SU1282255A1 - Controlling element for pulse measuring members of relay protection - Google Patents

Description

ND 00

Yu

N9 SL SL

The invention relates to electrical engineering and can be used in relay protection devices. The reactive element for the pulse measuring bodies of the relay protection is intended for use in the field of automation of energy systems.

The purpose of the invention is to increase the stability of the reacting element,

 The drawing shows a diagram of the proposed device

The reactive element for the pulse measuring bodies of relay protection contains the first 1 and second 2 elements of NAND, capacitor 3, generator 4 of pulses, first inverter 5, counter 6, second inverter 7.

The device works as follows

In the initial state (the absence of zero-level pulses at the input) of the NAND element is in the state of logical zero and the capacitor 3 is discharged. The IS-NE 2 element, regardless of the signal level, coming from the output of the second inverter 7, is in the state of logical one and 1 blocks the operation of the 4-pulse generator on the control input. When a noise element appears at the input of a reacting element in the form of narrow zero-level pulses, a charge of the condenser 3 occurs.

With a short pulse duration, the capacitor 3 does not have time to charge before the switching voltage

ment of AND-NOT 2. At the same time, the first inverter 5, switching to the state of the logical unit, zeroed the counter 6,

When a pulse appears at the input of the reacting element with a duration that ensures the charge of the capacitor 3 before the switching voltage of the second element AND-NOT 2, the output of the second element AND-NOT 2 will be a pulse signal with a zero level. The signal at the second input of the element AND-NOT 1 supplied from the output of the element AND-NOT 2, the circuit is also self-retaining after the end of the pulse. At the same time, the output of the element IS-NOT 2 starts the generator of 4 pulses, and after the high level signal disappears at the output of the inverter 5, the counter 6 starts counting. The counter is reset by each pulse at the input of the reacting element. After the last pulse disappears, after a time determined by the frequency of the pulse generator and the division factor of the counter, the signal of the logical unit appears at the output of the counter,

This signal, through the second inverter 7, returns the AND-HE 2 element, and then the AND-HE element 1 to the initial state.

The pulse generator 4 is again blocked. The device returns to its original state.

Claims (1)

RESPONSE ELEMENT FOR PULSE MEASURING · RELAY PROTECTION BODIES, containing two AND-NOT elements, a capacitor, and the output of the first AND-NOT connected element to the first input of the second element NAND, and the first input of the first NAND element is connected to the output of the second NAND element, one end of the capacitor is connected to the output of the first NAND element, and the other is connected to a common bus, characterized in that, in order to increase stability, In addition, a pulse generator, a counter and two inverters are introduced, and the resetting counter input through the first inverter is connected to the second input of the first NAND element, and the counting input is connected to the pulse generator output, the counter output through the inverter is connected to the second $ the input of the second element AND NOT, the input of the pulse generator * is connected to the output V of the second element AND NOT. Λ 1282255 A1 1 1282255 2