JPS6366719B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a shaft power generator with higher cost performance by adding new functions to a shaft power generator for ships.

Since shaft power generators can generate electricity at low cost, they are attracting attention as useful power generators that meet the current demands for energy conservation and fuel efficiency. Among these, inverter-converter-type shaft power generators are attracting the most attention because they can efficiently supply high-quality constant-frequency, constant-voltage power to the ship's AC power system over a wide rotational variation range of the main shaft.

Figure 1 shows a conventional example of a converter-inverter type shaft power generator. In Fig. 1, 1 is a propulsion main engine that drives a propulsion propeller 3, that is, a propulsion shaft system, via a reduction gear 2, 4 is a shaft generator mechanically coupled to the propulsion shaft system, and 5 is a diode. 6 is a DC reactor, and 7 is an inverter composed of a thyristor.
The DC reactor 6 and inverter 7 constitute a power converter. 8 is a prime mover for an auxiliary generator, 9 is a clutch, and 10 is an auxiliary generator. The prime mover 8, the clutch 9, and the auxiliary generator 10 constitute an auxiliary power generator. 11 is an excitation device for the shaft generator, 12 is an automatic voltage regulator for the auxiliary generator (hereinafter abbreviated as AVR), 1
3 is a control device that controls the inverter 7 of the power converter, and has a constant frequency control function. 14 is a frequency setter that outputs a setting signal to the control device 13 and sets the output frequency of the power converter; 15 is a voltage detection transformer; 16 is a current detection current transformer; 17,1
8 is a line disconnector, 19 is an inboard AC bus, and 20 is an inboard load.

FIG. 2 shows an example of the configuration of the conventional control device 13 shown in FIG. In FIG. 2, 13-1 is a frequency detection circuit that detects the output frequency _B of the inboard AC bus 19 via the voltage detection transformer 15, and 13-2 is the output frequency of the shaft generator set by the frequency setting device 14. Signal _S and frequency detection circuit 13-
13-3 is a current detection circuit that detects the output current of the inverter via the current detection current transformer 16; 13-4 is a frequency control amplification circuit 13-4 that amplifies the deviation signal of the output signal from 1; 13-5 is a phase control circuit, and 13-6 is a pulse amplification circuit.

Next, the operation of the conventional example shown in FIG. 1 will be described. When a ship is at anchor or when entering or exiting a port, the clutch 9 connects the auxiliary generator 10 and the prime mover 8, and the auxiliary generator 10 is operated. The generated power is supplied to the ship's load 20 via the breaker 18 and the ship's AC bus 19.

When the ship goes out to the open sea and the shaft generator 4 becomes usable, the sheath disconnector 17 is turned on, and then the shaft generator excitation device 11 excites the field winding of the shaft generator 4, and the shaft generator 4 starts generating electricity. The AC power generated by the shaft generator 4 is converted to DC power by the converter 5, smoothed by the DC reactor 6, and then converted again to AC power at a constant frequency according to the setting signal of the frequency setting device 14 by the inverter 7. is,
It is supplied to the inboard AC bus 19.

The control device 13 has a constant frequency control function, and although not shown, has a characteristic that simulates the drooping characteristics of the governor of the prime mover 8 using an electronic circuit, so the inverter 7 of the power converter is used as an auxiliary power generator. It is stably operated in parallel with machine 10.

Finally, after the inboard load 20 is transferred to the shaft generator 4 and the auxiliary generator 10 is left unloaded, the clutch 9 is opened and the prime mover 8 is disconnected and then stopped.

On the other hand, the auxiliary generator 10 continues to operate as a synchronous phase modifier using the output power of the inverter 7, and supplies the reactive power required by the inverter 7 and the inboard load 20. The AVR 12 controls the voltage of the inboard AC bus 19 to be constant. In this way, all inboard loads are supplied from the shaft generator 4, and all motive power is supplied from the main engine 1.

Even if there is a change in the rotation of the main engine, as long as the change is within the normal range, the constant frequency and constant voltage control function of the shaft generator with this configuration allows high quality AC power to be supplied at low cost during the entire voyage of the ship. continue to be supplied.

Before the ship enters the port, the engine 8 is started and the clutch 9 is closed. After the load is transferred to the auxiliary generator, the excitation of the shaft generator 4 is stopped, the disconnector 17 is turned off, the shaft generator is disconnected, and from then on, all loads are handled by the auxiliary generator 10. Power is supplied to the

The shaft power generator constructed as described above has the advantage of being able to supply power to the ship's AC bus bar at a low cost, but its equipment is relatively large.

By the way, the operational reliability of the main engine 1 is said to be higher than that of auxiliary equipment, but it is not guaranteed that there will be no failures, and if the main engine 1 fails and stops, the shaft power generator will become unusable and large equipment will become unusable. It ends up. Also, in terms of the operation of a ship, if the main engine fails and stops, the ship will become unable to operate and will drift adrift.
If something like this were to occur, it could lead to a serious accident involving human life.

Therefore, if the main engine fails and stops, it would be extremely effective for the safe operation of the ship if it could somehow be able to navigate under its own power even at extremely low speeds, and this type of device is eagerly awaited.

The present invention has been made in view of the above points, and
Its purpose is to operate as a shaft generator with good characteristics when the main engine is normal, and once the main engine breaks down, it uses the power from the onboard auxiliary generator instead of the main engine to operate at extremely low speeds. It is an object of the present invention to provide a shaft power generator for a ship that can drive a propulsion propeller even if there is a propeller.

An embodiment of the present invention is shown in FIG.

In FIG. 3, 21 is a clutch that mechanically disconnects the main engine 1 and the propulsion shaft system in the event of a failure of the main engine 1, 22 is a rotor position detector that detects the position of the rotor of the shaft generator 14, and 23 24 is a speed generator that detects the rotation speed of the shaft generator, and 24 is a speed setter that sets the rotation speed of the shaft generator.

Further, the converter 5 differs from the conventional example in that all elements are composed of thyristors.

FIG. 4 shows a block diagram of the control device 13 according to one embodiment of the present invention. Further, FIGS. 5 and 6 are diagrams illustrating the operation of the control circuit shown in FIG. 4. In FIGS. 5 and 6, the suffix n such as N _o , V _o , and W _o indicates the rated speed, rated voltage, and rated voltage of the shaft generator, respectively.

Other components are the same as those given the same numbers in the conventional example shown in FIG.

In Fig. 4, 13-1 is a frequency detection circuit that detects the output frequency of the shaft power generator as in Fig. 2, 13-2 is a frequency control amplifier circuit, and 13-3 is a current detection circuit that detects the output current of the inverter. circuit,
13-4 is a current control amplifier circuit, 13-5 is a phase control circuit, and 13-6 is a pulse amplifier circuit, and these circuit configurations constitute a constant frequency control function. On the other hand, 13-7 is a speed control amplifier circuit that amplifies the deviation signal between the output signal of the speed setter 24 and the output signal of the speed generator 23, and 13-8 is a speed control amplifier circuit 13.
-Absolute value circuit that outputs the absolute value of the output of 7, 13
-9 is a torque direction selection circuit that outputs an output signal in the direction of torque generation based on the output polarity of the speed control amplifier circuit 13-7, and 13-10 is a rotor position detector 22.
13-11 is a pulse amplifier circuit, which outputs a pulse with a firing phase based on the output signal of the output signal and the output signal of the torque direction selection circuit 13-9. With this circuit configuration, a constant speed control function can be achieved. It consists of 13-12 is a disconnection circuit that switches between constant frequency control function and constant speed control function in response to a mode switching signal; 13-13 is a disconnection circuit that switches between a constant frequency control function and a constant speed control function in response to a mode switching signal; This is a starting control circuit that controls the control circuit 13-5 and controls the current flowing through the inverter 7.

The operation of the control device 13 shown in FIG. 4 will be explained with reference to FIGS. 5 and 6.

When the main engine is normal and operates as a normal shaft power generation device, the control device 13 is operated in a shaft-generated mode, that is, with the contact of the switching circuit 13-12 on the B contact side. Further, it is assumed that the relationship between the rotational speed _NSG of the shaft generator 4 and the output voltage _VSG is shown in FIG. It is assumed that the operating range of the shaft generator is N _nio < N _SG < N _nax . It is assumed that the excitation device 11 of the shaft generator 4 controls the excitation current of the shaft generator 4 so as to satisfy the characteristics shown in FIG. On the other hand, the relationship between the output voltage W of the speed generator 23 for detecting the rotation speed of the shaft generator 4 and the rotation speed _NSG of the shaft generator 4 is shown in FIG.

In the axis mode during normal operation, the speed setting signal W _S of the speed setting device 24 is kept at zero, and the switching circuit 13
Since -12 is on the b contact side of the axis output side, the setting input to the current control amplifier circuit 13-4 is connected to the frequency control amplifier circuit 13-2. The rotational speed of the main engine 1 increases and the rotational speed _NSG of the shaft generator 4 rotates forward.
When a command to start operating the time axis generator exceeding N _nio is issued, the control device 13 starts operating.

Frequency control amplifier circuit 13-2 is frequency setter 1
The switching circuit amplifies the current setting signal according to the deviation signal between the frequency setting signal _S of 4 and the frequency signal _B of the inboard AC bus 19 obtained by the frequency detection circuit 13-1 via the voltage detection transformer 15. It is output to the current control amplifier circuit 13-4 via 13-12. The current control amplifier circuit 13-4 outputs a control signal to the phase control circuit 13-5 so that this current setting signal and the current value detected by the current detection circuit 13-3 match, and the phase control circuit 13-5 outputs the control signal to the phase control circuit 13-5. The phase of the output pulse is changed according to the The pulse amplification circuit 13-6 amplifies this pulse and fires the thyristor constituting the inverter. In other words, the phase control circuit 13-
If the input voltage of 5 increases in the direction, the firing phase angle of the inverter advances (α angle decreases), and conversely, if it decreases in the direction, it retards (α angle increases). FIG. 7 shows an example of the characteristics of the phase control circuit 13-5.

On the other hand, the control on the converter side is performed by sending the speed setting signal W _S of the speed setting device 24 to the speed control amplifier circuit 13-7.
is zero as described above, and the speed signal W from the speed generator 23 is a negative value, so a negative output signal is generated at the output of the speed control amplifier circuit 13-7. Since the torque direction selection circuit 13-9 uses a negative input signal to command torque in the reverse direction, the firing phase switching circuit 13-10 generates a pulse with a firing phase that should produce torque in the reverse direction. This firing phase pulse is amplified by a pulse amplification circuit 13-11 and then works to fully fire the thyristors constituting converter 5. In other words, the converter 5 performs forward conversion operation (rectifier operation) because a current with a phase that produces reverse torque is passed through the shaft generator rotating in the forward direction.
Converts AC power to DC power as before.

Now, if the actual frequency _B is lower than the frequency setting _S to the frequency control amplifier circuit 13-2, the positive input voltage of the current setting signal to the current control amplifier circuit 13-4 increases, so the current control amplifier circuit 13 The output of −4 increases in the direction. Phase control circuit 13-5
Accordingly, the ignition phase of the inverter 7 is advanced, the control delay angle α is decreased, and the current is increased.
Note that the starting control circuit 13-13 does not operate in the shaft-starting mode. During normal operation of the inverter, this operation reduces the DC voltage that appears at the DC input terminal of the inverter, making it easier for current to flow, and increasing the current in the inverter 7, so the inverter increases the converted power and output frequency. increase. Conversely, when frequency _B increases, the output frequency decreases by performing the opposite operation.

As explained above, the rotational speed N _SG of the shaft generator is
In the range of N _nio <N _SG < N _nax , and when the operation mode of the control device 13 is the shaft power generation mode, the shaft power generation device operates as a shaft power generation device with the same performance as a conventional shaft power generation device. The so-called control device 13 forms a constant frequency control device.

Next, the operation when the main engine 1 breaks down will be explained. In this case, the control device 13 enters the emergency navigation mode, the switching circuit 13-12 switches to the propulsion side a contact side, and the current control amplifier circuit 13-4 connects the frequency detection circuit 13-1 and the frequency control amplifier circuit 13-2. It becomes unrelated to the operation. Electric power generated by the auxiliary generator 10 is supplied to the inboard AC bus 19, and its frequency _B is controlled by the governor of the prime mover 8. This AC power from the inboard AC bus 19 is supplied to the shaft generator 4 via the inverter 7, DC reactor 6, and converter 5, where the shaft generator 4 converts it into mechanical power, and the propulsion propeller 3 is reversed through the reducer 2. It is intended to be driven. And at this time clutch 2
1 is opened to disconnect the main engine 1 from the propulsion shaft system. This not only means to disconnect the failed main engine 1, but also has the important meaning of eliminating the mechanical loss required for its rotation and increasing the rotational force supplied to the propulsion propeller 3.

Now, in the case of forward rotation drive (forward), the speed setting signal of the speed setting device 24 to the speed control amplifier circuit 13-7
Since W _S is set to a positive value, the output of the speed control amplifier circuit 13-7 is positive, and the torque direction selection circuit 13-9 commands torque in the forward rotation direction, and the firing phase angle switching circuit 13-10 , pulse amplification circuit 13-1
1, the thyristor of the converter 5 is fired at a firing phase that produces torque in the forward rotation direction. On the other hand, the absolute value circuit 13-8 outputs the absolute value of the output of the speed control amplifier circuit 13-7 (the absolute value of the speed deviation) and applies it to the current control amplifier circuit 13-4, so the inverter 7
The thyristor is fired at a firing phase corresponding to its value by the action of the current control amplifier circuit 13-4, the phase control circuit 13-5, and the pulse amplifier circuit 13-6. Therefore, the thyristors of the inverter 7 and converter 5 are fired as appropriate and current flows, so the shaft generator 4 begins to rotate in the forward rotation direction due to the torque in the forward rotation direction.
The propulsion propeller is driven via the reduction gear 2.
In this case, converter 5 is performing a reverse conversion operation (inverter operation). On the other hand, the inverter 7 advances the firing phase (decreases α) and increases the current when the input voltage of the phase control circuit 13-5 increases in the same direction as in the shaft mode.

In the emergency navigation mode, the inverter 7 is in forward conversion operation (rectifier operation), and the power is transferred from the auxiliary generator 10 →
The power is supplied as follows: inboard AC bus 19 → inverter 7 → DC reactor 6 → converter 5 → shaft generator 4.
Also, the commutation of the converter 5 is determined by the rotor position detector 22.
The output of the DC current is intermittent and the shaft generator voltage is used.

The focus of the operation of the control device 13 in the emergency navigation mode is to switch the firing phase of the converter 5 according to the polarity of the deviation between the speed setting signal W _S and the speed signal W of the speed generator 23 to determine the direction of the torque to be generated. In addition, the magnitude of the torque is controlled by flowing a current proportional to the absolute value of the speed deviation. The so-called control device 13 forms a constant speed control device.

Also, the torque required by the propeller is approximately 2 times the rotational speed.
Since it decreases in inverse proportion to the power of the main engine, it is possible to drive the propeller at low speed with a shaft generator with a smaller capacity than the main engine.

As described above, in the emergency navigation mode, by driving the propeller at low speed using the power of the onboard auxiliary generator, it is possible to prevent the ship from completely drifting and maintain the minimum level of safety.

It should be noted that the clutch 21 may not be provided to disconnect the main engine from the propulsion shaft, and the configuration may be such that the connection is disconnected by means such as removing the bolts of the coupling only in an emergency. It goes without saying that instead of the speed generator 23, a combination of a pulse generator and an F/V conversion circuit may be used as a rotational speed detector. If conditions permit, the rotor position detector 22 may be used as a pulse generator.

As described above, according to the present invention, by only adding some of the peripheral components of the shaft power generator, it is possible to maintain the functions of the conventional shaft power generator, and even in the event of a failure of the main engine, the power of the inboard auxiliary generator can be maintained. A shaft power generation device that can be used to drive a propulsion propeller at low speed is obtained.

This prevents the occurrence of serious accidents such as drifting of the ship due to failure of the main engine, and enables minimal maneuverability, which is highly effective in terms of safe operation of the ship and increasing the usefulness of the shaft power generator.

Further, according to the present invention, even during emergency navigation, the rotation control of the propulsion propeller is performed by the control device of the shaft power generator as described in detail above, so that it is performed extremely stably and efficiently. In other words, since it is operated under constant speed control with a current control minor loop, good control characteristics similar to those of electric propulsion by stationary Leonard control of a DC motor are obtained, and the operation is extremely smooth and stable.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of a conventional marine shaft power generator, FIG. 2 is a circuit diagram of the power converter control device shown in FIG. 1, FIG. 3 is a circuit diagram of a marine shaft power generator of the present invention, and FIG.
The figure is the circuit diagram of the power converter control device in Figure 3, and the circuit diagram of the power converter control device in Figure 5.
The figure shows the rotational speed vs. output voltage characteristic diagram of a shaft generator.
The figure is a characteristic diagram of the speed generator output voltage versus the shaft generator rotation speed, and FIG. 7 is a characteristic diagram of the phase control circuit. 1... Main engine, 4... Shaft generator, 5... Converter, 7... Inverter, 8... Prime mover, 10...
...Auxiliary generator, 13...Power converter control device, 1
9...AC bus bar, 22...Rotor position detector, 2
3...Speed generator.

Claims (1)

[Claims] 1 Normally, the output power of the shaft generator driven by the main engine that drives the propulsion shaft system is converted to constant frequency power by a power converter consisting of a converter and inverter, and then supplied to the ship's AC bus bar. In a system in which the output power of an auxiliary power generator connected to the inboard AC bus is frequency-converted by the power converter and the propulsion shaft system is driven by a shaft generator,
When the main engine fails, the direction of torque to be generated is determined by switching the firing phase of the converter according to the polarity of the deviation between the speed setting signal and the shaft generator speed signal, and the absolute value of the speed deviation is determined. A shaft generator for a ship, characterized in that it is equipped with a control device that controls the magnitude of torque of the shaft generator by flowing a current proportional to .