JP5532211B2 - Ship power supply system - Google Patents

Description

  The present invention, when navigating a ship, supplies power to a propulsion motor from a power source installed in the ship via a frequency converter, and propels the ship. The present invention relates to a ship power supply system that supplies power to a propulsion motor or the like.

  The ship receives power from the power supply installed in the ship during navigation and supplies power via the ship's internal bus.The propulsion motor is driven at variable speed via the inverter to drive the propeller, The load is operating.

  When the ship is docked at the port and anchored, power to drive the propulsion motor is not necessary, but power is supplied not only to normal loads such as lighting but also to non-propulsion motors such as cargo handling. Need arises.

  When power is supplied to the load in the ship, power is supplied from the power supply in the ship at the time of navigation, but at the time of berthing, in recent years, it has been desired to reduce the emission of exhaust gas including warming gas Therefore, the diesel generator, which is the power source in the ship, is stopped, and power is supplied using land power instead.

  FIG. 2 shows an example of a conventional ship power supply system. When navigating the ship, electric power is supplied from the diesel generator 1 installed in the ship to the propulsion motor 4 via the ship bus 2 and the frequency converter 3, and the propeller 5 is driven to propel the ship. When the ship is anchored, electric power is supplied from the land power source 6 to the non-propulsion motor 7 for cargo handling or the like and the normal load 8 such as lighting. Reference numerals 9 to 13 denote switches.

  In this case, the power system in the ship is preset at, for example, a frequency of 60 Hz, whereas the power of the land power source 6 may be supplied at a frequency of 50 Hz. The normal load 8 can be selected so as not to be affected by the supplied power frequency, but the non-propulsion motor 7 for cargo handling or the like is a device whose operation is controlled at a preset frequency. If it is different, it will be affected by this, so it is necessary to convert the frequency from 50 Hz to 60 Hz so that the power of the land power source 6 can be used in the ship power system.

  In order to convert the frequency, a frequency converter 14 such as an MG set combining an electric motor and a generator or an inverter device using a stationary semiconductor switch is provided between the onshore power source 6 and the ship's bus 2. However, both devices require the cost of the device and the cost for installation, and also require a large installation space in the ship.

  Therefore, for example, as described in FIG. 4 of Patent Document 1, a frequency conversion device such as an inverter device installed in a ship and used to stabilize power generated by a shaft generator in the ship is used. It is considered that power of a frequency of 50 Hz supplied from a land power source is converted to 60 Hz and supplied to a normal load or the like in a ship.

JP 2007-151218 A

  However, as described above, when power is supplied from the onshore power source to the normal load or the like in the ship through the frequency converter, the existing frequency converter in the ship can be used, but all the power is transmitted through this frequency converter. Electricity is supplied to the ship's internal load, and the frequency converter is operated for a long time due to the use of a normal load that is often used at all times, or the current carrying capacity of the frequency converter increases. There is a problem that consumption is increased and energy is not efficient.

  The object of the present invention is to solve the problems of the prior art described above, and when power is supplied from the onshore power source to the ship when the ship is anchored, it is not affected by the difference in the power supply frequency. In addition, it is possible to provide a ship power supply system that can supply appropriate power to a non-propulsion motor without using a frequency converter, and that can further reduce power consumption and save energy. With the goal.

In order to achieve the above object, the ship power supply system according to the present invention, when navigating the ship, supplies power to the propulsion motor from the power supply installed in the ship via the ship internal bus and the frequency converter for variable speed operation. When the ship is anchored , the power source in the ship is disconnected from the in-ship bus and the on-shore power source is connected to the in-ship bus, and the propulsion motor is disconnected from the frequency converter and the on-site power source A non-propulsion motor for cargo handling or the like is selected and connected to either the frequency converter or the on-board bus in accordance with the frequency so as to supply electric power from the land power source to the non-propulsion motor. It is characterized by comprising.

  According to the power supply system for a ship according to the present invention, a non-propulsion motor for cargo handling or the like that is affected by a difference in power supply frequency when supplying power from a land power source to the ship when the ship is anchored. By connecting to the inverter of the installed frequency converter for variable speed operation and performing frequency conversion, appropriate power can be supplied to the non-propulsion motor without using the frequency converter separately. .

1 is a system configuration diagram showing an embodiment of a ship power supply system according to the present invention. It is a system block diagram which shows one Embodiment of the power supply system of the conventional ship.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a system configuration diagram showing an embodiment of a ship power supply system according to the present invention. The same reference numerals are given to the same parts as those in FIG.

  In FIG. 1, a diesel generator 1 installed in a ship is connected to a ship internal bus 2 via a switch 9. In an actual ship, a plurality of diesel generators 1 are provided, but one is shown in the figure.

  A frequency converter 3 for variable speed operation having a converter 3a, a capacitor 3b, and an inverter 3c is connected to the in-boat bus 2 via a switch 10. Converter 3a converts AC power received from shipboard bus 2 via switch 10 into DC power, capacitor 3b smoothes the DC voltage output from converter 3a, and inverter 3c converts DC power into variable voltage. Convert to AC power of variable frequency and output.

  A propulsion motor 4 for propelling a ship is connected to the output side of the frequency conversion device 3 via a switch 15 and a non-propulsion motor 7 for cargo handling or the like is connected via a switch 16 and a filter 17. It is connected. Further, the non-propulsion motor 7 is also connected to the in-ship bus 2 via the switch 12, and it is possible to select and connect either the frequency converter 3 or the in-ship bus 2. It can be separated from either.

  When the propulsion motor 4 is connected to the frequency converter 3 and operated at a variable speed, the propeller 5 directly connected to the propulsion motor 4 is driven at a variable speed to propel the ship.

  The non-propulsion motor 7 for cargo handling or the like is generally a load that is used only when the ship is anchored at the port and is controlled to operate at a preset frequency. is there. Although there may be a plurality of non-propulsion motors 7 in the drawing, one is shown in the figure. Further, the filter 17 provided on the non-propulsion motor 7 side reduces harmonics and can be omitted if it is not necessary to reduce the harmonics.

  When the non-propulsion motor 7 is supplied with power of the same frequency as a power frequency of 60 Hz, for example, which is preset as a power system in the ship, the switch 16 is opened and the switch 12 is opened. Is closed and power is directly supplied from the in-ship bus 2.

  On the other hand, when power with a power supply frequency of 50 Hz is supplied to the ship's internal bus 2, the switch 16 is closed and the switch 12 is opened, and the power converted to 60 Hz is supplied via the frequency converter 3. It has come to be.

  When the non-propulsion motor 7 is not used, the switches 12 and 16 can be opened to be disconnected from the power system on the ship's bus 2 side.

  In addition to the system for supplying power to the propulsion and non-propulsion motors 4 and 7, the ship internal bus 2 is provided with a system for supplying power to the normal load 8 via the switch 13. The normal load 8 is a load that is not affected by the difference in power supply frequency such as lighting and air conditioning in the ship, and is not a load that is directly required for propulsion of the ship. It is a load that is often used all the time.

  Further, a land power source 6 can be connected to the in-ship bus 2 via a switch 11, and when the ship is anchored, a power is received from the on-site power source 6 and a predetermined inside of the ship via the in-bus bus 2. Power is supplied to the load.

  In the ship power supply system configured as described above, an operation during navigation of the ship will be described first. The switch 9 is closed to navigate the ship, and the power generated by the operation of the diesel generator 1, for example, the power of frequency 60 Hz, is the ship's bus 2, switch 10, frequency converter 3, and switch. The propeller 5 that is supplied to the propulsion motor 4 through 15 and directly connected to the propulsion motor 4 is driven to propel the ship. At this time, the switch 16 is open and the non-propulsion motor 7 for cargo handling or the like is not energized.

  On the other hand, the switch 13 on the side of the normal load 8 is closed, and electric power with a frequency of 60 Hz is supplied to the normal load 8 through the ship bus 2.

  Next, the operation while the ship is anchored will be described. When the ship berthed at the port and anchored, the diesel generator 1 was stopped, the switch 9 was opened to stop the power supply at a frequency of 60 Hz, the switch 11 was closed, and the onshore power supply 6 was connected to the in-ship bus 2. Then, for example, power with a power frequency of 50 Hz is supplied from the land power source 6.

  Since the propulsion motor 4 for propelling the ship does not need to be operated, the switch 15 is opened and separated from the frequency converter 3. On the non-propulsion motor 7 side, the switch 16 is closed, the switch 12 is opened, and the AC power of 50 Hz from the ship internal bus 2 is converted into DC power by the converter 3a of the frequency converter 3, and the inverter 3c Is converted into 60 Hz AC power and output, and supplied to a non-propulsion motor 7 for cargo handling or the like that is affected by the difference in power supply frequency via a filter 17.

  The normal load 8 that is not affected by the difference in power supply frequency is maintained in the state in which the switch 13 is closed, and power with a frequency of 50 Hz is directly supplied from the land power supply 6 via the ship bus 2.

  For example, when power with a power frequency of 60 Hz is supplied from the land power source 6, the non-propulsion motor 7 side opens the switch 16, closes the switch 12, and 60 Hz alternating current from the in-ship bus 2. Electric power is supplied directly to the non-propulsion motor 7.

  As described above, according to the present embodiment, the power frequency 60 Hz that is set in advance as the power system in the ship such that the frequency of the land power source 6 is 50 Hz, for example, for the non-propulsion motor 7 for cargo handling or the like. Even if they are different from each other, the frequency converter 3 for variable speed operation installed in the ship can be used to convert the frequency to 60 Hz, which is the same as the power system in the ship. Appropriate power can be supplied without being provided in the ship.

  Further, for the normal load 8 that is not affected by the power supply frequency, the power of the frequency 50 Hz of the land power supply 6 is directly supplied without passing through the frequency converter 3, so that power is supplied to the normal load 8 that is often used at all times. Therefore, it is not necessary to always operate the frequency conversion device 3 to supply power, the operation time can be shortened, and the current-carrying capacity of the frequency conversion device 3 is reduced, so that power consumption can be suppressed and energy saving can be achieved. .

  Further, when the power frequency of the onshore power source 6 is the same as the power frequency of 60 Hz set in advance as the power system in the ship, power is directly supplied from the in-bus bus 2 to the non-propulsion motor 7 via the switch 12. The frequency converter 3 is not routed. As a result, the frequency conversion device 3 can be operated only when necessary, and power consumption can be reduced to save energy.

  Note that, when an instantaneous voltage drop occurs in the supplied power due to an abnormality in the onshore power supply 6, the input voltage of the converter 3a of the frequency conversion device 3 is reduced. If the decrease time is short, the voltage of the capacitor 3b hardly decreases. Therefore, the output voltage of the inverter 3c is not affected, and the non-propulsion motor 7 is not affected.

  Moreover, although the said embodiment demonstrated the case where the electric power system in a ship was set to the frequency of 60 Hz, conversely, it can implement similarly also when the frequency is set to 50 Hz.

DESCRIPTION OF SYMBOLS 1 ... Diesel generator 2 ... Ship internal bus 3 ... Frequency converter 3a ... Converter 3b ... Capacitor 3c ... Inverter 4 ... Propulsion motor 5 ... Propeller 6 ... Land power supply 7 ... Non-propulsion motor 8 for cargo handling etc ... Normal load 9, 10, 11, 12, 13, 15, 16 ... switch 14 ... frequency converter 17 ... filter

Claims (1)

When navigating the ship, power is supplied to the propulsion motor from the power source installed in the ship via the ship's internal bus and the frequency converter for variable speed operation, and when the ship is anchored, the power source in the ship is Disconnecting from the bus in the ship and connecting a land power source to the bus in the ship, and further disconnecting the propulsion motor from the frequency converter and the non-propulsion motor for cargo handling or the like according to the power frequency of the land power A ship power supply system that supplies power from the land power source to the non-propulsion motor by selecting and connecting either the converter or the ship internal bus .

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