JPH089608A - Self-excited brushless generator - Google Patents

Abstract

PURPOSE:To provide a self-excited brushless generator which can quickly and surely establish the voltage at the operation starting time. CONSTITUTION:A first permanent magnet 36 is fitted to a field coil 34 for exciter counterposed to an exciter coil 24 provided to a rotor 20 and a second permanent magnet 25 is fitted to a field coil 22 constituting a rotating field pole counterposed to an armature coil 31. The partial output of the armature coil 31 is rectified by means of a rectifier 33 and supplied to the field coil 34 through a controller 35. The controller 35 supplies an appropriate current to the field coil 34 so as to make the output voltage of the armature coil 31 coincident with a reference value. The output of the exciter coil 24 is supplied to the filed coil 22 through a rectifier 23.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention rectifies a part of electric power generated by itself and supplies it to a field coil for an exciter machine without exciting it by an external power source. The present invention relates to a brushless self-excited generator that rectifies and supplies the field coil of the generator body.

[0002]

2. Description of the Related Art Usually, a generator operated as a commercial power source is a three-phase synchronous generator, which is operated in synchronization with an associated power source. Therefore, it is easy to excite with an external power source, and it is often the case that starting is started under sufficiently prepared conditions from the start of operation and the excitation is also in a complete state.

However, there are many small-sized generators that can be operated independently under the condition that no other power source exists in the surroundings. For example, many generators for vehicles, ships, emergencies, disaster prevention, hospitals, etc. are operated independently. In these applications, low cost and high reliability are often required, equipment used is as simple as possible, and maintenance is also easy. In order to meet such demands, for example, brushless self-excited generators are often used. Many generators of this type are not equipped with an exciter including a secondary battery, which is disadvantageous in terms of cost, structure and maintenance.

As described above, many of the general-purpose small-sized self-excited AC generators do not have a special excitation mechanism suitable for starting, so that it takes some time to establish the voltage and is not stable. There is a face. In particular, in the case of emergency equipment that is rarely operated, frequent maintenance and maintenance cannot be performed, and there is considerable concern about the voltage probability itself. Naturally, the load cannot be supplied with power until the voltage is established.

To establish the voltage in the self-excited generator, the residual voltage of the generator core is used to generate the first voltage.
Thereafter, this generated voltage is used as a power source to gradually increase to a specified voltage determined by the no-load saturation curve and the field resistance line. In this case, if the residual magnetism of the generator core is small, it takes some time to establish the voltage, and in extreme cases, the voltage establishment may fail.

As described above, the time until the voltage is established in the self-excited generator, that is, the time until the load can be connected after starting is said to depend on the magnitude of the residual magnetism of the generator core. But it's not an exaggeration. However, improvements in iron core materials have progressed, and the residual magnetism tends to be rather small.
Nevertheless, there is also a demand for supplying power to the load competing for minutes and seconds, especially in the case of a small generator for use in disaster prevention, hospitals, fire engines, and the like.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a brushless self-excited generator which eliminates the above-mentioned drawbacks of the prior art and can quickly and reliably establish the voltage at the start of operation. And

[0008]

The gist of the structure of the present invention is that, in an exciter machine, a first permanent magnet is arranged in a stator portion facing an exciter machine coil provided in a rotor,
The generator main body is a brushless self-exciting generator in which a second permanent magnet is arranged in the rotating field magnetic pole portion facing the armature coil, which can solve the above problems.

Further, in the present invention, a conductor for inducing an electromotive force to be supplied to the field coil for the exciter machine can be provided together with the armature coil.

[0010]

Therefore, according to the present invention, in the exciter machine,
With respect to the exciter coil provided on the rotor, the magnetic force lines of the first permanent magnet arranged on the stator side act even when the generator is started. Therefore, it is possible to expect a quicker and more reliable voltage establishment than in the case of the conventional self-excited generator that first establishes the voltage using the residual magnetism of the iron core, and to supply power to the load in a shorter time. It will be possible.

Further, according to the present invention, in the generator main body, the second permanent magnet is arranged in the rotating field magnetic pole portion corresponding to the armature coil, and the magnetic force line by this permanent magnet is from the exciter portion. Even if there is no such current or there is only a very weak current, it acts so as to generate an electromotive force in the armature coil. The electromotive force induced in the armature coil is rectified by the rectifier and fed back to the field coil for the exciter machine via the controller, so the electromotive force in the exciter coil is superimposed on the electromotive force of the first permanent magnet. Therefore, quicker and more reliable voltage establishment is achieved.

Further, if a part of the armature coil is made independent as a conductor for feeding back to the field coil for the exciter machine, quicker voltage establishment can be promoted. this is,
Even before the feedback is generated from the armature coil after the voltage is established, the electromotive force generated by the second permanent magnet arranged at the portion facing the armature coil can be efficiently fed back to the exciter field coil side. Because you can.

[0013]

The present invention will be disclosed below with reference to the accompanying drawings showing the embodiments. First, the first embodiment will be described. Figure 1
It is explanatory drawing which shows the basic composition of the brushless self-exciting generator 10 of this invention. The generator 10 is composed of a generator main body and an exciter attached thereto, and is roughly classified into a rotor 20 mainly composed of a field coil 22 of the generator main body and a fixed main body composed of an armature coil 31 of the generator main body. And a child 30.
In addition, in this figure, for convenience of explanation, mainly an electrical configuration is shown, and iron cores are omitted. The rotor 20 has a rotating shaft 2
1 and is connected to the power shaft of various prime movers such as an internal combustion engine, a water turbine, or a turbine (not shown).

The rotor 20 of the generator configured as described above
As described above, the field coil 22 of the main body of the generator is arranged so as to generate a necessary field magnetic flux, and in addition, the exciter coil 24 for generating an exciting current is additionally provided. The field coil 22 is connected to the exciter coil 24 in order to supply a current generated by an electromotive force induced in the latter to the former via the rectifier 23, thereby making it brushless.

As described above, the stator 30 is provided with the armature coil 31 of the generator body, and an electromotive force is generated according to the change in the magnetic flux generated by the field coil 22 on the rotor 20 side. Then, the power is supplied to the external load connected to the output terminal 32a.

Further, at a portion on the stator 30 which opposes the exciter coil 24 of the rotor 20 so as to act the generated magnetic flux, an exciting magnetic pole is formed together with an iron core (not shown). A machine field coil 34 is provided. However, the exciter field coil 34 and the exciter coil 24 constitute an exciter machine.

In the exciter field coil 34, the AC output obtained from the output terminal 32b of the armature coil 31 of the generator body is rectified by the rectifier 33, and the DC current thus obtained is passed through the controller 35. As supplied
It is connected. The output terminal 32a and the output terminal 32b are connected in parallel to the output of the armature coil 31.

Although various types of controllers can be adopted as the controller 35, here, the DC output of the rectifier 33 supplied to the exciter field coil 34 forming the exciting magnetic pole is For example, it is intermittent at 1500 Hz, and the ratio of the ON time is compared with the output voltage of the armature coil 31 with a reference voltage, and if it is low, it becomes as large as necessary, and if it is high, it becomes small as necessary. Therefore, it is configured to change. Thus, the average current supplied to the exciter field coil 34 is appropriately changed, and the exciter coil 2 is changed correspondingly.
By the output current of No. 4, the field coil 22 of the generator main body
Generates an appropriate magnetic flux so that an output voltage that substantially matches a predetermined reference value can be obtained from the armature coil 31.

Further, a first permanent magnet 36 is attached to the exciter field coil 34 for generating a magnetic flux acting on the exciter coil 24. The first permanent magnet 36 starts to rotate when power is applied to the generator 10 from an external prime mover, but naturally, the exciter coil 24 does not have a voltage even when the voltage is not yet established. The magnetic flux acts on it. The exciter coil 24 links the magnetic flux of the first permanent magnet 36 to generate an exciting current, which is rectified by the rectifier 23 and supplied to the field coil 22. Therefore, the voltage is surely established within a short period of time, which is not comparable to the conventional case of using only the residual magnetism.

A second permanent magnet 25 is attached to the field coil 22 which constitutes the rotating field pole acting on the armature coil 31. The second permanent magnet 25 generates a magnetic flux that links the armature coil 31 on the stator 30 side when the rotor 20 rotates. Therefore, at the time of starting the operation of the generator, even if the field coil 22 is not yet supplied with sufficient current, the rotor 20
It is possible to generate an electromotive force in the armature coil 31 with the rotation of the.

The current resulting from the electromotive force induced in the armature coil 31 is rectified by the rectifier 33 and supplied to the exciter field coil 34 via the controller 35. The magnetic flux formed by this current acts on the exciter coil 24 while being superposed on the magnetic flux generated by the first permanent magnet 36.

As is apparent from the above description, the shapes of the first permanent magnet 36 attached to the exciter field coil 34 and the second permanent magnet 25 attached to the field coil 22,
The dimensions, arrangement mode, and the like can be appropriately selected. However, in any case, at the stage of voltage establishment, it is set so that the magnetic fluxes are superposed on the magnetic fluxes generated by the field coil for exciter machine 34 or the field coil 22 to promote each other. Needless to say, it is necessary.

FIG. 2 is an explanatory view showing the second embodiment of the present invention. In this embodiment, the exciter field conductor 131 is arranged in parallel with the armature coil 31. The output of the exciter field conductor 131 is connected to the output terminal 32b, rectified by the rectifier 33 connected to the output terminal 32b, and the DC output is connected to the exciter field coil 34 via the controller 35. . Other points are exactly the same as the first embodiment.

With such a configuration, at the time of starting the generator 10, even if a load is connected to the output terminal 32a to which the output of the armature coil 31 is connected, the voltage can be established. Even when the load suddenly increases during operation, stable operation can be continued with almost no effect such as a decrease in the output voltage of the armature coil 31 associated therewith.

That is, when the output of the armature coil 31 is fed back as it is, if the load temporarily increases rapidly due to lighting of a large-capacity incandescent lamp, the output voltage of the armature coil 31 suddenly increases. As a result, the magnetic field generated by the exciter field coil 34 driven by this also decreases, and the electromotive force generated by the exciter coil 24 also decreases.
Therefore, the magnetic flux generated by the field coil 22 driven by the output current also decreases. Therefore, there is a problem that the voltage generated in the armature coil 31 is likely to fall further, which easily causes a vicious circle. However, as described above, when the exciter machine field conductor 131 which is not affected by the load fluctuation is configured and its output is supplied to the exciter machine field coil 34, the following is performed. The problem goes away. Then, if necessary, the voltage can be established without being influenced by the current of the load even when the load is connected.

Although a separate conductor groove can be provided as the exciter field conductor 131, a winding groove for a normal armature coil 31 is used and the armature coil 3 is used.
It is also possible to apply one of the multiple conductors forming one.

[0027]

According to the present invention, due to the influence of the first permanent magnet and the second permanent magnet, the voltage can be established quickly and reliably at the time of starting the generator. High reliability can be obtained with respect to the conventional generator that established the voltage in the expectation of the presence of residual magnetism. Therefore, it can be adopted with peace of mind even in applications requiring quick and reliable start-up, such as for emergency use, disaster prevention use, or medical field use.

When a conductor is provided in parallel with the armature coil in combination with the above two sets of permanent magnets and the electromotive force induced in the conductor is used to form the exciter field. As a result, more reliable and quick voltage establishment is performed.
With such a configuration, it is unlikely to be affected by the fluctuation of the load, and even if the load is connected to the armature coil, the voltage can be established.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a basic configuration of a first embodiment.

FIG. 2 is a partial explanatory diagram showing a configuration of a second embodiment.

[Explanation of symbols]

 10 generator 20 rotor 21 rotary shaft 22 field coil 23 rectifier 24 exciter coil 25 second permanent magnet 30 stator 31 armature coil 32a output terminal 32b output terminal 33 rectifier 34 field coil for exciter 35 controller 36 First permanent magnet 131 Exciting machine field conductor

Claims (2)

[Claims] 1. In an exciter machine, a first permanent magnet is disposed in a stator portion of a rotor, which is opposed to an exciter coil, and a rotor is opposed to an armature coil in a generator body. A brushless self-excited generator with a second permanent magnet in the field pole. 2. The brushless self-excited generator according to claim 1, wherein a conductor that induces an electromotive force to be supplied to the field coil for the exciter is provided side by side with the armature coil.