Propulsion system, control program, and control method for hybrid propulsion ship

Abstract

The propulsion system is a propulsion system for a hybrid propulsion ship having a variable pitch propeller, an engine for controlling the rotational speed in accordance with a rotational speed command value, a motor generator, a power converter, and a controller for controlling the power converter, the controller including a processing circuit that acquires blade angle data of the variable pitch propeller and transmits the acquired blade angle data to the variable pitch propeller. When the rate of change in the blade angle of the variable pitch propeller is equal to or greater than a predetermined threshold value, a command value for adjusting the power received by the power converter from the motor generator or the power supplied from the power converter to the motor generator is generated, and the command value is output to the power converter.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a propulsion system of a hybrid propulsion ship, a control program, and a control method. BACKGROUND

[0002] A hybrid propulsion ship in which either of an engine and an electric motor generator can drive a propeller is known. As an engine for a ship, a gas engine that uses natural gas as a fuel or the like is used. Such an engine for a ship generally has a limit in coping with a drastic load variation. Therefore, in a ship in which an engine is used as a propulsive force, there is a ship in which a variable pitch propeller that can change a blade angle according to a blade angle command value is adopted as a propeller. In such a ship, by changing the blade angle of the variable pitch propeller while controlling the rotation speed of the engine to be constant, speed adjustment of the ship and switching between forward and reverse can be performed.

[0003] In a hybrid propulsion ship having a variable pitch propeller, changing the blade angle of the variable pitch propeller becomes one cause of a load variation of the engine. In Patent Literature 1 described below, in order to suppress the load variation of the engine, a method is proposed in which, according to whether a blade angle command value is changed in an increasing direction or a decreasing direction, a power generation electric power in a case where power generation is performed in the electric motor generator according to the power of the engine or a motor electric power for driving the electric motor generator according to the electric power from an accumulator connected to the electric motor generator is controlled.

[0004] PRIOR ART DOCUMENTS

[0005] PATENT LITERATURE

[0006] Patent Literature 1: Japanese Patent No. 6697218 SUMMARY

[0007] PROBLEMS TO BE SOLVED BY THE INVENTION

[0008] However, if such control is performed, the command value of the electric motor generator needs to be changed every time the blade angle is changed. As a result, in a case where the load variation of the engine is not large, it becomes excessive control. On the other hand, in a case where the load variation of the engine is large, it can also become insufficient control.

[0009] The present disclosure was completed in view of the above circumstances, and aims to provide a propulsion system of a hybrid propulsion ship, a control program, and a control method that can appropriately suppress a load variation of an engine.

[0010] MEANS FOR SOLVING THE PROBLEMS

[0011] The propulsion system of one embodiment of the present disclosure is a propulsion system of a hybrid propulsion ship having a variable-pitch propeller capable of changing a pitch angle according to a pitch angle command value, an engine mechanically connected to the variable-pitch propeller, controlling a rotation speed according to a rotation speed command value, a motor generator mechanically connected to the variable-pitch propeller, capable of transmitting power to the variable-pitch propeller and generating power using driving force of the engine, a power converter electrically connected to the motor generator, and a controller controlling the power converter, in which the controller includes a processing circuit that acquires pitch angle data of the variable-pitch propeller, generates a command value adjusting power received by the power converter from the motor generator or power supplied from the power converter to the motor generator, and outputs the command value to the power converter in a case where a change speed of the pitch angle of the variable-pitch propeller in a predetermined driving state is equal to or higher than a prescribed threshold value.

[0012] The control program of another embodiment of the present disclosure is a control program of a hybrid propulsion ship having a variable-pitch propeller capable of changing a pitch angle according to a pitch angle command value, an engine mechanically connected to the variable-pitch propeller, controlling a rotation speed according to a rotation speed command value, a motor generator mechanically connected to the variable-pitch propeller, capable of transmitting power to the variable-pitch propeller and generating power using driving force of the engine, a power converter electrically connected to the motor generator, and a controller controlling the power converter, in which the control program causes the controller to perform actions of acquiring pitch angle data of the variable-pitch propeller, and generating a command value adjusting power received by the power converter from the motor generator or power supplied from the power converter to the motor generator, and outputting the command value to the power converter in a case where a change speed of the pitch angle of the variable-pitch propeller in a predetermined driving state is equal to or higher than a prescribed threshold value.

[0013] Another aspect of the control method of the present disclosure is a control method of a hybrid propulsion vessel having a variable pitch propeller capable of changing a pitch angle according to a pitch angle command value, an engine mechanically connected to the variable pitch propeller and controlled in rotation speed according to a rotation speed command value, a motor generator mechanically connected to the variable pitch propeller and capable of transmitting power to the variable pitch propeller and generating power using driving force of the engine, a power converter electrically connected to the motor generator, and a controller that controls the power converter, wherein pitch angle data of the variable pitch propeller is acquired, in a case where a change speed of the pitch angle of the variable pitch propeller in a predetermined driving state is equal to or more than a prescribed threshold value, a command value that adjusts power received by the power converter from the motor generator or power supplied from the power converter to the motor generator is generated, and the command value is output to the power converter.

[0014] Effects of the Invention

[0015] According to the present disclosure, a load variation of the engine can be appropriately suppressed. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is a block diagram showing an outline structure of a propulsion system of a hybrid propulsion vessel of one embodiment of the present disclosure.

[0017] Figure 2 is a flowchart showing an example of the load variation suppression control in the present embodiment. Figure 1 is a graph showing a correspondence relationship of the pitch angle, the mechanical output, and the electric output in the first control mode of the propulsion system shown in

[0018] Figure 3 is a flowchart showing an example of the load variation suppression control in the present embodiment.

[0019] Figure 4 is a graph showing a correspondence relationship of the pitch angle, the mechanical output, and the electric output in the second control mode of the propulsion system shown in Figure 1 DETAILED DESCRIPTION

[0020] Hereinafter, one embodiment will be described in detail with reference to the drawings. Note that the same or similar elements are denoted by the same reference numerals throughout the drawings, and repeated description is omitted.

[0021] Figure 1 is a block diagram showing an outline structure of a propulsion system of a hybrid propulsion vessel of one embodiment of the present disclosure. The propulsion system 1 in the present embodiment has a variable pitch propeller 2, an engine 3, a motor generator 4, and a power conversion system 20. The variable pitch propeller 2 is configured to be capable of changing a pitch angle according to a pitch angle command value.​

[0022] The engine 3 is a gas engine that uses fuel containing fuel gas obtained by gasifying liquefied natural gas to generate driving force. In addition, the engine 3 can be a gas-only engine that burns only the fuel gas obtained by gasifying the liquefied natural gas, can be a dual fuel engine that can switch between the fuel gas and liquid fuel such as heavy oil to burn, or can be a diesel engine that uses liquid fuel as fuel.

[0023] The engine 3 and the motor generator 4 are mechanically connected to the variable pitch propeller 2 via a reduction gear 5. The motor generator 4 is electrically connected to a power conversion system 20. The power conversion system 20 includes a direct current wiring 6 and a first power converter 7. The first power converter 7 is interposed between the direct current wiring 6 and the motor generator 4. The motor generator 4 is capable of transmitting power to the variable pitch propeller 2 by generating power by electric power supplied via the direct current wiring 6. At this time, the first power converter 7 converts direct current voltage in the direct current wiring 6 into alternating current voltage and outputs to the motor generator 4. In addition, the motor generator 4 is also capable of generating power using driving force of the engine 3 and supplying electric power to the direct current wiring 6. At this time, the first power converter 7 converts alternating current voltage generated by the motor generator 4 into direct current voltage and outputs to the direct current wiring 6.

[0024] In addition, the power conversion system 20 includes a second power converter 8 and a third power converter 10. A storage battery 9 is connected to the direct current wiring 6 via the second power converter 8. The storage battery 9 is a secondary battery or a capacitor or the like. The second power converter 8 is a DC-DC converter that converts direct current voltage of the direct current wiring 6 into a prescribed direct current voltage. In addition, an alternating current wiring 11 is connected to the direct current wiring 6 via the third power converter 10. The third power converter 10 converts direct current voltage of the direct current wiring 6 into alternating current voltage and outputs to the alternating current wiring 11, and converts alternating current voltage of the alternating current wiring 11 into direct current voltage and outputs to the direct current wiring 6. An electric generator 12 and an alternating current onboard load 13 can be connected to the alternating current wiring 11. In addition, a direct current onboard load can be connected to the direct current wiring 6.

[0025] According to such a propulsion system 1, it is possible to harmoniously generate the propulsion force of the ship between the engine 3 as a mechanical propulsion unit and the motor generator 4 as an electrical propulsion unit. In addition, according to the propulsion system 1, it is possible to recover the remaining amount of the propulsion force generated by the engine 3 as electric power by the motor generator 4, and supply electric power to the onboard load 13 or accumulate in the storage battery 9.

[0026] The propulsion system 1 has a controller 14. The controller 14 has a processing circuit 15 that performs various signal processing. The processing circuit 15 has, for example, a microcontroller, a personal computer, a PLC (Programmable Logic Controller), or the like. More specifically, the processing circuit 15 includes a processor, a memory, and a peripheral circuit. The processor includes, for example, a CPU or an MPU. The memory includes a ROM, a RAM, a register, a nonvolatile storage device, or the like. The peripheral circuit includes an input-output interface or the like. The controller 14 is connected to an operation inputter 16 that operates the hybrid propulsion ship. The controller 14 can also be connected to a monitor that displays a control state or a speaker that performs sound output, or the like.

[0027] In addition, the functions of the elements disclosed in this specification can be performed using a general-purpose processor, a dedicated processor, an integrated circuit, an ASIC (Application Specific Integrated Circuit), a conventional circuit, and / or a circuit or processing circuit including a combination of them configured or programmed to perform the disclosed functions. The processor includes a transistor or other circuit and is therefore considered a processing circuit or circuit. In this specification, a circuit, unit, member, or section is hardware that performs the listed function or is hardware that is programmed to perform the listed function. The hardware can be hardware disclosed in this specification or can be other known hardware programmed or configured to perform the listed function. In the case where the hardware is a processor considered one of the circuits, the circuit, unit, or member is a combination of the hardware and software for the constitution of the hardware and / or the processor.

[0028] A control program for controlling a control object is stored in the memory of the controller 14. The controller 14 controls the control object in accordance with the control program. The control object of the controller 14 includes the variable-pitch propeller 2, the engine 3, and the first power converter 7. The controller 14 can be configured as one controller that controls these structures 2, 3, 7, or can be configured by two or more controllers. In addition, the controller 14 can be configured to be able to control the other power converters 8, 10, the generator 12, or the shipboard load 13.

[0029] The controller 14 controls the blade angle of the variable-pitch propeller 2 in accordance with a blade angle command value. The blade angle command value is input from the operation inputter 16. The operation inputter 16 can be configured by, for example, an operation lever or an operation handle for operating the speed adjustment and the switching of the forward and reverse of the ship. For example, the operation lever is configured such that a position at which the maximum amount of operation in a first direction corresponds to the maximum ship speed on the forward side, a position at which the maximum amount of operation in a second direction opposite to the first direction corresponds to the maximum ship speed on the reverse side, and a neutral position corresponds to the ship speed 0.

[0030] The operation inputter 16 generates a propeller angle command value corresponding to the operation position of the operation lever, which is larger as the ship speed is faster. For example, in the case where the operation lever is positioned in the first direction, a propeller angle command value that becomes a positive propeller angle is generated, and in the case where the operation lever is positioned in the second direction, a propeller angle command value that becomes a negative propeller angle is generated.

[0031] In addition, in the present embodiment, the propulsion system 1 has a propeller angle sensor 17 that detects the propeller angle of the variable pitch propeller 2. The controller 14 acquires the value detected by the propeller angle sensor 17 to perform feedback control in such a manner that the propeller angle of the variable pitch propeller 2 becomes the propeller angle command value.

[0032] Further, the controller 14 controls the rotation speed of the engine 3 in accordance with a rotation speed command value. The rotation speed command value can be a fixed value, or can be changed by the operation inputter. The controller 14 controls the engine 3 in such a manner that the rotation speed of the engine 3 is maintained at a rotation speed corresponding to the rotation speed command value.

[0033] Further, the controller 14 controls the first power converter 7 in accordance with a power conversion command value. For example, the controller 14 controls in such a manner that the motor generator 4 outputs a prescribed electric power and supplies it to the direct current wiring 6 in a normal control mode at the time of sailing. In the present embodiment, the control mode for the first power converter 7 at the time of normal sailing is referred to as a first control mode. In the first control mode, the motor generator 4 always generates electric power. Therefore, the rotation speed command value for the engine 3 is set to a rotation speed at which an output larger than the output generated by the variable pitch propeller 2 is generated.

[0034] In the first control mode, the electric power supplied from the first power converter 7 to the direct current wiring 6 is supplied to the alternating current wiring 11 via the third power converter 10, and is supplied to the on-board load 13. The remaining electric power is supplied to the accumulator 9 via the second power converter 8, and is accumulated in the accumulator 9. In the case where the charge rate of the accumulator 9 is equal to or higher than a prescribed value, the controller 14 can control the second power converter 8 in such a manner that the electric power accumulated in the accumulator 9 is supplied to the on-board load 13 or the motor generator 4. In this case, the controller 14 performs control such that the electric power supplied from the motor generator 4 to the direct current wiring 6 is reduced from that in the first control mode, or the electric power supplied from the direct current wiring 6 to the motor generator 4 is controlled.

[0035] In the present embodiment, the control mode for the first power converter 7 at the time of discharging the accumulator 9 is referred to as a second control mode. The second control mode is a hybrid mode in which the driving force of the engine 3 and the driving force of the motor generator 4 are used to generate a propulsive force.

[0036] Figure 2 is a view showingFigure 1 A graph showing the correspondence of the blade angle, the mechanical output, and the electric output of the propulsion system in the 1st control mode. As for the blade angle θ, a positive value indicates an angle of forward travel, and a negative value indicates an angle of reverse travel. The blade angle θ = 0 indicates that the variable-pitch propeller 2 is in the neutral position. The mechanical output indicates the output Ml of the engine 3 and the output M2 of the variable-pitch propeller 2.

[0037] The electric output indicates the electric power El exchanged between the 1st power converter 7 and the DC wiring 6 and the electric power E2 in the DC wiring 6. The electric output is referenced to the DC wiring 6. Therefore, the electric power E2 in the DC wiring 6 is in principle 0. However, an error can occur due to exchange of electric power with the power converters 7, 8, 10, etc. connected to the DC wiring 6. In the electric output, a positive value indicates electric power output from the DC wiring 6 to the outside of the electric power conversion system 20, and a negative value indicates electric power supplied to the DC wiring 6.

[0038] In the example of Fig. 9, before time tl, the blade angle θ is the maximum angle θl (> 0) on the forward travel side, and at time tl, the operation lever is changed from the 1st direction maximum position to the 2nd direction maximum position, whereby the blade angle θ is changed to the maximum angle θ2 (< 0) on the reverse travel side in a short time before time t2. Such an operation is called emergency reverse, and is one of the methods of boat operation used in the case of emergency stop of the ship, etc. Figure 2 When the blade angle θ is greatly changed in the direction of reduction of the speed in a short time as in the emergency reverse, a load variation corresponding thereto occurs in the variable-pitch propeller 2. That is, the output M2 of the variable-pitch propeller 2 is reduced from time tl. In accordance with such a load variation, the output Ml of the engine 3 is also reduced from time tl.

[0039] In the case where the change of the control mode of the 1st power converter 7 described later is not performed, that is, in the case where the electric power El exchanged by the 1st power converter 7 during the period from time tl to time t2 is not changed from that until time tl as shown by the broken line portion El o in Fig. 10, the maximum value of the variation amount of the output Ml of the engine 3 is approximately the same as the maximum value B of the variation amount of the output M2 of the variable-pitch propeller 2 as shown by the broken line portion Ml o in Fig. 10. Thus, the response speed of the engine 3 to the abrupt variation of the load is not fast, and therefore in the case where the abrupt variation of the load occurs, it is not possible to maintain the rotational speed of the engine 3 constant.

[0040] Figure 2 Therefore, in the present embodiment, in the case where the abrupt variation of the load occurs, the variation of the load in the engine 3 is suppressed by adjusting the electric power El exchanged by the 1st power converter 7 via the motor generator 4. Figure 2

[0041] Therefore, in the present embodiment, in the case where the abrupt variation of the load occurs, the variation of the load in the engine 3 is suppressed by adjusting the electric power El exchanged by the 1st power converter 7 via the motor generator 4. Therefore, in the present embodiment, in the case where the abrupt variation of the load occurs, the variation of the load in the engine 3 is suppressed by adjusting the electric power El exchanged by the 1st power converter 7 via the motor generator 4.​

[0042] Figure 3 This is a flowchart illustrating an example of load variation suppression control in this embodiment. The processing circuit 15 of the controller 14 obtains blade angle data for the variable-pitch propeller 2 (step S1). In this embodiment, the blade angle data is a blade angle command value. The processing circuit 15 obtains the blade angle command value input by the operation input device 16 and calculates the rate of change per unit time as the blade angle change velocity V (step S2).

[0043] Processing circuit 15 determines whether the blade angle change rate V of variable-pitch propeller 2 during deceleration or reversal between forward and reverse travel is greater than or equal to a first threshold value Vt1 (step S3). If the blade angle change rate V during deceleration or reversal is greater than or equal to the first threshold value Vt1 ("YES" in step S3), processing circuit 15 generates a first command value for increasing the power received by first power converter 7 from motor generator 4 or for decreasing the power supplied from first power converter 7 to motor generator 4 (step S4). The generated first command value is output to first power converter 7.

[0044] exist Figure 2 In the example shown in FIG. 1 , at time t1, the blade angle change rate V exceeds the first threshold value Vt1, and the controller 14 controls the first power converter 7 based on the generated first command value. In this embodiment, the control mode of the first power converter 7 based on the first command value is referred to as the third control mode. In this example, until time t1, the first power converter 7 is controlled in the first control mode. Therefore, the first command value is a command value that increases the electric power E1 received by the first power converter 7 from the motor generator 4.

[0045] like Figure 2 As shown, between time t1 and time t2, the electric power E1 received by the first power converter 7 from the motor generator 4 changes in accordance with the change in output M2 of the variable-pitch propeller 2 as the blade angle changes. In other words, the processing circuit 15 generates the first command value as a value corresponding to the change in blade angle. As a result, the electric power E1 received by the first power converter 7 from the motor generator 4 changes between time t1 and time t2 in accordance with the change in output M2 of the variable-pitch propeller 2.

[0046] By performing such control, Figure 2As shown, the maximum value A of the change in the output M1 of the engine 3 in the third control mode is smaller than when the third control mode is not performed, that is, when the first control mode is performed. More specifically, the maximum value A of the change in the output M1 of the engine 3 in the third control mode is the value obtained by subtracting the maximum value C of the change in the electric power E1 received by the first power converter 7 from the motor generator 4 from the maximum value B of the change in the output M2 of the variable-pitch propeller 2, that is, A=BC.

[0047] In the third control mode, first power converter 7 outputs power E1 received from motor generator 4 to DC wiring 6. Controller 14 controls second power converter 8 to charge battery 9 with power E2 in DC wiring 6 until power E2 in DC wiring 6 reaches zero. Alternatively, controller 14 may reduce or stop the output of generator 12 and control third power converter 10 to supply power E2 in DC wiring 6 to AC wiring 11 for consumption as power to drive onboard load 13.

[0048] The third control mode may also be started from a control state other than the first control mode. For example, a transition to the third control mode may occur in the second control mode in which the first power converter 7 supplies power from the DC line 6 to the motor generator 4 to discharge the battery 9. Figure 4 It shows Figure 1 Graph showing the correspondence between the blade angle, mechanical output, and electrical output in the second control mode of the propulsion system shown in FIG. In the second control mode, when the rate of change V of the blade angle of the variable-pitch propeller 2 during forward or reverse rotation exceeds a first threshold value Vt1, the processing circuit 15 generates a first command value for reducing the power supplied from the power converter 7 to the motor generator 4.

[0049] In the second control mode, the electric output E1 is the power output to the outside, so it is a positive value, unlike the first control mode. However, the changes in the outputs M1, M2, and E1 when switching from the second control mode to the third control mode are different from those in the first control mode. Figure 2 That is, the maximum value A of the variation in the output M1 of the engine 3 in the third control mode becomes smaller than that in the case where the third control mode is not performed, that is, in the case of the second control mode.

[0050] Thus, in the present embodiment, in a case where the change speed V of the blade angle in the variable-pitch propeller 2 becomes the first threshold value Vtl or more, the load to be borne by the engine 3 is increased by adjusting the electric power El accepted or supplied by the first power converter 7 via the motor generator 4. Thereby, even if a temporary decrease in the load accompanying the variation of the blade angle Θ occurs, the variation of the load of the engine 3 can be suppressed. Further, since the change speed V of the blade angle is used as a trigger to shift to the third control mode, in a case where the engine 3 cannot follow the variation of the load, the execution of the third control mode can be appropriately performed. Thus, the variation of the load of the engine 3 can be appropriately suppressed.

[0051] As a result, at the time of the change in the ship speed, the influence of the response characteristic of the engine 3 can be reduced. Thus, the time from the execution of the change operation of the ship speed to the completion of the change of the ship speed or the time from the execution of the emergency stop operation to the stop of the ship can be shortened. Further, in the engine 3, the low-load operation with a poor thermal efficiency can be avoided, and thus the fuel consumption amount can be improved. Thereby, the ship with a low environmental load can be realized.

[0052] Further, in the example of the third control mode, Figure 2 In the example of the third control mode, the case of the emergency astern is exemplified as a representative example of the case where the change speed V of the blade angle is fast. However, the third control mode is not limited to the case of the emergency astern, and can be executed at the time of other deceleration and at the time of the reverse rotation.

[0053] Further, the controller 14 can perform the same control at the time of the increase of the speed of the ship. That is, the controller 14 can generate the second command value to decrease the electric power accepted by the first power converter 7 from the motor generator 4 or to increase the electric power supplied from the first power converter 7 to the motor generator 4, and output the second command value to the first power converter 7 in a case where the change speed V of the blade angle in the variable-pitch propeller 2 at the time of the increase of the speed of the ship is the second threshold value Vt2 or more. In the present embodiment, the control mode of the first power converter 7 based on the second command value is referred to as a fourth control mode.

[0054] If the blade angle Θ is greatly changed in the increasing direction of the speed in a short time, the output M2 of the variable-pitch propeller 2 is also greatly increased. According to such a variation of the load, the output Ml of the engine 3 is also greatly increased. In such a case, by executing the fourth control mode, the electric power El accepted or supplied by the first power converter 7 via the motor generator 4 is adjusted, and the load to be borne by the engine 3 can be decreased. Thereby, even if a temporary increase in the load accompanying the variation of the blade angle Θ occurs, the variation of the load of the engine 3 can be suppressed.

[0055] Further, the second threshold value Vt2 for determining whether to execute the fourth control mode can be the same size as the first threshold value Vt1 for determining whether to execute the third control mode, or can be a different size. For example, the second threshold value Vt2 can also be set to a value larger than the first threshold value Vt1.

[0056] The above describes embodiments of the present disclosure, but the present disclosure is not limited to the above-described embodiments, and various modifications, changes, and corrections can be made within the scope of the gist thereof.

[0057] [Other Embodiments]

[0058] For example, in the above-described embodiments, a mode in which the third control mode is executed when the change speed V of the blade angle is the first threshold value Vt1 or more at the time of deceleration of the ship, and the fourth control mode is executed when the change speed V of the blade angle is the second threshold value Vt2 or more at the time of acceleration of the ship is exemplified. However, this is not limiting, and the switching to the third control mode or the fourth control mode for generating an instruction value for suppressing a load variation of the engine 3 to the first power converter 7 is performed in a case where the variable pitch propeller 2 is in a predetermined driving state. The predetermined driving state includes any one of the time of deceleration of the ship, the time of acceleration of the ship, the time of reversal from forward to reverse, and the time of reversal from reverse to forward. The predetermined driving state can also be limited to a case where a prescribed condition is satisfied, such as a case where the engine 3 is in a prescribed output range, a case where the ship speed before the change or the ship speed after the change is in a prescribed range, or a case where the blade angle of the variable pitch propeller 2 before the change or the blade angle of the variable pitch propeller 2 after the change is in a prescribed range.

[0059] For example, in the above-described embodiments, the switching to the fourth control mode can also not be performed. That is, at the time of acceleration of the ship, the first control mode or the second control mode can be maintained regardless of the change speed V of the blade angle. Alternatively, it can be that, at the time of acceleration of the ship, the fourth control mode is switched in a case where the change speed V of the blade angle is the second threshold value Vt2 or more, and on the other hand, at the time of deceleration of the ship or at the time of reversal, the first control mode or the second control mode is maintained regardless of the change speed V of the blade angle.

[0060] Further, in the above-described embodiments, a mode in which the third control mode, which is the same as the control at the time of deceleration, is executed in a case where the change speed V of the blade angle is the first threshold value Vt1 or more at the time of reversal of the ship is exemplified, but this is not limiting. For example, it can be that, in a case where the change speed V of the blade angle is the first threshold value Vt1 or more at the time of reversal of the ship, the third control mode is executed during a period in which the magnitude of the blade angle θ becomes smaller and becomes 0, that is, during a deceleration period, the fourth control mode is executed during a period in which the magnitude of the blade angle θ becomes larger from 0, that is, during an acceleration period, or the original first control mode or the second control mode is restored.

[0061] In addition, the control content in the third control mode can be made different between when advancing and when retreating, or between when reversing from advancing to retreating and when reversing from retreating to advancing. For example, the first threshold value Vt1 can be different therebetween, or the amount of increase in the electric power El accepted by the first power converter 7 from the motor generator 4 or the amount of decrease in the electric power supplied from the first power converter 7 to the motor generator 4 can be different therebetween. Similarly, the control content in the fourth control mode can be made different therebetween.

[0062] In addition, in the above-described embodiment, a manner of acquiring the blade angle data from the blade angle command value is exemplified, but a value of the blade angle θ acquired from the blade angle sensor 17 can be used as the blade angle data instead of the blade angle command value.

[0063] In addition, in the above-described embodiment, a structure in which the engine 3 and the motor generator 4 are connected in parallel to the variable-pitch propeller 2 via the reduction gear 5 is exemplified, but as long as a structure in which the driving force of the engine 3 and the motor generator 4 can be transmitted to the variable-pitch propeller 2 and the motor generator 4 can generate electric power using the driving force of the engine 3, the structure of the propulsion system 1 is not limited to the structure of the above-described embodiment.

[0064] The control program in the above-described embodiment can be configured as a program product provided by downloading from an external computer or recorded on a non-transitory recording medium readable by a computer, or as a computer product in which the control program is installed in advance.

[0065] [Summary of the Disclosure]

[0066] [Item 1]

[0067] The propulsion system of one embodiment of the present disclosure is a propulsion system of a hybrid propulsion ship having a variable-pitch propeller capable of changing a blade angle in accordance with a blade angle command value, an engine mechanically connected to the variable-pitch propeller and controlled in accordance with a rotation speed command value, a motor generator mechanically connected to the variable-pitch propeller, capable of transmitting power to the variable-pitch propeller, and generating electric power using the driving force of the engine, a power converter electrically connected to the motor generator, and a controller controlling the power converter, in which the controller includes a processing circuit that acquires blade angle data of the variable-pitch propeller, generates a command value that adjusts electric power accepted by the power converter from the motor generator or electric power supplied from the power converter to the motor generator in a case where a change speed of the blade angle of the variable-pitch propeller in a predetermined driving state is equal to or higher than a prescribed threshold value, and outputs the command value to the power converter.

[0068] According to the above structure, in a case where the change speed of the blade angle of the variable pitch propeller at the predetermined driving state becomes equal to or greater than a predetermined threshold value, a control mode of adjusting the load to be borne by the engine by adjusting the electric power given and received by the electric power converter via the motor generator is executed. Thus, even if a temporary change in the load accompanying the change in the blade angle occurs at the predetermined driving state, the change in the load of the engine can be suppressed. Further, since the change speed of the blade angle is used as a trigger for switching to the above control mode, in a case where the engine cannot follow the change in the load, the execution of the above control mode can be appropriately performed. Thus, the change in the load of the engine can be appropriately suppressed.

[0069] [Item 2]

[0070] In the propulsion system of Item 1, it can also be that the processing circuit generates a first instruction value that increases the electric power accepted by the electric power converter from the motor generator or decreases the electric power supplied from the electric power converter to the motor generator, and outputs the first instruction value to the electric power converter, in a case where the change speed of the blade angle of the variable pitch propeller at the time of deceleration or at the time of reversal between forward travel and reverse travel is equal to or greater than a first threshold value.

[0071] According to the above structure, in a case where the change speed of the blade angle of the variable pitch propeller becomes equal to or greater than a first threshold value, a control mode of increasing the load to be borne by the engine by adjusting the electric power given and received by the electric power converter via the motor generator is executed. Thus, even if a temporary decrease in the load accompanying the change in the blade angle occurs at the time of deceleration or at the time of reversal, the change in the load of the engine can be suppressed.

[0072] [Item 3]

[0073] In the propulsion system of Item 1 or 2, it can also be that the processing circuit generates a second instruction value that decreases the electric power accepted by the electric power converter from the motor generator or increases the electric power supplied from the electric power converter to the motor generator, and outputs the second instruction value to the electric power converter, in a case where the change speed of the blade angle of the variable pitch propeller at the time of acceleration is equal to or greater than a second threshold value. When the blade angle is greatly changed in the direction of increase in speed in a short time, the output of the variable pitch propeller also greatly increases. According to such a change in the load, the output of the engine also greatly increases. In such a case, by adjusting the electric power given and received by the electric power converter via the motor generator, the load to be borne by the engine can be decreased. Thus, even if a temporary increase in the load accompanying the change in the blade angle occurs, the change in the load of the engine can be suppressed.

[0074] [Item 4]

[0075] In the propulsion system of any one of items 1 to 3, it can also be that the processing circuitry obtains the blade angle data from the blade angle command value. Thereby, it is possible to start the control to suppress the load variation to the engine before the blade angle actually varies and a load variation to the engine occurs.

[0076] [Item 5]

[0077] In the propulsion system of any one of items 1 to 3, it can also be that the propulsion system has a blade angle sensor that detects the blade angle of the variable-pitch propeller, and the processing circuitry obtains the blade angle data from a value detected by the blade angle sensor.

[0078] [Item 6]

[0079] In the propulsion system of any one of items 1 to 5, it can also be that the engine is a gas engine that generates driving force using fuel containing fuel gas that is gasified from liquefied gas.

[0080] [Item 7]

[0081] Another aspect of the control program of the present disclosure is a control program of a hybrid propulsion ship having: a variable-pitch propeller that can change a blade angle in accordance with a blade angle command value; an engine that is mechanically connected to the variable-pitch propeller and controls a rotation speed in accordance with a rotation speed command value; a motor generator that is mechanically connected to the variable-pitch propeller, can transmit power to the variable-pitch propeller, and generates electric power using driving force of the engine; a power converter that is electrically connected to the motor generator; and a controller that controls the power converter, wherein the control program causes the controller to perform actions of: obtaining blade angle data of the variable-pitch propeller; and in a case where a change speed of the blade angle of the variable-pitch propeller in a predetermined driving state is equal to or higher than a prescribed threshold value, generating a command value that adjusts electric power accepted by the power converter from the motor generator or electric power supplied from the power converter to the motor generator, and outputting the command value to the power converter.

[0082] [Item 8]

[0083] Another aspect of the control method of the present disclosure is a control method of a hybrid propulsion vessel having a variable-pitch propeller capable of changing a pitch angle according to a pitch angle command value, an engine mechanically connected to the variable-pitch propeller and controlled at a rotational speed according to a rotational speed command value, a motor generator mechanically connected to the variable-pitch propeller, capable of transmitting power to the variable-pitch propeller and generating power using driving force of the engine, a power converter electrically connected to the motor generator, and a controller that controls the power converter, wherein pitch angle data of the variable-pitch propeller is acquired, and in a case where a change speed of the pitch angle of the variable-pitch propeller in a predetermined driving state is equal to or greater than a prescribed threshold value, a command value that adjusts power received by the power converter from the motor generator or power supplied from the power converter to the motor generator is generated, and the command value is output to the power converter.

[0084] Explanation of Reference Signs

[0085] 1: Propulsion system; 2: Variable-pitch propeller; 3: Engine; 4: Motor generator; 7: 1st power converter (power converter); 9: Power accumulator; 14: Controller; 15: Processing circuit; 17: Pitch angle sensor.

Claims

1. A propulsion system for a hybrid propulsion vessel, the hybrid propulsion vessel comprising: A variable pitch propeller capable of changing the blade angle according to a blade angle command value; an engine, mechanically connected to the variable-pitch propeller, and having a rotational speed controlled according to a rotational speed command value; an electric generator mechanically connected to the variable-pitch propeller, capable of transmitting power to the variable-pitch propeller and generating electricity using the driving force of the engine; a power converter electrically connected to the motor generator; and a controller that controls the power converter, in, The controller includes a processing circuit, The processing circuit obtains blade angle data of the variable-pitch propeller, and when a change rate of the blade angle of the variable-pitch propeller in a predetermined driving state is greater than a specified threshold value, generates a command value for adjusting the power received by the power converter from the electric generator or the power provided from the power converter to the electric generator, and outputs the command value to the power converter.

2. The propulsion system according to claim 1, wherein: The processing circuit generates a first command value for increasing the power received by the power converter from the electric generator or reducing the power supplied from the power converter to the electric generator when the speed of change of the blade angle of the variable-pitch propeller during deceleration or reversal between forward and reverse is greater than a first threshold value, and outputs the first command value to the power converter.

3. The propulsion system according to claim 1 or 2, wherein: When the speed of change of the blade angle of the variable-pitch propeller during acceleration is greater than a second threshold value, the processing circuit generates a second command value for reducing the power received by the power converter from the electric generator or increasing the power supplied from the power converter to the electric generator, and outputs the second command value to the power converter.

4. The propulsion system according to claim 1 or 2, wherein: The processing circuit obtains the blade angle data from the blade angle command value.

5. The propulsion system according to claim 1 or 2, wherein: The propulsion system includes a blade angle sensor for detecting a blade angle of the variable-pitch propeller. The processing circuit acquires the blade angle data from a value detected by the blade angle sensor.

6. The propulsion system according to claim 1 or 2, wherein: The engine is a gas engine that generates driving force using fuel including fuel gas obtained by gasifying liquefied gas.

7. A control program for a hybrid propulsion ship, the hybrid propulsion ship having: A variable pitch propeller capable of changing the blade angle according to a blade angle command value; an engine, mechanically connected to the variable-pitch propeller, and having a rotational speed controlled according to a rotational speed command value; an electric generator mechanically connected to the variable-pitch propeller, capable of transmitting power to the variable-pitch propeller and generating electricity using the driving force of the engine; a power converter electrically connected to the motor generator; and a controller that controls the power converter, in, The control program causes the controller to perform the following actions: Acquiring blade angle data of the variable-pitch propeller; and When the speed of change of the blade angle of the variable-pitch propeller in a predetermined driving state is greater than a specified threshold value, a command value for adjusting the power received by the power converter from the electric generator or the power provided from the power converter to the electric generator is generated, and the command value is output to the power converter.

8. A control method for a hybrid propulsion vessel, the hybrid propulsion vessel comprising: A variable pitch propeller capable of changing the blade angle according to a blade angle command value; an engine, mechanically connected to the variable-pitch propeller, and having a rotational speed controlled according to a rotational speed command value; an electric generator mechanically connected to the variable-pitch propeller, capable of transmitting power to the variable-pitch propeller and generating electricity using the driving force of the engine; a power converter electrically connected to the motor generator; and a controller that controls the power converter, in, Obtaining blade angle data of the variable-pitch propeller, When the speed of change of the blade angle of the variable-pitch propeller in a predetermined driving state is greater than a specified threshold value, a command value for adjusting the power received by the power converter from the electric generator or the power provided from the power converter to the electric generator is generated, and the command value is output to the power converter.

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