JPS5839323B2 - Control device for shaft drive generator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control device for a shaft-driven generator, and more specifically, the present invention relates to a control device for a shaft-driven generator, and more specifically, the shaft-driven generator is driven by a main engine, and the voltage and frequency are always maintained at a constant level without being affected by external loads such as waves or the generator load. The present invention relates to a control device for a shaft-driven generator for ships, which is capable of supplying generated energy.

Normally, this type of marine generator is driven by an auxiliary diesel engine or an auxiliary steam turbine independent of the main engine for driving the propulsion shaft, so two engines are installed in the tower.

Therefore, if the main engine can drive something that is driven by a generator or other auxiliary equipment, the auxiliary equipment becomes unnecessary, the space occupied by the auxiliary equipment can be effectively used, and it is very advantageous in terms of maintenance.

In reality, small fishing boats and variable-pitch propeller ships have traditionally used shaft-driven power generators, which divert a portion of the main engine's output to drive a generator.

However, with this method, when the load on the propeller of the propulsion shaft changes periodically due to external load fluctuations such as waves, this effect appears as a change in the rotation speed of the propulsion shaft, which inevitably causes a large change in the rotation speed of the generator. The voltage and frequency will fluctuate.

For this reason, the above method is not currently used on large ships.

However, the main conventional shaft-driven power generators are: ■ A method used in combination with an auxiliary diesel generator, ■ A method that electrically converts the frequency, and ■ A method that mechanically keeps the generator rotation speed constant. Yes, method (■) automatically switches to the diesel drive of the auxiliary equipment when the frequency fluctuation of the transformer exceeds a certain limit value due to fluctuations in the main engine speed. This is a method of converting the electric power generated by a generator directly driven by the engine into electric power of the required frequency by electrically processing it using an inverter or Ward Leonard, etc. Method (2) also involves installing an electromagnetic coupling on the generator drive shaft. This control is performed by controlling the slip or by increasing or decreasing the additional rotation speed using a differential device.

However, even with these three methods, there are problems in that the device becomes complicated and the generated electricity cannot be controlled reliably.

Therefore, an object of the present invention is to solve the drawbacks of these conventional systems by adopting a propulsion shaft drive system in which power is supplied from the main engine, and to avoid fluctuations in the propulsion shaft, or in other words the main engine rotational speed, due to waves, etc. It is an object of the present invention to provide a control device for a shaft-driven generator suitable for a ship, which can always control the generator drive rotation speed at a constant level regardless of changes in the generator load.

An example of implementation of the present invention will be described below with reference to the drawings.

Most of the output of the main engine 1 is transmitted to the propulsion shaft 2 via the operating gear 4 to rotationally drive the propeller 3, and the remaining output is divided into the input of the planetary gear system 5 and the input of the hydraulic pump 60, respectively. is converted into power.

The rotation speed of the propulsion shaft 20 is determined by an electric speed detector 8 via a gear 7.
The signal from the detector 8 is sent to an electrical signal processing device 9.

The output shaft 10 of the planetary gear system 5 drives a generator 11, and this generator 11 supplies electrical energy to electrical equipment inside the ship.

A gear 12 is interlocked with the output shaft, in other words, the input shaft 10 of the generator 110, and the rotation speed of the input shaft 10 is detected by the electrical speed detector 13 via the gear 12. The output signal is sent to an electrical signal processing device 14.

On the other hand, the hydraulic pump 6 is hydraulically connected to a hydraulic motor 17 via a pipe line 15 and a hydraulic unit 16 to form a closed circuit.
The hydraulic motor 17 supplies hydraulic pressure commensurate with the tilting angle of the hydraulic pump 6.
and drive it.

The output shaft of the hydraulic motor 17 is meshed with a ring gear 18 of the planetary gear device 5.

That is, the output to the planetary gear set 5 and the fluid power to the hydraulic pump 6, which are divided by the operating gear 4, are combined again by connecting the hydraulic motor 17 and the ring gear 18, and the output shaft 10
This output drives the generator 11.

Incidentally, each gear coating 4, 5 is supplied with lubricating oil from a lubrication unit 40 to improve the rotation of the gear.

Furthermore, after the output signals of each of the electrical speed detectors 8.130 are processed by the signal processing devices 9 and 14, they are amplified by the power amplifier 19, and the output signals are sent to the tilting angle control device 20. The tilting angle of the hydraulic pump 6 is increased or decreased according to an input signal.

That is, when there is a variation in the rotational speed of the propulsion shaft 2, the input shaft 10 of the generator 110, this variation is electrically detected and sent to the tilt angle control device 20 to change the discharge amount of the hydraulic pump 6.

For this reason, the hydraulic motor 17 is driven in accordance with this discharge amount, and the planetary gear 5 is controlled via the ring gear 18 to correct the output shaft 100 rotation speed.

In this case, when an external load is applied to the propeller 3 due to waves etc., the rotation speed of the propulsion shaft 2 and the main engine 10 will fluctuate, so this fluctuation will also affect the input shaft 10 of the generator 110; It may be detected, it may be detected from the input shaft 10, or it may be detected at the same time.

When detected simultaneously, the two signals are collectively processed by one signal processing device and input to the power amplification device.

The tilt angle control device 20 may be a combination of an electrohydraulic servo valve and an operating cylinder, or may be a combination of an electric servo motor or an electric pulse motor and a feed screw mechanism.

Here, the hydraulic unit 16 and the hydraulic drive mechanism in the case of using the tilting angle control device consisting of the electromagnetic proportional pressure control valve and the servo regulator are shown in FIG. 2, and will be explained.

The hydraulic pump 6 is connected to a hydraulic motor 17 via a circuit 15, and this circuit 15 is supplied with hydraulic oil from a boost pump 21.

At startup or in an emergency, if the short-circuit valve 22 is switched to the right position, the hydraulic fluid discharged from the hydraulic pump 6 is returned to the pump 6 via the relief valve 24 and check valve 25 of the valve unit 23, but normally the short-circuit valve 22 is switched to the right position. 22 to the left position, the hydraulic oil flows to the relief valve 2.
4, the entire amount of oil is supplied to the hydraulic motor 17 to drive it.

On the other hand, the hydraulic pump 6 is connected to a tilting angle control device 20, and this control device 20 consists of a servo regulator 26 and an electromagnetic proportional pressure control valve 27.
Pump 3 for servo regulator is installed in cylinder 28 in 6.
1 through a switching valve 29, which is connected to a cylinder 30 on one side.

The hydraulic power source pump 32 of the electromagnetic proportional pressure control valve has a throttle 33
and a tank 34 via the pressure control valve 27, and hydraulic pressure is led to the cylinder 30 from between the throttle 33 and the pressure control valve 27.

A signal from the power amplifier 19 is sent to the pressure control valve 27, and this signal activates a solenoid to control the pressure and flow rate.

When the pressure increases or decreases in this pressure control valve 27, this pressure fluctuation acts on the cylinder 30, switches the switching valve 29 in one direction, and expands or compresses the cylinder 28.

Therefore, the tilting angle of the hydraulic pump 6 is changed, and the rotation speed of the hydraulic motor 17 is changed.

That is, the tilting angle of the hydraulic pump 6 is displaced by an amount commensurate with the input signal of the pressure control valve 27.

Next, in this control device, the feedback control method is
Let's talk about the diagram.

The output of the main engine 1 is supplied to a variable displacement axial piston pump 6 and a planetary gear system 5.

Main engine speed fluctuation caused by waves etc. from this state 5
0 and generator load fluctuation 35 act on the generator 11 , a generator rotational speed fluctuation 51 is detected by the electrical speed detector 13 , and this detected signal is further sent to the electrical signal processing device 14 .

A reference signal 38 is constantly sent to the electrical signal processing device 14, and the signal from the detector 13 is compared with the reference signal 38 to perform error detection 36 and signal processing 37.

The error signal processed by the signal processing device 14 is sent to the power amplification device 19 and amplified.

The amplified signal is sent to the tilting angle control device 20 to change the tilting angle of the pump 6, and accordingly, the rotation speed of the hydraulic motor 17 changes depending on the increase or decrease in the flow rate corresponding to the change, and the rotation speed of the hydraulic motor 17 changes.
In other words, the rotation speed of the generator 11 is maintained constant.

As mentioned above, even if the rotation speed of the generator 110 fluctuates, this fluctuation is fed back and in order to correct it, the generator 11
is always maintained at a constant speed.

Next, the feedforward control method will be explained with reference to FIG.

The control system shown in Figure 3 directly feeds back the generator 110 rotation speed, but the fact that there is a fluctuation in the generator 110 rotation speed means that there is a fluctuation in the propulsion shaft 2 and main engine 10 rotation speed. Therefore, in the case of Figure 4, the main engine 10
The purpose is to detect and control rotational speed fluctuations 50.

That is, the main engine rotational speed is detected by a turning speed detector 8, and the signal thereof is directly sent to an electrical signal processing device 9, and other operations are the same as in the case of FIG.

Comparing this feed-forward method and the feedback method shown in FIG. In the system shown in the figure, fluctuations in the rotational speed of the propulsion shaft are detected and corrective actions are started before fluctuations appear on the input shaft 10, so fluctuations in the rotational speed of the output shaft due to fluctuations in the rotational speed of the main engine are reduced.

On the other hand, the amount of leakage in the hydraulic system changes due to the load fluctuation of the generator 11, and the rotational speed of the hydraulic motor 17 and the generator 11 changes, but this is not compensated for and remains as a deviation, but it is generally small enough to be practical.

Furthermore, since the signal flow in FIG. 4 is an open loop, the stability is relatively good.

Furthermore, the feedback/feedforward control method shown in FIG.
Use two 3s.

This uses the engine speed fluctuation as a feedforward control signal, detects the generator speed fluctuation as a feedback control signal, and processes these with the electrical signal processing device 14, using the same route as the two control methods described above. It is for controlling.

In this method, feedforward control is used to reduce fluctuations 51 in the number of generator circuits caused by fluctuations 50 in the main engine speed, and feedback control is used to reduce load fluctuations 3.
In addition, the error caused by 5 is further reduced.

As described above, the features and effects of this control device are as follows.

■ Since signal processing is performed electrically, there is no need for a complicated mechanism for signal processing, and reliability and maintenance and inspection are easy, and the system is not only compact, but also easy to improve system characteristics.

■ Power transmission is not done entirely by hydraulic pressure, but uses a combination of mechanical and hydraulic pressure, so efficiency is relatively high, and safety against transient phenomena is increased.

■ Since the operating section of the control system is a hydraulic motor, relatively fast response can be achieved.

[Brief explanation of drawings]

The attached drawings relate to embodiments of the present invention; FIG. 1 is a system diagram, FIG. 2 is a hydraulic circuit diagram, and FIGS. 3, 4, and 5 are block diagrams showing the signal flow of the control system, respectively. .

Claims (1)

[Claims] 1. Part of the output of the main engine drives the propulsion shaft via the operating gear, and the rest is divided on the input shaft side of the control system, and one of the divided outputs is applied to the input shaft of the planetary gear system. The other side is applied to a hydraulic pump and converted into fluid power, and this fluid power is added to the planetary gear system again via a hydraulic motor to drive a generator. Alternatively, it is equipped with a speed detector that detects the rotation speed of the generator, and a signal processing device that calculates and outputs an error signal between the output signal of the speed detector and a reference signal, and corrects the error based on the error signal. 1. A control device for a shaft-driven generator, characterized in that the tilting angle of a hydraulic pump is displaced in the direction.