RU2247455C1 - Disconnecting protective device - Google Patents

Abstract

FIELD: electrical engineering; retrofitting lead-in power distribution boards of habitable apartments.

SUBSTANCE: proposed device designed for protecting power installations in emergency situations and for preventing contact between persons and live parts has release, miniature toroidal current transformer, analog-to-digital converter, memory unit, microprocessor, device serviceability check push-button unit, and adjustment push-button unit. Quantity of miniature toroidal current transformers equals that of conductors under protection. Device adjustment button is used for recording information about transients due to connection of new power consumer in memory unit. If adjustment button has not been depressed on connection of new power consumer, device will disconnect section under protection. In this way it takes "friend-or-foe" function. Device also affords protection of power installations and personnel against leakage currents between any circuit conductors at supply mains section under protection.

EFFECT: enlarged functional capabilities of device.

1 cl, 1 dwg

Description

The present invention relates to the protection of electrical installations, for example, electrical installations of residential apartments, from emergency conditions, including accidental contact of people with live parts. It can be used in the reconstruction of electrical input panels in residential apartments.

Residual current circuit breakers that are triggered by earth leakage current are widely known, for example, from the book of N.V. Shchipunov. Protective shutdown. M .: Energy, 1968. Known devices, in principle, can work both in single-phase electrical installations, and in three-phase. Their common disadvantage is that they do not provide protection against current leaks arising between two working conductors (phase and zero or between two-phase) and thus do not prevent the occurrence of short circuits, which, in turn, are sources of fire.

Closest to the claimed device is a residual current circuit breaker, known from the book of M.R.Nayfeld. Grounding and other protective measures. M .: Energy, 1975. In this book on page 35 a description is given, and in fig. 20, b shows a circuit breaker, which is selected as a prototype.

The known device contains a differential (differential, summing) current transformer of zero sequence, to the secondary winding of which a sensitive organ (relay) is connected, acting on a circuit breaker (protective device). Through the window of the core of the transformer, zero and phase wires pass, which are the primary winding of the differential current transformer. In three-phase electrical installations, three phase wires and zero wire pass through the core window. The prototype works as follows. If the currents in the zero and phase (or three-phase) wires (load current) are equal, their geometric sum is known to be zero (the current in the phase wire flows in one direction, and the current in the neutral wire flows in the same direction) and therefore, there is no current in the secondary of the differential transformer. If a current is shorted or leaked to the grounded case of the power receiver, or if a person accidentally touches the phase wire of the electrical network, the equality of currents in the primary winding of the differential transformer will be violated, since in addition to the load current, a fault or leakage current will pass through the phase wire and in its secondary winding will appear current. If it is equal to or exceeds the response current of the sensitive organ (relay), then literally in a matter of seconds, the emergency section of the network will turn off.

The disadvantage of the prototype is the inability to protect the electrical installation when a leakage current occurs between the working conductors (phase and zero or between two or three phase) and thus the prototype is not able to prevent the occurrence of short circuits, which are overwhelmingly sources of fire, and does not protect people by accident touching two wires of an electric network (simultaneously phase and zero or two phase wires).

The objective of the invention is to remedy the above disadvantage inherent in the prototype.

As a result of using the present invention, it becomes possible to protect the electrical installation in the event of a leakage current not only to the ground, but also between any wires of the electrical network in the protected area.

The above technical result is achieved by using a fundamentally new residual current device, which includes a circuit breaker with a trip unit that responds to a digital signal (for example, as in computers with a case and an ATX power supply unit), toroidal mini current transformers, the number of which is equal to the number of protected wires ( two in single-phase two-wire networks and four in four-wire three-phase networks), the secondary windings of which are connected to the converter of analog information to digital, a memory lock with memory modules on microcircuits, a microprocessor connected to a converter of analog information (i.e. current values) to digital and to a memory block, dependent and independent current sources (microcircuit power sources), a setup button block and a device health check button block .

The drawing shows a diagram of the device. It contains a circuit breaker 1, toroidal mini-current transformers 2, a trip unit that responds to a digital signal 3, a converter of analog information (current value) to digital 4, a memory unit 5, a dependent power supply 6, a microprocessor 7, an independent power source (battery) 8, a setting button block 9 and a device checking button block of a device 10.

Toroidal current transformers 2 are connected to an analog to digital information converter 4, which in turn is connected to a memory unit 5 and a microprocessor 7, and it is connected to a trip unit 3 that responds to a digital signal, a dependent power source 6, an independent power source 8, a button block settings 9 and to the button block of the health check device 10.

The proposed device operates as follows. When any electric receiver (light bulb, refrigerator, iron, electric stove, electric shaver, hair dryer, etc.) is turned on in the protected zone through the toroidal mini-transformer, a transient current will flow at the moment of switching on, which will induce current in the secondary winding of the toroidal mini-transformer. The current from the secondary winding of the transformer will be transferred to the analog information to digital converter and then, in the form of a digitized signal, measured in fractions of a second, it will be transferred to the microprocessor and then to the memory unit. If at this moment the setup button is pressed, the memory unit will remember this information, and if the setting button is not pressed, the microprocessor and memory unit will begin to search for this information among previously recorded in the memory unit, and if the information is not found, the device in a split second disconnect the protected area. In order to exclude false alarms, it is necessary to periodically press the setup button, and then turn on and turn off all power receivers located in the protected zone in turn. Thus, after pressing the “settings” button, the device will be given the “friend or foe” function. The device will not respond to “their own”. But if a person gets under voltage, or in the event of insulation failure, a leakage current appears in the protected area, the device will work and turn off the power in a split second. The health check button, as its name says, checks the health of the device by connecting to the protected zone “foreign” load automatically for all possible options.

Claims (1)

A residual current device containing a circuit breaker, characterized in that it contains a trip unit that responds to a digital signal, toroidal mini-current transformers, the number of which is equal to the number of protected wires, the secondary windings of which are connected to an analog information to digital converter, a memory unit with memory modules on microchips, a microprocessor connected to a converter of analog information into digital and with a memory block, dependent and independent power sources for microchips, a button block on settings and button block device health check.