SU1464239A2 - Protective disconnection device for a.c. network - Google Patents

Abstract

The invention relates to electrical engineering and is intended to protect a person from AC damage in the network. The purpose of the invention is to ensure operability at high load currents and increase noise immunity. When a person touches any of the phases in the protection zone, current will flow through him, as a result, the voltage at the output of leakage current sensor 1 and blocks 3.5 and 7 abruptly changes. The voltage jump at the input of differentiating unit 9 passes through it in the form of a pulse unit 11, which generates a pulse of the required amplitude and duration. This impulse passes through the prohibition body 13 to the executive body 14 and triggers the operation of the entire device. If the change in leakage current is caused by switching of the load, then simultaneously with a change in the signal at the output of the leakage current sensor 1, a signal jumps from the load current sensor 2. This signal jump will be detected by the inhibition channel (blocks 4, 6, 8, 10 and 12) in the form of a pulse the voltage from the output of the imaging device 12, applied to the control input of the prohibition authority 13. In this case, the prohibition authority 13 prohibits the passage of a signal, so that the device does not work. Elimination of false positives of channels from switching voltage pulses is provided by turning on synchronous detectors (controlled keys) and integrators (memory of CI elements) provided that the sync pulses of control voltages from drivers 15 and 16 do not match in time. Stable shift. Chaxo– pulses in time (in phase) are achieved by connecting the phasing signal generator 16 to the phase-recirculating circuits of the imaging device 15. 1 sludge. eight (/)

Description

The invention relates to electrical engineering, in particular · ": devices for protecting people from electric shock · and is an improvement on the device by ed. St. No. 1359842.

. The purpose of the invention is to ensure the operability of the device at high load currents and increase noise immunity from pulsed electromagnetic interference.

The drawing shows the fuikdaonal scheme of the proposed g-device.

The device for protective shutdown contains two identical channels: a leakage channel and a prohibition channel, each of which represents, respectively, a serial connection of the leakage current sensor 1 of the current sensor 2 to the load _s phase-sensitive rectify rectifiers 3 and 4, synchronous detectors 5 and 6, integrators 7 and 8 , differentiation of blocks 9 and 10, shaper 11 pulses of operation, shaper 12. pulses:, prohibition. The output of the forward pulser of the operation pulses is connected to the signal input of the prohibition organ 13, and the output of the shaper 1.3 of the prohibition pulses is connected to the control input of the organ 13 "The output of the prohibition organ .12 is connected to the input of the executive organ 14, The control inputs of the phase-sensitive rectifiers 3 and 4 are connected to the output of the shaper 15 pulses of phase synchronization having an additional output for controlling an additional driver 16 pulses of phase synchronization, the output of which is connected. e control inputs of synchronous detectors 5 and b, the input of the shaper 15 is connected to the phase voltage of the network.

The device operates as follows.

The natural leakage current in the network of an arbitrary phase leads to the appearance on the output of the sensor 1 of a signal proportional to the leakage current. At the output of the first phase-sensitive rectifier 3, made., For example, on the basis of a controlled electronic key, synchronized with the mains voltage, a certain constant voltage appears. This voltage is supplied to the synchronous detector 5, also made in the form of a controlled electronic switch, which passes the pulses of the rectified voltage to the integrator 7, the Integrator smooths and stores the voltage value. ‘'If the voltage is constant or changes slowly, then at the output of the differentiating unit 9, the signal is zero, the driver 11 of the operation pulses is in the initial state and the device does not operate.

When a person touches any of the phases in the protection zone, a current flows through it, as a result, the voltage at the output of the sensor 1 and blocks 3, 5 and 7 changes abruptly and the voltage jump at the input of the differentiating block 9 passes through it in the form of a voltage pulse and starts block 11, which forms a pulse of the required amplitude and duration. This pulse passes through the body 13 of the ban on the executive body 14 and causes the operation of the entire device.

If the change in the leakage current is caused by switching the load, then simultaneously with the change in the signal at the output of the leakage current sensor, a jump in the signal from the load current sensor 2 occurs. This jump in the signal is recorded by the inhibit channel (blocks 4, b ₅ 8, 10 and 12) in the form of a pulse voltage from the output of the shaper 12, supplied to the control input of the prohibition body 13. Moreover, the prohibition authority prohibits the passage of the signal from block 11 to the organ 14, so that the device does not work "

When a phase-sensitive rectifier reveals an opening voltage in the output signal, a switching voltage pulse appears in its output signal, the value of which depends on the amplitude and phase of the input voltage, and the phase is determined by the phase of the input voltage and the setting of the phase-synchronization pulse generator 9. These switching voltage pulses freely pass through the differentiating blocks and cause a false channel response.

Elimination of false channel responses from switching voltage pulses is ensured by switching on between blocks 3, 4 and 9 ,. 10 synchronous detectors (controlled key) 5 and 6 and integrators (storage element) J9 and 10, provided that the sync pulses of the control voltages from the shapers 15 and 16 do not coincide in time. A stable shift of the clock pulses in time (in phase) is achieved by connecting the shaper 16 of the phasing signals to the phase-turn gate circuits of the shaper 15.

The proposed device has a high noise immunity to pulse

Claims (1)

Claim Device for protective shutdown in the alternating current main according to ed. St. No. 1359842, which is related to the fact that, in order to ensure operability at high load currents and to increase noise-immunity interference from current sensors, since the signal from the sensors passes through blocks 3, 4 and 5, 6 into two mismatching moments synchronized by the clock pulses time, as well as to pulsed electromagnetic interference, acting directly on the amplifying elements of the circuit, provided by the operation of the noise from the prohibition channel and, as a consequence, the prohibition of operation from the interference of the entire device. The application of the proposed device can increase the total power of electrical installations in the protection zone while ensuring high reliability of electrical safety and power supply. . 10, two synchronous detectors with integrators at the outputs, included between the phase-sensitive rectifiers and differentiating blocks of each 15 channels, an additional phase synchronizer, and the sync inputs are sync _; The main detectors are connected to the output of an additional 2Q imager. pulses of phase synchronization, the input of which is connected to the additional output of the selection of control pulses of the pulse generator of the phase synchronization, while the output pulses of both formers are shifted in time relative to each other.