demand P0 increases further from about 45%, the power generation control unit 63 starts up a new diesel generator 23 because the two diesel generators 21 and 22 with an output of 70% alone cannot cover the power demand P0.

[0043] The output P3 of the newly started diesel generator 23 increases gradually at first and then sharply. In the region where the power demand P0 is between approximately 45% and approximately 55%, the output P3 increases gradually at a predetermined slope a3 while the outputs P1 and P2 are maintained at 70% of the start-up threshold. Then, when the power demand P0 reaches approximately 55%, the output P3 of the newly started diesel generator 23 increases sharply to approximately 55%, and the outputs P1 and P2 of the already started diesel generators 21 and 22 decrease sharply from 70% of the start-up threshold to approximately 55%. This is the overall fuel consumption F when the output P3 of the third diesel generator 23 continues to increase gradually at a slope a3 while the outputs P1 and P2 of the first and second diesel generators 21 and 22 are maintained at 70%. 1(70%) +F 2(70%) +F 3(約20%) Therefore, the total fuel consumption F when the outputs P1 and P2 of the first and second diesel generators 21 and 22 are suddenly reduced to about 55% and the output P3 of the third diesel generator 23 is suddenly increased to about 55% is 1(約55%) +F 2(約55%) +F 2(約55%) This is because the difference between the two is smaller, i.e., the fuel efficiency is improved.

[0044] As described above, when the power demand P0 increases from left to right in FIG. 4 and the power generation control unit 63 activates a new diesel generator 23, the power generation amounts E1, E2 or outputs P1, P2 of the activated diesel generators 21, 22 decrease from 70% to approximately 55%. Conversely, when the power demand P0 decreases from right to left in FIG. 4 and the power generation control unit 63 stops some of the activated diesel generators 23, the power generation amounts E1, E2 or outputs P1, P2 of the diesel generators 21, 22 that are not shut down increase from approximately 55% to 70%. In the example of FIG. 4 , a power demand P0 of approximately 45% serves as the threshold for switching the number of operating diesel generators 2 between two and three. When the power demand P0 increases, it becomes the activation threshold. When the power demand P0 exceeds this threshold from left to right, a new diesel generator 23 is activated. When the power demand P0 decreases, it becomes the shutdown threshold. When the power demand P0 decreases, it becomes the shutdown threshold. When the power demand P0 exceeds this threshold from right to left, the activated diesel generators 23 are shut down.

[0045] To prevent a blackout caused by a shortage of the total power generation amount (E1 + E2 + E3) relative to the power demand P0, it is preferable to immediately start a new diesel generator 23 when the power demand P0 increases to the start threshold. On the other hand, it is preferable to stop the started diesel generator 23 only if the state where the power demand P0 is below the stop threshold continues for a predetermined grace period, rather than immediately stopping the started diesel generator 23 when the power demand P0 decreases to the stop threshold. By providing such a grace period, if the power demand P0 temporarily falls below the stop threshold and then quickly exceeds the stop threshold, the three diesel generators 21, 22, and 23 can easily meet the power demand P0 without stopping the started diesel generator 23, thereby effectively preventing the occurrence of a blackout.

[0046] Furthermore, by setting a startup threshold (70%) that is lower than the rated power generation capacity (100%) for the outputs P1 and P2 of the diesel generators 21 and 22, even if a sudden increase in power demand P0 occurs before the newly started diesel generator 23 begins operation, the outputs P1 and P2 of the diesel generators 21 and 22 can be increased above the startup threshold in an emergency, thereby effectively preventing the occurrence of blackouts. In other words, a startup threshold that is lower than the rated power generation capacity creates a margin of error in the outputs P1 and P2 of the diesel generators 21 and 22 to respond to emergencies.

[0047] Next, when the power demand P0 starts to increase from approximately 55%, the three diesel generators 21, 22, and 23 generate power as described above. At this time, the designated power generation amount deriving unit 62 derives designated power generation amounts (P1, P2, and P3) such that P1, P2, and P3 are all non-zero, in accordance with the power demand P0 (approximately 55% to 100%) acquired by the power demand acquisition unit 61. When the power demand P0 reaches its maximum value of 100%, the output P1 of the diesel generator 21, the output P2 of the diesel generator 22, and the output P3 of the diesel generator 23 reach 100%, which is the rated power generation amount or upper limit power generation amount, which is greater than the start-up threshold of 70%.

[0048] Returning to the explanation of FIG. 1 , the recording unit 64 includes an input / output characteristics recording unit 641 and a cumulative operating time recording unit 642. The input / output characteristics recording unit 641 records the power generation amount and fuel consumption amount of each diesel generator 2 while the ship is sailing. Specifically, the input / output characteristics recording unit 641 records the relationship between the output (corresponding to the power generation amount) and fuel consumption (corresponding to the fuel consumption amount) of each diesel generator 2 as shown in FIG. 2 . As described above, the fuel consumption characteristics of each diesel generator 2 are the basis of the tables and polynomials stored in the designated power generation amount deriving unit 62. Therefore, if the fuel consumption characteristics of each diesel generator 2 recorded by the input / output characteristics recording unit 641 deviate from the initial ones, the designated power generation amount correction unit 65 corrects the tables and polynomials used to derive the designated power generation amount based on the records in the input / output characteristics recording unit 641. Note that the designated power generation amount deriving unit 62 may directly derive the designated power generation amount based on the records in the input / output characteristics recording unit 641 without providing the designated power generation amount correction unit 65.

[0049] The cumulative operating time recording unit 642 records the cumulative operating time of each diesel generator 2. The power generation control unit 63 prioritizes power generation by the diesel generator 2 with the shortest cumulative operating time recorded by the cumulative operating time recording unit 642. As described with reference to FIGS. 3 and 4, when the power demand P0 starts to increase from 0%, only one diesel generator 2 initially generates power. In this case, if the same diesel generator 2 (e.g., the first diesel generator 21) is always operated first, deterioration of that diesel generator 2 will progress. Therefore, for example, if the cumulative operating time of the first diesel generator 21 is significantly longer than the cumulative operating time of the second diesel generator 22 or the third diesel generator 23, the power generation control unit 63 changes the diesel generator 2 to be operated first to the second diesel generator 22 or the third diesel generator 23. This also applies when starting a second diesel generator 2 in response to an increase in power demand P0. For example, if the first diesel generator 21 has already been started and either the second diesel generator 22 or the third diesel generator 23 is to be started, the second diesel generator 22 or the third diesel generator 23, whichever has the shorter cumulative operating time, will be started first.

[0050] Figure 5 is a functional block diagram showing the configuration of a marine vessel power supply system 1 according to the second embodiment. Components similar to those in the first embodiment (Figure 1) are given the same reference numerals, and duplicate explanations will be omitted. The power generation control device 6 includes a power demand acquisition unit 61, a designated power generation amount derivation unit 62, a power generation control unit 63, a power demand map storage unit 66, a vessel location detection unit 67, a vessel movement detection unit 681, a nearby area estimation unit 682, a power consumption measurement unit 683, a power demand map update unit 684, a related information acquisition unit 685, and a power demand correction unit 686.

[0051] The power demand map storage unit 66 stores a power demand map that records the power demand forecast, which is the total amount of power generated by each diesel generator 2, for each area in which the ship can navigate. FIG. 6 schematically shows an example of area division of the Earth's ocean surface. In this example, the longitude from -180 degrees to +180 degrees is divided in 0.1-degree increments into 3,600 x-axis sections from 0 to 3,599 along the x-axis (horizontal direction in FIG. 6 ). The latitude from -90 degrees to +90 degrees is divided in 0.1-degree increments into 1,800 y-axis sections from 0 to 1,799 along the y-axis (vertical direction in FIG. 6 ). As a result, the Earth or world map is divided into 3,600 x 1,800 areas. Note that the world map in FIG. 6 is shown schematically using the Mercator projection, and the dimensions and areas of each area are not accurate. In this embodiment, it is sufficient to divide only the ocean area in which the ship navigates; dividing the land area is not necessary. Furthermore, for ships that navigate only in specific sea areas, it is sufficient to divide only those sea areas into regions.

[0052] FIG. 7 shows a schematic example of a power demand map stored in the power demand map storage unit 66. Each small rectangular area stores a power demand forecast or total required power, which is the sum of the required power generation amounts of each diesel generator 2. In this example, it is assumed that each of the three diesel generators 21, 22, and 23 can generate power ranging from 0% to 100%. Therefore, the minimum value of the power demand forecast for each area is 0 (none of the three diesel generators 21, 22, and 23 need to generate power), and the maximum value of the power demand forecast for each area is 300 (all of the three diesel generators 21, 22, and 23 need to generate power at 100%).

[0053] The predicted power demand value for each region is based on the power consumption, preferably the maximum power consumption, of one or more ships in each region during past voyages. For example, for a region in which the maximum power consumption of multiple ships during past voyages was "100," "120," or "80," the largest of these, "120," is recorded as the predicted power demand. The average or median of these values, "100," may be recorded as the predicted power demand. However, if a predicted power demand of "120," which actually occurred in the past, occurs, the amount of power generation will be insufficient. Therefore, it is preferable to record the largest possible value, "120," as the predicted power demand. Note that the ships used to create the power demand map are not limited to ships equipped with the power generation control device 6, and may be ships other than the ships equipped with the power generation control device 6.

[0054] The ship location area detection unit 67 detects the ship location area where the ship is sailing among the areas in the power demand map stored in the power demand map storage unit 66. For example, the ship location area detection unit 67 measures the current position of the ship using a ship positioning unit 671 that uses a satellite positioning system such as GPS (Global Positioning System) to detect the ship location area. Alternatively, the ship location area detection unit 67 estimates the current position of the ship in accordance with the navigation plan based on the ship's navigation plan stored in the navigation plan storage unit 672 and the current time measured by the timing unit 673 to detect the ship location area.

[0055] The power demand acquisition unit 61 acquires the maximum power demand forecast for the area near the ship's location detected by the ship location area detection unit 67 from the power demand map stored in the power demand map storage unit 66. The power generation control unit 63 starts up the number of diesel generators 2 determined according to the maximum power demand forecast for the area near the ship acquired by the power demand acquisition unit 61 before the ship enters the area near the ship.

[0056] A more detailed explanation will be given with reference to Figure 7. In this example, a ship will travel from the start point indicated by ▲ to the end point indicated by ★. As indicated by the numbers "1" to "9," the ship will travel through areas "1" to "9" in order.

[0057] The range of the vicinity of the ship's location area from which the power demand acquisition unit 61 acquires the power demand forecast is arbitrary, but in the following, the vicinity area will be defined as eight areas surrounding the ship's location area. As a variant, the vicinity area may be 24 areas surrounding the ship's location area twice. Furthermore, the range of the vicinity of the ship's location area from which the power demand acquisition unit 61 acquires the power demand forecast may be changed depending on the ship's movement speed (measured by the ship movement detection unit 681). For example, when the ship's movement speed is slow, the range of the vicinity of the ship's location area from which the power demand acquisition unit 61 acquires the power demand forecast is narrowed, and when the ship's movement speed is fast, the range of the vicinity of the ship's location area from which the power demand acquisition unit 61 acquires the power demand forecast is widened.

[0058] The power demand acquisition unit 61 acquires the maximum power demand forecast in eight neighboring areas surrounding each of the ship presence areas "1" to "9" detected by the ship presence area detection unit 67 from the power demand map stored in the power demand map storage unit 66. In the following, it is assumed that when the power demand forecast acquired by the power demand acquisition unit 61 is equal to or greater than "0" and less than "80", one diesel generator 2 is started or operated, when the power demand forecast acquired by the power demand acquisition unit 61 is equal to or greater than "80" and less than "160", two diesel generators 2 are started or operated, and when the forecast is equal to or greater than "160", three diesel generators 2 are started or operated.

[0059] When the vessel is in vessel location area "1", the maximum predicted power demand in the eight nearby areas is "70". Therefore, the power generation control unit 63 starts one diesel generator 2 in advance so that it can meet the predicted power demand of "70" before the vessel enters the nearby area (i.e., while the vessel is in vessel location area "1"). When the vessel is in vessel location area "2", the maximum predicted power demand in the eight nearby areas is "80". Therefore, the power generation control unit 63 starts two diesel generators 2 in advance so that it can meet the predicted power demand of "80" before the vessel enters the nearby area (i.e., while the vessel is in vessel location area "2"). Here, because one diesel generator 2 has already been started in vessel location area "1", one new diesel generator 2 is started in vessel location area "2".

[0060] When the vessel is in vessel location area "3," the maximum predicted power demand in the eight nearby areas is "90." Therefore, the power generation control unit 63 operates the two diesel generators 2 in advance before the vessel enters the nearby area (i.e., while the vessel is in vessel location area "3") so that the predicted power demand of "90" can be met. When the vessel is in vessel location area "4," the maximum predicted power demand in the eight nearby areas is "100." Therefore, the power generation control unit 63 operates the two diesel generators 2 in advance before the vessel enters the nearby area (i.e., while the vessel is in vessel location area "4") so that the predicted power demand of "100" can be met. When the vessel is in vessel location area "5," the maximum predicted power demand in the eight nearby areas is "120." Therefore, the power generation control unit 63 operates the two diesel generators 2 in advance before the vessel enters the nearby area (i.e., while the vessel is in vessel location area "5") so that the predicted power demand of "120" can be met. When the ship is in the ship location area "6", the maximum predicted power demand in the eight nearby areas is "140". Therefore, the power generation control unit 63 operates the two diesel generators 2 in advance before the ship enters the nearby area (i.e., while the ship is in the ship location area "6") so as to be able to respond to the predicted power demand of "140".

[0061] When the vessel is in vessel location area "7," the maximum predicted power demand in the eight nearby areas is "160." Therefore, the power generation control unit 63 starts up three diesel generators 2 in advance before the vessel enters the nearby area (i.e., while the vessel is in vessel location area "7") so that the predicted power demand of "160" can be met. Here, because two diesel generators 2 have already been started in the previous vessel location area, one new diesel generator 2 is started up in vessel location area "7." When the vessel is in vessel location area "8," the maximum predicted power demand in the eight nearby areas is "180." Therefore, the power generation control unit 63 starts up three diesel generators 2 in advance before the vessel enters the nearby area (i.e., while the vessel is in vessel location area "8") so that the predicted power demand of "180" can be met. When the vessel is in vessel location area "9," the maximum predicted power demand in the eight nearby areas is "190." Therefore, the power generation control unit 63 operates the three diesel generators 2 in advance before the ship enters the nearby area (i.e., while the ship is in the ship location area "9") so as to respond to the predicted power demand "190".

[0062] 8 briefly shows the power generation control process of the power generation control unit 63. As explained above, the power generation control unit 63 operates one diesel generator 2 in advance in the vessel location area "1" so that it can respond to the maximum power demand forecast of "70" in the surrounding area, operates two diesel generators 2 in advance in the vessel location area "2" so that it can respond to the maximum power demand forecast of "80" in the surrounding area, operates two diesel generators 2 in advance in the vessel location area "3" so that it can respond to the maximum power demand forecast of "90" in the surrounding area, operates two diesel generators 2 in advance in the vessel location area "4" so that it can respond to the maximum power demand forecast of "100" in the surrounding area, and operates two diesel generators 2 in advance in the vessel location area "5" so that it can respond to the maximum power demand forecast of "60" in the surrounding area. Two diesel generators 2 are started in advance to be able to respond to the forecast of "120", two diesel generators 2 are started in advance in the ship's location area "6" to be able to respond to the maximum power demand forecast of "140" in the nearby area, three diesel generators 2 are started in advance in the ship's location area "7" to be able to respond to the maximum power demand forecast of "160" in the nearby area, three diesel generators 2 are started in advance in the ship's location area "8" to be able to respond to the maximum power demand forecast of "180" in the nearby area, and three diesel generators 2 are started in advance in the ship's location area "9" to be able to respond to the maximum power demand forecast of "190" in the nearby area.

[0063] In the above example, the power demand acquisition unit 61 acquired the maximum power demand forecast for eight nearby areas surrounding each ship location area, but the power demand acquisition unit 61 may selectively acquire the power demand forecast for the estimated nearby areas by using the nearby area estimation unit 682, which estimates one or more nearby areas to which the ship is heading based on the direction and speed of movement of the ship detected by the ship movement detection unit 681 or the ship's navigation plan stored in the navigation plan storage unit 672. For example, if the nearby area estimation unit 682 can estimate that a ship in location area "7" is heading toward the (next) ship location area "8", the power demand acquisition unit 61 may acquire only the power demand forecast "160" for the (next) ship location area "8".

[0064] Next, we will explain an example in which a ship travels from the start point indicated by a star to the end point indicated by a triangle, which is the opposite of the above example. To simplify the explanation, the numbers of the ship's locations will be the same as in the above example. Therefore, the ship will travel from area "9" to area "1" in order.

[0065] When the vessel is in vessel location area "9," the maximum predicted power demand in the eight nearby areas is "190." Therefore, the power generation control unit 63 starts up the three diesel generators 2 before the vessel enters the nearby area (i.e., while the vessel is in vessel location area "9") so that the predicted power demand of "190" can be met. When the vessel is in vessel location area "8," the maximum predicted power demand in the eight nearby areas is "180." Therefore, the power generation control unit 63 starts up the three diesel generators 2 before the vessel enters the nearby area (i.e., while the vessel is in vessel location area "8") so that the predicted power demand of "180" can be met. When the vessel is in vessel location area "7," the maximum predicted power demand in the eight nearby areas is "160." Therefore, the power generation control unit 63 starts up the three diesel generators 2 before the vessel enters the nearby area (i.e., while the vessel is in vessel location area "7") so that the predicted power demand of "160" can be met.

[0066] When the ship is in the ship location area "6", the maximum predicted power demand in the eight nearby areas is "140". Therefore, the power generation control unit 63 operates the two diesel generators 2 before the ship enters the nearby area (i.e., while the ship is in the ship location area "6") so as to be able to respond to the predicted power demand of "140". Here, because three diesel generators 2 have already been started in the previous ship location area "7", it is preferable to start preparations for shutdown while the ship is in the ship location area "6" so that the third diesel generator 2 can be shut down when the ship enters the nearby area of ​​the predicted power demand of "140".

[0067] Furthermore, even when the vessel enters a region near the power demand forecast "140," it is preferable not to immediately shut down the activated diesel generators 2, but to shut down the activated diesel generators 2 only if the vessel remains in the region continuously for a predetermined grace period. By providing such a grace period, if the vessel moves again into the region of the power demand forecast "160" immediately after entering the region near the power demand forecast "140," for example, the activated diesel generators 2 can be easily supplied with three diesel generators 2 without shutting down the activated diesel generators 2, thereby effectively preventing blackouts. As described above, in this embodiment, if the number of diesel generators 2 determined according to the power demand forecast in the region near the power demand forecast becomes smaller than the number of activated diesel generators 2 and this state continues for a predetermined grace period, the power generation control unit 63 shuts down some of the activated diesel generators 2.

[0068] When the vessel is in vessel location area "5," the maximum predicted power demand in the eight nearby areas is "120." Therefore, the power generation control unit 63 operates the two diesel generators 2 before the vessel enters the nearby area (i.e., while the vessel is in vessel location area "5") so that the predicted power demand of "120" can be met. When the vessel is in vessel location area "4," the maximum predicted power demand in the eight nearby areas is "100." Therefore, the power generation control unit 63 operates the two diesel generators 2 before the vessel enters the nearby area (i.e., while the vessel is in vessel location area "4") so that the predicted power demand of "100" can be met. When the vessel is in vessel location area "3," the maximum predicted power demand in the eight nearby areas is "90." Therefore, the power generation control unit 63 operates the two diesel generators 2 before the vessel enters the nearby area (i.e., while the vessel is in vessel location area "3") so that the predicted power demand of "90" can be met. When the ship is in the ship location area "2", the maximum predicted power demand in the eight nearby areas is "80". Therefore, the power generation control unit 63 operates the two diesel generators 2 before the ship enters the nearby area (i.e., while the ship is in the ship location area "2") so as to meet the predicted power demand of "80".

[0069] When the ship is in the ship location area "1," the maximum predicted power demand in the eight nearby areas is "70." Therefore, the power generation control unit 63 operates one diesel generator 2 before the ship enters the nearby area (i.e., while the ship is in the ship location area "1") so as to be able to respond to the predicted power demand of "70." Here, because two diesel generators 2 have already been activated in the previous ship location area "2," it is preferable to start preparations for shutdown while the ship is in the ship location area "1" so that the second diesel generator 2 can be shut down once the ship enters the nearby area of ​​the predicted power demand of "70."

[0070] Furthermore, even when the vessel enters an area near the power demand forecast of "70," it is preferable not to immediately shut down the diesel generators 2 that have already been activated, but to shut down the diesel generators 2 that have already been activated only if the vessel remains in the area continuously for a predetermined grace period. By providing such a grace period, if the vessel moves again into an area with a power demand forecast of "80" immediately after entering an area near the power demand forecast of "70," the two diesel generators 2 can easily meet the power demand forecast of "80" without shutting down the diesel generators 2 that have already been activated, thereby effectively preventing the occurrence of blackouts.

[0071] In the example of the power demand map shown in Figure 7, all regions have the same shape and area. However, the shape and area of ​​each region may be arbitrary and may vary from region to region. In particular, it is preferable to make the average area of ​​all regions within a specified distance from the port smaller than the average area of ​​all regions outside the specified distance from the port. In waters close to a port, not only is precise ship maneuvering required to avoid other ships, land, and obstacles on or underwater, but power demand at cargo handling facilities and on board fluctuates significantly immediately after boarding or immediately before disembarking. Therefore, by reducing the area of ​​the power demand map (e.g., by using latitude and longitude coordinates in increments of 0.01 degrees), precise power generation control according to power demand can be achieved. On the other hand, in waters far from a port, power demand fluctuations are also small. Therefore, by increasing the area of ​​the power demand map (e.g., by using latitude and longitude coordinates in increments of 1 degree), the load on power generation control can be reduced. Furthermore, in waters close to ports, the frequency of use of electric power units 52 such as side thrusters and cargo handling equipment increases, and the onboard load 51 also increases due to the need to set up living spaces after boarding and prepare for disembarkation, so as a result, the average power demand forecast for all areas within a specified distance from the port will be higher than the average power demand forecast for all areas outside the specified distance from the port. For example, in Figure 7, the ★ represents the port.

[0072] Returning to the explanation of Figure 5, the power consumption measurement unit 683 measures the power consumption of the onboard loads 51 and / or the electric power unit 52 in each area where the ship is located while it is sailing. The power demand map update unit 684 updates the power demand map stored in the power demand map storage unit 66 based on the power consumption in each area where the ship is located measured by the power consumption measurement unit 683. For example, if the actual power consumption in area "1" in Figure 7 is "80," this is greater than the predicted power demand of "60" recorded in the power demand map, so the power demand map update unit 684 updates the predicted power demand for area "1" to the newly measured "80." This improves the accuracy of power generation control when the ship or other ships sail through this sea area in the future.

[0073] The related information acquisition unit 685 acquires related information such as sea conditions around the ship, weather around the ship, number of passengers on the ship, time of day, usage status of the electric power unit 52, sailing speed of the ship (measured by the ship movement detection unit 681), current power consumption (measured by the power consumption measurement unit 683), etc. The power demand correction unit 686 corrects the power demand forecast acquired by the power demand acquisition unit 61 based on at least any of the related information acquired by the related information acquisition unit 685. For example, when the power demand acquisition unit 61 acquires a power demand forecast of "70" in the vessel location area "1" in Fig. 7 as shown in Fig. 8, if related information is acquired that suggests the actual power demand forecast is lower than the power demand forecast in the power demand map, such as extremely calm sea conditions around the vessel, extremely good weather around the vessel, very few passengers on board the vessel, a time period such as late night when power consumption is extremely low, all electric power units 52 are not in use, the vessel's sailing speed is above a certain level and therefore there is an extremely low possibility that electric power units 52 such as side thrusters or loading and unloading equipment will be used, or the current power consumption in the vessel location area "1" is much lower than "60" shown in the power demand map in Fig. 7, the power demand correction unit 686 corrects the power demand forecast of "70" acquired by the power demand acquisition unit 61 to, for example, "60." Note that if the power demand map value is linked to and recorded with related information when the power demand map value is updated, the accuracy of the power demand correction based on the related information can be improved.

[0074] The present invention has been described above based on the embodiments. The embodiments are merely examples, and it will be understood by those skilled in the art that various modifications are possible in the combination of the respective components and treatment processes, and that such modifications are also within the scope of the present invention.

[0075] The functional configuration of each device described in the embodiments can be realized by hardware resources, software resources, or a combination of hardware and software resources. Examples of hardware resources include processors, ROMs, RAMs, and other LSIs. Examples of software resources include operating systems, applications, and other programs.

[0076] Among the embodiments disclosed in this specification, those in which multiple functions are provided in a distributed manner may have some or all of the multiple functions integrated together, and conversely, those in which multiple functions are provided in a distributed manner may have some or all of the multiple functions integrated together. Regardless of whether the functions are integrated or distributed, it is sufficient that the configuration can achieve the object of the invention. [Explanation of symbols]

[0077] 1 power supply system, 2 diesel generator, 3 AC distribution board, 4 inverter, 6 power generation control device, 51 onboard load, 52 electric power unit, 61 power demand acquisition unit, 62 designated power generation amount derivation unit, 63 power generation control unit, 64 recording unit, 65 designated power generation amount correction unit, 66 power demand map storage unit, 67 ship location area detection unit, 641 input / output characteristics recording unit, 642 cumulative operating time recording unit, 671 ship positioning unit, 672 navigation plan storage unit, 673 timing unit, 681 ship movement detection unit, 682 nearby area estimation unit, 683 power consumption measurement unit, 684 power demand map update unit, 685 related information acquisition unit, 686 power demand correction unit.

Claims

1. A power generation control device for a ship provided with a plurality of generators that generate power by burning input fuel, an electric power demand acquisition unit that acquires electric power demand; a designated power generation amount deriving unit that derives a designated power generation amount of each of the power generators, the total of which is equal to the power demand and which substantially minimizes the total fuel consumption of each of the power generators; a power generation control unit that controls the power generator based on the designated power generation amount; Equipped with When the power generation control unit starts a new power generator in response to an increase in the power demand, the power generation amount of the power generator that has already been started is reduced; When the power generation control unit stops some of the power generators that have already been started due to the decrease in the power demand, the power generation control unit stops the reduction in the power generation amount of the power generators that are not stopped; A power generation control device in which, after the power demand has decreased to a predetermined shutdown threshold, if the state where the power demand is below the shutdown threshold continues for a predetermined grace period, the power generation control unit shuts down some of the power generators that are already running.

2. The power generation control device according to claim 1 , wherein the designated power generation amount is determined based on a relationship between the power generation amount and fuel consumption amount of each of the power generators.

3. a recording unit that records the amount of power generated and the amount of fuel consumed by each of the generators; the designated power generation amount deriving unit derives the designated power generation amount based on the record in the record unit. The power generation control device according to claim 1 or 2.

4. 3. The power generation control device according to claim 1, wherein when the amount of power generated by each activated power generator increases to a predetermined activation threshold value in response to the increase in the power demand, the power generation control unit activates a new power generator.

5. The power generation control device according to claim 4 , wherein each of the start-up threshold values ​​is smaller than a rated power generation amount of each of the power generators.

6. A power generation control device for a ship equipped with multiple generators that generate electricity by burning input fuel, an electric power demand acquisition unit that acquires electric power demand; a designated power generation amount deriving unit that derives a designated power generation amount of each of the power generators, the total of which is equal to the power demand and which substantially minimizes the total fuel consumption of each of the power generators; a power generation control unit that controls the power generator based on the designated power generation amount; Equipped with When the power generation control unit stops some of the power generators that have already been started due to the decrease in the power demand, the power generation control unit stops the reduction in the power generation amount of the power generators that are not stopped; A power generation control device in which, after the power demand has decreased to a predetermined shutdown threshold, if the state where the power demand is below the shutdown threshold continues for a predetermined grace period, the power generation control unit shuts down some of the power generators that are already running.

7. A power generation control device as described in Claim 6, which increases the power generation amount of generators that are not stopped when the power generation control unit stops some of the generators that have already been started due to a decrease in the power demand.

8. A power generation control device as described in any one of claims 1 to 6, wherein the specified power generation amount derivation unit is provided with a table that corresponds the power demand as input with the specified power generation amount of each generator as output, or a function that calculates the specified power generation amount of each generator as output based on the power demand as input.

9. further comprising an accumulated operating time recording unit that records the accumulated operating time of each of the generators; the power generation control unit preferentially causes the power generator with the shortest cumulative operating time to generate power. The power generation control device according to any one of claims 1 to 6.

10. 7. The power generation control device according to claim 1, wherein at least a portion of the electric power generated by each of the generators is consumed by an electric power plant that drives the vessel.

11. A power generation control method for a ship provided with a plurality of generators that generate power by burning input fuel, comprising: a power demand acquisition step of acquiring power demand; a designated power generation amount deriving step of deriving a designated power generation amount of each of the generators, the total of which is equal to the power demand and which substantially minimizes the total fuel consumption of each of the generators; a power generation control step of controlling the power generator based on the designated power generation amount; Equipped with When the power generation control step starts a new power generator in response to an increase in the power demand, the power generation amount of the power generator that has already been started is reduced; When the power generation control step stops some of the power generators that have already been started in response to the decrease in the power demand, the power generation control step stops the reduction in the power generation amount of the power generators that are not stopped; A power generation control method in which, after the power demand has decreased to a predetermined shutdown threshold, if the state where the power demand is below the shutdown threshold continues for a predetermined grace period, the power generation control step shuts down some of the power generators that are already running.

12. A power generation control method for a ship equipped with multiple generators that generate electricity by burning input fuel, comprising: a power demand acquisition step of acquiring power demand; a designated power generation amount deriving step of deriving a designated power generation amount of each of the generators, the total of which is equal to the power demand and which substantially minimizes the total fuel consumption of each of the generators; a power generation control step of controlling the power generator based on the designated power generation amount; Equipped with When the power generation control step stops some of the power generators that have already been started in response to the decrease in the power demand, the power generation control step stops the reduction in the power generation amount of the power generators that are not stopped; A power generation control method in which, after the power demand has decreased to a predetermined shutdown threshold, if the state where the power demand is below the shutdown threshold continues for a predetermined grace period, the power generation control step shuts down some of the power generators that are already running.

13. A power generation control program for a ship having a plurality of generators that generate power by burning fuel, the program comprising: a power demand acquisition step of acquiring power demand; a designated power generation amount deriving step of deriving a designated power generation amount of each of the generators, the total of which is equal to the power demand and which substantially minimizes the total fuel consumption of each of the generators; a power generation control step of controlling the power generator based on the designated power generation amount; on the computer, When the power generation control step starts a new power generator in response to an increase in the power demand, the power generation amount of the power generator that has already been started is reduced; When the power generation control step stops some of the power generators that have already been started in response to the decrease in the power demand, the power generation control step stops the reduction in the power generation amount of the power generators that are not stopped; A power generation control program in which, after the power demand has decreased to a predetermined shutdown threshold, if the state where the power demand is below the shutdown threshold continues for a predetermined grace period, the power generation control step shuts down some of the power generators that are already running.

14. A power generation control program for a ship equipped with multiple generators that generate electricity by burning input fuel, comprising: a power demand acquisition step of acquiring power demand; a designated power generation amount deriving step of deriving a designated power generation amount of each of the generators, the total of which is equal to the power demand and which substantially minimizes the total fuel consumption of each of the generators; a power generation control step of controlling the power generator based on the designated power generation amount; on the computer, When the power generation control step stops some of the power generators that have already been started in response to the decrease in the power demand, the power generation control step stops the reduction in the power generation amount of the power generators that are not stopped; A power generation control program in which, after the power demand has decreased to a predetermined shutdown threshold, if the state where the power demand is below the shutdown threshold continues for a predetermined grace period, the power generation control step shuts down some of the power generators that are already running.

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