Power generation system for ship

Abstract

To provide a power generation system for a ship capable of improving energy saving while providing the necessary performance for electrical equipment mounted on the ship.SOLUTION: A power generation system for a ship has a generator 3, a control unit 1 to control the generator 3 so that the output frequency of the generator 3 becomes a prescribed target frequency less than a commonly used frequency, electric equipment 5 driven by the generated power by the generator 3, and a detection unit 6 to detect the operating state of the electric equipment 5. The control unit 1 sets the target frequency based on the operating state of the electric equipment 5 detected by the detection unit 6.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a marine power generation system. [Background technology]

[0002] A ship is equipped with a large number of electrical devices such as electric pumps, ventilators, etc. To supply power to these electrical devices, the ship is usually equipped with a generator driven by a power-generating engine (see, for example, Patent Document 1 below).

[0003] Normally, the output power of a generator is set with a margin to ensure that all electrical equipment operates normally under any conditions. Therefore, under normal operating conditions, each electrical equipment operates with more output than necessary. In order to optimize the output of each electrical equipment, it is effective to lower the frequency of the electricity supplied to each electrical equipment.

[0004] For example, if an inverter is provided for each electrical device and the output of the electrical device is optimized according to the situation, power consumption can be reduced, which makes it possible to reduce the fuel supplied to the generator engine and save energy. However, if an inverter is provided for each of the many electrical devices installed on a ship, costs will rise and control will become complicated.

[0005] Another method, for example, in Patent Document 1 listed below, is to switch the generator output frequency between the normal frequency (60 Hz) and a lower energy-saving frequency (57 Hz). Lowering the generator output frequency reduces the power consumption of each electrical device, which in turn reduces the demand for electricity on board the ship, making it possible to reduce the fuel used by the engine that drives the generator and thereby achieving energy conservation. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-12738 Summary of the Invention [Problem to be solved by the invention]

[0007] However, if the output frequency of the generator, that is, the frequency of the electricity supplied to each electrical device, is lowered too much as described above, there is a risk that the electrical device will not be able to exhibit the required performance.

[0008] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a marine power generation system that achieves energy savings while allowing electrical equipment mounted on a marine vessel to exhibit the required performance. [Means for solving the problem]

[0009] In order to solve the above problem, the present invention provides a marine power generation system having a generator, a control unit that controls the generator so that the output frequency of the generator becomes a predetermined target frequency that is lower than a normal frequency, electrical equipment driven by power generated by the generator, and a detection unit that detects the operating status of the electrical equipment, wherein the control unit sets the target frequency based on the operating status of the electrical equipment detected by the detection unit.

[0010] In this way, in the present invention, the operating status of the electrical equipment is detected by the detector, and the detection results are fed back to the controller to set the target frequency of the generator. This makes it possible to lower the target frequency of the generator and achieve energy savings while confirming from the detection results of the detector that the electrical equipment is performing as required.

[0011] When setting the target frequency of the generator, it is preferable that the control unit first checks whether the operating status of the electrical equipment detected by the detection unit is within a normal range. If the operating status of the electrical equipment is outside the normal range, it can be assumed that some abnormality has occurred in the power generation system including the electrical equipment. In this case, it is preferable to set the target frequency to the normal frequency and supply sufficient power to the electrical equipment.

[0012] If the operating status of the electrical equipment detected by the detector is within the normal range, it is preferable to further check whether the operating status of the electrical equipment is within a good range set within the normal range. If the operating status of the electrical equipment is within the normal range but outside the good range, it can be assumed that there is no abnormality in the power generation system including the electrical equipment, but that there is little spare power supplied to the electrical equipment. In this case, it is preferable that the controller increase the target frequency to increase the output of the generator and increase the power supplied to the electrical equipment.

[0013] If the operating conditions of the electrical equipment detected by the detector are within a good range, it is preferable to further check whether the output frequency of the generator has reached a preset lower limit. If the output frequency of the generator is higher than the lower limit, the target frequency can be lowered to save energy.

[0014] The control unit can set one frequency selected from the normal frequency and a plurality of frequencies lower than the normal frequency as the target frequency. In this case, even if the power supplied to the electrical equipment is insufficient and it becomes necessary to increase the target frequency of the generator, it is possible to set a frequency lower than the normal frequency, thereby achieving energy savings.

[0015] The target frequency may be set by feedforward control based on a disturbance that may affect the operating status of the electrical equipment, in addition to or instead of the feedback control based on the operating status of the electrical equipment as described above. Specifically, the marine power generation system may have a disturbance detection unit that detects a disturbance that may affect the operating status of the electrical equipment, and the control unit may set the target frequency based on the detection result of the disturbance detection unit.

[0016] In this way, by detecting disturbances that may affect the operating status of the electrical equipment using the disturbance detection unit, it is possible to predict the future power requirements and set the target frequency. For example, if the disturbance detection unit detects a disturbance, the target frequency can be increased to supply sufficient power to the electrical equipment, thereby preventing malfunction of the electrical equipment due to a power shortage. On the other hand, if the disturbance detection unit does not detect a disturbance, the target frequency of the generator can be maintained or decreased to achieve energy conservation.

[0017] For example, when sea conditions are bad, the load on the ship's main engine fluctuates significantly. If the generator's output frequency is low at this time, the power supplied to the electric pump that supplies lubricating oil and cooling water to the main engine will be reduced, and as a result, the output (capacity) of the electric pump will be reduced, which may make it unable to respond to increases and decreases in the load on the main engine during bad weather. Therefore, if the disturbance detection unit detects worsening sea conditions, it is preferable to increase the target frequency and supply sufficient power to electrical equipment, including the electric pump, when this disturbance detection unit detects worsening sea conditions.

[0018] Furthermore, for example, when the ship accelerates, the load on the ship's main engine increases. If the output frequency of the generator is low at this time, the output of the electric pump that supplies lubricating oil and cooling water to the main engine will be reduced, which may result in the main engine being unable to cope with the increased load. Therefore, if the disturbance detection unit detects the load on the main engine of the ship equipped with the marine power generation system, it is preferable that, when the disturbance detection unit detects that the load on the main engine of the ship exceeds a predetermined value, the disturbance detection unit raises the target frequency to supply sufficient power to electrical equipment including the electric pump.

[0019] Furthermore, when a ship navigates in narrow waters, it may be necessary to suddenly increase the output of the ship's main engine. In this case, if the output frequency of the generator is low, the output of the electric pump that supplies lubricating oil and cooling water to the main engine will be reduced, and there is a risk that it will not be able to respond to the increase in the output of the main engine. Therefore, if the disturbance detection unit detects the position of the ship, it is preferable to increase the target frequency and supply sufficient power to electrical equipment including the electric pump when the disturbance detection unit detects that the ship has entered a sea area (e.g., narrow waters) where the output of the main engine may need to be increased.

[0020] Furthermore, when an electrical device that consumes a lot of power (for example, a drive motor for operating a bow thruster) is operated, the output of the generator increases. Therefore, if the disturbance detection unit detects a start signal for an electrical device, it is preferable that, when the disturbance detection unit detects a start signal for an electrical device that consumes a lot of power, the target frequency be increased to supply sufficient power to the electrical device. [Effects of the Invention]

[0021] As described above, the marine power generation system of the present invention can achieve energy conservation while allowing the electrical equipment mounted on the marine vessel to exhibit the required performance. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a block diagram of a marine power generation system according to an embodiment of the present invention. [Figure 2] FIG. 2 is a block diagram of a control unit of the marine power generation system of FIG. [Figure 3] 2 is a flowchart showing a procedure for setting a target frequency in the marine power generation system of FIG. 1. [Figure 4] FIG. 10 is a block diagram of a marine power generation system according to another embodiment of the present invention. [Figure 5] 5 is a flowchart showing a procedure for setting a target frequency in the marine power generation system of FIG. 4. DETAILED DESCRIPTION OF THE INVENTION

[0023] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0024] As shown in Fig. 1, a marine power generation system according to one embodiment of the present invention includes a control unit 1, a prime mover 2, a generator 3, a switchboard 4, and electrical equipment 5. In this embodiment, multiple sets of prime movers 2 and generators 3 driven thereby are provided. The marine power generation system of this embodiment also includes multiple electrical equipment 5. The electrical equipment 5 is connected to the main bus of the switchboard 4 without going through a frequency control device such as an inverter, and may include, for example, an electric pump for supplying lubricating oil and cooling water to machinery mounted on the marine vessel (such as a main engine that drives a propulsion propeller), a ventilator for ventilating and air-conditioning the interior of the vessel, lighting inside the vessel, or a drive motor for operating the bow thruster.

[0025] The prime mover 2 has a generator engine 2a and a governor 2b. The generator engine 2a uses, for example, gas fuel or liquid fuel as fuel. The governor 2b controls the rotation speed of the generator engine 2a based on instructions from the control unit 1. In this embodiment, the governor 2b has a governor motor that adjusts the amount of fuel supplied to the generator engine 2a. When the governor 2b increases the fuel supplied to the generator engine 2a, the rotation speed of the generator engine 2a increases, and when the governor 2b decreases the fuel supplied to the generator engine 2a, the rotation speed of the generator engine 2a decreases.

[0026] The generator 3 has a rotor and a stator, and when the rotor is rotated, electricity is generated in a coil provided on the stator. The rotor of the generator 3 is connected to the output shaft of the generator engine 2a, and they rotate integrally.

[0027] The switchboard 4 supplies the power generated by the generator 3 to each electrical device 5 via a bus. The switchboard 4 has a frequency measuring unit that measures the frequency (actual frequency) of the electricity flowing through the bus, and information on the actual frequency measured by this frequency measuring unit is transmitted to the control unit 1.

[0028] The rotation speed of the generator 3 is equal to the rotation speed of the generator engine 2a, and the rotation speed of the generator engine 2a is proportional to the frequency (output frequency) of the electricity generated by the generator 3. Furthermore, the output frequency of the generator 3 is equal to the frequency (actual frequency) of the electricity flowing through the bus bar of the switchboard 4. Therefore, the actual frequency can be measured by the frequency measurement unit provided in the switchboard 4 as described above, or can be calculated from the rotation speed of the generator engine 2a, the rotation speed or output frequency of the generator 3. In this embodiment, a frequency measurement unit is provided that measures the output frequency of the generator 3, and the frequency measured by the frequency measurement unit of the switchboard 4 and the output frequency measured by the frequency measurement unit of the generator 3 are transmitted to the control unit 1.

[0029] The marine power generation system is provided with a detection unit 6 that detects the operating status of each electrical device 5. For example, if the electrical device 5 is an electric pump, the detection unit 6 may be provided with a pressure gauge that detects the discharge pressure of the electric pump, a flow meter that detects the discharge flow rate of the electric pump, or a thermometer that measures the temperature of the fluid (e.g., cooling water) pumped by the electric pump. If the electrical device 5 is a ventilator, the detection unit 6 may be provided with a thermometer that measures the temperature of the area where the ventilator is installed (such as an engine room or a hold), a barometer that measures the air pressure in that area, or a measuring instrument that measures the air properties in that area (e.g., CO concentration, NOx concentration, combustible gas concentration, etc. in that area).

[0030] The control unit 1 controls the output frequency of the generator 3 by controlling the rotation speed of the prime mover 2. As shown in Fig. 2, the control unit 1 of this embodiment has a memory 1a, an output unit 1b, and a target frequency setting unit 1c.

[0031] The memory 1a stores an actual load factor 11, a target load factor 12, an actual frequency 13, and a target frequency 14.

[0032] The actual load factor 11 is the ratio of the current output to the individual rated output of each generator 3. For example, the output voltage and current of each generator 3 are measured at short time intervals, and the actual load factor 11 is calculated from these values. This actual load factor 11 is stored in the memory 1a, or the value of the actual load factor 11 already stored in the memory 1a is updated.

[0033] The target load factor 12 is a target value of the load factor of each generator 3, and is input by an input means provided in the control unit 1. The target load factor 12 is set appropriately according to the capacity of each generator 3, etc.

[0034] The actual frequency 13 is the actual frequency of the electricity generated by the generator 3. In this embodiment, the frequency of the electricity flowing through the bus is measured by a frequency measuring unit provided in the switchboard 4, and this frequency is stored in the memory 1a as the actual frequency 13, or the value of the actual frequency 13 already stored in the memory 1a is updated.

[0035] The target frequency 14 is a target value of the output frequency of the generator 3. In this embodiment, the frequency optimally set by the target frequency setting unit 1c is stored as the target frequency 14 in the memory 1a.

[0036] The output unit 1b calculates a command value (driving time) for the governor 2b of the prime mover 2 based on the actual load rate 11, target load rate 12, actual frequency 13, and target frequency 14 stored in the memory 1a, and outputs the value to the governor 2b. That is, while monitoring the actual load rate 11 and the actual frequency 13, the output unit 1b drives the governor 2b of the prime mover 2 so that the actual load rate 11 and the actual frequency 13 approach the target load rate 12 and the target frequency 14, respectively.

[0037] In this embodiment, the target frequency 14 is not a fixed value but is optimally set by the target frequency setting unit 1c. Specifically, the target frequency setting unit 1c stores three or more frequency levels, including a regular frequency, a lower limit frequency, and frequencies between these, and sets a frequency selected from these as the target frequency 14. For example, the target frequency setting unit 1c stores four frequency levels: 60 Hz (regular frequency), 59 Hz, 58 Hz, and 57 Hz (lower limit), and sets a frequency selected from these as the target frequency 14. Note that the regular frequency and the lower limit, and the frequencies between the regular frequency and the lower limit, may be set in any manner. For example, the regular frequency may be set to 50 Hz, and the frequencies between the regular frequency and the lower limit may be set in increments of 0.5 Hz or 0.1 Hz.

[0038] The procedure for setting the target frequency 14 by the target frequency setting unit 1c will be described below with reference to FIG.

[0039] When the marine power generation system starts, it is first checked whether the frequency optimization mode is ON (step S1). The marine power generation system is provided with a switching means for switching the frequency optimization mode ON / OFF, and the crew operates the switching means to set the frequency optimization mode ON or OFF. If the frequency optimization mode is OFF, the normal frequency is set as the target frequency (step S6). On the other hand, if the frequency optimization mode is ON, the process proceeds to the next step S2.

[0040] In step S2, it is confirmed whether or not an abnormality has occurred in the power generation system (plant) including the plurality of electric devices 5. In this embodiment, an alarm is issued when the operating status of each electric device 5 detected by the detection unit 6 is outside of a normal range, i.e., when the temperature, pressure, flow rate, load, etc. related to the electric device 5 are outside of the normal range. For example, if the electric device 5 is an electric pump, an alarm is issued when the discharge pressure, discharge flow rate, fluid temperature, etc. of the electric pump detected by the detection unit 6 are outside of a predetermined normal range. Also, if the electric device 5 is a ventilator, an alarm is issued when the temperature, air pressure, air properties, etc. of the corresponding area detected by the detection unit 6 are outside of a predetermined normal range. The normal range in this case is the range that can be reached when each electric device 5 is operating normally.

[0041] If the detection result of any of the detectors 6 is outside the normal range, i.e., if any of the detectors 6 issues an alarm, it is determined that an abnormality has occurred in the power generation system, and the target frequency setting unit 1c sets the normal frequency as the target frequency (step S6).If the detection results of all the detectors 6 are within the normal range, i.e., if none of the detectors 6 has issued an alarm, it is determined that the entire power generation system is operating normally, and the process proceeds to the next step S3.

[0042] In step S3, the power reserve of the power generation system including each electrical device 5 is confirmed. Specifically, it is confirmed whether the operating status of each electrical device 5 detected by the detection unit 6 is within a good range set within the normal range. For example, if the electrical device 5 is an electric pump, it is confirmed whether the discharge pressure, discharge flow rate, fluid temperature, etc. of the electric pump detected by the detection unit 6 are within a good range. Also, if the electrical device 5 is a ventilator, it is confirmed whether the temperature, air pressure, air properties, etc. of the relevant area detected by the detection unit 6 are within a good range. The good range in this case is a range that can be reached when each electrical device 5 is operating with sufficient power reserve.

[0043] If the detection result of any of the detectors 6 is outside the acceptable range, the current target frequency stored in the memory 1a is checked (step S4). If the current target frequency is lower than the normal frequency, the target frequency setting unit 1c raises the target frequency by one step (step S7). On the other hand, if the current target frequency is the normal frequency, the target frequency setting unit 1c maintains that target frequency (normal frequency) (step S8). If the detection results of all the detectors 6 are within the acceptable range, it is determined that all the electrical devices 5 are exhibiting the required performance and that the power generation system has sufficient reserve capacity, and the process proceeds to step S5.

[0044] In step S5, the bus frequency (actual frequency) measured by the frequency measurement unit provided in the switchboard 4 is checked. Specifically, it is checked whether the actual frequency has reached the lower limit (57 Hz). If the actual frequency has reached the lower limit, the target frequency setting unit 1c maintains the target frequency at the current value (lower limit) (step S8). On the other hand, if the actual frequency is greater than the lower limit, the target frequency setting unit 1c lowers the target frequency by one step (step S9).

[0045] When the target frequency setting unit 1c sets a target frequency in any of the above steps S6 to S9, the target frequency is overwritten in the memory 1a, updating the already stored target frequency 14. Thereafter, the process returns to step S1 again, and the above procedure is repeated.

[0046] As described above, the operating status of each electrical device 5 detected by the detection unit 6 is fed back to the control unit 1 (steps S2 and S3), and the target frequency is set based on the operating status of each electrical device 5. This makes it possible to save energy by setting the target frequency to as small a value as possible while confirming that each electrical device 5 is performing as required.

[0047] Furthermore, in this embodiment, the target frequency setting unit 1c can set the target frequency 14 not only to the regular frequency and the lower limit value, but also to a frequency set between these. As a result, even if it is determined in step S3 that there is "no margin," for example, the target frequency can be set to a frequency lower than the regular frequency (for example, 58 Hz) rather than being raised all at once to the regular frequency (60 Hz). In this way, setting the frequency to the minimum necessary to ensure margin of power generation system energy conservation is achieved.

[0048] On the other hand, when lowering the target frequency in step S9, the target frequency is not lowered all at once to the lower limit (57 Hz), but is lowered gradually and stepwise, thereby reliably preventing malfunction of the electrical device 5 due to insufficient power.

[0049] The present invention is not limited to the above-described embodiment. Other embodiments of the present invention will be described below, but redundant explanations of the same points as those in the above-described embodiment will be omitted.

[0050] The embodiment shown in FIG. 4 differs from the above-described embodiments in that it includes disturbance detectors 7a to 7d that detect disturbances that may affect the operating status of each electrical device 5. FIG.

[0051] The first disturbance detection unit 7a detects a deterioration in sea conditions. The first disturbance detection unit 7a of this embodiment detects a change in the state of the ship due to a deterioration in sea conditions. For example, the first disturbance detection unit 7a may be provided with an accelerometer that detects the vertical acceleration of the ship (i.e., the magnitude of the waves) or a measurement unit that measures the ship's propeller slip (the ratio of the main engine rotation speed to the ship's speed).

[0052] The second disturbance detection unit 7b detects the load on the main engine that drives the propeller of the ship on which this power generation system is installed. For example, the second disturbance detection unit 7b detects the load on the main engine based on a command signal to the main engine. Specifically, the second disturbance detection unit 7b detects the load on the main engine by detecting the difference between the command rotation speed to the main engine and the actual rotation speed of the main engine, or the rate of change per hour of the command rotation speed to the main engine.

[0053] The third disturbance detector 7c detects the position of the ship that the power generation system is installed in. For example, a GPS device that detects the position of the ship can be provided as the third disturbance detector 7c.

[0054] The fourth disturbance detection unit 7d is provided in the control unit 1 and detects start signals from the control unit 1 to each electrical device 5, in particular start signals to electrical devices that consume a large amount of power (for example, a drive motor for operating a bow thruster).

[0055] In this embodiment, the detection results of the disturbance detectors 7a to 7d are transmitted to the controller 1, and the target frequency is set based on these detection results (feedforward control). Specifically, as shown in Fig. 5, step S11 is provided to check whether or not there is a disturbance. In the illustrated example, step S11 to check whether or not there is a disturbance is provided between step S1 and step S2.

[0056] For example, when sea conditions are bad, the load on the main engine increases or decreases significantly, and the moment the load on the main engine increases, there is a risk that the output (capacity) of each electrical device 5, particularly the electric pump that supplies cooling water and lubricating oil to the main engine, will be insufficient. Therefore, if the first disturbance detection unit 7a detects a deterioration in sea conditions, specifically if the vertical acceleration of the ship measured by the accelerometer or the propeller slip value measured by the measurement unit exceeds a preset allowable range, the control unit 1 that receives this detection result determines in step S11 that "a disturbance has occurred," and the target frequency setting unit 1c sets the normal frequency as the target frequency (step S6), and sufficient power is supplied to each electrical device 5.

[0057] Furthermore, when the ship accelerates, the load on the ship's main engine increases, which may cause a shortage of output from each electrical device 5, particularly the capacity of the electric pump that supplies cooling water and lubricating oil to the main engine. In this embodiment, the second disturbance detection unit 7b detects the load on the main engine based on a command signal to the ship's main engine, and determines the presence or absence of a disturbance based on this detection result. For example, if the second disturbance detection unit 7b detects that the difference between the command rotation speed and the actual rotation speed of the ship's main engine or the rate of change per unit time of the command rotation speed exceeds a predetermined value, the control unit 1 that receives this detection result determines in step S11 that a "disturbance is present," and the target frequency setting unit 1c sets the normal frequency as the target frequency (step S6), thereby supplying sufficient power to each electrical device 5, including the electric pump.

[0058] Furthermore, when a ship navigates in narrow waters, the output of the main engine may increase suddenly, which may cause a shortage of capacity in the electric pump that supplies cooling water and lubricating oil to the main engine. Therefore, when the third disturbance detection unit 7c detects that the ship is about to navigate an area of ​​sea (e.g., narrow waters) where the output of the main engine may increase suddenly, the control unit 1, which has received this detection result, determines in step S11 that "a disturbance has occurred," and the target frequency setting unit 1c sets the normal frequency as the target frequency (step S6), thereby supplying sufficient power to each electrical device 5, including the electric pump.

[0059] Furthermore, when an electric device 5 with high power consumption (for example, a drive motor for operating a bow thruster) is operated, the output of the generator 3 increases. Therefore, when the fourth disturbance detection unit 7d detects a start signal to the electric device 5, particularly a start signal to an electric device 5 with high power consumption, the control unit 1, which receives this detection result, determines in step S11 that "a disturbance has occurred," and the target frequency setting unit 1 sets the normal frequency as the target frequency (step S6). This increases the amount of power generated by the generator 3, and by supplying sufficient power to the electric device 5 with high power consumption, malfunctions of the electric device 5 due to insufficient power can be prevented.

[0060] On the other hand, if none of the disturbance detection units 7a to 7d detects a disturbance, that is, if the first disturbance detection unit 7a does not detect a worsening of sea conditions, the main engine load detected by the second disturbance detection unit 7b is below a predetermined value, the position of the ship detected by the third disturbance detection unit 7c is not in an area where an increase in main engine output is expected, and the fourth disturbance detection unit 7d does not detect the start of an electrical device 5 with high power consumption, then in step S11 it is determined that there is no disturbance and the process proceeds to the next step S2.

[0061] As described above, when the disturbance detection units 7a to 7d detect a disturbance, the target frequency is set as the normal frequency and sufficient power is supplied to each of the electrical devices 5, thereby preventing malfunction of each of the electrical devices 5 due to insufficient power. Note that if not particularly necessary, any one or more of the disturbance detection units 7a to 7d may be omitted, or a disturbance detection unit that detects another disturbance may be provided.

[0062] Furthermore, when the disturbance detection units 7a to 7d detect a disturbance, the target frequency may be set to the minimum necessary frequency rather than being uniformly set to the normal frequency. Specifically, if it is determined in step S11 that "a disturbance has occurred," the process proceeds to step S4, where the current target frequency is confirmed, rather than proceeding to step S6 as shown in Fig. 5. If the current target frequency is lower than the normal frequency, the target frequency is increased (step S7), and if the current target frequency is the normal frequency, the target frequency is maintained (step S8).

[0063] Furthermore, in the embodiment shown in FIG. 5, both feedback control based on the operating status of each electrical device 5 (steps S2, S3) and feedforward control based on the presence or absence of disturbance (step S11) are provided, but this is not limited thereto. For example, in the flow chart shown in FIG. 5, the feedback control based on the operating status of each electrical device 5 (steps S2, S3) may be omitted. [Explanation of symbols]

[0064] 1. Control section 2. Prime Mover 2a Generator engine 2b Governor 3. Generator 4 Switchboard 5. Electrical Equipment 6. Detection unit 7a to 7d Disturbance detection section

Claims

1. A generator and a control unit that controls the generator so that the output frequency of the generator becomes a predetermined target frequency that is equal to or lower than a normal frequency; an electric device driven by the electric power generated by the generator; a detection unit for detecting an operating state of the electrical equipment, The control unit sets the target frequency based on the operating conditions of the electrical equipment detected by the detection unit.

2. 2. A marine power generation system according to claim 1, wherein the control unit checks whether the operating conditions of the electrical equipment detected by the detection unit are within a normal range, and if the operating conditions of the electrical equipment are outside the normal range, sets the target frequency to the normal frequency.

3. When the working status of the electrical equipment detected by the detection unit is within the normal range, the control unit confirms whether the operating status of the electrical device detected by the detection unit is within a good range set within the normal range, 3. The marine power generation system according to claim 2, wherein the target frequency is increased if the operating conditions of the electrical equipment are outside the favorable range.

4. When the work status of the electrical equipment detected by the detection unit is within the good range, the control unit confirms whether the output frequency of the generator has reached a lower limit value, 4. The marine power generation system according to claim 3, wherein the target frequency is lowered when the output frequency of the generator is higher than a lower limit value.

5. 2. The marine power generation system according to claim 1, wherein the control unit sets one frequency selected from the normal frequency and a plurality of frequencies lower than the normal frequency as the target frequency.

6. a disturbance detection unit that detects a disturbance that may affect the operating status of the electrical device; The marine power generation system according to claim 1 , wherein the control unit sets the target frequency based on a detection result of the disturbance detection unit.

7. 7. A marine power generation system according to claim 6, wherein the disturbance detection unit detects a deterioration in sea conditions.

8. 7. A marine power generating system according to claim 6, wherein the disturbance detection unit detects a load on a main engine of a marine vessel on which the marine power generating system is mounted.

9. 7. A marine power generating system according to claim 6, wherein the disturbance detection unit detects the position of the marine vessel on which the marine power generating system is mounted.

10. 2. The marine power generation system according to claim 1, wherein the disturbance detection unit detects a start signal sent to the electrical device.

11. A generator and a control unit that controls the generator so that the output frequency of the generator becomes a predetermined target frequency that is equal to or lower than a normal frequency; an electric device driven by the electric power generated by the generator; a disturbance detection unit that detects a disturbance that may affect the operating status of the electrical equipment, The control unit sets the target frequency based on the detection result of the disturbance detection unit.

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