JPS60136812A - Control device of shaft driving motor - Google Patents

Abstract

PURPOSE:To control the rotational frequency for driving a motor always at a constant value with a simple structure by detecting the variation of the rotational frequency of a main engine as a signal for feedforward control and the variation of the rotational frequency of a motor as a signal for feedback control. CONSTITUTION:The output of the main master 1 is transmitted to a propeller gear 2 through a working gear 4 and divided into the input of planetary gears 5 and the input of a hydraulic pump 6 to be converted into respective powers. The rotational frequency of the propeller shaft 2 is detected by an electric speed detector 8 and sent to a signal processor 9. The rotational frequency of an input shaft 10 of the motor 11 is detected by an electric speed detector 13 and sent to a signal processor 14. An output to the planetary gears 5 and fluid power to the hydraulic pump 6 which are divided by the working gear 4 are combined again by a hydraulic motor 17 and a ring gear 18 and the combined signal is outputted to the input shaft 10 to drive the motor 11. The outputs of the detectors 8, 13 are processed by the processors 9, 14 and then supplied to an inclined rotation angle control device 20 for controlling the inclined rotation angle of the hydraulic pump 6.

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. For this reason, if the main engine can drive something that is driven by a generator or other auxiliary equipment, the auxiliary equipment is not needed.) The space occupied by the auxiliary equipment can be used effectively, and it is very advantageous from the point of view of maintenance. In reality, small fishing boats and variable pitch propeller boats have traditionally used shaft-driven generator machines, which branch off a portion of the main engine's output to drive a generator. However, with this method, if the load on the propeller of the propulsion shaft changes periodically due to external load transformation such as waves, this effect will appear as a change in the rotation speed of the propulsion shaft, and the rotation speed of the generator will inevitably change significantly. As a result, 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 conjunction with an auxiliary diesel generator, ■ A method that electrically converts the frequency, and ■ A method that keeps the generator rotation speed constant at the machine height. Yes, the method (■) automatically switches to the diesel drive of the auxiliary equipment when the frequency fluctuation of the generator exceeds a certain limit 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 equipment becomes complicated and the generator 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.

The configuration of the present invention to achieve this objective is to use main engine rotational speed fluctuations as a feedback control signal, detect generator rotational speed fluctuations as a feedback control signal, and process them with a signal processing device. This is a characteristic feature.

That is, to explain in more detail, there are speed detectors that detect the rotation speeds of the propulsion shaft and generator, and signal processing devices that calculate and output error signals between the output signals of these speed detectors and the reference signal. The hydraulic pump is characterized in that the tilting angle of the hydraulic pump is displaced in a direction that corrects the error based on the error signal.

An example of the implementation of the present invention will be explained below with reference to the drawings. Most of the output of the main engine l is transmitted to the propulsion shaft 2 via the operating gear 4 to rotationally drive the propeller 3, and the remaining output is transmitted to the planetary The input is divided into the input of the gear device 5 and the input of the hydraulic pump 6 and converted into respective motive power.

The rotational speed of the propulsion shaft 2 is determined by an electrical 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 1O of the generator 11, and the rotation speed of the input shaft 10 is detected by the electrical speed detector 13 via the gear 12. The resulting 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 circuit 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 divided by the operating gear 4 and the fluid power to the hydraulic pump 6 are transmitted by the hydraulic motor 17 and the ring gear 1.
8 are combined again and output to the j input shaft 10, and this output drives the generator 11. Incidentally, lubricating oil is supplied to each gear loading 4.5 from a lubrication unit 40 to improve the rotation of the gears. Furthermore, the output signals of the electrical speed detectors 8 and 13 are processed by the electrical signal processing devices 9 and 14, and then amplified by the power amplifier 19, and the output signals are sent to the tilting angle control device 20. The tilting angle control device 20 increases or decreases the tilting angle of the hydraulic pump 6 according to an input signal.

That is, when there is a variation in the rotational speed of the propulsion shaft 2 or the input shaft 10 of the generator 11, this variation is electrically detected and sent to the tilt angle control device 20 to change the discharge amount of the hydraulic pump 6. Therefore, the hydraulic motor 17 is driven in accordance with this discharge amount to control the planetary gear 5 via the ring gear 18 and correct the rotational speed of the input shaft 10. In this case, if an external load is applied to the shiburobura 3 due to waves etc., the rotation speed of its propulsion shaft 2 and main engine 1 will fluctuate, and this fluctuation will also affect the input shaft 10 of the generator 11; It is possible to detect from the axis 2, from the input shaft 1O, or from the input shaft 1O, or 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 tilting 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, we will explain the hydraulic unit 16 and hydraulic drive mechanism when using the tilting angle control device consisting of an electromagnetic proportional pressure control valve and a servo regulator.
It is shown in the figure 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 entire amount of hydraulic oil shut off by the relief valve 24 is transferred to the hydraulic motor 17.
is supplied to drive this.

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 the pressure control valve 2.
It is connected to a tank 34 via a valve 7, and hydraulic pressure is introduced to a 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. For this reason, the tilting angle of the hydraulic pump 6 is changed, and the rotation speed of the hydraulic motor 170 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, we will use the feedback control method in this control device.
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. In this state, when the main engine speed fluctuation 50 and generator load fluctuation 35 caused by wandering etc. act on the generator 11, the generator speed fluctuation 51 is detected by the electrical speed detector 13. The generated signal is sent to an electrical signal processing device 14. A reference signal 38 is constantly sent to this electrical signal processing device 14, and the signal from the detector 13 is compared with the reference signal 38 and signal processing 37 is performed. The output 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 described above, even if the rotational speed of the generator 110 fluctuates, this fluctuation is fed back and corrected, so that the generator 11 is always maintained at a constant speed.

Next, the feedforward control method will be explained with reference to Figure 4.

The control system shown in Figure 3 directly feeds back the rotational speed of the generator 11, but the fact that there is a fluctuation in the rotational speed of the generator A means that there is a fluctuation in the rotational speed of the propulsion shaft 2 and the main engine L. Therefore, in the case of Fig. 4, the rotation speed varying shaft 50 of the main engine 1 is detected and controlled.

That is, the main engine rotational speed is detected by an electrical speed detector 8 and its signal is sent directly to an electrical signal processing device 9, and other operations are the same as in the case of Figure 3. Comparing this feedforward method and the feedback method shown in Figures 2 and 3, the former performs control after the fluctuation in rotational speed appears as a result on the input shaft 10 of the generator 11, so the control operation is relatively slow. In the method shown in Fig. 4, 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 that 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, FIG. 5 relates to an embodiment of the present invention, which is a combination of the former two methods of feedback/feedforward control and uses two electrical speed detectors 8.1B. This uses the main 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, the fluctuation 5 of the generator rotation speed caused by the fluctuation 50 of the main engine rotation speed is caused by feedforward control.
1 is reduced, and the error due to the load fluctuation 35 is also reduced by feedback control to further reduce the error.

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 it is easy to improve reliability, maintenance and inspection, and to make the system more compact, making it easy to improve the characteristics of the system.

■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. Furthermore, by using the main engine rotational speed fluctuation as a feedforward control signal and the generator rotational speed fluctuation as a feedback control signal, and by constantly using the two control systems in combination, the following unique effects are obtained.

■ Feedforward control quickly cancels out the effects of fluctuations in the main engine speed, which is a disturbance, and feedback control further eliminates deviations that would remain under feedforward control, including deviations due to generator load fluctuations. Therefore, very high accuracy can be obtained.

■ Feedforward control detects fluctuations in the main engine speed and initiates control operations before the effects of these fluctuations become significant as changes in the generator speed, resulting in fast response.

(2) Since the deviation is greatly reduced by feedforward control, the feedback control loop chain needed to reduce the residual deviation is small and the system is therefore highly stable.

[Brief explanation of the drawing]

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 blocks showing the signal flow of the control method. It is a diagram. Representative Patent Attorney Izumi Amano

Claims (1)

[Claims] A 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. and a speed detector that detects the rotational speed of the generator, and a signal processing device that calculates an output signal based on the output signals of these speed detectors and a reference signal, and Control device for a shaft-driven generator-0, characterized in that the tilting angle of the hydraulic pump is displaced in a direction that corrects errors.