SU1288809A1 - Device for protection of polyphase using equipment against non-symmetry - Google Patents

Abstract

This invention relates to electrical engineering, in particular, to relay protection. The purpose of the invention is to increase the reliability of the device. In the event of a break of one or several phases, there is no pulse or several pulses corresponding to half-periods of phase voltage or current, at the output of the first and second elements SH1I-; HE 3 pulse signals 1 are formed, shifted in phase relative to each other. The OR 4 and NAND 5 elements are used to block the action of protection while simultaneously appearing at the output of the OR-NO elements 3 signals, which cannot serve as a criterion for emergency operation. The charge element 6 protects against false triggers of protection in the event of a thyristor switching violation. The first and second elements And 7 and 8 form the output signal of a pulse form. 3 il. § (L ff / g. F

Description

The invention relates to electrical engineering, in particular, to converter technology, and can be used in various industries to protect multiphase consumers from asymmetry, by magnetizing with direct current, in the case of power supply from converting devices, and can function as a state sensor. thyristors.

The aim of the invention is to increase reliability.

FIG. 1 shows a functional diagram of a device for protecting multi-phase consumers from asymmetry in FIG. 2 is a timing diagram for the normal operation of the device; FIG. 3 - timing diagrams for emergency operation of the device.

The device diagram (Fig. 1) contains current sensors 1 (voltages), the outputs of which are connected to analog and digital converters 2, the outputs of which are connected to the corresponding inputs of the first and second elements OR-NOT 3, the outputs of which are connected to the inputs of the elements OR 4 and NAND 5, the output of the OR element 4 is connected to the input of the delay element 6 and the first input of the first element AND 7, the output of which is connected with -) - responsibly with the first and second inputs of the second element And 8, moreover

the second input of the first element AND 7 soi-35 thyristors and the load of the load from the terminal with the output of the element AND-NOT 5.

FIG. 2 and 3 the following notation is accepted: U,, Uc + are pulses corresponding to the positive half cycles of the current (voltage) of the phases

magnetizing by direct current.

Claims (1)

Invention Formula 40 A device for protection of multiphase consumers from asymmetry, containing three current sensors included in the supply mains phases, the OR element, the NAND element, the executive authority, A, B, C, respectively, etc. Ug. Uq. - impulses corresponding to negative half-periods of current (voltage) of phases A, B and C, respectively signal 3 protection. The device works as follows. The variable currents of the I or the voltage and each phase (Fig. 2) of the multi-phase installation are converted into a binary code, according to which the presence of a half-period voltage or current corresponds to, and the absence - O. Duration (and,., and., and ..., and, and, 1 impulses, d., ..,,,, i) is proportional to the phase voltage half-cycle or current. The pulses. Corresponding to positive half-periods (and d, and b, Uc), arrive at ten 15 20 25 thirty the first element is OR-NOT 3, and the pulses of the negative half-period (U, Ug, U ..-) are at the inputs of the second element OR-NOT 3. In the absence of a pulse or several pulses, the corresponding half-periods of the phase voltage or current (breakage of one or several phases) at the output of the first and second elements OR-NOT 3, pulse signals 1 are formed, shifted in phase relative to each other (FIG. 3), Elements OR 4 and AND-NOT 5 serve to block the action of protection while simultaneously appearing the output of elements OR -NOT 3 signals that cannot serve as a criterion ariynogo mode. The delay element 6 prevents false alarms of protection in case of thyristor switching disturbances that are accidental in nature. The first and second elements And 7 and 8 form the output signal of a pulse form. The design of the proposed device for protection of multiphase consumers from asymmetry in non-contact devices of alternating current allows to simplify protection devices by eliminating bridge rectifiers, increase their efficiency through the use of microelectronic elemental base, and extend the functionality by controlling the state of thyristors and vaschity load from magnetizing by direct current. Invention Formula A device for protection of multiphase consumers from asymmetry, containing three current sensors included in the supply mains phases, the OR element, the NAND element, the executive authority, characterized in that, in order to increase reliability, it additionally introduces two elements SHSHE ,, two elements AND, a delay element., three analog-digital converters, while the inputs of analog-digital converters are connected to the outputs of current sensors, the inputs of the first the OR-NOT element is connected to the first outputs of the analog-digital converters, the inputs of the second element OR-NOT. are connected to the second outputs of the specified converters, the output: the first element of the WL- is NOT connected to the first inputs of the elec. OR and NONE, repeat the inputs of which are connected to the output of the second element OR NONE, the output of the element OR is connected To the input of the delay element and the first input of the first element AND, the second input of which is connected to you ooog / LXJCX.A. s the course of the NAND element, the outputs of the delay element and the first element AND are connected respectively to the first and second inputs of the second element AND, the output of which is connected to the executive body. Q} a.E Compiled by L. Anisimova. Editor L. Grathillo Tehred M. Khodanych Proofreader  op In Order 7818/53 "Nishty g Subscription YNIIPI State Committee. USSR for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab: 4/5 Production and printing company, Uzhgorod, st. ort  Oh. V. But ha Prestna, 4