JP2006180653A - Shaft driven generator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent an occurrence of overcurrent trip in an externally commutated converter and burnout of a thyristor element and make it possible for a ship to continue navigation using a shaft generator for electric propulsion or propulsion assistance. <P>SOLUTION: A shaft driven generator 1 is obtained by connecting: the shaft generator 4; the externally commutated converter 5 that converts frequencies, outputted from the shaft generator, into a constant value; a reactor 7 that smooths voltage waveform distortion in the externally commutated converter; and a synchronous condenser 6 that supplies reactive power to the externally commutated converter and an electric power system, and forms the output voltage waveform of the shaft generator and reduces its voltage distortion factor. A current transformer 12 is installed on the side of the externally commutated converter as viewed from the reactor. When the shaft generator is operated as motor, the current of the externally commutated converter is controlled by the output of the current transformer. Therefore, the output current of the externally commutated converter can be properly controlled, and an occurrence of overcurrent trip can be prevented in the externally commutated converter and burnout of a thyristor element. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a shaft drive power generator that is installed and used in a main engine and a propeller shaft system of a ship.

A system for operating a shaft generator as an electric motor in a conventional shaft drive generator will be described with reference to FIG.
In the figure, reference numeral 1 denotes a shaft drive power generator, which includes a shaft generator 4, a separately excited converter 5, a synchronous phase adjuster 6, a reactor 7, and a current transformer 11. 2 is a main engine and 3 is a propeller shaft system. 8 is a power system, and 9 is an onboard power source.

As part of measures to save fuel and energy during general voyages, the shaft-driven power generator 1 uses the shaft generator 4 provided in the propeller shaft system 3 to change the frequency of the rotational energy of the main engine 2 whose speed changes. The energy is converted into energy, converted into electric power of a constant voltage and a constant frequency via the separately excited conversion device 5, the synchronous phase shifter 6 and the reactor 7, and supplied to the power system 8.
However, when the main engine 2 fails or when there is surplus power in the power system 8, the shaft generator 4 may be operated as an electric motor and used for electric propulsion or propulsion.

  When the shaft generator 4 is operated as an electric motor, power is supplied from the inboard power source 9 to the shaft generator 4 via the reactor 7, the synchronous phase adjuster 6, and the separately excited converter 5, and the failed main engine 2 is replaced. The propeller shaft system 3 is driven to perform electric propulsion. Alternatively, the propulsion boost is performed to compensate for the lack of horsepower of the main engine 2 due to stormy weather or deterioration over time.

  Further, as shown in FIG. 4, there is a shaft drive power generator in which the reactor 7 is replaced with the double winding reactor 10 in order to further enhance the effect of reducing the voltage distortion rate of the power system 8, but the other configurations are the same. The operation is also the same as described above.

  During electric propulsion or propulsion, power is supplied from the inboard power supply 9 to the shaft generator 4 and operated as an electric motor to obtain the thrust of the ship, but it is necessary for propulsion due to the increase in ship speed and the influence of waves. When the horsepower increases, a voltage drop occurs in the power system 8 to which the inboard power supply 9 is connected as the load increases. The synchronous phase adjuster 6 is connected to the power system 8 because it has the effect of reducing the voltage distortion rate of the power system 8 and suppressing the power factor delay. The synchronous phase adjuster 6 receives a small amount of active power from the inboard power supply 9 and generates reactive power. Even if a voltage drop occurs in the power system 8, the synchronous phase adjuster 6 continues to maintain the voltage with its own inertial force. Therefore, when viewed from the power system 8 where the voltage drop occurs, the voltage of the synchronous phase adjuster 6 becomes higher, and as a result, a current called a cross current flows from the synchronous phase adjuster 6 to the power system 8. The separately excited converter 5 calculates the output current from the output current of the current transformer 11, and the current that actually flows into the separately excited converter 5 due to the cross current of the synchronous phase adjuster 6 and the output current of the current transformer 11. If a difference occurs between them, the output current of the separately-excited conversion device 5 is distorted, and the shaft generator 4 is changed in magnetism, causing an overcurrent trip in the separately-excited conversion device 5 and burning the thyristor element. There is a problem.

  The present invention has been made to solve the above problems, and the problem is that a current transformer is installed in a place that takes into account the influence of the cross current flowing from the synchronous phase adjuster even when the load on the shaft generator increases. It is possible to correctly control the output current of the separately excited converter, preventing the overcurrent trip of the separately excited converter and burning of the thyristor element, and continuing the navigation with the shaft generator as electric propulsion or propulsion. It is providing the shaft drive electric power generating apparatus which can do.

  In order to solve the above-mentioned problem, the invention according to claim 1 converts a shaft generator driven by a main engine of a ship whose rotational speed changes, and a variable frequency output from the shaft generator to a constant value. A separately excited converter, a reactor for smoothing the voltage waveform distortion of the output power of the separately excited converter, a reactive power supply to the separately excited converter and the power system, formation of an output voltage waveform of the shaft generator, and In a shaft drive power generator connected to a synchronous phase adjuster that reduces the voltage distortion rate, when operating the shaft generator as an electric motor, a current transformer is installed on the side of the separately-excited converter when viewed from the reactor, and The current of the separately excited conversion device is controlled by the output of the flow device.

  With this configuration, even when the load on the shaft generator increases, the overcurrent trip of the separately-excited converter and the thyristor element can be prevented from burning, and the vessel can navigate with the shaft generator as an electric propulsion or propulsion booster. It is possible to provide a shaft drive power generator that can continue the operation.

  According to the present invention, in a system in which a shaft generator is operated as an electric motor by a shaft drive power generator, a current transformer is installed in a place that takes into consideration the influence of the cross current flowing from the synchronous phase adjuster even when the load on the shaft generator increases. This makes it possible to control the output current of the separately-excited converter correctly, prevents overcurrent trip of the separately-excited converter and prevents the thyristor element from being burned out, and the vessel navigates with the shaft generator as electric propulsion or propulsion. Can continue.

Hereinafter, the best mode for carrying out the present invention will be described.
FIG. 1 is a system configuration diagram according to the first embodiment of the present invention.
In FIG. 1, the configuration different from the conventional shaft drive power generator of FIG. 3 already described is that the current transformer 12 is viewed from the reactor 7 instead of the current transformer 11 of the conventional shaft drive power generator. Since other configurations are the same, the same components are denoted by the same reference numerals, and description thereof is omitted.

  In the present embodiment, the separately excited converter 5 calculates the output current from the output current of the current transformer 12, and the current flowing through the current transformer 12 is finally considered in consideration of the influence of the cross current flowing out of the synchronous phase adjuster 6. The current flowing into the separately excited conversion device 5 is equal to the current actually flowing into the separately excited conversion device 5, and the influence of the cross current generated from the synchronous phase adjuster 6 due to the load fluctuation of the shaft generator 4 can be prevented.

  Therefore, there is no difference between the output current of the current transformer 12 and the current that actually flows into the separately excited converter 5 due to the cross current of the synchronous phase adjuster, so that the output current of the separately excited converter 5 is distorted. Problems such as occurrence of an overcurrent trip or burning of the thyristor element in the separately excited conversion device 5 due to the occurrence of a change of magnetic field in the shaft generator 4 do not occur.

FIG. 2 is a system configuration diagram showing a second embodiment of the present invention.
As shown in FIG. 2, the present embodiment is different from the first embodiment in FIG. 1 in that a double-winding reactor 10 is provided instead of the reactor 7, and other configurations are the same. The same components are denoted by the same reference numerals, and the description thereof is omitted.

  In the present embodiment, the reactor 7 is replaced with the double-winding reactor 10 in order to further increase the voltage distortion rate reduction effect of the power system 8, but the operation is the same as that of the first embodiment. That is, in this embodiment, the separately excited converter 5 calculates the output current from the output current of the current transformer 12, and the current flowing through the current transformer 12 takes into account the influence of the cross current flowing out of the synchronous phase adjuster 6. This is the current that finally flows into the separately excited conversion device 5, and is equal to the current that actually flows into the separately excited conversion device 5, so that it is possible to prevent the influence of the cross current generated from the synchronous phase adjuster 6 due to the load fluctuation of the shaft generator 4.

  Therefore, there is no difference between the output current of the current transformer 12 and the current that actually flows into the separately excited converter 5 due to the cross current of the synchronous phase adjuster, so that the output current of the separately excited converter 5 is distorted. Problems such as occurrence of an overcurrent trip or burning of the thyristor element in the separately excited conversion device 5 due to the occurrence of a change of magnetic field in the shaft generator 4 do not occur.

The system block diagram of the shaft drive electric power generating apparatus of the 1st Embodiment of this invention. The system block diagram of the shaft drive electric power generating apparatus of the 2nd Embodiment of this invention. The system block diagram of the conventional shaft drive electric power generating apparatus. The system block diagram of the other conventional shaft drive electric power generating apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Shaft drive power generation device, 2 ... Main engine, 3 ... Propeller shaft system, 4 ... Shaft generator, 5 ... Separately excited conversion device, 6 ... Synchronous phase adjuster, 7 ... Reactor, 8 ... Electric power system, 9 ... Inboard power supply 10 ... Double winding reactor, 11 ... Current transformer, 12 ... Current transformer.

Claims (1)

A shaft generator driven by a main engine of a ship whose rotational speed changes, a separately excited conversion device that converts the fluctuation frequency output from the shaft generator to a constant, and a voltage waveform of the output power of the separately excited conversion device In a shaft-driven power generator connected to a reactor that smoothes distortion, and a synchronous phase adjuster that supplies reactive power to the separately-excited converter and the power system, and forms an output voltage waveform of the shaft power generator and reduces a voltage distortion rate When the shaft generator is operated as an electric motor, the current transformer is installed on the side of the separately excited converter when viewed from the reactor, and the current of the separately excited converter is controlled by the output of the current transformer. A shaft drive power generator characterized by the above.

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