SU993387A1 - Method of stopping asynchronous run in electric power transmission line - Google Patents

Description

(54) METHOD OF TERMINATION OF ASYNCHRONOUS PROCESS IN ELECTRICAL TRANSMISSION

This invention relates to electrical engineering, in particular, to methods for terminating asynchronous modes in high and ultra high voltage networks.

Methods are known for stopping an asynchronous run in power transmission, in which, in order to prevent the breaking of large equalizing currents and reduce overvoltages, the transmission is interrupted near the moment of coincidence of the phases of the voltages at the ends of the power transmission rj and 2.

The disadvantage of these methods is the tightening of the asynchronous mode, which leads to an increase in the duration of the voltage reduction in the power system and the possibility of additional auto- mation. emergency shutdowns of consumers and the development of the accident.

The closest to the proposed invention is a method of stopping an asynchronous run in an ultrahigh voltage power transmission by detecting an asynchronous run on a line and then disconnecting the line from one end of P.

According to a known method, one-way disconnection of the line is performed, and the disconnection is set at that end.

lines where overvoltages are less. However, at large angles between the EMF vectors, they can no less significantly exceed the permissible level. For power transmission. containing two consecutive line sections and an intermediate substation with two or more transformers, this method of termination

10 asynchronous, the stroke may not provide the lowest levels of overvoltages,

The purpose of the invention is to reduce overvoltages in power lines,

15 containing .two consecutive line sections and an intermediate substation with two or more transformers operating in parallel (autotransformers).

20

The goal is achieved by the fact that in a known method of stopping an asynchronous run in a power transmission by fixing an asynchronous run

Claims (2)

25 and disconnection of the line from one end, between the asynchronous stroke fixation and disconnection. The lines open the connection at a high voltage between the transformers remaining connected to the pasHfcjM lines, in the case. if the swing center is on the line off. The essence of the invention is that when placing a center of oscillations on a switched line, the proposed sequence of operations makes it possible to shift the center of oscillations to the switched end of the line, which reduces the difference in the instantaneous voltage values of the contacts of the linear switch after its switching and, therefore, reduces the amplitude com mutational overvoltages. The position of the center of oscillations can be known in advance (based on preliminary calculations) or controlled from automatically when the asynchronous stroke is fixed using known devices. The proposed method should not be changed if the center of oscillations is located on the other side of the switched end of the line. The drawing proves the block diagram of a device implementing the proposed method. The transmission scheme contains two after; auxiliary sections of line 1 and 2 parallel-connected transformers .3 and switches 4-7, connected, for example, according to the scheme of a quadrilateral. The device contains a logical block 8, a block 9 of simultaneous shutdown, a block of 10 speed off, executive bodies 11-13 and a block 14 of delay. The first input of the logic unit 8 receives a signal about the location of the electrical center of oscillations (e.ts.k), and the second input is a signal from the automatic asynchronous stroke stopping device (APAH) for power outage. Allow signal on the placement of EC on commutative line 1, it can be set to the operative first or to be formed automatically. The outputs of the logic unit 8 are connected to the inputs of the simultaneous shutdown unit 9 and the step disconnect unit 10. The outputs of block 10 are connected to the executive bodies 11 and 13 of the switches 4 and 6 and to the input of the delay block 14, the output of which is connected to the executive body 12 of the switch 5. The output of the block 9 is connected to the executive bodies 11, and 12 of the switches 4 and 5. The device works by following in a way. If logical signal 8 receives a signal that the swing center is located on the switched line 1, then its shutdown is performed in two stages as follows. In block 8, a signal is generated, which enters the input of block 10. Then, from the first output, the signal goes to the executive bodies 11 and 13, which directly disconnects the switches 4 and 6, as a result of which the transmission transit is opened. From the second output of block 10, the signal is fed to the input of block 14, which delays the required time delay and transmits a signal to the executive unit 12, which turns off the switch 5, as a result of which the resulting circuit containing the transformers is disconnected. stepwise. If the signal about the place of ec.c. indicates that the center of oscillations is outside the switching zone, then after fixing the asynchronous stroke to disconnect line 1, the signal from logic block 8 is fed to the input of block 9, which simultaneously issues a command to executive units 11 and 12 directly connected by switches 4 and 5, As a result, line 1 is immediately disconnected. In the event that there is an APAX device, operating under certain conditions to disconnect line 2, the same step-disconnecting device acting in case of a p can be installed on this line. Moving the swing center on line 2, for example, first by turning off the switches 7 and 5, and then turning off the switch 6. The proposed method for stopping the asynchronous operation reduces the amplitude of switching overvoltages and thereby extends the service life of the equipment being operated and reduces the cost of the design solutions for projected transmissions. The invention method of stopping asynchronous running in power transmission by fixing asynchronous running and disconnecting a line from one end, so that, in order to reduce overvoltages in power transmission, containing two consecutive line sections and an intermediate substation with two or more transformers operating in parallel, in the period between fixing the asynchronous operation and disconnecting the line, open the connection at a high voltage between the transformers remaining connected to different lines, in the case of If the swing center is on the line you want to disable. Sources of information taken into account during the examination 1. USSR author's certificate No. 688958, cl. And 02 J 3/24, 1977. 2. USSR author's certificate 811403, cl. H 02 J 3/24, 1979. Z.Lyskov Yu.I. On the effect of emergency control automation, relay sewn up and regulating the excitation of generators on internal overvoltages Proceedings of the Energy Network Project i Vyp.Z, M., Energie, 1972, p.126.