JPS6333371B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention detects the rotational speed of a generator rotating shaft, and connects two or more alternating current generators with different rated rotational speeds directly connected to an internal combustion engine at a predetermined rotational speed to a pole corresponding to the load. The invention relates to a multi-speed alternator with an automatic switching device.

Generators driven by internal combustion engines such as diesel engines have conventionally been driven by one internal combustion engine, so it is difficult to operate without changing the rotation speed even when the load changes. Alternatively, when low-load operation is performed for a long time, another low-load generator set is installed and operated.

However, constantly maintaining two generator sets like this is wasteful both in terms of space and economy, and one generator set can handle both high and low loads. However, continuous low-load operation for long periods of time not only shortens the life of the internal combustion engine, but also increases fuel consumption.

Therefore, with the aim of solving the problems that such a generator set had, the present applicant proposed a practical application
According to No. 191550 (Utility Model Publication No. 57-111079), two or more alternating current generators with different rated rotation constants are coaxially integrated, and this is directly connected to an internal combustion engine, and the alternating current generator is We proposed a multi-speed alternator that can be used appropriately.

The present invention was made for the purpose of automatically performing a generator switching operation in a multi-speed alternating current generator previously proposed by the applicant, and its characteristic configuration is that of a multi-speed alternating current generator. A detection means for detecting the rotation speed is provided on the rotating shaft, and when the rotation speed detected by the detection means reaches a predetermined value between the detection means and an exciter installed in parallel with each of the generators. ,
The present invention is characterized in that an excitation switching circuit is provided for selectively switching the power supply to each of the exciters.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained in detail below based on embodiments shown in the accompanying drawings.

Figure 1 is an example of the multi-speed AC generator of the present invention.
The control system diagram of the high-speed alternating current generator, Fig. 2, shows the connection diagram of the control circuit applicable to the same embodiment. In each figure, 1 is the internal combustion engine mounted on the common platform 2 , 3 is an electronic governor connected via a link 6 to a control lever 5 of a fuel injection pump 3 provided on the operating side of the internal combustion engine 1, and the electronic governor 4 is located at the operator's hand position, for example on a ship. In this case, the fuel injection pump 3 is turned on by operating the governor control switch 7 located in the wheelhouse or the like.
The injection amount is adjusted, and the engine speed is set in advance.
That is, idling speed, 1200r.pm, 1800r.p.
It is designed to maintain the setting to one of m. On the output shaft protruding side of the internal combustion engine 1 on the common platform 2, there are 6 poles, 80KVA, 1200R.P. inside.
an alternator 8 having a rating of M, and 4 poles;
Generator casing 1 containing a coaxially arranged alternator 9 with a rating of 125KVA, 1800R.PM
0 is provided, and the field coil 8' of the generator 8 and the field coil 9' of the generator 9 are supported by a common rotating shaft 11 in a so-called skewed state, and the rotation One end of the shaft 11 is directly connected to the output shaft of the internal combustion engine.

Moreover, on the outer surface of the generator casing 10,
Field coils 8' of each of the generators 8, 9;
An exciter case 16 containing exciters 14 and 15 for exciting the generators 9' is fixedly installed, and each rotor 14' and 15' of the exciters 14 and 15 rotates the generators 8 and 9. It is attached to the extending end of the shaft 11, and the rotary shaft 1 is attached to the end of the rotary shaft 11.
A tacho generator 17 is installed to detect the rotation speed of 1 and output this as an increase/decrease in the generated voltage.

On the other hand, 18 indicates a control panel attached near the generator, and the control panel 18 includes the tacho generator 1
A speed relay 19 that operates a relay circuit by the voltage change of 7, and contacts 2 provided in the exciters 14 and 15 by the operation of the speed relay 19.
An excitation switching circuit 22 is provided which switches the generators 8 and 21 to one side and selectively supplies power to either of the exciters 14 and 15, and connects the generators 8 and 9 to the load side. The power supply circuit to be connected includes a generator 8.
When the output voltage on the side reaches a predetermined value or higher, contact 23
magnetic switch 24 that turns on the power, and a generator 9.
When the output voltage on the side reaches a predetermined value or higher, contact 25
An interlock mechanism 27 equipped with a magnetic switch 26 for turning on the power is incorporated.

Note that the excitation switching circuit 22 has the following functions in conjunction with the switching operation of the governor control switch 7:
Contact 28 when switch 7 is turned on at 1200r.pm
is closed, contact 29 is closed at 1800 rpm, and speed selection contact 30 is provided in which both contacts 28 and 29 are open at idling. In addition, in FIG. 2, 31 and 32 are automatic voltage regulators provided for each generator 8 and 9, and 33 and 34 are exciters 14 and 34, respectively.
15 shows an initial excitation circuit for supplying an initial excitation current to the exciters 14 and 15 to promote the exciters 14 and 15.

The multi-speed alternator of the present invention has the above-mentioned configuration. Next, its operation will be explained. First, when the engine is operating at 1800 R.PM, the governor control switch 7 and Interlockingly, since the contact 29 of the speed selection contact 30 in the excitation switching circuit 22 is closed and the tachogenerator 17 is generating a voltage corresponding to the rotation speed of the rotating shaft 11, the contact 1 of the speed relay 19 is closed.
9a, 19b, 19c are all turned on, auxiliary relays 35, 36, 37 are excited, contacts 35', 36' of relays 35, 36 are turned on, contact 3
7' is turned OFF, relay 38 is deenergized and relay 39 is energized. Therefore, by energizing the relay 39, its contact 39' is opened, voltage is applied to the terminal 32a of the automatic voltage regulator 32, the exciter 15 on the generator 9 side is energized, and the field coil 9'
Current flows through the generator 9 and the generator 9 continues to generate voltage, and while the voltage generated by the generator 9 is above the specified value, the magnetic switch 26 acts to close the contact 25 and supply power to the load side. Ru.

Next, from this state, when the governor control switch 7 is operated to switch to the 1200 rotation (1200 rpm) side, the power-off governor 4 interlocks with this and rotates the control lever 5 of the fuel injection pump 3 toward the deceleration side. As the engine begins to decelerate, the contact 28 of the speed selection contact 30 of the excitation switching circuit 22 closes. Then, when the engine speed drops to 1530r.pm,
First, contact 19b of speed relay 19 is turned OFF, auxiliary relay 36 is demagnetized and contact 36' is opened, and accordingly relay 39 is demagnetized and contact 36' is opened.
9' is closed, the terminal 32a of the automatic voltage regulator 32 becomes voltageless, the current to the exciter 15 on the generator 9 side is interrupted, the generator 9 stops generating electricity, and the magnet Switch 26 opens contact 25.

When the engine speed further decreases to 1380 rpm, the contact 19c of the speed relay 19 turns OFF due to a drop in the voltage generated by the tachogenerator 17, the auxiliary relay 37 is demagnetized, the contact 37' is closed, and the relay 38 is energized. The automatic voltage regulator 3 installed on the generator 8 side opens the contact 38' when
When a voltage is applied to the terminal 31a on the 1 side, the exciter 14 is excited, current flows through the field coil 8', the generator 8 starts generating electricity, and the voltage generated by the generator 8 reaches a specified value or higher. , the magnetic switch 24 is activated, the contact 23 is closed, and power is supplied from the generator 8 to the load side.

Also, during idling, etc., both contacts 28 and 29 of the speed selection contact 30 are opened,
In addition, when the engine speed becomes 1020 rpm or less, both exciters 14 and 15 are demagnetized, so
The generators 8 and 9 stop generating electricity.

In addition, in the above embodiment, the speed relay 1
The power generation rotation speed of the generator according to 9 is set to 1380r.pm and
The speed is set at 1580r.pm to prevent the occurrence of abnormal voltages that would exceed the withstand strength of the generator, exciter, and load, but the power generation speed of the generator may be changed arbitrarily within the permissible range. is possible.
Further, in the above embodiment, the speed selection contact 30 of the excitation switching circuit 22 is shown to be linked with the governor control switch 7, but the speed selection contact 30 is adapted to respond to changes in load current or load capacity. For example, if the load capacity decreases while operating at 1800rpm and the power generation capacity of 1200rpm is sufficient to cover the load, you can set the change in advance. It is possible to automatically shift to 1200rpm operation.

Figure 3 shows the relationship between the load in the above-mentioned multi-speed alternator and the fuel consumption of the internal combustion engine.Curve l shows the characteristics of the 4-pole, 1800rpm high-load generator 9. , the curve m shows the characteristics of the 6-pole, 1200 rpm low-load generator 8, and the point P on the curve l shows the rated state of the generator 9, and the point Q on the curve m represents the rated load of the generator 8. Therefore, if the load is larger than point P, it is more advantageous to use generator 9, and if the load is smaller than point Q, it is more economical to use generator 8. If the generators 8 and 9 are switched at a corresponding point and the operation is performed to satisfy the two fuel efficiency curves, the fuel efficiency at low loads can be greatly improved.

As described above, the multi-speed alternator of the present invention is provided with a detection means for detecting the rotation speed on the rotating shaft of the multi-speed alternator equipped with two or more alternators with different rated rotation speeds, and When the rotational speed detected by the detection means reaches a predetermined value between the detection means and the exciter machines installed in parallel with each of the alternating current generators, the power supply to each of the exciter machines is selectively switched. By installing an excitation switching circuit, the operation of the generator is automatically switched according to the engine speed, so for example, in the case of a ship, it can be used to change the operation of the generator according to the load conditions such as when sailing, entering and leaving a port, and loading/unloading. By simply operating the governor control switch manually, the exciter on the generator side with the number of poles corresponding to the rotation speed is excited, and the generator can be switched safely and reliably, which is an excellent effect. In addition, since it is possible to use a generator with an appropriate rating depending on the load, there is an effect of suppressing an increase in fuel consumption of the internal combustion engine.

[Brief explanation of drawings]

Figure 1 is an example of the multi-speed AC generator of the present invention.
FIG. 2 is a wiring diagram of a control circuit applicable to the two-speed alternator, and FIG. 3 is a diagram showing the operation of the multi-speed alternator of the present invention. 1...Internal combustion engine, 8, 9...Alternator, 11
... Rotating shaft, 14, 15 ... Exciter, 17 ... Detection means (tacho generator), 22 ... Excitation switching circuit.

Claims (1)

[Claims] 1. A multi-speed alternator consisting of two or more coaxially integrated alternators with different rated rotational speeds directly connected to an internal combustion engine, the multi-speed alternator having a rotational speed on its rotating shaft. and between the detecting means and an exciter installed in parallel with each of the generators, when the rotational speed detected by the detecting means reaches a predetermined value, each of the exciters A multi-speed alternating current generator characterized by being equipped with an excitation switching circuit that selectively switches power supply to the generator.