RU2700659C2 - Method for determination of sparking point in electric network and device for implementation thereof - Google Patents

Abstract

FIELD: electrical equipment.

SUBSTANCE: use: in the field of electrical engineering and power engineering. Method of sparking point determination in electric network consists in the fact that electric current of controlled electric network of direct or alternating current is measured, determining the signal-feature of the cycle "appearance and damping of spark", determining the value of sparking current, determining the total duration of sparking on the specified cycle of its measurement, forming the level of spark hazard. At that, signals-indications of cycle "appearance and damping of spark" of controlled sections are measured and their preset addresses are stored, comparing the results of measurements of the feature signals at the input of the monitored network with the corresponding signals at the inputs of each monitored section, by coincidence of these results with only one of all signals of the monitored sections, determining the accident risk level taking into account the width of the spark gap and the shunting current value in the electric network and displaying it, forming the address of the monitored section with a sparkling electric circuit and displaying it, if the signal at the input of the monitored network coincides with signals at the inputs of more than one monitored area, the signal is identified as a noise signal.

EFFECT: technical result is increase in the accident risk assessment reliability by suppressing the existing interference in the absence of arcing; improving reliability of systems by including in the controlled sections of electric power circuits of these systems implementing the principle of separation of redundant systems between these sections.

6 cl, 2 dwg

Description

The invention relates to the field of fire safety and electric power, and in particular to methods and devices for protection against sparking (defective arc) in an electric network (electrical installation) of alternating and direct current, as well as determining the location of a sparking circuit in a controlled electric network, leading to an accident or disaster.

Hereinafter, a sparkling circuit is understood to mean an electrical circuit from one pole (phase) of a power source to its opposite pole (phase), in any previously unknown place of which a break occurs (violation of circuit integrity), no more than which is sufficient to create a spark gap occupied by ionized plasma, providing the required conductivity of the electric load current in this circuit, at which its value remains practically unchanged.

The incident manifests itself through a fire, explosion, or dangerous failure of the system or facility as a whole. This failure refers to a latent (undetectable) type of failure.

The operation of residential, public, industrial, and other civilian, military, and special-purpose facilities is often accompanied by incidents of sparking that occurs at the break of an electrical circuit with the formation of ionized plasma. In this case, thermal energy is released on the spark gap, leading either to a fire or explosion, or to the destruction of the insulation (in particular, to melting) of the wire with a malfunction of the system.

As a result, great material and moral damage is inflicted, often accompanied by the death and (or) injury of people.

A known method [1] for preventing an incident), including: measuring the electric current of a controlled electrical network (ES); the formation of low-frequency and high-frequency components of a given current; the formation of a signal-sign of the cycle "occurrence-suppression of the spark" (RF signal) in the region of zero current value; measurement and calculation of the frequency of repetition of cycles; measurement of the amplitude of the pulses at the generating and / or decaying stages of the cycle; measuring the duration of the generating and decaying stages of the cycle, as well as / or the number of pulses at these stages of the cycle, the amplitude of which exceeds the set value; measurement of at least one of the short circuit current, overload current, leakage current, the deviation of the mains voltage from the required values; determination of the width of the spark gap formed at the place of violation of the integrity of the electric circuit; measurement and calculation of the value of the sparking current, taking into account the influence of the shunt current.

This technical solution establishes the occurrence and development of sparking in a branched ES, measures and calculates the level of its danger. However, it is not able to determine in it the place of sparking in a controlled electrical network.

In the conditions of sparking reaching the upper danger level, this leads to the need to turn off the entire branched controlled ES. Thus, in addition to a dangerous sparking circuit, normally functioning electrical circuits are disconnected with working consumers.

In addition, the named technical solution does not allow to achieve high reliability of identification of the obtained analysis results with the sparking process due to the impact of a wide range of interference on it in a capacious and branched electric network.

A technical solution [2] is aimed at eliminating this drawback, which controls at least two potentially hazardous sections of a branched ES, to which, with the exception of load resistance, the inputs of the spark measurement modules are connected in parallel with the exception of the load resistance. In case of violation of the integrity of one of the electrical circuits, for example, section 1, its corresponding module measures the magnitude of the sparking voltage and / or its current. By a given number or other symbol of this module, a conventional number or other symbol of this sparking circuit is assigned. In good condition of the said section, the inputs of the mentioned modules are shunted by a controlled closed electric circuit, and their conditional number or other designation remains equal to zero, and the effect of possible interference is weakened.

The disadvantage of this technical solution is the complication of the design of the cable or electric harness, the development of which requires the introduction of an additional wire, which, in turn, requires control of its connection to the protected circuit, as well as worsening the weight, volume and cost characteristics of the object using this cable (harness ) In addition, the wiring diagram of the controlled electric network is significantly complicated, in general, and, therefore, the reliability of the controlled electric system and its readiness for use when restoring a damaged electrical circuit are reduced.

The aim of the invention is to determine the address of the controlled area with a sparking electric circuit, which increases the efficiency of operation of the controlled ES and improves its volumetric-mass characteristics, as well as increases the reliability of the measurement results and calculations of the level of danger of the accident.

The goal is achieved by comparing the results of measuring signal-signs or other parameters of each cycle “occurrence-suppression of the spark” almost simultaneously at the inputs of the controlled network and each controlled area. By the coincidence of the measurement results of the RF signals from the sensor 6 and the sensor 7 of only one section 8 of the entire set from 1 to n (Fig. 1), a conclusion is drawn about the selected address of the controlled section with a sparking electric circuit and, at the same time, about the correspondence of the analyzed high-frequency signals on sensors 6 and 7 to the sparking process.

The separation of the controlled ES into its controlled areas leads to an increase in the level of reliability of the measurements and calculations, and also provides higher reliability of the functioning of the controlled ES, in general, and its readiness for use when eliminating failures in it.

The proposed method for preventing an accident from arcing in the ES is carried out by the following set of actions:

- measurement of the total electric current of the controlled ES;

- determination of signal-signs of the cycle "occurrence-suppression of the spark" when passing the total load current through the region of zero values;

- determination of the total duration of sparking at a given cycle (time period) of its measurement, for example, lasting 4 seconds;

- determination of the parameters of the sparking current, taking into account the width of the spark gap and the magnitude of the shunt current in the electric network;

- calculation of the indicator of the danger of sparking current;

- calculation of the level of danger of the accident;

- determination of the address of the controlled area with a sparking electrical circuit;

- identification of the input high-frequency signals to the sparking process by suppressing the same type of interference coming from the sensor 6 and at the same time from no more than one sensor 7;

- the formation of a signal of the danger level of the incident and / or command to disable the monitored section of the electric network;

- display of the address of the controlled area with a sparking circuit and, if necessary, serviceable electrical circuits included in this area of the controlled electrical network;

- display of the command to disable the monitored section of the controlled electrical network;

- display of the level of danger of the incident;

- if necessary, displaying the address (s) of a working electrical circuit located in one disconnected area due to the most dangerous level of the sparking circuit.

Each of the sections of the controlled ES can contain one or more electric circuits, each of which is a closed potentially dangerous circuit when an electric current flows in it and is determined by the quality of the connection of conductors and other functionally significant elements in it.

This circuit may contain from two to ten or more closed switching elements (contacts of automatic machines, switches, relays, load disconnectors, etc.). In this case, the role of the connection with screws 28 can be replaced by soldering, welding, twisting, or other technological technique, which is also potentially dangerous, in terms of the possibility of violating the integrity of this connection.

The essence of the claimed technical solution is illustrated by the drawings of FIG. 1. The block diagram of the determination of the place of sparking, where:

1 - external electrical network or autonomous power source;

2 - controlled electric network;

3 - electric harness from the input of the controlled network;

4 - circuit breaker at the input of a controlled network;

5 - circuit breakers at the entrance of the controlled areas (site);

6 is a variant of the sensor for the perception of sparking at the input of a controlled network;

7 is a variant of the sensor (s) for the perception of sparking at the input of the controlled area (s) of the controlled network;

8 - controlled sections 1, 2, ... i ... n (section 1) of the controlled network;

9 - communication wires of the controlled areas (section) with the output of the controlled network;

10 - communication channel for transmitting the RF signal from the sensor for sensing sparking to the unit for determining the parameters of the sparking current and to the unit for determining the address (conditional number or other symbol) of the controlled section;

11 - unit for determining the level of danger of the incident and the address of the damaged controlled area;

12 - block determining the address of the controlled area with a sparking circuit;

13 - unit for determining the parameters of the sparking current at the stages of the cycle “occurrence-suppression of the spark”, performing operations of measuring the total electric current of the controlled electric network, determining signal signs of the occurrence and suppression of sparking, determining the sparking current taking into account the width of the spark gap and the magnitude of the shunt current in the electric Networks

14 - module M1 (M2 ... Mn) measuring and calculating the signal from the sensor 7;

15 is a board of modules for measuring the RF signal of sparking, "coming from the sensor (s) 7 and storing the specified addresses included in each of these sections;

16 - module determining the address of the controlled area with a sparking electrical circuit;

17 - module display address of the controlled area;

18 - module displaying the level of danger of sparking;

19 is a block displaying the level of danger of the incident;

20 - block forming the level of danger of sparking;

21 - block forming a team to disable the controlled area of the ES;

22 - power supply;

and FIG. 2. A fragment of the wiring diagram of the controlled section of the controlled electrical network, where:

23 - switch (contactor, automatic, remote switch or other switching element of electric current);

24 - movable contact switch;

25 - fixed contact switch;

26 is a fragment of sparking in the place of a loose circuit of the pair of contacts of the switch B1;

27 - a metal block for connecting wires;

28 - screw clamping wire;

29 - load electrical circuit;

30 - metal part of the exposed wire;

31 - protected part of the wire (braid).

In order to better visualize the nature of the functioning of the device by determining the address of the monitored section with a sparking circuit and improving its operational characteristics, the procedure for the operation of this device in its practical application is presented below.

Each electric circuit of the controlled electric network must have a pre-assigned address (conventional number or other symbol) and is fixed in the corresponding controlled area. The controlled area must also have a pre-assigned address. All these numbers are stored in the board 15 of the modules for measuring the RF signal of sparking and storing the specified addresses of the electric circuits of the ES and controlled sections.

From the point of view of controlling a structurally redundant object in emergency mode, for example, of an airplane or a rocket, each of the electric circuits of the controlled area, before their emergency shutdown, if necessary, perform the power functions of the corresponding redundant system in the "hot" or "cold" mode.

"Hot mode" - the backup channels are simultaneously in the operating mode, in which a continuous mode of operation of the object is ensured and its continued operation if one of these channels is disconnected.

"Cold mode" - the functioning of one main channel, other channels are redundant. Disabling the main channel leads to a short-term disruption of the system’s performance, in general, while the backup channel is turned on.

In case of disconnection of the controlled area with a sparking circuit and its other main or backup electrical circuits that provide power to the corresponding electrical systems of the facility, the facility continues to work on the backup channel or channels.

Such a division of the controlled electrical network into controlled areas, realizing the separation of redundant systems, ensures the successful exit of the facility from an emergency. For example, this will allow you to complete the entire long flight route of the aircraft or to carry out, if necessary, its accident-free emergency landing.

In the absence of sparking.

If there is no violation of the integrity of the electric circuit when its load current flows from the sensor 6 at the input of the controlled network, then through the controlled section 8 (number 1 ... n or other designation) and terminating it at the output of the same controlled network. Moreover, if at the stages of the “occurrence-extinguishing of the spark” cycle zero values of the high-frequency components of the load current from the sensor 6 in the block 13 for determining the parameters of the spark current and from the sensors 7, coming sequentially from the measurement modules of the RF signal of sparking of all possible addresses of the board 15 to module 16 coincide, then at the output of module 16 determining the address of the monitored section with a sparking circuit will have a zero value, which indicates the absence of violation of the integrity of any electrical circuit of the monitored network.

If on one or several sections from the sensors 7 at the same time or only on block 13 from the sensor 6 a high-frequency interference appears, it will not be perceived as arcing in any of the controlled sections.

The coincidence of the RF signal at the input of a branched controlled network with the RF signals at the inputs of more than one monitored section indicates the effect of interference with a frequency spectrum that is close enough to the RF signal of sparking. The conclusion about the absence of real sparking is justified by the almost impossible violation of the integrity of electrical circuits simultaneously in several controlled areas and, all the more, having the same amplitude and phase-frequency characteristics.

This implies a high level of identification of the studied RF signals to the real sparking process, which confirms the high reliability of the assessment of the accident hazard level as a result of the invention.

If arcing occurs.

When the switch 23 is turned on, there is a violation of the integrity of its electric circuit, which consists in a loose connection of the movable contact 24 with the fixed contact 25 (Fig. 2).

Between these contacts at a small gap (for example, up to 10 microns), an electrical breakdown occurs, followed by the formation of an ionized plasma on this spark gap, which acts as a pseudo-closed metal pair of these contacts (fragment 26).

Sparking can also be caused if the poor connection of bare wires 30 with screws 28 with metal blocks 27 or with a load 29 is broken.

At the time of formation of the sparking circuit passing sequentially through the main sensor 6 of the controlled network and the additional sensor 7 of its controlled portion 8, simultaneously at the inputs of Block 13 "determine the parameters of the spark current at the stages of the cycle" occurrence-suppression of the spark "" and, for example, Module 1 of the Board 15 of the “modules for measuring the RF signal of sparking and storing the specified addresses” pass identical RF signals. A similar identity of the RF signals will be absent between the sensor 6 and other sensors 7 of the Modules (2 ... n).

After the unit 13 determines the correspondence of the RF signal from the main sensor 6 to the sparking process, the result of its further identification is transmitted to the input of Module 16 "determining the address of the monitored section with a sparking circuit". To determine this address and increase the reliability of the RF signal from the main sensor 6, the result of the previous evaluation in this module is compared with the result of measuring the spark signal from the sensor 7, received from the Board 15 "modules for measuring the RF signal of the spark and storage of the specified addresses" in Module 16 " determining the address of the controlled area with a sparking chain. "

If the comparison results in Module 16 coincide in the absence of such RF signals from other monitored sections of a branched ES, the signal of Block 12 "determining the address of the monitored section" is transmitted to Module 17 "displaying the address of the monitored section" in the form of a conditional number or other symbol for the damaged monitored section . If there are other electric circuits in this damaged area along with the sparking electric circuit, if necessary, all their addresses are displayed in the same Module 17.

When disconnecting operable electrical circuits together with a sparking circuit, these addresses are displayed in block 19 "displaying the level of danger of the accident."

Technical result:

- improving the efficiency of operation of the facility by forming the address of the monitored area with a sparking circuit and, if necessary, the addresses included in it workable electrical circuits;

- improving the reliability of the operation of the object by dividing its controlled ES into controlled areas, each electrical circuit of which, if necessary, can perform the functions of powering the object in the “hot” or “cold” backup mode before the emergency shutdown of this controlled area, which will ensure successful use the intended purpose, for example, to complete the successful flight of an aircraft with a malfunction;

- suppression of existing interference in the absence of sparking by identifying the simultaneous action of RF signals at the input of the monitored network and only at one input of the monitored section of all possible.

The proposed technical solution differs from the known ones in that it contains operations and devices that form the address of the monitored area with a sparking circuit, ”and also significantly increases the reliability of the systems and the operation efficiency of the facility under the influence of sparking. At the same time, the effects of interference in the absence of this sparking are effectively suppressed, eliminating the formation of dangerous false commands and reports. This extends the functionality of the currently existing methods and devices for preventing incidents from sparking during the occurrence of abnormal (unauthorized) sparking in the electrical network and, in particular, in the electrical installation.

In the scientific and technical literature, no technical solutions with the above set of distinctive features were found. Therefore, these differences allow us to conclude that the claimed technical solution meets the criterion of NOVELTY.

Moreover, the purpose of the invention is achieved by the entire set of signs of operations, elements and relationships that were not known prior to the date of application of the technical solution, which allows us to conclude that the proposed technical solution meets the Critical differences criterion.

The proposed technical solution regarding the above methods and devices virtually eliminates the issuance of false reports and commands and increases the reliability indicator when monitoring DC and AC networks, which reduces the cost of implementing protection for the prevention of fires, explosions and dangerous failures of systems from sparking in ES , and also increases the reliability of electrical systems in general.

The introduction of devices that implement the proposed technical solution, allows the use of already mass-produced ISKRA products according to technical solutions [1] and [2] with their minor circuit and software refinement. In this case, blocks 13, 20, 21, and 22 functioning in the ISKRA product can be used almost completely.

It also does not require the restructuring of industrial enterprises and private firms to produce a new product range.

The introduction of devices that implement the proposed method involves the use of serial components and components. This does not require the restructuring of industrial enterprises and private firms to produce a new product range. Devices can be designed and manufactured in one design with well-known circuit breakers, which will expand their functionality and significantly increase their efficiency.

Thus, the introduction of the proposed method for the prevention of fires, explosions and dangerous system failures in the event of sparking in the electrical system will provide effective protection for people, residential, industrial and other civil, military and special purpose objects from the damaging effects of fires, explosions and dangerous system failures, as well as will provide significant savings in material and financial resources of each citizen and the state as a whole.

INFORMATION SOURCES.

1. Patent of Russia RU 2571513 C2, IPC G08B 17/00 (2006.01).

2. Patent of Russia RU 2342711 C2, IPC G08B 17/06.

Claims (6)

1. The method of determining the place of sparking in the electric network, which consists in measuring the electric current of the controlled electric network of direct or alternating current, determining the signal-sign of the cycle “occurrence and extinguishing of the spark”, determining the value of the sparking current, and determining the total duration of sparking for a given cycle its measurements, form a danger level of sparking, characterized in that they measure the signal-signs of the cycle "occurrence and extinguishing of the spark" of the controlled areas and store their specified addresses at astkov, compare the results of measurements of signal-signs at the input of the controlled network with the corresponding signals at the inputs of each controlled area, by the coincidence of these results with only one of all the signals of the controlled areas, the hazard level of the incident is determined taking into account the width of the spark gap and the magnitude of the shunt current in the electric network and display it, form the address of the monitored area with a sparking electrical circuit and display it, when the signal at the input of the monitored network matches with signals at the inputs of more than one controlled area, it is identified as an interference signal. 2. The method according to p. 1, characterized in that upon reaching the maximum value of the level of danger of the accident, the controlled area is turned off. 3. The method according to p. 1, characterized in that when displaying the address of the monitored area with a sparking electric circuit, the electric circuits included in it are displayed. 4. The method according to p. 1, characterized in that the systems of controlled areas are divided along the main and backup channels by distributing them between these areas. 5. The method according to p. 4, characterized in that the disconnection of the controlled area is carried out taking into account the separation of the main and backup channels. 6. A device for implementing the method according to claim 1, comprising a unit for measuring an electric current of a controlled electric network, a module for determining a signal-sign of the cycle “occurrence and suppression of sparks”, a unit for determining the magnitude of the sparking current, a unit for determining the total duration of the sparking for a given cycle of measuring it, unit for calculating the level of danger of sparking, a module for displaying the level of danger of sparking, and a power supply unit, characterized in that an additional board of modules for measuring signal-signs of the cycle “occurrence and extinguishing the spark ”of controlled areas and storage of the specified addresses of these sections and electrical circuits included in each of them, a unit for determining the address of a controlled area with a sparking electric circuit, a unit for displaying the danger level of an incident, and a unit for generating a command to disconnect a controlled network section, while exiting devices for measuring the total current of the monitored section is connected to the input of the module for measuring the signal-sign of the cycle "occurrence and suppression of sparks" of this section, the output of which through the indicated board of modules and storage of the set addresses is connected to the input of the module for determining the address of the monitored section, the other input of which is connected to the output of the block for determining the parameters of the spark current at the stages of the cycle “occurrence and suppression of the spark”, the input of which is connected to the output of the device for measuring the total current of the controlled electric network, the output of the block for determining the address of the monitored section is connected to the input of the display module of the address of the monitored section, the output of which together with the output of the ur The spark hazard level is connected to the incident hazard level display unit, while the input of the spark hazard level display module is connected to the output of the spark hazard level formation unit.

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