DE1057210B - Arrangement to increase the stability of a synchronous machine - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

PATENT 1 057

INTERNATIONAL KL.

H 02p; j

REGISTRATION DATE: JANUARY 30, 1952

NOTICE
THE REGISTRATION
AND ISSUE OF
EDITORIAL:

ISSUE OF
PATENT LETTERING:

May 14, 1959

OCTOBER 22, 1959

AGREES WITH EXPLAINING LETTER 1 057 210 (M 127160 VIII b / 21 c)

The stability of energy transmission with synchronous generators is known to be particularly important in two ways Cases endanger ^, on the one hand with the transmission of electrical energy over great distances and on the other in low-load operation of power plants working in parallel, if the generators for the generation of capacitive Reactive power run in the underexcited state and come close to the stability limit. There is a risk that the generators will begin to oscillate. The onset of pendulums expresses itself among other things due to fluctuations in the load angle. A well-known process, the stability of synchronous machines to increase sees the influencing of the arousal depending on the first or further Derivatives of the load angle change.

Devices are known which electrically detect the size of the load angle change or the load angle. The new arrangement has the advantage that it is simple compared to these devices and allows to use an element (stroboscopic measuring device) which is widely used in other fields is. The invention is based on the fact that the stroboscopic measuring device for detecting the Change in load angle contains a photocell tap which generates a voltage proportional to it (e.g. in the form of a pulse) supplies, and the photocell tap an electrical differentiation device to form the Derivation (derivatives) of the change in load angle is connected.

For further explanation, reference is made to the drawing; it shows

Fig. 1 shows an embodiment of the stroboscopic arrangement, namely in the Teilfig. (a) in front view and in the Teilfig. (b) in side view;

2 shows a schematic representation of the circuit for generating flashes of light.

In Fig. 1, W denotes the shaft end of the synchronous machine to be measured or controlled. A circular disk 5 ^{1 is} mounted on it, one half of which is opaque and the other is transparent. This disc is illuminated by the flashes of light from the stroboscopic device .B ₁ and B _2; which are synchronized with the grid or the generator voltage. Opposite the light flash stroboscopes B ₁ and B ₂ are one or more interconnected photocells P ₁ and P ₂ , which are arranged on the carrier T approximately diametrically to one another. The carrier T can be rotated coaxially with the disk. At its lower end there is a voltage divider Sp, on which different voltage values can be tapped depending on the position of the carrier. A scale is attached to the circumference of the girder, which allows the size of the respective load angle to be read off.

Order to increase
the stability of a synchronous machine

Patented for:

Dr.-Ing. Richard Modlinger,
Unterföhring near Munich

IO Dr.-Ing. Richard Modlinger, Unterföhring near Munich, has been named as the inventor

When the machine is in stationary synchronous operation, the photocells are located behind the opaque half of the circular disk and are thus shielded from light sources B ₁ and B _2. When the load angle changes, one photocell is first partially or completely illuminated, and with larger changes several photocells are illuminated, resulting in voltage pulses with an amplitude that is proportional to the size of the load angle change and with a number of pulses corresponding to the number of flashes of light from the stroboscope. Proportional to the level of the voltage, an automatic capacitor is activated, which - possibly via an amplifier - rotates the carrier T with the photocells arranged on it until they are covered by the opaque part of the disc 5 "and thus deprived of the light effect of the light stroboscope are.

Depending on whether the load angle increases or decreases, one of the diametrically positioned photocell arrangements P ₁ or P _{2 is} excited, which results in a clockwise or counterclockwise rotation of the carrier according to the function of the compensator. As a result, the carrier is brought into a position corresponding to the size of the load angle. The speed of adjustment of the carrier can be varied by known means in accordance with the feedback of a control. The running times are coordinated so that they are long in relation to the period of oscillation of pendulums. In the event of instabilities, the rapid oscillations of the load angle will thus generate tensions which are proportional to the magnitude of the change in the load angle, because the post-turning device cannot follow these rapid oscillations. The speed of the change in the load angle is obtained in a known manner by a downstream differentiation device. The acceleration can also

909 626/219

can be achieved by further differentiation in a known manner. She is z. B. can be represented by a voltage across a resistor. In multi-pole synchronous machines, the disc used for stroboscopic measurement can be rotated via a gear so that its speed corresponds to that of the two-pole machine. The load angle can be increased by translating the drive speed of the pulley to a multiple of the speed of the two-pole machine. The number of flashes of light does not have to be increased for this. If the arrangement is operated in this form, then, for. B. a flash of light on four revolutions of the disc. If the disk is operated at a fraction of the speed of the two-pole machine, a corresponding number of opaque segments must be attached to the circular disk. Instead of the transparent disk, a disk that is half black and the other half white can also be used. The photocells are then arranged on the carrier T on the same side as the light flash strobes.

In order to obtain precise measurements, the stroboscope lamps B ₁ and B ₂ must generate light flashes with a steep limitation over time, for example by switching the light flashing stroboscopes, as shown schematically in FIG. In FIG. 2, B _{2 shows} the light generator, and St shows a discharge path connected in parallel with B _2. The lamp is extinguished by igniting the discharge path.

The arrangement described above is used to stabilize synchronous machines by the Output voltage of the differentiation device influences a voltage regulator and this the excitation of the synchronous machine increases when the load angle increases in the sense of stabilization.

Claims (2)

Patent claims: 1. Arrangement for increasing the stability of a synchronous machine by influencing its excitation depending on the first and / or second derivative of the change in load angle, to the detection of which a stroboscopic measuring device is used, characterized in that the stroboscopic measuring device for detecting the load angle change a photo cell pickup which supplies a voltage proportional to it (e.g. in pulse form), and at the photocell tap an electrical differentiation device for forming the derivative (s) of the change in load angle connected. 2. Arrangement according to claim 1, characterized in that the exact stroboscopic Visualization of the angle change lamps, e.g. B. controlled power gates are used that Generate flashes of light with a steep limitation over time. Considered publications:
Journal ETZ, 1933, p. 491;
German patents No. 570662, 602 557,
100, 817 771, 600 097. 1 sheet of drawings © 909 510/358 5. (909 626/219 10:59)