JPS645447B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the structure of a reactor mounted on an electric vehicle.

FIG. 1 is a front view showing an example of a conventional reactor. 1 is a U-shaped core, 2 is an iron core formed by laminating electric iron plates in a short fence shape or having a wound core, 3 is a coil formed by winding a conductor in a ring shape, G is an iron core 1, This is the void formed by 2.

The reactor mounted on such a vehicle is often installed under the floor of the vehicle in relation to other equipment, and when an intermittent current flows through the reactor, the leakage magnetic flux of the reactor causes damage to the vehicle. It is known that inductive disturbances occur in signal systems.

FIG. 2 is a current-inductance characteristic diagram of the reactor. L∽ is the inductance of the reactor when the iron core is completely saturated, and Lo is the inductance of the reactor when the iron core is unsaturated.

Now, if the inductance L∽ of the reactor is much smaller than the inductance Lo of the reactor, the structure of the reactor with the conventional closed magnetic circuit iron core shown in FIG. 1 will be as follows.

That is, in order to reduce the inductance L∽ of the reactor when the iron cores 1 and 2 are completely saturated, the number of turns of the coil 3 must be reduced.On the other hand, when the iron cores 1 and 2 are unsaturated, In order to increase the inductance Lo of the reactor,
Iron cores 1 and 2 must have a large cross-sectional area. As a result, the reactor becomes an iron machine and becomes large in size.

In addition, equipment connected to the reactor may malfunction.
When a faulty large current flows through the reactor, the iron cores 1 and 2 of the reactor become saturated, and magnetic flux leaks to the outside of the reactor, causing an induction failure in the vehicle's signal system, similar to when an intermittent current flows through the reactor. There is a risk.

The present invention was made to solve these drawbacks, and it minimizes the leakage flux of the reactor when the iron core is unsaturated, and reduces the inductance of the reactor when a large current flows and the iron core is completely saturated. The aim is to make the reactor smaller and to minimize the leakage magnetic flux outside the reactor. Hereinafter, details of the present invention will be explained with reference to the drawings.

3 and 4 show an embodiment of the present invention, with FIG. 3 being a front view of the reactor, and FIG. 4 being a longitudinal sectional view thereof.

The coil of the reactor consists of an inner coil 4, an outer coil 5, and an intermediate coil 6.The central axes of these coils are made to coincide with each other, and the dimensions in the winding direction and axial direction are aligned, and the inner coil 4 and the outer coil 5 are
have the same number of turns, and the middle coil 6 is the inner coil 4.
It is formed to have twice the number of turns.

The coils thus formed are arranged such that the inner coil 4 is arranged inside the intermediate coil 6 and the outer coil 5 is arranged outside the intermediate coil 6 with their axial ends aligned.

The iron core 7 is formed in a U-shape, and the iron core 8 is formed in a short fence shape by laminating electric iron plates or having a wound core. The inserted iron core 8 has the required number of gaps G within the coil.

The connection of the reactor formed in this way is that when the inner coil 4, intermediate coil 6, and outer coil 5 are connected in series and energized, these inner coils 4
The magnetomotive force of the outer coil 5 is selected to be in the same direction, and the magnetomotive force of the intermediate coil 6 is selected to be in the opposite direction.

In the reactor with the coil connected in this way,
In Figure 4, when current flows through each coil as shown in the circles (indicates that the current flows from the opposite side to the front) and the marks (indicates that the current flows from the front to the opposite side), the generated magnetic flux is indicated by the arrows. It occurs as shown. In this case, when the iron cores 7 and 8 are not magnetically saturated, most of the magnetic flux passes through these iron cores 7 and 8,
There is almost no leakage to the outside. Further, if a large current flows through each coil and the iron cores 7 and 8 are completely saturated, the reactor becomes the same as an air-core reactor. At this time, if the distance between the inner coil 4, the intermediate coil 6, and the outer coil 5 of the intermediate coil 6 is smaller than the average radius D of the coils, the sum of the magnetomotive forces of the inner coil 4 and the outer coil 5 is the magnetomotive force of the intermediate coil 6. , and the inductance of the reactor becomes extremely small. That is, it is possible to prevent almost any magnetic flux from leaking outside the reactor. this is,
By appropriately selecting the dimensions and shapes of the coils and iron cores 7 and 8, it is possible to provide a reactor with low inductance during large currents.

Next, the advantages of the reactor of the present invention will be explained in comparison with conventional reactors.

Example 1 Chiyotsupari Actor Currently, from the viewpoint of energy conservation in railways, many Chiyotspa electric vehicles are being adopted as electric railway vehicles. Chippers used in railway vehicles use thyristors to control the main current of the vehicle drive DC motor on and off, so a large reactor is used to smooth the current. As mentioned above, the reactor is often installed under the floor of the vehicle due to its connection with other equipment, and if an intermittent current flows through the reactor, the leakage magnetic flux of the reactor may cause inductive disturbances in the vehicle signal system. known to occur.

In order to prevent this induction failure on the Chiyotsupa train, which uses a conventional reactor, (1) the method of outfitting the reactor should be devised;

(2) Apply a magnetic shield to the reactor.

(3) The reactor shall be a closed magnetic circuit iron core type reactor.

Measures such as these were implemented.

In the case of (1), there are many control devices installed under the floor of the train, and there are constraints such as installing the reactor in a specific direction on the center line of the train, and deciding the rigging position in preference to other devices, which is disadvantageous. It is.

In the case of (2), when a large current flows through the reactor due to a chopper failure, there is a risk of magnetic flux leaking outside the shield, and it is necessary to prevent leakage magnetic flux from leaking outside even when a fault current flows. The shield of the reactor is large, and the weight and shape of the reactor are large, which is disadvantageous in terms of rigging.

In case (3), the fault current flows as in case 2,
The iron core becomes saturated and leakage magnetic flux occurs. If you try to reduce the leakage flux in response to a large fault current, the iron core will become larger. Therefore, the reactor becomes large, which is disadvantageous.

As described above, there are problems with the conventional Chiyotsupari Actor.

If the reactor of the present invention is applied to a chopper train, almost no magnetic flux leaks to the outside of the reactor even when the chopper is normal or when a faulty large current flows, making it possible to prevent induction disturbances to vehicle traffic signals. .

Example 2 Reactor with small inductance when the iron core is saturated Figure 2 shows the current-inductance characteristics of the reactor. In the case of a reactor having a conventional closed magnetic circuit iron core shown in FIG. 1, the structure is as follows, as described above.

In order to reduce the inductance L∽ of the reactor when the cores 1 and 2 are completely saturated, the number of turns of the coil must be reduced. In order to increase the inductance Lo, iron core 1,
2, the cross-sectional area must be increased. That is, the reactor becomes an iron machine and becomes large in size.

If the reactor of the present invention is designed with the characteristics shown in Figure 2, the inductance of the reactor when the iron core is completely saturated will be Since the magnetomotive force is canceled out by each other, the number of turns of the coil can be increased compared to the conventional reactor described above, and the iron core can be made smaller with a smaller cross-sectional area.

Therefore, the reactor of the present invention can be made smaller and lighter than the conventional reactor, and its effects are significant.

[Brief explanation of drawings]

Fig. 1 is a front view showing an example of a conventional reactor, Fig. 2 is a current-inductance characteristic diagram of the reactor, Fig. 3 is a front view showing an embodiment of the reactor of the present invention, and Fig. 4 is a longitudinal section thereof. It is a front view. 1, 2, 7, 8... Iron core, 3... Coil, 4...
...Inner coil, 5...Outer coil, 6...Middle coil, D...Average radius, G...Gap.

Claims (1)

[Claims] 1. An annularly wound inner coil and an annularly wound outer coil having the same axial dimension and the same number of turns as the inner coil are arranged concentrically, and between these two coils, An annularly wound intermediate coil having the same axial dimension as both coils and twice the number of turns as the inner coil is arranged concentrically so that the gaps between the two coils are equal; An iron core is inserted into the gap between the two coils so that at least two equal gaps are formed in the axial direction so as to surround the intermediate coil, and the magnetomotive force of the intermediate coil is equal to the magnetomotive force of the inner coil and the outer coil. A reactor characterized by connecting these three coils in series so that they are in opposite directions.