DE503934C - Arrangement for monitoring the starting process by means of speed display devices for three-phase DC control sets - Google Patents

Description

GERMAN EMPIRE

ISSUED ON
JULY 30, 1930

REICH PATENT OFFICE

PATENT LETTERING

CLASS 21 d ² GROUP

S 86144 VIIIb121 d * Date of the announcement of the grant of the patent: / 7. July

Siemens-Schuckertwerke Akt-Ges. in Berlin-Siemensstadt *)

for three-phase direct current rule sets Patented in the German Empire from June 14, 1928

When starting three-phase DC rule sets, in which the induced part of the main engine is connected to the armature of a single anchor ceramic former during the starting process one must ensure that at the moment when the two machines are at the relevant Speeds have caught up, the starter is shorted, or if the machines at the speeds in question do not fantasize about turning off the main oil switch. In order to avoid that, if the machines do not catch at the relevant speeds, the One armature converter goes through and can reach dangerous speeds, so far equip the single armature converter with centrifugal switches, which switches off the main oil switch if the single armature converter reaches too high speeds. Since starting is mostly done from the control platforms, from which you cannot overlook the single-armature converter, you can be sure that you can work safely the centrifugal switch instructed, which can easily fail.

According to the invention an arrangement is created which is directly from the control platform from catching or not catching the two machines. An arrangement according to the invention can also be designed so that when catching the machines the starter between the induced parts of both machines automatically short-circuited and If the machine does not catch the main motor, it is automatically switched off from the mains, without any centrifugal switch still present needing to take effect.

According to the invention, the speeds of the main motor and the speeds of the single armature converter monitored by a speed display device for each machine, the scales of which are arranged one above the other or next to one another are that the scale zero points are offset from one another, the pointer deflections are in opposite directions, and the pointer deflections lying next to one another correspond to those speeds for which in the induced part of every machine has the same number of periods. Used appropriately a DC voltmeter with a proportional scale is used as a speed display device, that of DC touring dynamos with the main motor or the single armature converter are coupled, are fed. Of course, you can also use both speed indicators in unite in a common instrument. At the speeds at which the machines can catch each other, the pointers are then always next to or on top of each other.

The corresponding scale divisions lying next to or on top of each other can be seen on the basis of the Fig. Ι easily determine. In Fig. 1, the speeds of the main motor are on the abscissa and the speeds of the single-armature converter are plotted on the ordinate. At a standstill of the main motor would have to be the single armature converter if the two induced parts are synchronized run at synchronous speed, in the selected embodiment with 1500 revolutions

*) The patent seeker stated as the inventor:

Fratty Winter in Berlin-Friedenau.

503984

per minute, since the number of periods of the rotor of the main motor at standstill is equal to the mains frequency and the number of periods of the rotor of the single armature converter at synchronous speed of the single armature converter is also equal to the line frequency. If the main engine has the synchronous speed, in the embodiment 333 revolutions per minute, has reached, on the other hand, the single-armature converter would have to stand still in the case of synchronism, since the frequency im Rotor of the main motor at synchronous speed zero and the frequency of the rotor of the single armature converter is also zero at standstill; all intermediate values with synchronism of the induced Parts of both machines must be on the straight line connecting the values 1500 are on the ordinate and 333 are on the abscissa.

Fig. 2 shows the pointer deflections of two instruments according to the invention at standstill of both machines, and Fig. 3 shows the pointer deflections of the two instruments in the Synchronism of the induced parts of both machines. When both machines are at a standstill both pointers are at the zero point, with synchronism of the induced parts of both machines are both pointers facing each other. 1 and 2 are the scales of a display instrument. the Zero points on both scales are on the opposite side End. The opposite scale divisions correspond to the individual synchronous speeds, which can be seen in Fig. 1. Fig. 4 shows the single line diagram using our arrangement. On the three-phase network 3 is above the oil switch 4, the stator of the main motor 5, the rotor of the starter 16 and the short circuiter 7 is connected to the rotor of the single armature converter 6. With the DC rear machine 8 is coupled to the main motor, which is the DC side of the single armature converter 6 feeds. The single-armature converter 6 and the rear machine 8 are energized by DC bus 9,1.0. The excitation of the rear machine 8 can through the controller 11 can be set, whereby one the different speeds for the synchronism of the induced parts of both machines. With the main engine 5 and the An armature converter 6 is one in use for monitoring the speed per se well-known touring dynamo 12 or 13 coupled, which the DC voltmeter 14 or 15 Food. The pointer 141 moves on the scale of the voltmeter 14, on the scale of the voltmeter 15 the pointer 151.

The mode of operation of the arrangement is as follows. Move when starting the rule set both pointers towards each other. In that eyes

Look, where both pointers are exactly opposite, a contact 17 is closed, whereby 60 the trip coil 161 through the control battery 18 is excited; as a result, the starter 16 is short-circuited. The machines catch up not, the hands 141 and 151 move past each other, and a second 65 contact 19 is closed, whereby the trip coil 162 is energized by the control battery 18; as a result, the oil switch is switched off. In normal operations when both machines are synchronized, on the other hand, both 70 hands move simultaneously, so that setting one other operating number can be monitored at any time.

Claims (5)

Patent claims: ι. Arrangement for monitoring the starting process by means of speed indicators for three-phase direct current rule sets in which the induced part of the main motor is during the starting process is connected to the armature of the single armature converter, characterized in that the scales of the speed display devices both machines are arranged one above the other or next to one another in such a way that the scale zero points offset against each other, the pointer deflections are opposite, and the adjacent ones Pointer deflections correspond to the speeds for which the same number of periods in the induced part of each machine prevails. 2. Arrangement according to claim i, characterized in that that DC voltage indicators with a proportional scale are used as speed indicators, the DC dynamos coupled with the main motor or with the single armature converter be fed. 3. Arrangement according to claim 1 and 2, characterized in that the two Speed display instruments are combined in a common instrument. 4. Arrangement according to claim 1, characterized in that when catching the machines the starter between the induced parts of both machines by means of a pointer contacts of the display device The trip coil is automatically short-circuited. 5. Arrangement according to claim i, characterized in that when not catching the Machines the mains switch of the main motor by means of a trip coil fed via pointer contacts of the display device is automatically switched off from the network. For this purpose ι sheet of drawings