JPS6128558B2 - - Google Patents

Description

[Detailed description of the invention]

This invention relates to an improvement in a marine vessel propulsion system that utilizes a propeller shaft generator. As for the shaft generator itself, the idea of using it as a propulsion motor in an emergency is known, but since it uses electromagnetic couplings, there are problems with cooling methods and efficiency, and rotating machines also use wound AC Many use machines, and when the capacity becomes large, problems such as maintenance of slip rings have been pointed out. On the other hand, shaft power generation systems using stationary frequency converters (thyristor inverters, etc.) have been put into practical use, but generally due to the need to flow short-circuit current,
A separately excited inverter is used. However, in this case, it is necessary to operate a synchronous phase modifier to supply reactive power to the grid, and it would be uneconomical to install this phase modifier independently. In addition, ships with variable pitch propellers (CPP) only need to have a constant main engine rotational speed, but usually high-speed and
It is common to use low-speed dual control. On ships with fixed pitch propellers (FPP), the main engine speed can be varied continuously depending on the maneuvering demands. During ocean voyages where the sea surface is calm, both CPP and FPP vessels operate at a nearly constant rotational speed for long periods of time. The problems with the propulsion systems of CPP ships and FPP ships can be summarized as follows. CPP ships: Generally, power cannot be generated on the low speed side of the main engine. Parallel operation of the shaft generator with other generators on board is also not possible. FPP ship: Requires a dedicated synchronous governor. The frequency converter is used even when the main engine speed is stable, which may cause waveform distortion, reduced efficiency, and reduced reliability. Therefore, this invention compensates for the shortcomings of CPP ships and FPP ships so that there is no waste in terms of equipment, and also uses one of the shaft generators as a propulsion motor to propel ships electrically in case of an emergency. It provides a propulsion device. The marine propulsion device of the present invention includes a first AC rotating machine connected via a first clutch that is removably controlled to a gear device that transmits the rotation of a main propulsion engine to a propeller; The first clutch is connected via a second clutch that is controlled to be engageable and detachable;
The second AC rotating machine with a difference in synchronous rotation speed
an AC rotating machine; a prime mover for driving a generator when the first AC rotating machine is used as a generator, the motor being connected to the second AC rotating machine via a detachable third clutch; A frequency conversion device provided between the armature circuit of the first and second AC rotating machines and the power supply bus, and a terminal that directly connects the armature circuit of the first and second AC rotating machines and the power supply bus. and a terminal for connecting the armature circuit to a power supply bus through a frequency converter, and selects the frequency converter according to the operation mode to connect the frequency converter to one of the first and second AC rotating machines. The three clutches are provided with a selector switch that selects and connects the clutches as desired, and the three clutches select the first, first, and third clutches depending on the operation mode of the selector switch during high speed rotation, low speed rotation, high speed stability, and low speed stability.
One of the second AC rotating machines is a shaft power generator, and one of the AC rotating machines is a synchronous phase modifier. Next, the present invention will be explained in detail based on illustrated embodiments. In FIG. 1, 1 is a main propulsion engine, and this power is transmitted to a propeller 4 (having a variable or fixed pitch) via a power coupling device 3, and to a shaft generator via a gear device 2. Reportedly.
An AC rotating machine 8 is connected to the gear device 2 via a detachable clutch 12, and an AC rotating machine 7 is connected via another detachable clutch 11. A generator drive motor 5 is connected via another detachable clutch 10. Both of these AC rotating machines 7 and 8 are mainly used for shaft power generation, but the AC rotating machine 7 can also be driven by the generator drive motor 5 and can also be used as a synchronous phase adjuster. Furthermore, the AC rotating machine 8 can be used both as a propulsion motor and as a synchronous phase modifier. However, the synchronous rotation speed of the AC rotating machine 7 is set higher than that of the AC rotating machine 8, and in a two-speed control CPP ship, the AC rotating machine 7 is set to have a higher synchronous rotation speed than the main engine 1 on the high-speed side.
The rotational speed of the AC rotary machine 8 corresponds to one rotational speed of the main engine on the low speed side. On the other hand, the armature circuits of the AC rotating machines 7 and 8 are provided with a changeover switch 13 and a frequency conversion device 14. The changeover switch 13 has terminals 1a and 2a connected to the AC rotating machines 7 and 8, a terminal 1b connected to the power supply bus 18 via the frequency conversion device 14, and a terminal 1b connected directly to the power supply bus 18 without going through the frequency conversion device 14. Terminal 2b is provided. This changeover switch 13 is designed to allow selection of six operating modes shown in the table below. In addition, the frequency converter 14 uses a separately excited inverter, and when used in an axis-generated system, changes AC power at an input of an indefinite frequency into an AC output at a constant frequency by controlling the thyristor firing therein, and
When the AC rotating machine 8 is used as a propulsion motor, the input section and the output section are reversed, and the speed of the propulsion motor is similarly controlled by ignition control of the thyristor. In addition, in this embodiment, a generator drive motor 6 and an AC rotating machine 9 are provided as another generator set. In addition, in the figure, 15, 16, and 17 indicate circuit protection devices provided in the armature circuit, respectively.

[Table] Next, the operation of the marine vessel propulsion system of this embodiment will be explained based on the above table. () During normal navigation, the main engine 1 is operated at approximately the rated speed. In addition, for CPP vessels with two-speed control system, the speed is set on the high-speed side. In this state, the operating mode is selected, and the AC rotating machine 7 supplies AC power of constant voltage and constant frequency to the power supply bus 18 via the frequency converter 14. Frequency conversion device 14
is a separately excited inverter, and reactive power to the inverter and load is obtained by operating the AC rotating machine 8 as a synchronous phase modifier. Clutches 10 and 12 are in the disengaged state, and clutch 11 is in the engaged state. An example of the rotation speed vs. output characteristic of a shaft power generation system is shown in Figure 2. When the rotation speed is 80 to 110% of the shaft generator synchronous rotation speed, the rated output is kW.
can be obtained. In this example, the synchronous rotation speed of the low-speed AC rotating machine 8 is 80% of that of the high-speed AC rotating machine 7. () If you are on a normal voyage and the sea surface is particularly calm,
Since the rotational speed of the propeller 4 has small fluctuations and is stable, the operation mode of the changeover switch 13 is selected. In this case, since the AC output of the AC rotating machine 7 is directly supplied to the power supply bus 18 without going through the frequency converter 14, the disadvantages of passing through the frequency converter 14 and complicated extra circuits, such as waveform distortion and efficiency Inconveniences such as deterioration and reliability can be avoided. () Next, when decelerating the main engine 1 for safety reasons such as when navigating in a port or through narrow channels, or when setting the main engine 1 to the low speed side on a two-speed controlled CPP ship, change the operation mode of the changeover switch 13. to select. The operation in this case is the same as above except that the AC rotating machines 7 and 8 are replaced. () Similarly, when the rotation is stable near the synchronous rotation speed of the AC rotary machine 8 during deceleration, by selecting the operation mode, the same effect as during normal voyage can be obtained. Furthermore, in this case, if the clutch 10 is engaged, the AC rotating machine 7 can be used as a standby AC generator to connect the generator sets 6 and 9.
Similarly, you can be prepared in case of an emergency. () If there is an abnormality in the main engine 1, engage the clutches 10 and 12, disconnect the clutches 11, and operate the generator sets 5 and 7 and the generator sets 6 and 9 in parallel. The coupling device 3 is disconnected, the operating mode is selected with the changeover switch 13, the input/output is reversely converted with the frequency converter 14, the constant frequency AC power of the power supply bus 18 is converted to the required frequency, and the AC power is supplied to the AC rotating machine 8. This is then used as an electric motor to control its speed. This causes the propeller 4 to rotate and propel the ship. Since the marine vessel propulsion device of the present invention has the above-described configuration and function, (1) fuel consumption can be reduced by the shaft power generation system; (2) By using two shaft generators, a constant frequency can be obtained over a wide range of main engine speeds. (3) Once the main engine speed is stabilized, the frequency converter is bypassed, so it is possible to prevent efficiency loss, waveform distortion, reliability loss, etc. (4) If there is an abnormality in the main engine, it can be disconnected and used for auxiliary electric propulsion. It is an efficient propulsion system that makes up for the shortcomings of CPP and FPP shaft launches and takes advantage of their advantages.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a marine vessel propulsion system according to an embodiment of the present invention, and FIG. 2 shows the relationship between rotation speed and output characteristics in a shaft power generation system according to the same embodiment. 1... Main engine, 2... Gear device, 4... Propeller, 5, 6... Generator drive prime mover, 7, 8...
AC rotating machine, 9...AC synchronous generator, 10,1
1, 12... removable clutch, 13... changeover switch, 14... frequency converter, 18... power supply bus.

Claims (1)

[Claims] 1. A first AC rotating machine connected via a first clutch which is controlled to be freely fitted and removable to a gear device that transmits the rotation of the main propulsion engine to the propeller; a second AC rotating machine connected via a second clutch and having a different synchronous rotational speed from the first AC rotating machine;
a motor for driving a generator when the first AC rotating machine is used as a generator, the motor being connected to the AC rotating machine via a detachable third clutch; and the first and second AC rotating machines. a frequency conversion device provided between the armature circuit and the power supply bus;
The second AC rotating machine has a terminal for directly connecting the armature circuit and the power supply bus, and a terminal for connecting the armature circuit to the power supply bus through the frequency conversion device, and the frequency conversion device is controlled according to the operation mode. and a changeover switch that selectively connects the changeover switch to either one of the first and second AC rotating machines, and the three clutches operate when the changeover switch rotates at high speed, when it rotates at low speed, A marine vessel propulsion system characterized in that one of the first and second AC rotating machines is used as a shaft power generator and one of the AC rotating machines is used as a synchronous phase modifier depending on the operation mode during high-speed stability and low-speed stability.