JP2000262085A - Electric propulsion device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase efficiency on lower output side by mounting a first steady state power converting means for driving a propulsion motor when the propulsion motor is operated at higher output than prescribed output, and a second steady state power converting means for driving the propulsion motor when the propulsion motor is operated at lower output than the prescribed output. SOLUTION: Respective high-output steady state power converting means 5, 6 and respective low-output steady state power converting means 20, 21 are mounted on an electric propulsion device for vessel having two propellers 11, 12. When a power apparatus 1 is operated and respective propulsion motors 9, 10 are driven by electric power generation on a generator 2, the respective steady state power converting means 5, 6 in driving them at high output, and the respective steady state power converting means 20, 21 in driving them at low output supply electric power to the respective propulsion motors 9, 10. It is thus possible to attain high efficient operation over a wide range from the higher output to the lower output, thereby saving fuel consumption.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric propulsion device applied to, for example, operating a ship at high speed and low speed.

[0002]

2. Description of the Related Art FIG. 7 is a configuration diagram of such an electric propulsion device.

[0003] A power generator (Ge) 2 is connected to a power unit (Eng) 1 such as a diesel or gas turbine. The output end of the generator 2 is connected to a main power supply bus 4 via a circuit breaker 3, and the output (power) of the generator 2 is supplied to the main power supply bus 4 via the circuit breaker 3.

[0004] A plurality of semiconductor power converters, here semiconductor power converters 5 and 6, are connected to the main power supply bus 4 via circuit breakers 7 and 8, respectively. These semiconductor power converters 5 and 6 each include an inverter or a cycloconverter or the like, and receive power supplied from the generator 2 to receive propulsion motors (Mo) 9 and Mo, respectively.
10 is driven. Propellers 11 and 12 are connected to the propulsion motors 9 and 10, respectively.

The efficiency of these semiconductor power converters 5 and 6 is generally equal to the rated output P1 as shown by an efficiency curve Q in FIG.
, The highest efficiency is obtained, and the efficiency decreases as the output decreases.

[0006]

With the semiconductor power converters 5 and 6 having such efficiency characteristics, the propulsion motors 9 and 10 are used.
Is operated in an inefficient state in a low output range of, for example, 10 to 30% of the rated output P1 as shown in FIG.

On the other hand, as shown in the output curve R of FIG. 9, the rotation speed and output characteristics of the propulsion device are such that when the speed is reduced to one half, the output is reduced to about one eighth.

[0008] For this reason, some vessels for special use have an output at a medium speed or lower and have a long operating time. Since such a ship operates for a long time in the low speed range, the efficiency characteristics on the low speed side, for example, lower than the output P2 shown in FIG. 8 and FIG. 9 are obtained. Bulky.

Accordingly, an object of the present invention is to provide an electric propulsion device capable of improving efficiency on a low output side.

[0010]

According to the first aspect, first semiconductor power conversion means for driving the propulsion motor when the propulsion motor is operated at a large output equal to or higher than a predetermined output; And a second semiconductor power conversion means for driving the propulsion motor when operating at a low output.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (1) Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. The same parts as those in FIG. 7 are denoted by the same reference numerals, and detailed description thereof will be omitted.

FIG. 1 is a configuration diagram of an electric propulsion device applied to a ship.

Each of the semiconductor power converters 5 and 6 has a predetermined output or higher, that is, a large output.
Used as 6. These semiconductor power converters 5, 6
Is, for example, 3000 kW, 5000 kW or 8000 k
For large output such as W ~, it is composed of, for example, a cycloconverter, a load commutation type inverter or a GTO inverter. FIG. 2 shows the efficiency curves Qa of these semiconductor power converters 5 and 6, and it can be seen that the higher the output, the higher the efficiency.

The semiconductor power converters 5 and 6 are connected in parallel with semiconductor power converters 20 and 21 for small output. These semiconductor power converters 20, 2
Reference numeral 1 denotes a transistor or an IGBT inverter for low output. FIG. 2 shows the efficiency curves Qb of these semiconductor power conversion devices 20 and 21, and it can be seen that the efficiency is high in the region where the output is small.

Each of the propulsion motors 9 and 10 has a large output winding 22 and a small output winding 23, for example, as shown in FIGS. 3 (a) and 3 (b).

Next, the operation of the apparatus configured as described above will be described.

When electric power is generated in the generator 2 by driving the power unit 1, the electric power of the generator 2 is supplied to the main power supply bus 4 through the circuit breaker 3, and further through the circuit breakers 7, 8 for a large output. The power is supplied to each of the semiconductor power converters 5 and 6 and each of the semiconductor power converters 20 and 21 for low output.

When the propulsion motors 9 and 10 are driven at a large output, power is supplied to the propulsion motors 9 and 10 by the large-output semiconductor power converters 5 and 6, respectively.

When each of the propulsion motors 9 and 10 is driven at a low output, each of the semiconductor power converters 20 and
Electric power is supplied to the propulsion motors 9 and 10 by 21.

Therefore, when the ship is operated at a high speed in order to reach the destination quickly, electric power is supplied to the propulsion motors 9 and 10 using the semiconductor power converters 5 and 6 for large output. Drive. When operating at high speed, the semiconductor power converters 5, 6, 2 for large output and low output are used.
The propulsion motors 9 and 10 are operated by supplying electric power using the motors 0 and 21.

When the work is processed at a low speed after the ship arrives at the destination, power is supplied to the propulsion motors 9 and 10 by using only the low-power semiconductor power converters 20 and 21. And drive.

As described above, in the first embodiment, in addition to the semiconductor power converters 5 and 6 for large output,
Since each of the semiconductor power converters 20 and 21 for low output is provided, when the ship is operated at a high speed, the semiconductor power converters 5 and 6 are operated with a large output, and when the ship is operated at a low speed with a low output, the output is reduced. The semiconductor power converters 20 and 21 operate efficiently, and efficient operation can be performed in a range from a large output to a low output, thereby saving fuel consumption.

On the low-speed side, semiconductor power converters 20, 21 such as IGBT inverters are used.
By switching at high frequency by the BT inverter, the output waveform becomes smooth, the propulsion motors 9 and 10 can be driven with low vibration and low noise, and are superior when performing work such as acoustic measurement at the destination.

Further, since there are two systems of semiconductor power converters, even if a failure occurs in one system, it can be operated in the remaining system, and the reliability is improved.

(2) Next, a second embodiment of the present invention will be described. The same parts as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted.

FIG. 4 is a configuration diagram of the electric propulsion device.

This device is a large output propulsion motor (Mo1)
24a, 24b and a low-power propulsion motor (Mo2) 25a,
25b, and semiconductor power converters 5 and 6 for large output.
Drives the high-output propulsion motors 24a and 24b, and drives the low-output propulsion motors 25a and 25b by the low-output semiconductor power converters 20 and 21.

In this case, the propulsion motors 24a, 24b, 25a, and 25b for the large output and the low output are integrated with the example shown in FIG. There is an example that is configured in a specific manner.

With such a configuration, it is needless to say that the same effects as those of the first embodiment can be obtained, and the propulsion motor 24 on the high output side when operating at a low output.
a and 24b play a role of inertia, and can perform stable operation with little change in speed.

[0030]

As described above, according to the present invention, it is possible to provide an electric propulsion device capable of improving the efficiency on the low output side.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a first embodiment of an electric propulsion device according to the present invention.

FIG. 2 is a diagram showing an efficiency curve of the device.

FIG. 3 is a configuration diagram of a propulsion motor used in the device.

FIG. 4 is a configuration diagram showing a second embodiment of the electric propulsion device according to the present invention.

FIG. 5 is a configuration diagram of a propulsion motor used in the device.

FIG. 6 is a configuration diagram of a propulsion motor used in the device.

FIG. 7 is a configuration diagram of a conventional device.

FIG. 8 is a view showing an efficiency curve of the apparatus.

FIG. 9 is a diagram showing the relationship between the number of rotations and the output of the apparatus.

[Explanation of symbols]

 1: Power unit, 2: Generator, 3, 7, 8: Circuit breaker, 4: Main power supply bus, 5, 6: High power semiconductor power converter, 9, 10: Propulsion motor, 11, 12: Propeller 20, 21: Low power semiconductor power converter, 24a, 24b: High power propulsion motor, 25a, 25b: Low power propulsion motor.

Claims (1)

[Claims] A first semiconductor power conversion means for driving the propulsion motor when the propulsion motor is operated at a large output equal to or higher than a predetermined output; and An electric propulsion device comprising: a second semiconductor power conversion means for driving a propulsion motor.