RU63611U1 - UNIVERSAL AUTOMATIC CIRCUIT BREAKER WITH VOLTAGE AND CURRENT PROTECTION - Google Patents

Abstract

Universal automatic circuit breaker with voltage and current protection (VAUZ-NT) refers to electrical devices and is designed to ensure safe operation in the power grid - protecting the line, electrical appliances and humans from adverse factors of the effects of electric current. VAUZ-NT involves the use of the ground wire in a 3-wire line as an information signal for recording signals from external sensors: current, temperature, gas, smoke, lightning arrestor, etc. Due to the use of forced electronic control of the electromagnetic release in the circuit breaker and the input for recording signals from external sensors, VAUZ-NT has great functionality and improved technical characteristics compared to existing circuit breakers that work together with protective circuit breakers, which puts it at a new level in the development of similar remedies.

Description

The invention relates to protection systems that automatically shut off and respond directly to an unacceptable deviation from normal electrical operating parameters. The proposed device is designed to ensure safe operation in the power grid - to protect the line, electrical appliances and people from adverse factors of electric current.

Universal automatic circuit breaker with voltage and current protection (VAUZ-NT) involves the use of the ground wire in a 3-wire line as an information wire for recording signals from external sensors: current, temperature, gas, smoke, lightning arrestor, etc.

VAUZ-NT analogues include automatic circuit breakers (AB) [1], working together with residual current circuit breakers (RCDs) [2] and mechanically connected to each other, but not involving the use of a ground wire to record signals from external sensors.

The closest in terms of its function is a VA47-29 circuit breaker [1] with a residual current circuit breaker AD-14 [2], which is selected as a prototype.

It is possible to connect a sensor to an AB with RCD in such a way that, when it is triggered, a leakage current is provided to the ground wire connected to zero. In view of the small sensitivity of the RCD when registering leakage currents, which depends on the load currents, and also because of the inability to ensure the universality of connecting external sensors via any of the “phase” or “zero” wires, the claimed mode of using AB with RCDs is not applied in practice.

The AB operation is based on the use of an electromagnet winding as a current sensor. Acting as an anchor on the lever of the mechanical part of the switch, the electromagnet opens its movable contacts, thereby breaking the electrical circuit.

The main task of AB is to protect the mains from short circuit in the load if the current in it exceeds the threshold of the machine.

Due to the design features and physical properties of the electromagnet, AB does not have a pronounced current threshold. Therefore, in order to eliminate false shutdowns of AB, the electromagnet is calculated on the response current, much

exceeding the rated working load, as can be seen from the technical characteristics of AB [1].

Such ABs have found application in industrial enterprises, since they eliminate false trips by inductive currents of inductive loads, the source of which, in particular, are electric motors.

In electrical networks designed to work with lighting loads and household electrical appliances, the characteristic feature of which are small values of inductive currents, the use of AB can lead to significant emergency consequences, since the design of such lines is most often carried out due to load sufficiency and economic considerations in choosing sections and brands of lead wires.

To connect external additional devices, the AV has access to the lever of the mechanical part of the circuit breaker, acting on it with an external mechanical drive, the RCD breaks the electrical circuit, disconnecting the load.

The disadvantages of AB are:

1. Long response time of the electromagnetic release (ER);

2. High current reliable operation of the ER during overload and short circuit in the line;

3. Dependence of the tripping current on the value of the rated load current;

4. The ambiguity in the operation according to claim 1 and claim 2;

5. The inability to monitor the malfunctioning load with currents not exceeding the threshold of operation AB, the absence of which can lead to a fire hazard situation;

6. The dependence of the current of reliable operation AB on the parameters of the line, its resistance and length, which, in some cases, may exceed the permissible limits as a result of:

- weakening of contacts, connected electrical devices;

- increase the resistance of the line with its heating;

- increase of transition resistance of twists in junction boxes;

- load connections via portable extension lines;

7. Inability to control the temperature of the line wires;

8. The inability to connect to AB more than one external additional device to expand the functionality of the machine.

The disadvantages of RCDs [2] include:

1. Large threshold values of the differential current (leakage current) lying at a level that is dangerous to human life and health in the event of electric shock;

2. A large excess of the trip threshold of the RCD from the value of the maximum allowable voltage value of the network;

3. External mechanical control AB limiting the connection of other additional devices.

The indicated shortcomings of the AB with RCD are completely eliminated in the VAUZ-NT.

The technical result is achieved by the fact that the universal automatic circuit breaker with voltage and current protection (VAUZ-NT), containing the VA47-29 circuit breaker, contains:

- an additional winding (DO) having electromagnetic coupling with a VA47-29 circuit breaker;

- an electronic key (EC) that controls the additional winding;

- an electronic key control device (UUEK) containing a current sensor (DT), a protective device against high voltage (ZUPN), a differential current detection device (UODT) and a device for tracking external sensors and leakage currents (USVDTU);

- n external sensors (VD), where n is a positive integer.

In this case, the input of the VA47-29 circuit breaker is the input “phase” of the electric network line, and the output is connected to the inputs of EC, ZUPN and through the current sensor with the “phase” inputs of UODT and USVDTU. The “zero” line of the electric network is connected to the “zero” inputs of the UODT and USVDTU and the output of the DO. The outputs ZUPN, DT, UODT, USVDTU connected to the control input of the EC, the output of which is connected to. The "phase" and "zero" outputs of the UODT are connected to the inputs of external sensors, the outputs of which are the outputs "phase" and "zero" of the electrical network, respectively. The signal outputs of external sensors are connected to the ground input of USVDTU.

As external sensors, current sensors, temperature sensors, gas sensors, smoke sensors, lightning arresters can be used.

The description of the claimed device is illustrated by the drawing of Figure 1, which schematically shows a block diagram of a VAUZ-NT with external sensors connected. The following notation is adopted on the block diagram: VA47-29 - circuit breaker; DO - additional winding; EK - electronic key; UUEK - electronic key control device; ZUPN - protective device against high voltage; DT -

current sensor; UODT - differential current detection device; USVTTU - a device for tracking external sensors and leakage currents.

Works VAUZ-NT as follows.

The mains voltage of 220 V is supplied via the “phase” and “zero” wires to the VA47-29 circuit breaker, from the output of which the voltage through the “phase” wire is supplied to the EC, which is the energy source for the additional DO winding, when the key from the control signal that comes from nodes DT, ZUPN, UODT, USVDTU unit UUEK. An additional winding DO has an electromagnetic connection with the electromagnetic release of the electronic relay, which allows forcing the contacts of the VA47-29 circuit breaker to be opened by a control signal supplied to the EC.

The “phase” wire is also fed to the measuring current winding of the current sensor DT with voltage, which is used to transmit the control signal to the EC via the signal circuits of the DT “input-output”.

The network voltage through the phase wire is applied to the impulse noise filter in the ZUPN node, followed by comparison with the reference voltage in the threshold device and by supplying a control signal to the EC when its value exceeds the permissible limits.

The wires “phase” and “zero” pass through the current transformer of the UODT unit. A signal is induced in the information winding of the transformer, which is amplified to the required value and fed to the EC from the output of the UODT.

The same wires are connected to the USVDTU and are used to create an EC control signal at its output by signals received at the input of the node from external sensors via the ground wire of a 3-wire line.

The introduction of electronic control in the ER allows you to expand the functionality of the AB, working in conjunction with the RCD, necessary for safe operation in the network and eliminate these disadvantages while maintaining the parameters of the VA47-29 machine:

1. The instantaneous response time is achieved by introducing a backup power source in the VAUZ-NT, made on a capacitor with a storage capacity sufficient to store the energy stored in it, enough to operate the ER. To exclude the discharge of the capacitor through the elements of the rest of the electrical circuit, it is necessary to connect it to a power source through a decoupling diode;

2. The exact threshold of operation of the electric current by current is achieved by the introduction of an internal current sensor DT, (Figure 1);

3. The independence of the VAUZ-NT from the line length and its resistance is achieved by a device that registers signals from external current sensors

data wire "ground" 3-wire line. On the block diagram (Figure 1) this device is designated as - USVDTU;

The device is implemented in such a way as to provide the possibility of connecting the RCCB through any of the wires of the “phase” or “zero” line for the convenience of installation by their consumer.

4. Individual control device USVTTU for loads:

- currents, which are less than the threshold of operation of VAUZ-NT;

- with leakage currents to the ground wire connected to VAUZ-NT;

- with currents that determine the operability of electrical appliances;

5. Ensuring electrical safety of a person from electric shock arising between the "phase" or "zero" and the metal parts of electrical appliances in case of failure;

6. Protection of a person from electric shock arising between the "phase" and non-conductive metal structures grounded to "zero", a differential current detection device UODT;

7. Protection, from unauthorized selection of electricity bypassing the machine with improved characteristics than its counterpart;

8. Protection of electrical appliances against increased voltage of the fault condition is performed while minimizing the overall dimensions of the unit and the need to bring the response threshold closer to the upper allowable voltage limit of the network, taking into account impulse noise that may occur in the line.

An experimental sample of the proposed device, implemented on a modern industrial base, allowed us to confirm its claimed high technical characteristics.

Information Sources Used

1. Interelectrokomplekt. Catalog. M., 2003. Third edition. S.4-5

2. Interelectrokomplekt. Catalog. M., 2003. Third edition. S.14-15.

Claims (1)

A universal automatic circuit breaker with voltage and current protection, comprising a BA47-29 circuit breaker, characterized in that an additional winding is introduced, having electromagnetic coupling with a BA47-29 circuit breaker, an electronic key controlling an additional winding, an electronic key control device containing a current sensor , overvoltage protection device, differential current detection device and tracking device for external sensors and leakage currents, n external sensors, where e n is a natural number, and the input of the VA47-29 circuit breaker is the phase input of the electric network line, and the output is connected to the inputs of the electronic key, protective device against increased voltage and through the current sensor with the phase inputs of the differential current detection device and devices for tracking external sensors and leakage currents, the “zero” line of the electric network is connected to the “zero” inputs of the differential current detection device and devices for tracking external sensors and leakage currents and output m additional windings, outputs of the protective device against overvoltage, current sensor, differential current detection device, device for monitoring external sensors and leakage currents are connected to the control input of the electronic key, the output of which is connected to the input of the additional winding, “phase” and “zero” outputs differential current detection devices are connected to the inputs of external sensors, the outputs of which are respectively the outputs "phase" and "zero" of the electrical network, the signal outputs of external sensors kov connected to the ground input of the device for tracking external sensors and leakage currents.