DE1007864B - Electromagnetic short-circuit release for direct current high-speed switches - Google Patents

Description

GERMAN

The invention relates to an electromagnetic short-circuit quick release for direct current with a tripping magnet, which is excited by the main current, and a holding magnet, which is also excited by the main current for a strike armature acting on the moving contact of the switch. In the event of short circuits or overloads increases the magnetic flux in the holding magnet and in the armature of such a quick switch relatively little, since the iron of the holding magnet is already below the rated current of the switch is saturated to some extent. On the other hand, the flux in the larger-sized tripping magnet, which works with lower induction in the iron, considerably amplified, so that in the event of a short circuit, the Switch triggering initial anchor torn off the holding magnet against the force of the holding flux will. The tripping of these quick switches is generally not sensitive to current rise, like this for the automatic shutdown of short circuits would be desirable in some cases.

According to the invention, a current rise-sensitive release is achieved by attaching a good conductor, for example a copper bar on which the excitation current path of the holding magnet forms reached fixed contact part of the switch and to this a bypass around the yoke of the holding magnet educated. The main current then splits statically according to the resistances of the two current paths on this on; When the current increases, the increasing current flows mainly via the additional busbar, this is the current path of the lower resistance. The one prevailing during the short circuit Holding flow, which is decisive for triggering the switch, can therefore not increase, and the switch receives a trip sensitive to the rise in current.

Is the switch in a known manner by energizing a between the legs of the Holding magnets lying polarization core polarized and / or to a certain extent sensitive to current rise made, the sensitivity to the increase in current is achieved by attaching the secondary current path still increased. Despite a certain saturation of the holding magnet, there would be no in the event of a short circuit Such a byway will result in a further increase in the holding flow. This is supported by the Current secondary path avoided, because the flux generated in the case of current changes in the polarization core can do not close via the yoke of the holding magnet, but almost only via the anchor, because through the Excitation current path of the holding magnet and the copper bar a short-circuit ring around the yoke of the holding magnet is formed.

High-speed switch with main current-excited holding and electromagnetic short-circuit release for DC high-speed switches

Applicant:

LICENTIA Patent-Verwaltungs-G. mb H. _f Hamburg 36, Hohe Bleichen 22

Dipl.-Ing. Hans-Joachim Freese, Munich, has been named as the inventor

Tripping magnets and armature are often used as high-speed rectifier switches to protect rectifiers used against flashback. The equal- ..

However, electricity has a higher-frequency superimposed alternating current component: (often 300 Hz). As a consequence of Eddy current and hysteresis losses also occur in peeled magnet parts of the high-speed switch unwanted heating. In such arrangements, the device according to the invention offers the Another advantage is that by creating a secondary current path, this heating in the holding magnet is significantly reduced because as a result of the smaller inductive resistance in the bypass superimposed alternating current mainly flows through this.

Another advantage of the arrangement according to the invention is the possibility, depending on the dimensions of the secondary current path, the trigger value of the high-speed switch to a limited extent to a desired one Decrease amount.

Fig. 1 shows a schematic representation of a view of the current-carrying parts of the Schnellisohailtars according to the invention;

FIG. 2 is a sectional view along the line AB in FIG. 1.

When the switch is closed, the current to be monitored flows via the excitation coil 2 'of the release magnet 2 to the movable contacts 3 'and further via the fixed contact 6, which is through the U-shaped holding magnet 1 is guided. The fixed contact piece 6 serves as an excitation winding for the Hook magnets. The fixed contact piece 6 carries according to the invention a copper bar 4, which to this contact piece 6 forms a bypass around the yoke of the holding magnet 1. Hence divides the Hauptsitrom statically according to the resistances of the contact piece 6 and the copper bar 4, as shown in FIG. 1 by arrows

709 508/360

marked current paths can be seen. If the current changes, the current distribution on the contact bridge changes 6 and the busbar 4 in such a way that the Teilifcrom over the contact piece 6 and the river in the holding magnet only slowly follows a change in current. The flux in the tripping magnet 2, however, follows a change in current immediately. Therefore, in the event of a short circuit with a large increase in current, the Impact armature 3 is already torn off from the holding magnet 1 at smaller currents and against the movable one Contact piece 3 'thrown as this would be the case in the absence of the copper bar 4. In the event of an overload with a slow rise in the current, however, the switch only opens at its set trigger value, since the power distribution on contact pieces 6 and rail 4 is only insignificantly different from the static Power distribution deviates.

If the switch is provided with a polarization core 5, the coil for the purpose of a different Trigger value of the switch is applied to a direct current source, so causes the attachment the copper bar 4 also causes a current rise ·· sensitive early tripping of the switch.

Claims (2)

Claim ε-1. Electromagnetic short-circuit release for DC high-speed switch, characterized by on which the excitation current path of the holding magnet ίο forming fixed contact part (6) of the switch arranged By-pass (4) around the yoke of the holding magnet in the form of a good conductor, in particular a copper bar. 2. Tripping according to claim 1, characterized by the use of a polarized holding magnet. Considered publications:
German patent specification No. 573 182. 1 sheet of drawings