Power generation control device, power generation control method, storage medium

Abstract

Provided is a power generation control device, a power generation control method, and a storage medium, which can reduce fuel consumption during power generation. The power generation control device (6) includes: a calculation unit (61) that calculates fuel consumption per unit generated energy of a diesel generator (4) having an engine unit (41) that outputs rotational power by combusting input fuel and a power generation unit (42) that converts the rotational power into electric power; a change unit (62) that changes an operating condition of the diesel generator (4) in such a manner that the output of the diesel generator (4) is changed; a determination unit (63) that compares the fuel consumption per unit generated energy calculated by the calculation unit (61) under the operating condition before the change with the fuel consumption per unit generated energy calculated by the calculation unit (61) under the operating condition after the change, and determines the operating condition of the less fuel consumption; and a power generation control unit (64) that causes the diesel generator (4) to operate in the determined operating condition.

Description

TECHNICAL FIELD

[0001] The present application relates to a power generation control technology. BACKGROUND

[0002] A power generation control device for a ship that limits the output of a diesel generator to a range of a prescribed proportion of a load in the ship is disclosed in Patent Literature 1. Specifically, the output of the diesel generator is limited to 60% or more and 90% or less of the load in the ship that is considered to be good in fuel efficiency of the diesel generator, that is, fuel consumption per unit generated energy of the diesel generator, whereby high fuel efficiency can be achieved.

[0003] PRIOR ART DOCUMENTS

[0004] PATENT LITERATURE

[0005] Patent Literature 1: Japanese Patent Application Laid-Open No. 2019-93735 SUMMARY

[0006] PROBLEMS TO BE SOLVED BY THE INVENTION

[0007] In Patent Literature 1, a fixed output range of 60% or more and 90% or less of the load in the ship is set, but it is conceivable that the fuel efficiency of the diesel generator differs depending on the diesel generator itself and the placement situation of the ship, and the above output range does not always achieve high fuel efficiency. In addition, it is conceivable that there is a portion in which the fuel efficiency is relatively low even within the above output range, and thus there is a concern that this leads to useless fuel consumption.

[0008] The present application was made in view of such a situation, and aims to provide a power generation control device that can reduce fuel consumption at the time of power generation.

[0009] SOLUTION TO PROBLEM

[0010] To solve the above problem, a power generation control device of a certain aspect of the present application includes: a calculation section that calculates fuel consumption per unit generated energy of a generator that has an engine section that outputs rotational power by combustion of fuel input and a power generation section that converts the rotational power into electric power; a change section that changes an operation condition of the generator in such a manner that the output of the generator changes; a determination section that compares the fuel consumption per unit generated energy calculated by the calculation section under the operation condition before the change with the fuel consumption per unit generated energy calculated by the calculation section under the operation condition after the change, and determines the operation condition of the side in which the fuel consumption is less; and a power generation control section that causes the generator to operate in the determined operation condition.

[0011] In this way, the changing section changes the operation condition of the generator, the determining section determines the operation condition with less fuel consumption per unit of generated energy, and the power generation control section causes the generator to operate with the determined operation condition, so that the fuel consumption at the time of power generation can be reduced.

[0012] Another aspect of the present application is a power generation control method. The method includes a calculating step of calculating fuel consumption per unit of generated energy of a generator having an engine section that outputs rotational power through combustion of input fuel and a power generation section that converts the rotational power into electric power, a changing step of changing an operation condition of the generator in such a manner that the output of the generator changes, a determining step of comparing the fuel consumption per unit of generated energy calculated by the calculating step under the operation condition before the change with the fuel consumption per unit of generated energy calculated by the calculating step under the operation condition after the change, and determining the operation condition of the smaller one, and a power generation control step of causing the generator to operate with the determined operation condition.

[0013] Furthermore, any combination of the above structural elements, a mode obtained by converting the present application between a method, a device, a system, a recording medium, a computer program, and the like is also effective as the present application.

[0014] Effects of the Invention

[0015] According to the present application, the fuel consumption at the time of power generation can be reduced. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is a functional block diagram showing the structure of a power supply system for a ship.

[0017] Figure 2 shows an example of the relationship between the fuel consumption and the output in a diesel generator.

[0018] Figure 3 schematically shows an example of the method of determining the optimum output by the power generation control device.

[0019] Figure 4 is a flowchart showing the processing of determining the optimum output by the power generation control device.

[0020] Figure 5 shows a table in which the output of a diesel generator, the loss at the time of charge and discharge of a battery, and the like are stored.

[0021] Figure 6 is a flowchart showing the power generation control processing by the power generation control device. DETAILED DESCRIPTION

[0022] Figure 1is a functional block diagram showing the structure of a power supply system 1 for a ship. The power supply system 1 is a system that supplies alternating current power to a shipboard load 3 via a power bus 2, and has a diesel generator 4 that generates alternating current power as a generator, a battery 5 that can charge and discharge between the power bus 2 via an AC / DC conversion section 51, and a power generation control device 6 that performs power generation control of the diesel generator 4 and charge / discharge control of the battery 5.

[0023] The diesel generator 4 has an engine section 41 that outputs rotational power by combustion of fuel supplied, and a power generation section 42 that converts the rotational power of the engine section 41 to electric power. The engine section 41 in the diesel generator 4 is constituted by a diesel engine, but the engine section of the generator in the present application can also be constituted by other kinds of engines. The power generation section 42 generates alternating current power from the rotational power of the engine section 41 and supplies the alternating current power to the power bus 2.

[0024] The battery 5 is connected to the power bus 2 for supplying alternating current power to the shipboard load 3 via the AC / DC conversion section 51 that is a power conversion section that converts alternating current power and direct current power to each other. When the battery 5 is charged, the alternating current power in the power bus 2 generated by the diesel generator 4 is converted to direct current power by the AC / DC conversion section 51 to charge the battery 5. When the battery 5 is discharged, the direct current power from the battery 5 is converted to alternating current power by the AC / DC conversion section 51 and then supplied to the power bus 2. The charge / discharge control of the battery 5, that is, the power conversion control of the AC / DC conversion section 51, is performed by the power generation control device 6.

[0025] The SOC (State Of Charge) of the battery 5 that is charged and discharged as described above is monitored by the power generation control device 6, and control is performed to avoid excessive charging / discharging of the battery 5.

[0026] The shipboard load 3 that is supplied with alternating current power from the power bus 2 can include lighting or an air conditioning system of a residential device in the ship, or a motor that rotationally drives a propeller that generates propulsive force in a hybrid ship or an electric ship. The hybrid ship can be either a series type in which the engine section 41, the power generation section 42 (including the battery 5), the motor, and the propeller are connected in series, or a parallel type in which the engine section 41 is able to directly rotationally drive the propeller, and a motor that is able to rotationally drive the propeller by power generated by the power generation section 42 based on the rotational power of the engine section 41 is provided in parallel.

[0027] The power generation control device 6 has a calculation section 61, a change section 62, a determination section 63, a power generation control section 64, a loss acquisition section 65, a power measurement section 66, and a power comparison section 67. These functional modules can be realized by the cooperation of hardware resources such as a central arithmetic processing device, a memory, an input device, an output device, and peripheral equipment connected to a computer, and software executed by them. Irrespective of the kind and the installation site of the computer, each of the above-described functional modules can be realized by the hardware resources of a single computer, or can be realized by combining the hardware resources distributed among a plurality of computers. In particular, in the present embodiment, part or all of the functional modules of the power generation control device 6 can be realized by a computer in the ship, or can be realized by a computer outside the ship capable of communicating with the computer in the ship.

[0028] The calculation section 61 calculates the fuel consumption per unit generated energy of the diesel generator 4. The fuel consumption per unit generated energy F [g / kWh] is also called the specific fuel consumption or the fuel efficiency, and is expressed as F = W / E if the measured fuel consumption of the diesel generator 4 is set as W [g] and the measured generated energy is set as E [kWh]. The smaller the fuel consumption per unit generated energy F, the better the specific fuel consumption or the fuel efficiency, and the larger the fuel consumption per unit generated energy F, the worse the specific fuel consumption or the fuel efficiency.

[0029] The change section 62 changes the operation condition of the diesel generator 4 in such a manner that the output of the diesel generator 4 changes. Here, the output P [kW] of the diesel generator 4 is determined by the torque T [Nm] and the rotational speed N [rpm] of the engine section 41, and is expressed as P = 2πTN / 60 / 1000. Thus, the set (T, N) of the torque T and the rotational speed N of the engine section 41 determines the operation condition of the diesel generator 4, and when the change section 62 changes at least either one of the torque T and the rotational speed N of the operation condition, the output P of the diesel generator 4 changes in accordance with the above-described equation. Further, since the case where the on-ship load 3 supplied with alternating current from the power bus 2 can operate only by alternating current of a fixed frequency (for example, 60 Hz) is many, it is preferable that the engine section 41 generate alternating current of a fixed frequency in accordance with the requirement of the on-ship load 3 by keeping the rotational speed N of the engine section 41 fixed. In this case, the rotational speed N of the engine section 41 is kept fixed, and thus the output P of the diesel generator 4 changes in accordance with the change in the torque T of the engine section 41. Hereinafter, the output P [kW] of the diesel generator 4 is sometimes expressed by the ratio P / P max [kW] of the rated output or the maximum output P max [%] of the diesel generator 4.

[0030] The determination section 63 determines the fuel consumption per unit generated energy F calculated by the calculation section 61 under the operation condition changed by the change section 62before The fuel consumption F per unit of energy generated, calculated by the calculation unit 61 under the changed operating conditions. after The operating conditions for the component with lower fuel consumption are determined by comparing the operating conditions. The power generation control unit 64 operates the diesel generator 4 based on the operating condition with lower fuel consumption determined by the determination unit 63. Thus, in this embodiment, the modification unit 62 changes the operating conditions of the diesel generator 4, the determination unit 63 determines the operating condition with lower fuel consumption F per unit of generated energy, and the power generation control unit 64 operates the diesel generator 4 based on this operating condition, thereby reducing fuel consumption during power generation.

[0031] Figure 2 This example illustrates the relationship between fuel consumption [g / kWh] (fuel consumption per unit of energy generated) and output [%] in diesel generator 4. For example... Figure 2 As shown in (A), the output P of diesel generator 4 is higher than the rated output P. max In the approximately 60% low-output region, fuel consumption per unit of energy generated is high and fuel efficiency is poor. The output P of diesel generator 4 is lower than its rated output P. max The high-output range of approximately 60% enables high fuel efficiency, but as shown in its magnified diagram... Figure 2 As shown in (B), even in the high-output region, there exists a minimum fuel consumption (F). min The optimal output of the diesel generator 4 is determined (85% in the illustrated example). In this embodiment, the aim is to efficiently determine this optimal output (85%) so that the diesel generator 4 operates with minimal fuel consumption (F). min To perform an action.

[0032] Figure 3 An example of the method for determining the optimal output of the power generation control device 6 is illustrated schematically. In this example, the change unit 62 gradually changes the operating conditions of the diesel generator 4 (specifically the torque T of the engine unit 41) in each of several periods (A) to (E) to change the output. The calculation unit 61 calculates the fuel consumption (fuel consumption per unit of generated energy) under each operating condition changed sequentially by the change unit 62. In the first period (A), the change unit 62 changes to the first operating condition, resulting in the diesel generator 4 displaying a first output P1, and the calculation unit 61 calculates the first fuel consumption F1. In the following second period (B), the change unit 62 changes from the first operating condition to the second operating condition, resulting in the diesel generator 4 displaying a second output P2 that is greater than the first output P1, and the calculation unit 61 calculates the second fuel consumption F2 that is less than the first fuel consumption F1.

[0033] As the transition from the first period (A) to the second period (B) occurs, the output of the diesel generator 4 increases from P1 to P2. However, by increasing the current command or charging command from the generator control unit 64 to the AC / DC converter 51, the excess power generated by the increased output is charged into the battery 5. This excess power, after being charged into the battery 5, is not supplied to the ship's load 3, therefore... Figure 3 The power supply to the ship's load 3 is kept approximately constant during the process. This minimizes variations in the state of the ship's load 3, resulting in the generator control unit 6 being able to accurately determine the minimum fuel consumption (F) of the diesel generator 4 with minimal impact from the ship's load 3. min The optimal output (85%). Furthermore, as a result of the increased current command or charging command during the second period (B), the rate of increase (slope of the straight line) of the battery 5's SOC (State of Charge) is greater than that of the first period (A). Additionally, as mentioned above, in order to maintain a fixed frequency (60Hz) for the AC power generated by the diesel generator 4, the engine speed N of the engine section 41 is kept constant. In this case, Figure 3 The change in the output of the diesel generator 4 is mainly caused by the change in the torque T (operating condition) of the engine section 41.

[0034] In the second period (B), the change unit 62 increases the output of the diesel generator 4, resulting in a decrease in fuel consumption calculated by the calculation unit 61 (improved fuel efficiency). Therefore, in the following third period (C), the change unit 62 further increases the output of the diesel generator 4 to further improve fuel efficiency. Specifically, in the third period (C), the change unit 62 changes from the second operating condition to the third operating condition. As a result, the diesel generator 4 exhibits a third output P3 that is greater than the second output P2, and the calculation unit 61 calculates a third fuel consumption F3 that is less than the second fuel consumption F2. At this time, similarly to the second period (B), along with the increase in output from P2 to P3, the current command or charging command from the generator control unit 64 to the AC / DC converter 51 increases, and more excess power is charged into the battery 5. Therefore, the rate of increase in the SOC of the battery 5 also becomes greater than in the second period (B).

[0035] As a result of the change section 62 increasing the output of the diesel generator 4 during the third period (C), the fuel consumption calculated by the calculation section 61 decreases (fuel efficiency improves), so during the next fourth period (D) the change section 62 further increases the output of the diesel generator 4 in the hope of further improving the fuel efficiency. Specifically, as a result of the change section 62 changing from the third action condition to a fourth action condition during the fourth period (D), the diesel generator 4 exhibits a fourth output P4 that is greater than the third output P3. However, unlike the second period (B) and the third period (C), the calculation section 61 calculates that the fourth fuel consumption F4 is greater than the third fuel consumption F3 (fuel efficiency is worse).

[0036] Through the above procedure, the determination section 63 recognizes that even if the output of the diesel generator 4 is set to be greater than the third output P3, the fuel efficiency will not improve any more. Therefore, the determination section 63 determines the third action condition during the third period (C) in which the least fuel consumption F3 was obtained as the action condition that should be used in future such operation of the diesel generator 4. The power generation control section 64 causes the diesel generator 4 to operate during the operation period after the fifth period (E) at the optimal output (85%) that achieves the least fuel consumption (F min ) determined by the determination section 63.

[0037] In the above example, the optimal output of the diesel generator 4 is a fixed value (85%), but it is also conceivable that it varies depending on the diesel generator 4 itself, the placement situation of the ship. Specifically, depending on differences in the temperature of the engine section 41, the type or state of the fuel within the engine section 41, the state of the fuel injection nozzle in the engine section 41, and the like, the optimal output of the diesel generator 4 can vary. Depending on the type of fuel, the optimal output of the diesel generator 4 can vary. For example, if the fuel is changed from heavy oil to light oil, the optimal output of the diesel generator 4 can increase. In this case, the procedure shown above can efficiently determine the optimal output for achieving the least fuel consumption even in the case where the optimal output of the diesel generator 4 has changed. In addition, in the above example, the optimal output of the diesel generator 4 is determined by the determination section 63 based on the fuel consumption calculated by the calculation section 61, but the optimal output of the diesel generator 4 can also be determined by the determination section 63 based on the fuel consumption calculated by the calculation section 61 and the fuel consumption calculated by the calculation section 61 during the second period (B). Figure 3 Figure 2 ​As also schematically shown in (B) in FIG. 6, the optimal output of the period (C) that becomes the minimum fuel consumption can be explored while gradually increasing the output of the diesel generator 4 in the periods (A) to (D), but it can also be the opposite, that is, the optimal output of the period (C) that becomes the minimum fuel consumption can be explored while gradually decreasing the output of the diesel generator 4 from around 90% to 95%. In the case of exploration while decreasing the output of the diesel generator 4, it is also conceivable to supply the insufficient power for the on-board load 3 with the power accumulated in the battery 5. Therefore, it is preferable that the change of the operation condition or the output by the change portion 62 be performed only in the case where the SOC indicating the charge amount of the battery 5 is equal to or more than a prescribed value, that is, in the case where there is a discharge margin. On the contrary, in the case of exploration while increasing the output of the diesel generator 4, the surplus power is charged into the battery 5, and therefore it is preferable that the change of the operation condition or the output by the change portion 62 be performed only in the case where the SOC indicating the charge amount of the battery 5 is equal to or less than a prescribed value, that is, in the case where there is a charge margin.

[0038] Figure 3 Such exploration of the optimal output with the change of the operation condition by the change portion 62 need not be performed all the time, and it is preferable to be performed when the output of the diesel generator 4, the placement condition of the ship, or other operation conditions change greatly. For example, in the case where fuel is supplied to the ship, depending on the difference between the existing fuel and the supplied fuel, there is a possibility that the optimal output that becomes the minimum fuel consumption changes greatly, and therefore the exploration of the optimal output with the change of the operation condition by the change portion 62 is performed. In addition, the change portion 62 can change the operation condition of the diesel generator 4 according to the change of the current position of the ship. For example, when the ship enters or exits a harbor, a near sea, an open sea, or the like, the operation condition of the diesel generator 4 can change greatly, and therefore the exploration of the optimal output with the change of the operation condition by the change portion 62 is performed. In addition, in the case where a plurality of diesel generators 4 are provided in the ship and the plurality of diesel generators 4 are sequentially switched for use, the optimal output that becomes the minimum fuel consumption can be different for each of the diesel generators 4, and therefore the exploration of the optimal output with the change of the operation condition by the change portion 62 is performed for the diesel generator 4 after the switching. Furthermore, the exploration of the optimal output can be periodically performed every fixed period.

[0039] Furthermore, it is preferable that the exploration of the optimal output be performed Figure 3In the search process of the optimum output with the change of the operation condition by the change unit 62, the amount of change of the operation condition of the diesel generator 4, i.e., the amount of change of at least either one of the number of revolutions N and the torque T of the engine unit 41, is determined in accordance with at least either one of the temperature of the engine unit 41, the type of fuel supplied to the engine unit 41, and the state of the fuel injection nozzle in the engine unit 41. For example, in the case where the temperature of the engine unit 41 is higher than the normal temperature, the fuel consumption amount is likely to greatly change even if the operation condition is slightly different, and therefore it is preferable that the change unit 62 set the amount of change of the operation condition small for each period.

[0040] Figure 4 is a flowchart showing the determination process of the optimum output by the power generation control device 6. In the explanation of the flowchart, "S" indicates a step. In S20 to S22, it is determined whether or not to execute the search process of the optimum output. In S20, it is determined whether or not fuel is supplied to the ship, in S21, it is determined whether or not the current position of the ship has greatly changed, and in S22, it is determined whether or not the diesel generator 4 is switched. In the case where it is determined "Yes" in any one of these steps, the process proceeds to S23, and the search process of the optimum output of S24 to S31 with the change of the operation condition by the change unit 62 is executed. In the case where it is determined "No" in all of these steps, the search process of the optimum output is not executed and the process is ended. Further, it is also possible not to provide the steps S20 to S22, to provide any one of the steps S20 to S22, or to provide any combination of the steps S20 to S22.

[0041] In S24, the change unit 62 sets the operation condition of the diesel generator 4 to the first operation condition. In S25, the calculation unit 61 calculates the first fuel consumption amount Fl under the first operation condition. In S26, the change unit 62 sets the operation condition of the diesel generator 4 to the second operation condition (N is a natural number of 2 or more). Here, it is assumed that the operation condition is changed by the change unit 62 in such a manner that the output of the diesel generator 4 is increased, as in the example of Figure 3 In S27, the calculation unit 61 calculates the second fuel consumption amount F2 under the second operation condition. In S28, the first fuel consumption amount Fl is compared with the second fuel consumption amount F2. In the case where the second fuel consumption amount F2 is less than the first fuel consumption amount Fl, as in the example of Figure 3 In S27, the calculation unit 61 calculates the second fuel consumption amount F2 under the second operation condition. In S28, the first fuel consumption amount Fl is compared with the second fuel consumption amount F2. In the case where the second fuel consumption amount F2 is less than the first fuel consumption amount Fl, as in the example of

[0042] Hereinafter, the process of S26 to S29 is repeatedly performed until the (N-1)th fuel consumption amount F N-1 becomes the Nth fuel consumption amount F N The following is until the process of S30 is executed. In S30, it is determined whether or not the Nth fuel consumption amount F Figure 3In the example, when N=4, the third fuel consumption F3 becomes the fourth fuel consumption F4 or less in S28. Therefore, in the following S30, the determination unit 63 determines the third (N-1) operating condition that yields the minimum fuel consumption F3 as the operating condition to be used in future operation of the diesel generator 4. In S31, the power generation control unit 64 operates the diesel generator 4 according to the operating condition determined in S30.

[0043] In addition, Figure 3 or Figure 4 In the process of exploring the optimal output, the output of the diesel generator 4 is gradually increased (or decreased) to explore the optimal output where the fuel consumption is about to increase and the fuel consumption becomes minimal. However, the output of the diesel generator 4 can also be changed regularly or irregularly a specified number of times (e.g., 10 times) to determine the output of the diesel generator 4 when the fuel consumption becomes minimal as the optimal output.

[0044] The loss acquisition unit 65 acquires the remaining power of the battery 5 during charging and discharging, which exceeds the power required by the ship's load 3 from the power generated by the diesel generator 4. The loss acquisition unit 65 can acquire power from the battery 5 during charging and discharging, as described later. Figure 5 The table shown above obtains the charging and discharging losses of battery 5 corresponding to the output and fuel consumption of diesel generator 4. Alternatively, the charging and discharging losses of battery 5 can be calculated based on the current command from generator control unit 64 to AC / DC converter 51 and the state of charge (SOC) of battery 5. In the latter case, the current command from generator control unit 64 to AC / DC converter 51 represents the current that should flow through battery 5 during charging and discharging, and the state of charge (SOC) of battery 5 represents the current that actually flows through battery 5. Therefore, the current loss in battery 5 can be calculated by comparing them. Furthermore, the loss acquisition unit 65 can also calculate the charging and discharging losses of battery 5 based on a comparison of the AC power on the power bus 2 side of AC / DC converter 51 measured by power measurement unit 66 and the DC power on the battery 5 side. The power comparison unit 67 will be described later. Figure 6 In the power generation control process shown, the power generation of the diesel generator 4, the charging amount of the battery 5, and the power requirements of the ship's load 3 are compared.

[0045] In explanation Figure 6 Before the power generation control process, explain Figure 5 The table. Regarding "Output (Internal Load)", the rated output P is expressed in units of [%] and [kW]. max This refers to the output of a 1000kW diesel generator 4. For example, 85% of the output means an output of 850kW. "Fuel consumption" [g / kWh] represents the fuel consumption per unit of energy generated by the diesel generator 4, calculated by the calculation unit 61. Figure 2 andFigure 3 In the example, the fuel consumption is also the least at the output of 85%. That is, in this example, the optimal output of the diesel generator 4 at which the least fuel consumption (198.40 g / kWh) is achieved is also 85%. The "fuel usage amount [g / s]" is an amount of fuel usage per unit time obtained by converting the fuel consumption.

[0046] The "fuel usage amount when operating at an output of 85% [g / s]" indicates the fuel usage amount when the diesel generator 4 is operated at 85% of the optimal output for each value of the "output (shipboard load)". For example, the fuel usage amount when the diesel generator 4 is operated at 85% of the optimal output for the shipboard load 3 of 85% (850 kW) is the same as the left column, which is 46.84. On the other hand, the fuel usage amount when the diesel generator 4 is operated at 85% of the optimal output for the shipboard load 3 of 10% (100 kW) is 5.51, which is less than 15.09 of the left column. The 15.09 of the left column is the fuel usage amount when the diesel generator 4 is operated at 10% of the output equal to the shipboard load 3 of 10% (100 kW), but the fuel consumption is 543.30, which is worse than the least fuel consumption of 198.40, and thus the 15.09 of the left column is more than 5.51 when the diesel generator 4 is operated at the least fuel consumption. As such, there is a case where the fuel usage amount is reduced by operating the diesel generator 4 at the optimal output even if the shipboard load 3 (for example, 10%) is different from the optimal output (85%) of the diesel generator 4.

[0047] This reduction in the fuel usage amount is shown as "(A) fuel usage amount improvement portion [g / s]". In the case where the shipboard load 3 is 10%, 9.58, which is the difference between 15.09 at 10% output and 5.51 at 85% output, is the fuel usage amount improvement portion. On the other hand, in the case where the diesel generator 4 is operated at 85% of the optimal output for the shipboard load 3 of 10%, 75% of the difference becomes surplus power and is charged to the battery 5 via the AC / DC conversion section 51. A value obtained by converting a loss (which can be acquired by the loss acquisition section 65) generated in the battery 5 at the time of charging of this surplus power into the fuel usage amount is shown as "(B) fuel usage amount of loss portion [g / s]". Furthermore, the loss at the time of charging and discharging of the battery 5 is assumed to be 15% in this figure.

[0048] The fuel consumption amount of the loss portion when the in-ship load 3 is 10% is 6.20, which is lower than the fuel consumption amount improvement portion of 9.58 in the left column, and therefore, when the in-ship load 3 is 10%, the fuel consumption amount or the oil consumption amount can be minimized by operating the diesel generator 4 at the optimum output of 85%. In contrast, when the in-ship load 3 is 50% to 80%, the "(B) fuel consumption amount of the loss portion" is higher than the "(A) fuel consumption amount improvement portion". Therefore, even if the diesel generator 4 is operated at the optimum output of 85%, the oil consumption amount deteriorates due to the loss of the battery 5 at the time of charging. In this case, the fuel consumption amount or the oil consumption amount can be minimized by operating the diesel generator 4 not at the optimum output of 85% but at the output equivalent to the in-ship load 3 (50% to 80%).

[0049] Figure 6 is a flowchart showing the power generation control processing of the power generation control device 6. In the explanation of the flowchart, "S" indicates a step. In S1, the power comparison section 67 compares the SOC (state of charge) of the battery 5 with the full charge judgment threshold value A. The full charge judgment threshold value A is a threshold value for judging whether the battery 5 is in a charged state close to full charge. In the case where the SOC of the battery 5 is larger than the full charge judgment threshold value A (S1: No), it is assumed that the battery 5 is in a full charged state and proceeds to S13. In the case where the SOC of the battery 5 is the full charge judgment threshold value A or less (S1: Yes), it is assumed that the battery 5 is not in a full charged state and proceeds to S2.

[0050] In S2, the power comparison section 67 compares the SOC of the battery 5 with the full discharge judgment threshold value B. The full discharge judgment threshold value B is a threshold value for judging whether the battery 5 is in a charged state close to full discharge. In the case where the SOC of the battery 5 is smaller than the full discharge judgment threshold value B (S2: No), it is assumed that the battery 5 is in a full discharged state and proceeds to S10. In the case where the SOC of the battery 5 is the full discharge judgment threshold value B or more (S2: Yes), it is assumed that the battery 5 is not in a full discharged state and proceeds to S3.

[0051] In S3, the power comparison section 67 compares the SOC of the battery 5 with the charge / discharge judgment threshold value C. The charge / discharge judgment threshold value C is a threshold value for judging which of the charging and discharging of the battery 5 is to be given priority in the subsequent processing, and is smaller than the full charge judgment threshold value A and larger than the full discharge judgment threshold value B. In the case where the SOC of the battery 5 is larger than the charge / discharge judgment threshold value C (S3: No), it is assumed that the discharging of the battery 5 should be given priority and proceeds to S8. In the case where the SOC of the battery 5 is the charge / discharge judgment threshold value C or less (S3: Yes), it is assumed that the charging of the battery 5 should be given priority and proceeds to S4.

[0052] In S4, it is judged whether the battery 5 can be charged. Specifically, the charging of the battery 5 is judged based on the SOC of the battery 5 and the state of the in-ship load 3. In the case where the battery 5 can be charged (S4: Yes), it proceeds to S5. In the case where the battery 5 cannot be charged (S4: No), it proceeds to S6.Figure 5 The fuel consumption amount α, which is equivalent to the fuel consumption amount of "(B) loss portion" and is equivalent to the fuel consumption amount during charging of battery 5, is the same as... Figure 5 The section on "(A) Fuel Consumption Improvement" compares the fuel savings β generated based on optimal output (85%). Fuel loss α is expressed as "(P... B -P L )×(1-η PC )×F min Fuel savings β are represented as “P”. L ×(F n -F min ")". Here, P B It is the best output ( Figure 5 (850kW in the middle), P L The ship's internal load 3 requires electricity, η PC It is the efficiency of the AC / DC converter 51, F min It is the lowest fuel consumption ( Figure 5 (198.40 g / kWh), F n This is the current fuel consumption.

[0053] When the fuel loss α is less than the fuel saving β (S4: "No"), by making the diesel generator 4 operate at its optimal output P B The system operates to achieve fuel savings exceeding the charging loss of battery 5. Therefore, charging of battery 5 is performed in S11, and in S12, diesel generator 4 (DG) operates at its optimal output P. B Or minimum fuel consumption F min Operation. Thus, when the fuel saving amount β is higher than the fuel loss amount α, the power generation control unit 64 changes the operating conditions of the diesel generator 4 to the optimal output P in S12. B In step S11, the remaining power generated by the diesel generator 4 is charged into the battery 5. Furthermore, in step S11, the power generation control unit 64 determines the current supplied to the battery 5 within a range where the frequency of the AC power in the power bus 2 will not change significantly, thereby generating a current command for the AC / DC converter 51.

[0054] When the fuel consumption α is greater than the fuel saving β (S4: "Yes"), the charging loss of battery 5 will be higher than that of diesel generator 4 at optimal output P. B The fuel-saving effect produced by operation means that battery 5 is not charged but enters S5. Thus, although in S12, the operating conditions of diesel generator 4 are changed to the optimal output P in modification section 62. BThe current fuel consumption per unit of generated energy calculated by the calculation section 61 under the current operation condition before the change is more than the minimum fuel consumption per unit of generated energy calculated by the calculation section 61 under the optimal operation condition after the change, but the fuel loss amount a equivalent to the loss of the battery 5 acquired by the loss acquisition section 65 is higher than the fuel saving amount β obtained by subtracting the minimum fuel consumption from the current fuel consumption, in which case the power generation control section 64 does not change from the current operation condition to the optimal operation condition.

[0055] In S5, it is determined whether or not the battery 5 can be discharged. Specifically, the current fuel consumption γ is compared with the fuel consumption δ required when charging the electric power to be discharged from the battery 5. The current fuel consumption γ is expressed as "F n x P L ", and the fuel consumption δ at the time of charging is expressed as "P L x F ave / η PC ". Here, F ave is the average fuel consumption of the diesel generator 4 at the time of charging.

[0056] In the case where the current fuel consumption γ is equal to or greater than the fuel consumption δ at the time of charging (S5: "No"), a fuel saving effect is obtained by discharging the battery 5, so S14 for discharging is entered. In the case where the current fuel consumption γ is less than the fuel consumption δ at the time of charging (S5: "Yes"), the battery 5 is not discharged, and only the required electric power of the shipboard load 3 is supplied by the diesel generator 4, so that the fuel consumption can be more suppressed, and therefore the charging and discharging of the battery 5 is not performed in S6, and the diesel generator 4 is operated with the current output or fuel consumption F n in S7. In this way, in the case where the operation condition of the diesel generator 4 is not changed in S7, the power generation control section 64 does not perform the charging and discharging of the battery 5 in S6.

[0057] In S8 branched from S3 in the case where the discharging of the battery 5 should be given priority (SOC > C), it can be determined whether or not the battery 5 can be discharged based on the comparison of the current fuel consumption γ with the fuel consumption δ at the time of charging, as in S5. In the case where the current fuel consumption γ is equal to or greater than the fuel consumption δ at the time of charging (S8: "No"), a fuel saving effect can be obtained by discharging the battery 5, so S14 for discharging is entered. In the case where the current fuel consumption γ is less than the fuel consumption δ at the time of charging (S8: "Yes"), the battery 5 is not discharged, and the fuel consumption can be more suppressed, so the battery 5 is not discharged but is entered into S9.

[0058] In S9, similar to S4, it is determined whether the battery 5 can be charged by comparing the fuel loss amount α equivalent to the loss during charging of the same battery 5 with the fuel savings amount β based on the optimal output. When the fuel loss amount α is less than or equal to the fuel savings amount β (S9: "No"), by operating the diesel generator 4 at the optimal output P B operation, a fuel savings effect higher than the charging loss of the battery 5 can be obtained. Therefore, in S11, the charging of the battery 5 is performed, and in S12, the diesel generator 4 operates at the optimal output P<000004o>or the minimum fuel consumption F min operation. When the fuel loss amount α is greater than the fuel savings amount β (S9: "Yes"), the charging loss of the battery 5 will be higher than the fuel savings effect generated by operating the diesel generator 4 at the optimal output P B operation. Therefore, the battery 5 is not charged and proceeds to S6.

[0059] In S10 branched from S2 when the battery 5 is in a fully discharged state (SOC < B), similar to S4, it is determined whether the battery 5 can be charged by comparing the fuel loss amount α equivalent to the loss during charging of the same battery 5 with the fuel savings amount β based on the optimal output. When the fuel loss amount α is less than or equal to the fuel savings amount β (S10: "No"), by operating the diesel generator 4 at the optimal output P B operation, a fuel savings effect higher than the charging loss of the battery 5 can be obtained. Therefore, in S11, the charging of the battery 5 is performed, and in S12, the diesel generator 4 operates at the optimal output P B or the minimum fuel consumption F min operation. When the fuel loss amount α is greater than the fuel savings amount β (S10: "Yes"), the charging loss of the battery 5 will be higher than the fuel savings effect generated by operating the diesel generator 4 at the optimal output P B operation. Therefore, the battery 5 is not charged and proceeds to S6.

[0060] In S13 branched from S1 when the battery 5 is in a fully charged state (SOC > A), similar to S5, it is determined whether the battery 5 can be discharged by comparing the current fuel consumption γ with the fuel consumption δ during charging. When the current fuel consumption γ is greater than or equal to the fuel consumption δ during charging (S13: "No"), a fuel savings effect can be obtained by discharging the battery 5, so it proceeds to S14 for discharging. When the current fuel consumption γ is less than the fuel consumption δ during charging (S13: "Yes"), the fuel consumption can be more suppressed without discharging the battery 5. Therefore, the battery 5 does not discharge and proceeds to S6.

[0061] In S14 for the discharge process of the battery 5, the maximum output P of the battery 5 is compared by the power comparison unit 67 cThe power requirement P for the ship's internal load 3 L Comparison. At the maximum output P of battery 5. c The power required for load 3 inside the ship P L In the above case (S14: "No"), the required power P for the ship's load 3 can be provided solely by battery 5. L Therefore, battery 5 is discharged in S18, and diesel generator 4 is stopped in S19. Thus, the charge or discharge capacity P of battery 5 is... c The power required for load 3 inside the ship P L In the above situation, the power generation control unit 64 stops the diesel generator 4 to supply power from the battery 5 to the ship's load 3. At the maximum output P of the battery 5... c The power required P is greater than the load 3 inside the ship. L In the case of a small load (S14: "Yes"), it is not possible to provide the required power P for the ship's load 3 solely through battery 5. L Therefore, diesel generator 4 does not stop but enters S15.

[0062] In S15, the power comparison unit 67 calculates the required power P of the ship's load 3. L With the optimal output P of diesel generator 4 B Comparison. The required power P for load 3 inside the ship. L For the optimal output P of diesel generator 4 B In the following case (S15: "No"), the required power P for the ship's load 3 can be provided solely by the diesel generator 4. L Therefore, charging and discharging of battery 5 is not performed in S6, and in S7, the current fuel consumption F is used. n Or minimum fuel consumption F min Start diesel generator 4. The ship's load 3 requires electricity P. L The best output P of the diesel generator 4 B In a major scenario (S15: "Yes"), it is impossible to provide the required power P for the ship's load 3 solely through the diesel generator 4. L Therefore, the battery 5 discharged in S16 and the battery output P in S17 are at optimal output. B The combination of operating diesel generator 4 and the power supply 3 onboard provides the necessary electricity P. L Thus, the power generation P of diesel generator 4 B The required power P is less than 3 times the internal load of the ship. L In this case, the power generation control unit 64 supplies the ship's load 3 with the optimal output P. B The diesel generator 4 is activated to generate electricity, which is then supplied to the load 3 inside the ship by charging the battery 5.

[0063] The present application has been described above based on the embodiments. It should be understood by those skilled in the art that the embodiments are illustrative, and various modifications of the combination of the respective elements, the respective processing procedures are possible, and the thus obtained modifications are also within the scope of the present application.

[0064] In the embodiments, the power generation control device 6 in the power supply system 1 for a ship is described, but the application target of the power generation control device of the present application is not limited to a ship. For example, the power generation control device of the present application can be applied to a power supply system of other transportation equipment such as a vehicle, an airplane, and the like.

[0065] Further, the functional configuration of each device described in the embodiments can be realized by a hardware resource or a software resource, or a cooperation of a hardware resource and a software resource. As the hardware resource, a processor, a ROM, a RAM, other LSIs can be utilized. As the software resource, an operating system, an application program, and the like can be utilized.

[0066] The distributed arrangement of the plurality of functions in the embodiments disclosed in the present specification can also be an integrated arrangement of a part or all of the plurality of functions, and vice versa. Whether the functions are integrated or distributed, as long as it is configured to achieve the object of the present application.

[0067] Explanation of Reference Signs

[0068] 1: power supply system; 2: power bus; 3: in-ship load; 4: diesel generator; 5: battery; 6: power generation control device; 41: engine section; 42: power generation section; 51: AC / DC conversion section; 61: calculation section; 62: change section; 63: determination section; 64: power generation control section; 65: loss acquisition section; 66: power measurement section; 67: power comparison section.

Claims

1. A power generation control device, comprising: a calculation section that calculates a fuel consumption amount per unit generated energy of a generator that has an engine section that outputs rotational power through combustion of fuel that is input, and a power generation section that converts the rotational power into electric power; a change section that changes an operation condition of the generator in such a manner that an output of the generator changes; a determination section that compares the fuel consumption amount per unit generated energy calculated by the calculation section under the operation condition before the change with the fuel consumption amount per unit generated energy calculated by the calculation section under the operation condition after the change, and determines the operation condition of the one of which the fuel consumption amount is less; and a power generation control section that causes the generator to operate in the determined operation condition, wherein the power generation control device further comprises a battery that can be charged with the electric power generated by the generator, and can discharge to a power bus inside a ship, wherein the power generation control section controls charge and discharge of the battery so as to keep a rotational speed of the engine section fixed at the time when the operation condition is changed by the change section, and wherein the change section changes the operation condition of the generator in a case where a charge amount of the battery is a prescribed value or more.

2. The power generation control device according to claim 1, wherein the change section changes the operation condition of the generator to a third operation condition in such a manner that the output of the generator further changes from the second operation condition in a case where a first fuel consumption amount per unit generated energy calculated by the calculation section under the first operation condition is more than a second fuel consumption amount per unit generated energy calculated by the calculation section under the second operation condition at the time when the change section changes the operation condition of the generator from a first operation condition to a second operation condition, and wherein the determination section determines the second operation condition in a case where a third fuel consumption amount per unit generated energy calculated by the calculation section under the third operation condition is more than the second fuel consumption amount.

3. The power generation control device according to claim 1 or 2, wherein the change section changes the operation condition in such a manner that at least either one of a rotational speed and a torque of the engine section changes.

4. The power generation control device according to claim 3, wherein the change section decides a change amount of at least either one of the rotational speed and the torque of the engine section in accordance with at least either one of a temperature of the engine section, a kind of the fuel, and a state of a nozzle that injects the fuel in the engine section.

5. The power generation control device according to claim 1 or 2, wherein the generator is provided to the ship, and wherein the electric power generated by the generator is supplied to the power bus inside the ship.

6. A power generation control device, comprising: a calculation section that calculates a fuel consumption amount per unit generated energy of a generator that has an engine section that outputs rotational power through combustion of fuel that is input, and a power generation section that converts the rotational power into electric power; ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ a changing unit that changes an operation condition of the generator in a manner that causes the output of the generator to change; a determining unit that compares the fuel consumption per unit of generated energy calculated by the calculating unit under the operation condition before the change with the fuel consumption per unit of generated energy calculated by the calculating unit under the operation condition after the change, and determines the operation condition of the smaller one of the fuel consumptions; a power generation control unit that causes the generator to operate in the determined operation condition, wherein the generator is provided in a ship, power generated by the generator is supplied to a power bus in the ship, the changing unit changes the operation condition of the generator in a manner that causes the output of the generator to change in response to fuel being supplied to the ship.

7. A power generation control device, comprising: a calculating unit that calculates a fuel consumption per unit of generated energy of a generator that has an engine unit that outputs rotational power through combustion of fuel supplied and a power generation unit that converts the rotational power into electric power; a changing unit that changes an operation condition of the generator in a manner that causes the output of the generator to change; a determining unit that compares the fuel consumption per unit of generated energy calculated by the calculating unit under the operation condition before the change with the fuel consumption per unit of generated energy calculated by the calculating unit under the operation condition after the change, and determines the operation condition of the smaller one of the fuel consumptions; a power generation control unit that causes the generator to operate in the determined operation condition, wherein the generator is provided in a ship, power generated by the generator is supplied to a power bus in the ship, the changing unit changes the operation condition of the generator in a manner that causes the output of the generator to change in accordance with a change in a current position of the ship.

8. A power generation control device, comprising: a calculating unit that calculates a fuel consumption per unit of generated energy of a generator that has an engine unit that outputs rotational power through combustion of fuel supplied and a power generation unit that converts the rotational power into electric power; a changing unit that changes an operation condition of the generator in a manner that causes the output of the generator to change; a determining unit that compares the fuel consumption per unit of generated energy calculated by the calculating unit under the operation condition before the change with the fuel consumption per unit of generated energy calculated by the calculating unit under the operation condition after the change, and determines the operation condition of the smaller one of the fuel consumptions; a power generation control unit that causes the generator to operate in the determined operation condition, wherein the generator is provided in a ship, power generated by the generator is supplied to a power bus in the ship, the generator includes a first generator and a second generator, the changing unit changes the operation condition of the second generator in a manner that causes the output of the second generator to change in response to the generator that supplies electric power to the power bus being switched from the first generator to the second generator. ​ ​ ​ 9. A power generation control device, comprising: a calculation section that calculates a fuel consumption amount per unit generated energy of a generator that has an engine section that outputs rotational power through combustion of fuel that is supplied and a power generation section that converts the rotational power into electric power; a change section that changes an operation condition of the generator in such a manner that an output of the generator changes; a determination section that compares the fuel consumption amount per unit generated energy calculated by the calculation section under the operation condition before the change with the fuel consumption amount per unit generated energy calculated by the calculation section under the operation condition after the change, and determines the operation condition of the one of which the fuel consumption amount is less; a power generation control section that causes the generator to operate in the determined operation condition; a loss acquisition section that acquires a loss of at least either of a charging time and a discharging time of a battery that can be charged with a surplus electric power exceeding a required electric power of a load from the electric power generated by the generator, in a case where, although the operation condition of the generator is changed from a first operation condition to a second operation condition by the change section, a first fuel consumption amount per unit generated energy calculated by the calculation section under the first operation condition is more than a second fuel consumption amount per unit generated energy calculated by the calculation section under the second operation condition, and a fuel loss amount equivalent to the loss of the battery acquired by the loss acquisition section is higher than a fuel saving amount obtained by subtracting the second fuel consumption amount from the first fuel consumption amount, the power generation control section does not change from the first operation condition to the second operation condition.

10. The power generation control device according to claim 9, wherein the power generation control section does not perform at least either of charging and discharging of the battery when the generator is caused to operate in the first operation condition.

11. The power generation control device according to claim 9, wherein in a case where the fuel saving amount is higher than the fuel loss amount at the charging time of the battery, the power generation control section changes from the first operation condition to the second operation condition, and charges the surplus electric power generated by the generator to the battery.

12. The power generation control device according to claim 9, wherein the loss acquisition section calculates the loss in the battery on the basis of a current command that flows to the battery by the power generation control section and a charging rate of the battery.

13. The power generation control device according to claim 9, wherein further comprising a power measurement section that measures input alternating current power and output direct current power of a power conversion section that converts alternating current power generated by the generator into direct current power to supply to the battery, the loss acquisition section calculates the loss in the battery on the basis of the input alternating current power and the output direct current power.

14. A power generation control device, comprising: ​ a calculating section that calculates a fuel consumption amount per unit generated energy of a generator that has an engine section that outputs rotational power through combustion of input fuel and a power generation section that converts the rotational power into electric power; a changing section that changes an operation condition of the generator in a manner that causes a change in output of the generator; a determining section that compares the fuel consumption amount per unit generated energy calculated by the calculating section under the operation condition before the change with the fuel consumption amount per unit generated energy calculated by the calculating section under the operation condition after the change, and determines the operation condition of the one with the smaller fuel consumption amount; a power generation control section that causes the generator to operate in the determined operation condition; and a power comparison section that compares a charge amount of a battery that can be charged with electric power generated by the generator with required electric power of a load, in a case where the charge amount of the battery is equal to or greater than the required electric power of the load, the power generation control section stops the generator and supplies electric power of the battery to the load.

15. A power generation control device, comprising: a calculating section that calculates a fuel consumption amount per unit generated energy of a generator that has an engine section that outputs rotational power through combustion of input fuel and a power generation section that converts the rotational power into electric power; a changing section that changes an operation condition of the generator in a manner that causes a change in output of the generator; a determining section that compares the fuel consumption amount per unit generated energy calculated by the calculating section under the operation condition before the change with the fuel consumption amount per unit generated energy calculated by the calculating section under the operation condition after the change, and determines the operation condition of the one with the smaller fuel consumption amount; a power generation control section that causes the generator to operate in the determined operation condition; and a power comparison section that compares a generated electric power of the generator based on the operation condition determined by the determining section with required electric power of a load, in a case where the generated electric power of the generator based on the operation condition determined by the determining section is less than the required electric power of the load, the power generation control section causes the generator to operate in the operation condition and supplies generated electric power to the load, and supplies electric power that can be charged in a battery that can be charged with electric power generated by the generator to the load.

16. A power generation control method, comprising: a calculating step that calculates a fuel consumption amount per unit generated energy of a generator that has an engine section that outputs rotational power through combustion of input fuel and a power generation section that converts the rotational power into electric power; a changing step that changes an operation condition of the generator in a manner that causes a change in output of the generator; a determining step that compares the fuel consumption amount per unit generated energy calculated by the calculating step under the operation condition before the change with the fuel consumption amount per unit generated energy calculated by the calculating step under the operation condition after the change, and determines the operation condition of the one with the smaller fuel consumption amount; determining the operation condition of the generator in which the fuel consumption per unit of generated energy is smaller, by comparing the fuel consumption per unit of generated energy calculated by the calculating step under the operation condition before the change with the fuel consumption per unit of generated energy calculated by the calculating step under the operation condition after the change; and controlling the generator to operate in the determined operation condition, wherein the electric power generated by the generator is chargeable to a battery, and the battery is dischargeable to a power bus inside a ship, in the changing the operation condition, controlling the charge and discharge of the battery in the generating control step so that the rotation speed of the engine section is kept constant, in the case where the charge amount of the battery is equal to or more than a predetermined value, changing the operation condition of the generator in the changing step.

17. A power generation control method comprising: calculating the fuel consumption per unit of generated energy of a generator having an engine section that outputs rotational power through combustion of fuel input and a power generation section that converts the rotational power into electric power; changing the operation condition of the generator in such a manner that the output of the generator is changed; determining the operation condition of the generator in which the fuel consumption per unit of generated energy is smaller, by comparing the fuel consumption per unit of generated energy calculated by the calculating step under the operation condition before the change with the fuel consumption per unit of generated energy calculated by the calculating step under the operation condition after the change; and controlling the generator to operate in the determined operation condition, wherein the generator is provided to a ship, the electric power generated by the generator is supplied to a power bus inside the ship, in the changing step, the operation condition of the generator is changed in such a manner that the output of the generator is changed in response to the fact that fuel is replenished to the ship.

18. A power generation control method comprising: calculating the fuel consumption per unit of generated energy of a generator having an engine section that outputs rotational power through combustion of fuel input and a power generation section that converts the rotational power into electric power; changing the operation condition of the generator in such a manner that the output of the generator is changed; determining the operation condition of the generator in which the fuel consumption per unit of generated energy is smaller, by comparing the fuel consumption per unit of generated energy calculated by the calculating step under the operation condition before the change with the fuel consumption per unit of generated energy calculated by the calculating step under the operation condition after the change; and controlling the generator to operate in the determined operation condition, wherein the generator is provided to a ship, the electric power generated by the generator is supplied to a power bus inside the ship, in the changing step, the operation condition of the generator is changed in such a manner that the output of the generator is changed in accordance with a change in the current position of the ship.

19. A power generation control method comprising: a calculating step of calculating a fuel consumption amount per unit of generated energy of a generator having an engine section that outputs rotational power through combustion of input fuel and a power generation section that converts the rotational power into electric power; a changing step of changing an operation condition of the generator in such a manner that an output of the generator is changed; a determining step of comparing the fuel consumption amount per unit of generated energy calculated by the calculating step under the operation condition before the change with the fuel consumption amount per unit of generated energy calculated by the calculating step under the operation condition after the change, and determining the operation condition of the smaller one of the fuel consumption amounts; a power generation control step of causing the generator to operate in the determined operation condition, wherein the generator is provided on a ship, electric power generated by the generator is supplied to a power bus in the ship, the generator includes a first generator and a second generator, in the changing step, in response to a change of the generator that supplies electric power to the power bus from the first generator to the second generator, the operation condition of the second generator is changed in such a manner that an output of the second generator is changed.

20. A power generation control method comprising: a calculating step of calculating a fuel consumption amount per unit of generated energy of a generator having an engine section that outputs rotational power through combustion of input fuel and a power generation section that converts the rotational power into electric power; a changing step of changing an operation condition of the generator in such a manner that an output of the generator is changed; a determining step of comparing the fuel consumption amount per unit of generated energy calculated by the calculating step under the operation condition before the change with the fuel consumption amount per unit of generated energy calculated by the calculating step under the operation condition after the change, and determining the operation condition of the smaller one of the fuel consumption amounts; a power generation control step of causing the generator to operate in the determined operation condition, the power generation control method further comprising: a loss acquisition step of acquiring a loss of at least either of a charging time and a discharging time of a battery that can charge a surplus of electric power exceeding a required electric power of a load out of electric power generated by the generator, in a case where a first fuel consumption amount per unit of generated energy calculated by the calculating step under a first operation condition is larger than a second fuel consumption amount per unit of generated energy calculated by the calculating step under a second operation condition, but a fuel loss amount equivalent to the loss of the battery acquired by the loss acquisition step is higher than a fuel saving amount obtained by subtracting the second fuel consumption amount from the first fuel consumption amount, in a case where the operation condition of the generator is changed from the first operation condition to the second operation condition in the changing step, in the power generation control step, the operation condition is not changed from the first operation condition to the second operation condition.

21. A power generation control method comprising: ​ ​ a calculating step of calculating a fuel consumption amount per unit of generated energy of a generator having an engine section that outputs rotational power by combustion of fuel input and a power generation section that converts the rotational power into electric power; a changing step of changing an operation condition of the generator in such a manner that the output of the generator is changed; a determining step of comparing the fuel consumption amount per unit of generated energy calculated by the calculating step under the operation condition before the change with the fuel consumption amount per unit of generated energy calculated by the calculating step under the operation condition after the change, and determining the operation condition of the smaller one of the fuel consumption amounts; a power generation control step of causing the generator to operate in the determined operation condition, the power generation control method further comprising: a power comparison step of comparing a charge amount of a battery that can be charged with electric power generated by the generator with required electric power of a load, in a case where the charge amount of the battery is equal to or greater than the required electric power of the load, in the power generation control step, causing the generator to stop and causing the electric power of the battery to be supplied to the load.

22. A power generation control method comprising: a calculating step of calculating a fuel consumption amount per unit of generated energy of a generator having an engine section that outputs rotational power by combustion of fuel input and a power generation section that converts the rotational power into electric power; a changing step of changing an operation condition of the generator in such a manner that the output of the generator is changed; a determining step of comparing the fuel consumption amount per unit of generated energy calculated by the calculating step under the operation condition before the change with the fuel consumption amount per unit of generated energy calculated by the calculating step under the operation condition after the change, and determining the operation condition of the smaller one of the fuel consumption amounts; a power generation control step of causing the generator to operate in the determined operation condition, the power generation control method further comprising: a power comparison step of comparing a charge amount of a battery that can be charged with electric power generated by the generator with required electric power of a load, in a case where the charge amount of the battery is equal to or greater than the required electric power of the load, in the power generation control step, causing the generator to stop and causing the electric power of the battery to be supplied to the load.

23. A storage medium storing a power generation control program that causes a computer to execute the following steps: a calculating step of calculating a fuel consumption amount per unit of generated energy of a generator having an engine section that outputs rotational power by combustion of fuel input and a power generation section that converts the rotational power into electric power; a changing step of changing an operation condition of the generator in such a manner that the output of the generator is changed; a determining step of comparing the fuel consumption amount per unit of generated energy calculated by the calculating step under the operation condition before the change with the fuel consumption amount per unit of generated energy calculated by the calculating step under the operation condition after the change, and determining the operation condition of the smaller one of the fuel consumption amounts; ​ determining the operation condition of the smaller one of the fuel consumption per unit of generated energy calculated by the calculating step under the operation condition before the change and the fuel consumption per unit of generated energy calculated by the calculating step under the operation condition after the change; and controlling the generator to operate in the determined operation condition, wherein the electric power generated by the generator is chargeable to a battery, and the battery is dischargeable to a power bus inside a ship, when the operation condition is changed, controlling the charge and discharge of the battery in the power generation control step so that the rotation speed of the engine section is kept constant, when the charge amount of the battery is equal to or more than a predetermined value, changing the operation condition of the generator in the changing step.

24. A storage medium storing a power generation control program that causes a computer to execute the steps of: calculating a fuel consumption per unit of generated energy of a generator having an engine section that outputs rotational power through combustion of fuel input and a power generation section that converts the rotational power into electric power; changing an operation condition of the generator in such a manner that the output of the generator is changed; determining the operation condition of the smaller one of the fuel consumption per unit of generated energy calculated by the calculating step under the operation condition before the change and the fuel consumption per unit of generated energy calculated by the calculating step under the operation condition after the change; and controlling the generator to operate in the determined operation condition, wherein the generator is provided to a ship, the electric power generated by the generator is supplied to a power bus inside the ship, in the changing step, the operation condition of the generator is changed in such a manner that the output of the generator is changed in response to fuel being replenished to the ship.

25. A storage medium storing a power generation control program that causes a computer to execute the steps of: calculating a fuel consumption per unit of generated energy of a generator having an engine section that outputs rotational power through combustion of fuel input and a power generation section that converts the rotational power into electric power; changing an operation condition of the generator in such a manner that the output of the generator is changed; determining the operation condition of the smaller one of the fuel consumption per unit of generated energy calculated by the calculating step under the operation condition before the change and the fuel consumption per unit of generated energy calculated by the calculating step under the operation condition after the change; and controlling the generator to operate in the determined operation condition, wherein the generator is provided to a ship, the electric power generated by the generator is supplied to a power bus inside the ship, in the changing step, the operation condition of the generator is changed in such a manner that the output of the generator is changed in response to fuel being replenished to the ship. ​ ​ ​ ​ ​ ​ ​ ​ ​ In the changing step, the operating condition of the generator is changed in such a manner that the output of the generator is changed in accordance with a change in the current position of the ship.

26. A storage medium storing a power generation control program that causes a computer to execute the steps of: a calculating step of calculating a fuel consumption amount per unit of generated energy of a generator having an engine section that outputs rotational power through combustion of fuel that is input and a power generation section that converts the rotational power into electric power; a changing step of changing an operating condition of the generator in such a manner that the output of the generator is changed; a determining step of comparing the fuel consumption amount per unit of generated energy calculated by the calculating step under the operating condition before the change with the fuel consumption amount per unit of generated energy calculated by the calculating step under the operating condition after the change, and determining the operating condition of the smaller one of the fuel consumption amounts; and a power generation control step of causing the generator to operate in the determined operating condition, wherein the generator is provided to a ship, the electric power generated by the generator is supplied to a power bus in the ship, the generator includes a first generator and a second generator, in the changing step, in response to a switch of the generator that supplies electric power to the power bus from the first generator to the second generator, the operating condition of the second generator is changed in such a manner that the output of the second generator is changed.

27. A storage medium storing a power generation control program that causes a computer to execute the steps of: a calculating step of calculating a fuel consumption amount per unit of generated energy of a generator having an engine section that outputs rotational power through combustion of fuel that is input and a power generation section that converts the rotational power into electric power; a changing step of changing an operating condition of the generator in such a manner that the output of the generator is changed; a determining step of comparing the fuel consumption amount per unit of generated energy calculated by the calculating step under the operating condition before the change with the fuel consumption amount per unit of generated energy calculated by the calculating step under the operating condition after the change, and determining the operating condition of the smaller one of the fuel consumption amounts; and a power generation control step of causing the generator to operate in the determined operating condition, the power generation control program further causes the computer to execute the steps of: a loss acquisition step of acquiring a loss of at least either of a charging time and a discharging time of a battery that can charge a surplus of electric power exceeding a required electric power of a load from the electric power generated by the generator, In a case where a first fuel consumption amount per unit of generated energy calculated by the calculation step under the first operation condition is more than a second fuel consumption amount per unit of generated energy calculated by the calculation step under the second operation condition, but a fuel loss amount equivalent to the loss of the battery acquired by the loss acquisition step is higher than a fuel saving amount obtained by subtracting the second fuel consumption amount from the first fuel consumption amount, in the power generation control step, the first operation condition is not changed to the second operation condition.

28. A storage medium storing a power generation control program that causes a computer to execute the steps of: a calculation step of calculating a fuel consumption amount per unit of generated energy of a power generator having an engine section that outputs rotational power through combustion of an input fuel and a power generation section that converts the rotational power into electric power; a change step of changing an operation condition of the power generator in a manner that causes a change in output of the power generator; a determination step of comparing the fuel consumption amount per unit of generated energy calculated by the calculation step under the operation condition before the change with the fuel consumption amount per unit of generated energy calculated by the calculation step under the operation condition after the change, and determining the operation condition of the smaller one of the fuel consumption amounts; a power generation control step of causing the power generator to operate in the determined operation condition, the power generation control program further causes the computer to execute the steps of: a power comparison step of comparing a charge amount of a battery that can be charged with electric power generated by the power generator with a required power of a load, in a case where the charge amount of the battery is equal to or more than the required power of the load, in the power generation control step, the power generator is stopped and the electric power of the battery is supplied to the load.

29. A storage medium storing a power generation control program that causes a computer to execute the steps of: a calculation step of calculating a fuel consumption amount per unit of generated energy of a power generator having an engine section that outputs rotational power through combustion of an input fuel and a power generation section that converts the rotational power into electric power; a change step of changing an operation condition of the power generator in a manner that causes a change in output of the power generator; a determination step of comparing the fuel consumption amount per unit of generated energy calculated by the calculation step under the operation condition before the change with the fuel consumption amount per unit of generated energy calculated by the calculation step under the operation condition after the change, and determining the operation condition of the smaller one of the fuel consumption amounts; a power generation control step of causing the power generator to operate in the determined operation condition, the power generation control program further causes the computer to execute the steps of: a power comparison step of comparing a generation amount of the power generator based on the operation condition determined by the determination step with a required power of a load, in a case where the charge amount of the battery is equal to or more than the required power of the load, in the power generation control step, the power generator is stopped and the electric power of the battery is supplied to the load. ​ In a case where the power generation amount of the generator based on the operation condition determined by the determination step is less than the required power of the load, in the power generation control step, the generator is caused to operate in the operation condition and the generated power is caused to be supplied to the load, and the power that can be charged in a battery to which the power generated by the generator is charged is caused to be supplied to the load.

30. A computer program product comprising a computer program which, when executed by a processor, performs the power generation control method according to any one of claims 16-22.

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