JP2017154510A - Vessel electric propulsion device, and propulsion force control device used for vessel electric propulsion device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vessel electric propulsion device capable of performing efficient propulsion force control by reducing an energy loss generated during vessel navigation, and a propulsion force control device.SOLUTION: In an electric propulsion device 10, in a first control mode, a governor control unit 35A maintains the rotational speed of an engine 33 at a first setting speed (750 min), and a CPP control unit 35B variably controls the pitch of a CPP 31 so as to be a target pitch. In a second control mode, the CPP control unit 35B maintains the CPP 31 at a reference pitch, and the governor 35A controls the rotational speed of the engine 33 within an engine speed range so as to match a vessel characteristic curve.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a marine electric propulsion device that supplies electric force to a variable pitch propeller to propel a marine vessel, and a propulsive force control device that is applied to the marine electric propulsion device.

  As a propulsion device for propelling a ship by rotationally driving a propeller provided in the ship, an electric propulsion apparatus for a ship for rotating the propeller by obtaining a rotational driving force of an electric motor driven by electric power of a generator connected to an internal combustion engine It has been known. For example, in Patent Document 1, a variable pitch propeller (CPP, hereinafter abbreviated as CPP) is connected to the output shaft of the electric motor, and the pitch (blade angle) of the CPP is adjusted. An electric propulsion device that increases or decreases the propulsive force of a ship is disclosed.

  An internal combustion engine such as a diesel engine used as a main engine of a ship has specifications such as its rated output determined in consideration of so-called marine characteristics of the ship. In general, when the vertical axis is the engine output of the main engine and the horizontal axis is the ship speed, the relationship between the engine output and the ship speed is represented by a cube curve. This cube curve is widely known as a curve indicating the marine characteristics (hereinafter sometimes referred to as a marine characteristic curve). That is, the marine characteristics refer to a relationship in which the engine output of the main engine is proportional to the cube of the ship speed. Since the propeller rotation speed at the reference pitch and the ship speed are approximately proportional to each other, the marine characteristic curve has the engine output of the main engine on the vertical axis and the propeller rotation speed (or the rotation of the main engine on the horizontal axis). It may be represented by a cube curve expressed as (number).

  Here, FIG. 5 shows an example of a marine characteristic curve for each pitch of the CPP when a CPP is used as a marine vessel propulsion apparatus. In FIG. 5, the vertical axis represents the engine output of the main engine, and the horizontal axis represents the propeller rotational speed. Further, in FIG. 5, the marine characteristic curves of the pitches αk (k = 1, 2,..., 11) that the CPP can take are indicated by solid lines. Generally, it is desired that a ship operates efficiently in various sea conditions encountered during actual voyage. Ships have a long life, and marine characteristics change when the performance of the hull and main engine deteriorates due to the effects of aging, etc. It is desirable to be able to operate efficiently. In the example of FIG. 5, the propeller design of the CPP is set at a point T1 that satisfies the most fuel efficient conditions (for example, the reference pitch is αa, the engine output is Pa, and the propeller rotational speed is Na) in the operating conditions that the ship regularly uses during voyage. A marine characteristic curve L1 passing through the propeller design point T1 is indicated by a dotted line. In general, in consideration of the engine output Pa and the propeller rotational speed Na at the propeller design point T1, the reference pitch αa, diameter, airfoil, etc. of the CPP are designed so as to obtain a fuel speed with good fuel efficiency.

  2. Description of the Related Art Conventionally, an automatic ship speed control device (Automatic Speed Control: ASC) that automatically controls a ship speed is known as a method for controlling the ship speed by an electric propulsion device using a CPP. When the actual ship speed changes with respect to the target speed, for example, when the sea condition changes, the automatic ship speed control device either the propeller rotation speed (the main engine rotation speed) or the CPP pitch, or the propeller Control is performed to maintain the target speed by controlling both the rotation speed and the pitch. FIG. 6 is a diagram in which a constant ship speed curve Vk (k = 1, 2,...) Is superimposed on FIG. For example, when the actual ship speed is reduced to a ship speed Vs lower than the target speed V2 during normal navigation, when the ship speed is controlled by changing the pitch while keeping the propeller rotational speed constant, the arrow D1 in FIG. As shown, the ship speed increases. On the other hand, when the propeller rotational speed is controlled with a constant pitch, the boat speed increases along the marine characteristic curve as shown by an arrow D2 in FIG.

JP 2007-131081 A

  By the way, the equal ship speed curve Vk shown in FIG. 6 is a curve connecting the points of the engine output and the propeller rotational speed at a predetermined ship speed, and draws a mortar-like curve. As shown in FIG. 6, the bottom part of each constant ship speed curve is the point where the fuel efficiency is the best and the engine output is the minimum. In FIG. 6, it can be seen that the marine vessel characteristic curve L1 passing through the propeller design point T1 substantially coincides with the curve connecting the bottom portions of the constant vessel speed curve Vk. As shown in FIG. 6, for example, when control is performed to change the pitch while maintaining the propeller rotational speed at a constant value (for example, Na), the constant ship speed curve Vk is low at the propeller rotational speed Na. The higher the boat speed, the lower the right shoulder. However, conventional automatic ship speed control devices do not perform ship speed control according to the characteristics of equal ship speed curves with different ship speeds. May increase. In general, since the engine output is proportional to the cube of the boat speed, if it is necessary to increase the engine output by three times the increase in the boat speed, the fuel consumption is approximately 3 with respect to the increase in the boat speed. Double the fuel efficiency, which may cause a problem that the fuel efficiency is remarkably deteriorated.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an electric propulsion device for a ship capable of performing efficient propulsive force control by reducing energy loss that occurs during navigation of the ship, and propulsion. It is to provide a force control device.

(1) The present invention is an electric propulsion device for a ship that propels a ship by supplying electric power to a variable pitch propeller. The marine electric propulsion device includes a power generation engine in which a generator is connected to an output shaft of an internal combustion engine, and an electric motor that is rotationally driven by AC power generated by the power generation engine and supplies the electric power to the variable pitch propeller. And a control device for controlling the pitch of the variable pitch propeller and the rotational speed of the internal combustion engine so as to achieve a target value corresponding to the speed command signal based on a speed command signal input from a ship maneuvering device. .
The control device sets the rotational speed of the internal combustion engine from a predetermined first set speed to a second set speed so as to generate AC power in a frequency band from a predetermined first frequency to a second frequency. A rotation speed control unit that controls within a speed range; and a pitch control unit that controls the pitch of the variable pitch propeller.
When the speed command signal is outside a predetermined reference range, the rotational speed control unit maintains the rotational speed of the internal combustion engine at either the first set speed or the second set speed, and the pitch The control unit controls the variable pitch propeller to a pitch corresponding to the target value. Further, when the speed command signal is within the reference range, the pitch control unit maintains the pitch of the variable pitch propeller at a reference pitch predetermined corresponding to the speed range, and the rotation speed control unit Controls the internal combustion engine to a rotational speed corresponding to the target value so as to follow a marine characteristic curve determined by the engine output of the internal combustion engine and the propeller rotational speed of the variable pitch propeller.

Generally, the speed of a ship is limited in a harbor or a specific route. Therefore, when the ship is navigating in the harbor, the marine electric propulsion device rotates the propeller in a region where the output is low in the output range. On the other hand, when sailing out of the harbor and navigating the open ocean, no speed limit is imposed on the ship. Therefore, after the ship leaves the outer port, the marine electric propulsion device rotates the propeller in a region where the output is relatively high in the output range and under the best fuel efficiency. With the exception of ships that work in harbors, such as tugboats, many ships take longer to navigate at high power in the open ocean than to navigate in harbors at low power. Therefore, in general, marine characteristics in a ship are determined based on navigation in the open ocean.
In the electric propulsion device for a ship according to the present invention, in view of the use situation of the ship, when the speed command signal from the control device is out of the reference range, the rotation speed control unit of the control device rotates the internal combustion engine. The speed is maintained at either the first set speed or the second set speed, and the pitch control unit controls the variable pitch propeller to a pitch corresponding to the target value. For example, when the speed command signal is below a lower limit value of the reference range, the rotational speed control unit maintains the rotational speed of the internal combustion engine at the first set speed, and the pitch control unit The variable pitch propeller is controlled to a pitch corresponding to the target value. When the speed command signal is above the upper limit value of the reference range, the rotational speed control unit maintains the rotational speed of the internal combustion engine at the second set speed, and the pitch control unit The variable pitch propeller is controlled to a pitch corresponding to the target value.
In general, in a speed region below the first set speed, it is difficult to control the ship speed based on the rotational speed of the internal combustion engine, and even if it can be controlled, the efficiency may deteriorate. For this reason, in the speed region below the first set speed, efficient propulsive force control with low energy loss can be achieved by controlling the pitch of the variable pitch propeller while maintaining the rotational speed at the first set speed. Realized.
On the other hand, when the speed command signal is within the reference range, the pitch control unit of the control device maintains the pitch of the variable pitch propeller at a reference pitch predetermined corresponding to the speed range, The rotational speed control unit controls the internal combustion engine to a rotational speed corresponding to the target value so as to follow a marine characteristic curve determined by an engine output of the internal combustion engine and a propeller rotational speed of the variable pitch propeller. Within the speed range, ship speed control based on the rotational speed of the internal combustion engine is easy, and fuel efficiency is good. For this reason, in the speed range, while maintaining the variable pitch propeller at the reference pitch, the rotational speed is variably controlled within the speed range, thereby realizing efficient propulsive force control with low energy loss. .

(2) The frequency band is an allowable range of a power frequency supplied as commercial power.

  Thereby, the electric power output from the power generation engine can be used as a commercial power source without frequency conversion. For this reason, electric power can be directly supplied from the electric power bus to an electrically driven load device used in the ship. That is, in the marine electric propulsion apparatus of the present invention, it is possible to supply power to the load device without providing an inverter for performing frequency conversion.

(3) It is preferable that the first frequency is 50 Hz and the second frequency is 60 Hz.

  In general, circuit protectors such as electromagnetic contactors and circuit breakers as general-purpose products, and electrical equipment used in ships are standardly designed to be driven with AC power of 50 Hz to 60 Hz, and other frequencies (for example, 40 Hz) ) Driving with AC power is not guaranteed. Therefore, if the frequency band is 50 Hz to 60 Hz, a highly versatile and inexpensive circuit protector or electrical device can be used.

(4) Further, the marine characteristic curve is preferably approximated to a curve connecting the minimum points of the constant ship speed curve of the marine vessel.

(5) Further, the present invention provides a power generation engine in which a generator is connected to an output shaft of an internal combustion engine, an electric motor that is rotationally driven by AC power generated by the power generation engine and supplies electric power to a variable pitch propeller Applied to a marine electric propulsion device for propelling a ship by supplying the electric power to the variable pitch propeller, and responding to the speed command signal based on a speed command signal input from a marine vessel maneuvering device. The propulsive force control device controls the pitch of the variable pitch propeller and the rotational speed of the internal combustion engine so as to achieve a target value.
The propulsive force control device changes the rotational speed of the internal combustion engine from a predetermined first set speed to a second set speed so as to generate AC power in a frequency band from a predetermined first frequency to a second frequency. A rotation speed control unit that controls within the speed range up to and a pitch control unit that controls the pitch of the variable pitch propeller.
When the speed command signal is outside a predetermined reference range, the rotational speed control unit maintains the rotational speed of the internal combustion engine at either the first set speed or the second set speed, and the pitch The control unit controls the variable pitch propeller to a pitch corresponding to the target value. When the speed command signal is within the reference range, the pitch control unit maintains the pitch of the variable pitch propeller at a reference pitch predetermined corresponding to the speed range, and the rotational speed control unit is The internal combustion engine is controlled to a rotational speed corresponding to the target value so as to follow a marine characteristic curve determined by an engine output of the internal combustion engine and a propeller rotational speed of the variable pitch propeller.

  According to the present invention, in a marine electric propulsion apparatus, it is possible to reduce energy loss that occurs during navigation of a ship and perform efficient propulsive force control.

FIG. 1 is a configuration diagram schematically showing a schematic configuration of an electric propulsion device according to an embodiment of the present invention. FIG. 2 is a graph showing a marine characteristic curve showing the relationship between the propeller rotational speed and the engine output in the electric propulsion device, and an equal ship speed curve showing the relationship between the propeller rotational speed, the engine output and the boat speed. FIG. 3 shows the correspondence among ship speed command, control mode (control state), engine speed, generator frequency, motor speed, reduction ratio, propeller speed, pitch (blade angle) in the electric propulsion device. FIG. FIG. 4 is a flowchart showing an example of the procedure of the propulsive force control process executed by the control device of the electric propulsion device. FIG. 5 is a graph showing a marine characteristic curve for explaining a conventional control method. FIG. 6 is a graph showing a marine characteristic curve and a constant ship speed curve for explaining a conventional control method.

  Embodiments of the present invention will be described below with reference to the drawings as appropriate. In addition, the following embodiment is only an example which actualized this invention, and does not limit the technical scope of this invention.

  An electric propulsion apparatus 10 according to an embodiment of the present invention (an example of an electric propulsion apparatus for a ship of the present invention) uses a variable pitch propeller 31 (hereinafter abbreviated as “CPP 31”), which is a propulsion mechanism of a ship, for electricity by an electric motor 39. It is rotated by a driving force to generate a propulsive force for the ship. As shown in FIG. 1, the electric propulsion apparatus 10 includes a diesel engine 33 (an example of an internal combustion engine of the present invention, hereinafter abbreviated as “engine 33”) and a generator 37 (an example of a generator of the present invention). ), An electric motor 39 (an example of the electric motor of the present invention), a speed reducer 41, and a control device 35 (an example of the control device of the present invention, an example of a propulsive force control device) that comprehensively controls the operation of the electric propulsion device 10. It is equipped with. The power generation engine of the present invention is realized by the engine 33 and the generator 37.

  Here, the marine electric propulsion apparatus of the present invention can be applied to all ships propelled using CPP, for example, cargo ships such as container ships and tankers, passenger ships such as ferries and passenger ships, marine research ships, etc. It can be widely applied to ships such as special ships that perform marine operations like the above, voyage training ships, and fishing ships used in fishing.

  The engine 33 is used as a drive source for supplying rotational driving force to the generator 37 in a ship. For example, the engine 33 is a large diesel engine having an engine output of several hundred kW to several thousand kW. The engine 33 is provided with an electronic governor 34. The electronic governor 34 is controlled by a governor control unit 35A (an example of a rotation speed control unit of the present invention) provided in the control device 35. Specifically, the electronic governor 34 adjusts the injection amount of the fuel injection pump of the engine 33 by changing the fuel rack position according to the signal input from the governor control unit 35A. Thereby, the rotational speed of the engine 33 is changed. The engine 33 is provided with a speed sensor 24 that detects the rotational speed of the engine 33. The speed signal detected by the speed sensor 24 is fed back to the control device 35. In the present embodiment, the engine 33 is illustrated as an example of the internal combustion engine. However, the present invention is not limited to this, and an internal combustion engine that can output a rotational driving force such as a gas engine or a gas turbine instead of the engine 33 may be used. Various types of institutions are applicable. Further, the speed sensor 24 may detect the speed from the power generation frequency of the generator 37, for example.

The generator 37 is connected to the output shaft 48 of the engine 33. The input shaft of the generator 37 is directly connected to the output shaft of the engine 33 by a coupling (shaft joint) (not shown), and the rotational driving force of the output shaft 48 of the engine 33 is directly transmitted to the generator 37 as it is. The The generator 37 rotates in response to the rotational driving force transmitted from the output shaft 48 of the engine 33, and generates AC power having a frequency corresponding to the rotational speed. Specifically, the generator 37 is an 8-pole 3-phase synchronous generator. In the present embodiment, the engine 33 has a rotational speed of 750 min ⁻¹ (= first set speed N1) to 900 min ⁻¹ (= second set speed N2) with respect to the generator 37 having 8 poles. The rotation is controlled by the control device 35 so as to be within the speed range.

Here, generally, between the shaft speed N and the frequency f and the number of poles P is, N = 120f / P because there is relationship ^{(min -1),} the engine speed range ^{(750min -1 ~900min} -1 ) By controlling the rotational speed of the engine 33, the generator 37 generates AC power within a frequency range of the frequency f from 50 Hz (= first frequency F1) to 60 Hz (= second frequency F2). Generate power and output. Specifically, generator 37 when the rotational speed of the engine 33 is 750Min ^-1 is generating the AC power of 50 Hz, the AC power of the generator 37 is 60Hz when the rotational speed of the engine 33 is 900 min ^-1 Generate electricity.

  The output side of the generator 37 is connected to a common power bus via a disconnector 54. Therefore, the AC power generated by the generator 37 flows into the power bus with the disconnector 54 being closed.

  Electric power is supplied from the electric power bus to the electric motor 39 through a power supply circuit 51 such as a power cable for power transmission and distribution. In the power supply circuit 51 extending from the power bus to the motor 39, a circuit breaker such as an ACB (Air Circuit Breaker) or MCCB (Molded Case Circuit Breaker) is used to protect circuits and equipment from overcurrent. Is provided.

  In addition, a power feeding circuit 52 different from the power feeding circuit 51 is provided in parallel with the power bus. The power feeding circuit 52 is for supplying electric power to a load device 58 that is electrically driven and used in a ship. The load device 58 corresponds to various electric devices such as an electric pump, an electric valve, a motor, a control device, and an alarm device used for ships. Further, the load device 58 corresponds to, for example, an electric device that is used by being connected to an onboard power source.

  In the present embodiment, neither of the power feeding paths 51 and 52 is provided with a frequency converter such as an inverter that converts the frequency of the AC power generated by the generator 37 into another frequency.

By the way, the switch and the load device 58 connected to the power bus and the feeding power lines 51 and 52 are designed to match the power frequency of the commercial power source. In Japan and other countries, commercial power sources of 50 Hz and 60 Hz are provided. That is, the allowable range of the power frequency supplied as commercial power is in the range of 50 Hz to 60 Hz. In the present embodiment, as described above, since the rotational speed of the engine 33 is controlled only between 750 min ⁻¹ and 900 min ⁻¹ , the frequency variation of the generator 37 is 50 Hz to 60 Hz. That is, the generator 37 generates AC power in a frequency band where the frequency f is 50 Hz to 60 Hz. Therefore, an electric circuit protector such as a switch or a circuit breaker connected to the electric power bus or the electric power supply circuits 51 and 52 and a load device 58 that receives electric power from the electric power supply circuit 52 operate with an AC power of 50 Hz to 60 Hz. As described above, an inexpensive product with high versatility designed as a standard can be applied.

The electric motor 39 is rotationally driven by the input AC power having a predetermined frequency. Specifically, the electric motor 39 is a so-called squirrel-cage three-phase induction motor using a six-pole squirrel-cage rotor. When AC power supplied through either the power supply circuit 51 or the power supply circuit 52 is input, the electric motor 39 is rotationally driven at a rotation speed corresponding to the frequency of the input AC power. In this embodiment, the motor 39 is rotated at a rotational speed of 1000min ^-1 by AC power 50Hz is input, rotates at a rotational speed of 1200Min ^-1 by AC power 60Hz is input. In the induction motor, since slip occurs in the rotation speed of the rotor, the actual rotation speed of the output shaft of the motor 39 is a speed obtained by subtracting the slip speed from the rotation speed described above. In the following, for convenience of explanation, the rotational speed of the electric motor 39 will be described without considering the slip speed.

The reduction gear 41 is connected to the output shaft of the electric motor 39 via a transmission gear (not shown). The reducer 41 decelerates the rotational speed of the electric motor 39 at a predetermined reduction ratio and transmits it to the propeller shaft 49 of the CPP 31. In the present embodiment, the reduction ratio of the reduction gear 41 is set to 7.69. Therefore, CPP31 is motor 39 rotates at a rotational speed of 130min ^-1 rotates at a rotation speed of 1000min ^-1, motor 39 is rotated at a rotational speed of 156min ^-1 rotates at a rotation speed of 1200min ^-1.

  The CPP 31 is a propulsion device that obtains a propulsive force that propels a ship by generating a thrust in the direction of its rotation axis. The CPP 31 is a screw propeller that can freely change the pitch of the blades 31A. By changing the pitch of the blades 31A, a propulsive force in an arbitrary front-rear direction is generated with a constant rotational direction and a constant rotational speed. The CPP 31 includes a pitch transition mechanism 31B. The plurality of blades 31A included in the CPP 31 are swingably attached to the propeller boss by a pitch change mechanism 31B. The pitch (blade angle) of the CPP 31 is changed by the pitch change mechanism 31B, that is, the CPP 31 is changed. The pitch can be changed. The pitch of the CPP 31 is changed when the pitch changing mechanism 31B is controlled by a CPP control unit 35B (an example of the pitch control unit of the present invention) described later included in the control device 35.

  The control device 35 controls the electric propulsion device 10 and controls the propulsive force that the electric propulsion device 10 imparts to the ship, and executes the propulsive force control process described later. Specifically, the control device 35, based on the speed command signal (ship speed command signal) input from the ship steering handle 15 (an example of the control device of the present invention), the target value corresponding to the speed command signal. The pitch of the CPP 31 and the rotational speed of the engine 33 are controlled so as to be (target pitch or target rotational speed). The control device 35 includes a calculation device such as a microcomputer, a main control board, and a PLC configured by a CPU, a ROM, a RAM, and the like, and the propulsive force control process is executed by the calculation device.

  The control device 35 includes a governor control unit 35A and a CPP control unit 35B. The governor control unit 35A and the CPP control unit 35B are functional units realized by the control device 35 when the arithmetic device executes a control program in the ROM. Note that the governor control unit 35A and the CPP control unit 35B may be realized by an integrated circuit such as an IC.

  A steering handle 15 is connected to the control device 35 by a signal line or the like. In addition to the “NEUTRAL (neutral)” scale, the steering handle 15 includes four scales “DEAD SLOW (low speed)”, “SLOW (low speed)”, “HALF (medium speed)” that indicate the ship speed in both forward and reverse directions. "FULL (high speed)" is engraved. When the control handle 15 is operated within the range of the scale, an electric signal (telegraph signal) corresponding to each ship speed is input to the control device 35 through the signal line from a potentiometer provided on the control handle 15. . This electric signal is the speed command signal. This electric signal indicates a target value (target pitch or target rotational speed) corresponding to the operation position of the steering handle 15, and the control device 35 determines the pitch of the CPP 31 and the engine 33 so as to be the target value. Control the rotation speed. The target value is stored in a storage device such as a RAM of the control device 35.

  In the present embodiment, a current signal in the range of 4 mA to 20 mA is output from the steering handle 15 to the control device 35 as the electrical signal. For example, when the steering wheel 15 is in the neutral position, a signal of 4 mA is output. Further, when the steering handle 15 is operated from the neutral position to the forward side, a first electric signal (4 mA to 10 mA) for instructing control in a first control mode to be described later according to the operation position, which will be described later. A second electric signal (10 mA to 18 mA) for instructing control in the second control mode is output, and a third electric signal (18 mA to 20 mA) for supporting control in the third control mode described later is output. Is done. Here, the range (range) of the second electric signal for instructing the control in the second control mode is an example of the reference range of the present invention. Note that the above-described electric signal is merely an example, and the signal form is not limited to the above-described one.

The governor control unit 35A predetermines the rotational speed of the engine 33 so that the generator 37 generates AC power in the frequency band from the first frequency F1 (50 Hz) to the second frequency F2 (60 Hz). The engine speed is controlled within the engine speed range from the first set speed N1 (750 min ⁻¹ ) to the second set speed (900 min ⁻¹ ). The governor control unit 35A controls the engine 33 so as to achieve a rotation speed according to a first control mode to a third control mode described later. Specifically, the governor control unit 35A changes the fuel rack position of the electronic governor 34 provided in the engine 33, and adjusts the injection amount of the fuel injection pump in accordance with each control mode, whereby the engine 33 Is controlled within the engine speed range from the first set speed N1 to the second set speed (900 min ⁻¹ ).

  The CPP control unit 35B controls the blade 31A by driving the pitch transition mechanism 31B so as to have an arbitrary pitch. In the present embodiment, the blade 31A of the CPP 31 can be changed from pitch 0 to αmax. Here, the reference pitch of the blade 31A of the CPP 31 is αa. In the present embodiment, the CPP control unit 35B adjusts the blade 31A in the range of pitch 0 to αmax so that the pitch according to a first control mode to a third control mode described later is obtained during forward control of the ship. Note that the CPP control unit 35B adjusts the blades 31A in the range of pitch -αmax to 0 during reverse control of the ship.

Here, in the first control mode, the rotation speed of the engine 33 is maintained at the first set speed N1, and the pitch command of the CPP 31 is within a range of 0 to αa, and the speed command from the steering handle 15 is rotated. This is a control mode in which control is performed so that a target value corresponding to the signal is obtained. In the first control mode, it is possible to control the boat speed in the range indicated by the arrow D1 in FIG. Although the first set speed N1 can be arbitrarily determined, in the present embodiment, the first set speed N1 is a rotational speed (750 min that can generate electric power of the first frequency F1 in the generator 37. ^-1 ). In the second control mode, the rotational speed of the engine 33 is set according to the speed command signal corresponding to the operation position of the steering handle 15 in the engine speed range from the first set speed N1 to the second set speed N2. In this control mode, the pitch of the CPP 31 is fixed to the reference pitch αa. In this second control mode, it is possible to control the ship speed in the range indicated by the arrow D2 in FIG. Note that the second set speed N2 is set to a rotational speed (900 min ⁻¹ ) that is used under the most fuel efficient conditions under the operational conditions that the ship regularly uses during voyage. In the third control mode, the rotation speed of the engine 33 is maintained at the second set speed N2, and the pitch of the CPP 31 is set within the range of αa to αmax. This is a control mode in which control is performed so as to obtain a target value corresponding to. In this third control mode, it is possible to control the boat speed in the range indicated by the arrow D3 in FIG.

  In the present embodiment, as shown in FIGS. 2 and 3, in the first control mode, the control device 35 keeps the rotational speed of the engine 33 at the first set speed N1 and moves it to the position of the steering handle 15. The pitch of the CPP 31 is controlled so as to obtain a corresponding target pitch. In other words, in the first control mode, the governor control unit 35A performs control so as to maintain the rotational speed of the engine 33 at the first set speed N1, and the CPP control unit 35B controls the target according to the position of the steering handle 15. The pitch of the CPP 31 is variably controlled so as to be the pitch. Here, FIG. 2 shows a marine characteristic curve L1 indicating the relationship between the propeller rotational speed and the engine output in the electric propulsion device 10, and an equal ship speed curve Vk indicating the relationship between the propeller rotational speed, the engine output and the boat speed. FIG. In FIG. 2, the marine characteristic curve L1 approximates to a curve connecting the minimum points of the ship's constant ship speed curve Vk. FIG. 3 is a diagram showing a correspondence relationship among the target speed, the control state, the engine speed, the reduction ratio, the generator frequency, the propeller speed, and the blade angle (pitch) in the electric propulsion apparatus 10. 2 are the same as those in FIGS. 5 and 6 and are not described here.

Further, in the second control mode, the control device 35 maintains the pitch of the CPP 31 at the reference pitch αa, and the marine characteristic curve L1 determined by the engine output of the engine 33 and the rotational speed of the CPP 31 (see FIG. 2). , The rotational speed of the engine 33 is controlled within the engine speed range (750 min ^{−1 to} 900 min ⁻¹ ). In other words, in the second control mode, the CPP control unit 35B controls the pitch of the CPP 31 so as to maintain the reference pitch αa, and the governor control unit 35A determines the target rotational speed according to the position of the steering handle 15. Thus, the rotational speed of the engine 33 is controlled within the engine speed range so as to follow the marine characteristic curve.

  Further, in the third control mode, the control device 35 controls the pitch of the CPP 31 so that the target pitch according to the position of the steering handle 15 is obtained while maintaining the rotational speed of the engine 33 at the second set speed N2. . In other words, in the third control mode, the governor control unit 35A performs control so as to maintain the rotational speed of the engine 33 at the second set speed N2, and the CPP control unit 35B performs the target according to the position of the steering handle 15. The pitch of the CPP 31 is controlled so as to be the pitch.

  Hereinafter, an example of the procedure of the propulsive force control process executed by the control device 35 will be described with reference to the flowchart of FIG. 4, S11, S12,... Represent processing procedure (step) numbers. In the following description, the propulsive force control process at the time of forward movement will be described, but the same process is performed at the time of backward movement.

The control device 35 controls the electronic governor 34 so as to maintain the rotational speed of the engine 33 at the first set speed N1 (750 min ⁻¹ ) when the steering handle 15 is in the neutral position. Further, the control device 35 changes the CPP 31 to the pitch 0. Hereinafter, the state controlled in this way is referred to as a standby mode. In the standby mode, since the engine 33 is rotating at the first set speed N1, the power generator 37 generates power of the first frequency F1 (50 Hz) that can be used as ship power. Moreover, since the pitch of CPP31 is 0, the electric propulsion apparatus 10 is not providing the propulsive force with respect to a ship.

  When the steering handle 15 is operated from the neutral position to forward while in the standby mode, the control device 35 starts control of the rotational speed of the engine 33 and control of the pitch of the CPP 31 so as to advance the ship. .

  In step S11, the control device 35 determines whether or not the current control mode is the first control mode. Such a determination is made based on the electric signal as the speed command signal output from the steering handle 15. For example, it is determined based on whether or not the speed command signal is the first electric signal. If it is determined in step S11 that the first control mode is set, the process proceeds to step S12.

In step S12, the governor control unit 35A of the control device 35 performs feedback based on the detection signal from the speed sensor 24 so as to maintain the rotational speed of the engine 33 at a predetermined 750 min ⁻¹ (first set speed N1). Perform control (constant speed control). At this time, the generator 37 generates AC power with a constant frequency of 50 Hz (first frequency F1) corresponding to a constant rotational speed of 750 mi, and receives the AC power, the motor 39 rotates at 1000 min ⁻¹ . As a result, the CPP 31 rotates at a rotation speed of 133 min ⁻¹ .

  In the next step S13, the CPP control unit 35B of the control device 35 variably controls the pitch of the CPP 31 within a range from 0 to αa so that the target pitch corresponding to the position of the steering handle 15 is obtained.

  If it is determined in step S11 that the mode is not the first control mode, the process proceeds to step S14. In step S14, the control device 35 determines whether or not the current control mode is the second control mode. Such a determination is made based on the electric signal as the speed command signal output from the steering handle 15. For example, it is determined based on whether the speed command signal is the second electric signal. If it is determined in step S15 that the second control mode is set, the process proceeds to step S15.

  In step S15, the CPP control unit 35B of the control device 35 controls the pitch transition mechanism 31B so that the pitch of the CPP 31 maintains the reference pitch αa.

In the next step S <b> 16, the governor control unit 35 </ b> A of the control device 35 controls the electronic governor 34 so as to achieve the target rotational speed corresponding to the position of the steering handle 15, thereby setting the rotational speed of the engine 33 to 750 to 750. Control within the range of 900 min ⁻¹ . Thereby, the generator 37 generates AC power having a frequency corresponding to the rotational speed of the engine 33, and the AC power is supplied to the electric motor 39. Thus, in a state maintaining the reference pitch .alpha.a, rotational speed of CPP31 is controlled within the range of ^{130min -1 ~156min} -1.

If it is determined in step S14 that the second control mode is not selected, the process proceeds to step S17. In step S17, the control device 35 determines that the current control mode is the third control mode, and the governor control unit 35A of the control device 35 sets the rotational speed of the engine 33 to a predetermined 900 min ⁻¹ ( Feedback control (constant speed control) is performed based on the detection signal from the speed sensor 24 so as to increase the speed to the second set speed N2) and maintain 900 min- ¹ . At this time, the generator 37 generates AC power with a constant frequency of 60 Hz (second frequency F2) corresponding to a constant rotational speed of 900 mi, receives the AC power, and the motor 39 rotates at 1200 min ⁻¹ . As a result, the CPP 31 rotates at a rotation speed of 156 min ⁻¹ .

  In the next step S18, the CPP control unit 35B of the control device 35 variably controls the pitch of the CPP 31 within the range of αa to αmax so that the target pitch according to the position of the steering handle 15 is obtained.

  If the steering handle 15 is returned to the neutral position after steps S13, S16, and S18, the series of propulsive force control processing ends, and if the steering handle 15 is not returned to the neutral position, the processing from step S11 is repeated (S19). ).

Thus, in the electric propulsion apparatus 10 of the present embodiment, the governor control unit 35A maintains the rotation speed of the engine 33 at the first set speed N1 (750 min ⁻¹ ) in the first control mode, and the CPP control unit 35B. Since the CPP 31 is variably controlled so as to be the target pitch, in the first control mode, which is the low speed control region, energy loss during navigation of the ship can be suppressed and efficiency can be improved.

  In the second control mode, which is the medium speed control region, the CPP control unit 35B maintains the reference pitch αa, and the governor control unit 35A is within the engine speed range so as to follow the marine characteristic curve. The rotational speed is variably controlled so as to be the target rotational speed. For this reason, in the second control mode, efficient propulsive force control with low energy loss is achieved by controlling the rotational speed of the engine 33 within the engine speed range while maintaining the pitch of the CPP 31 at the reference pitch αa. It is possible to realize.

In the third control mode, which is the high speed region, the governor control unit 35A maintains the rotational speed of the engine 33 at the second set speed N2 (900 min ⁻¹ ), and the CPP control unit 35B sets the pitch of the CPP 31 to Variable control is performed to achieve the target pitch. Thus, in all the control modes of the first control mode, the second control mode, and the third control mode, the generator 37 does not generate electric power outside the range of 50 Hz to 60 Hz. Therefore, the electric power generated by the generator 37 can be directly supplied to the load device 58 used on the ship. That is, in the electric propulsion apparatus 10, it is possible to supply the generated power to the load device 58 without providing an inverter that performs frequency conversion.

  Moreover, in the electric propulsion apparatus 10, the reduction ratio of the reduction gear 41 can be made small compared with the conventional structure, and the reduction gear 41 can be reduced in size. As a result, the gear loss of the reduction gear is reduced, the reduction efficiency in the reduction gear 41 is improved, and consequently the efficiency of the electric propulsion device 10 is improved.

  In the above-described embodiment, the electric propulsion device 10 configured by one engine 33, one generator 37, one electric motor 39, and one CPP 31 is illustrated, but the present invention has this configuration. It is not limited. The present invention is also applicable to a marine electric propulsion apparatus configured to rotationally drive the electric motor 39 using AC power generated by a power generation engine including a plurality of engines 33 and a power generator 37.

In the above-described embodiment, the configuration in which the engine 33 is rotated in the range of 750 min ⁻¹ to 900 min ^{−1 and} the configuration in which the CPP 31 is rotated in the range of 130 min ⁻¹ to 156 min ⁻¹ are illustrated. The control range of the rotational speed of each CPP 31 is merely an example, and can be set to an arbitrary range. For example, as the control range of the rotational speed of the engine ^33, and the range of 600min ^-1 ~750min ^-1, it may be applied to a range of 1000min ^-1 ~1200min -1.

DESCRIPTION OF SYMBOLS 10: Electric propulsion apparatus 15: Steering handle 31: Variable pitch propeller 33: Diesel engine 35: Control apparatus 35A: Governor control part 35B: CPP control part 37: Generator 39: Electric motor 41: Reduction gear

Claims (5)

An electric propulsion device for a ship that supplies electric force to a variable pitch propeller to propel the ship,
A power generation engine in which a generator is connected to the output shaft of the internal combustion engine;
An electric motor that is rotationally driven by AC power generated by the power generation engine and supplies the electric power to the variable pitch propeller;
A control device for controlling the pitch of the variable pitch propeller and the rotational speed of the internal combustion engine so as to obtain a target value corresponding to the speed command signal based on a speed command signal input from a ship maneuvering device; Prepared,
The controller is
The rotational speed of the internal combustion engine is controlled within a predetermined speed range from a first set speed to a second set speed so as to generate AC power in a frequency band from a predetermined first frequency to a second frequency. A rotation speed control unit,
A pitch controller for controlling the pitch of the variable pitch propeller,
When the speed command signal is outside a predetermined reference range, the rotational speed control unit maintains the rotational speed of the internal combustion engine at either the first set speed or the second set speed, and the pitch The control unit controls the variable pitch propeller to a pitch according to the target value,
When the speed command signal is within the reference range, the pitch control unit maintains the pitch of the variable pitch propeller at a reference pitch predetermined corresponding to the speed range, and the rotational speed control unit is A marine electric propulsion device that controls the internal combustion engine to a rotational speed according to the target value so as to follow a marine characteristic curve determined by an engine output of the internal combustion engine and a propeller rotational speed of the variable pitch propeller.   The marine electric propulsion apparatus according to claim 1, wherein the frequency band is an allowable range of a power frequency supplied as commercial power.   The marine electric propulsion device according to claim 2, wherein the first frequency is 50 Hz, and the second frequency is 60 Hz.   4. The marine electric propulsion device according to claim 1, wherein the marine characteristic curve approximates a curve connecting the minimum points of the constant ship speed curve of the marine vessel. A power generation engine in which a generator is connected to an output shaft of the internal combustion engine; and an electric motor that is rotationally driven by AC power generated by the power generation engine to supply an electric power to a variable pitch propeller. Applied to a marine electric propulsion device for propelling a vessel by supplying it to a variable pitch propeller, and based on a velocity command signal input from a vessel maneuvering device, the target value corresponding to the velocity command signal is obtained. A propulsive force control device for controlling the pitch of a variable pitch propeller and the rotational speed of the internal combustion engine,
The rotational speed of the internal combustion engine is controlled within a predetermined speed range from a first set speed to a second set speed so as to generate AC power in a frequency band from a predetermined first frequency to a second frequency. A rotation speed control unit,
A pitch controller for controlling the pitch of the variable pitch propeller,
When the speed command signal is outside a predetermined reference range, the rotational speed control unit maintains the rotational speed of the internal combustion engine at either the first set speed or the second set speed, and the pitch The control unit controls the variable pitch propeller to a pitch according to the target value,
When the speed command signal is within the reference range, the pitch control unit maintains the pitch of the variable pitch propeller at a reference pitch predetermined corresponding to the speed range, and the rotational speed control unit is A propulsive force control device that controls the internal combustion engine to a rotational speed according to the target value so as to follow a marine characteristic curve determined by an engine output of the internal combustion engine and a propeller rotational speed of the variable pitch propeller.

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