RU115501U1 - DIAGNOSTIC DEVICE FOR SECONDARY CHAINS OF MEASURING TRANSFORMERS - Google Patents

Abstract

1. A device for diagnostics of secondary circuits of measuring transformers, containing a first interface intended for receiving data of synchronous measurements, a second interface intended for receiving data on the current state of primary connections, a database of updated data on primary connections, a block for allocating calculated segments of the primary connection circuit, a calculation block balances and damage localization, while the output of the first interface is connected to the first input of the balance calculation and damage localization unit, the output of the second interface is connected to the input of the database of updated data on primary connections, the output of which is connected to the second input of the calculation unit through the block for selecting the calculated segments of the primary connection diagram balances and damage localization. ! 2. A device according to claim 1, in which a warning signal generation unit and an archive of balances and damages equipped with an external access interface are connected to the output of the balance calculation and damage localization unit. ! 3. The device according to claim 2, in which a configuration module equipped with external access is introduced, the outputs of which are connected to the setting inputs of the balance calculation and fault localization unit, the warning signal generation unit, the unit for allocating the calculated segments of the primary connection diagram, the balance and damage archive.

Description

FIELD OF TECHNOLOGY

The utility model relates to the provision of continuous monitoring of the integrity of the secondary circuits of measuring current and voltage transformers at power facilities.

BACKGROUND

A known system for monitoring the integrity of circuits [US Patent No. US5532601, IPC G01R 31/02, 1996], which provides monitoring of the integrity of the secondary circuits of measuring sensors, is considered as an analogue of a utility model for diagnosing secondary circuits of current and voltage transformers. The specified system is a device (or a functional module as part of another device) that provides continuous monitoring of the integrity of the secondary circuit of the measuring sensor to which this device is connected.

One of the drawbacks of the above system for monitoring the integrity of circuits is that it is quite suitable for monitoring the integrity of only unbranched circuits (for example, secondary circuits of measuring current transformers in single-phase AC networks); the possibilities of using this system for monitoring the integrity of branched secondary chains are significantly limited, in particular for:

- secondary circuits of three-phase groups of measuring transformers

current (with a common neutral wire);

- secondary circuits of three-phase groups of single-phase voltage transformers or secondary circuits of three-phase voltage transformers (with a common neutral wire);

- secondary circuits of single-phase voltage transformers in single-phase AC networks in the presence of several electrical measuring instruments connected to the secondary circuit of one voltage transformer.

Moreover, the system allows you to detect damage in the secondary circuit (breaks and short circuits) only in the unbranched section of the specified circuit to which it is connected; damage is not detected in other parts of the branched secondary chain.

The disadvantages of the above analogue are also:

- low sensitivity of the device to certain types of damage in the secondary circuits, in particular, to short circuits in the secondary circuit cable near the measuring sensor or in the sensor itself (for example, during inter-turn short circuits in a current or voltage measuring transformer);

- introduction of additional load into the secondary circuit of the measuring sensor, limiting the permissible value of the secondary load created by the secondary circuit cable and other devices connected to the secondary circuit, respectively, imposing a restriction on the minimum cross-section of the secondary circuit cable and the possibility of connecting individual devices consuming from the specified circuit a certain load.

The closest in technical essence to the utility model under consideration is a monitoring device for secondary circuits of measuring transformers in the power system [International application No. W02010 / 034149 A1; IPC G01R 31/00, G01R 31/06; 2010], made on the basis of an intelligent electronic relay protection device (Protection Intelligent Electronic Device, abbreviated as Protection IED).

The above-mentioned device provides monitoring of secondary circuits of measuring transformers at a power facility based on continuous analysis of signals in the secondary circuits of measuring transformers to which this device is connected and detecting, based on the above analysis, “disturbance” in the secondary circuit. In this case, the signal perturbation in the secondary circuit means the occurrence of a current or voltage signal in the secondary circuit, the level of which can potentially correspond to some emergency situation, or a change in the signal level in the secondary circuit, the value of which can also correspond to an emergency. An abnormal situation in this case may be a damage in the secondary circuit of a measuring transformer, but there may also be an accident in the primary power supply system.

The disadvantage of the above secondary circuit monitoring device [2] is the high probability of false detection of damage in the secondary circuits of measuring transformers. In particular, a high probability of false detection of damage occurs when damage (short circuit) occurs in the primary power grid of the power facility. In case of damage in the primary network of the power facility, the resulting signal values (the magnitude of changes in signal levels) in the secondary circuits of the measuring transformers, due to the indicated damage, depend significantly on the location of the damage in the primary electrical network. In particular, in case of damage in the primary power network at a considerable distance from the installation site of the current or voltage measuring transformer, the resulting change in signal in the secondary circuit of the measuring transformer will be insignificant and may not be defined as a “disturbance”. In this case, the monitoring device that does not detect a change in the signal in the secondary circuit of the measuring transformer as a disturbance will not send a signal to the other monitoring devices about the occurrence of a corresponding disturbance, respectively, therefore, other monitoring devices of the secondary circuits can potentially detect damage in the secondary circuits of the measuring transformers, to which they are connected. An obvious solution to this problem is to increase the sensitivity of monitoring devices of individual connections to the values of signal disturbances in the secondary circuits. However, this increase in sensitivity can lead to unnecessarily frequent detection of disturbances by monitoring devices, which in turn can cause:

- additional false detection of damage in the secondary circuits of measuring transformers;

- failure to detect damage in the secondary circuits of measuring transformers (and, accordingly, failure to ensure timely localization of these damage) due to false detection of damage in the primary network of an energy object, caused by the almost simultaneous recording of disturbances in the secondary circuits of measuring transformers by various monitoring devices of secondary circuits within the energy object.

Thus, this solution to the problem does not exclude the possibility of false detection of damage in the secondary circuits of measuring transformers.

DISCLOSURE OF A USEFUL MODEL

The task to which the utility model is aimed is to reduce the number of false detection of damage in the secondary circuits of measuring current and voltage transformers.

The above technical result is achieved through the use of an advanced secondary circuit diagnostic device, which includes a first interface for receiving data of synchronous measurements, a second interface for receiving data on the current state of primary connections, a database of updated data on primary connections, a block for allocating calculation segments primary connection schemes, a unit for calculating balances and localizing damage, while the output of the first interface is connected to the first mu input of the unit for calculating balances and localizing damage, the output of the second interface is connected to the input of the database of updated data on primary connections, the output of which is connected to the second input of the unit for calculating balances of primary connections and damage localization via the block for selecting the calculated segments of the circuit of primary connections.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 shows a diagram of the proposed device for the diagnosis of secondary circuits of current and voltage transformers, including the main blocks and showing the relationship of these blocks.

IMPLEMENTATION OF A USEFUL MODEL

The device 1 for the diagnosis of secondary circuits of current and voltage transformers includes the following blocks:

-first interface 2, intended for receiving data of synchronous measurements;

-second interface 3, designed to receive data on the current state of primary connections;

- a base of 4 updated data on primary compounds;

-block 5 allocation of the calculated segments of the primary connection diagram;

- block 6 calculating balances and localization of damage;

- block 7 forming a warning signal;

- archive of 8 balances and damages;

- module 9 configuration.

In the process of its functioning, the secondary circuit diagnostics device 1 performs a cyclic collection of synchronous measurement data coming from the power facility connections, which through the communication interface 2 enter the balance calculation and damage localization unit 6.

Device 1 also performs a cyclical (and, if necessary, event-based) data collection on the current state of the circuit of primary connections of the power facility (including the position of individual switching devices). The indicated data is transmitted via communication interface 3 to the base 4 of updated data on the primary connections, providing continuous updating of the data contained in the base 4 on the current state of the primary connection diagram of the power facility.

Block 5 of allocation of the calculated segments of the primary connection diagram based on continuously updated data on the current state of the primary connection diagram of the energy object stored in database 4, forms a list of segments of the primary connection diagram of the energy object, for each of which the balance (currents and / or capacities) is further calculated.

For each of the segments of the primary connection diagram of the energy object formed by block 5, the block 6 for calculating balances and localizing damage performs the calculation (reduction) of the balance for this segment. Balancing the segment can be performed, for example, by balancing the currents, or by balancing the power balance (active and reactive). When summarizing balances for individual segments of the primary object circuit of an energy facility, unbalances for individual segments are identified in accordance with the criteria for detecting unbalance specified in block 6. Based on the identified imbalances, localization of damage in the secondary circuits of current and voltage transformers is performed.

Additionally, the secondary circuit diagnostics device 1 may include a warning signal generation unit 7 and an archive 8 of balances and damages. Block 7 provides the broadcast received from block 6 signal about unbalance or damage:

-the personnel of the power facility using means, in particular, visual and sound alarms;

- external devices and alarm systems in the format required by these devices and systems.

An archive of 8 balances and damages provides archiving of data on unbalances and damages received from block 6 with a given time depth in the internal database. At the same time, archive 8 is equipped with an external access interface through which access to the data on balances and damage from external systems contained in the archive is provided.

Additionally, the device 1 may include a configuration module 9, through which the configuration is provided:

- block 5 allocation of the calculated segments of the primary connection diagram;

- block b calculation of balances and localization of damage;

- block 7 forming a warning alarm;

- archive of 8 balances and damages.

The module 9 configuration provides the configuration of the functioning parameters of the above blocks of the device through the installation inputs of these blocks. In particular, the configuration module provides:

- setting criteria for the allocation of design segments of the primary object circuit of the power facility in block 5;

-specification of the criteria for identifying imbalances in block b, the calculation of balances and localization of damage;

-customizing the output signals issued by block 7, in particular, the types of signals issued separately when damage occurs in the secondary circuits, and separately when unbalance is detected without detecting damage;

-configuration of the temporary depth of storage of data on balances and damage in the archive 8.

Claims (3)

1. A diagnostic device for secondary circuits of measuring transformers, comprising a first interface for receiving data of synchronous measurements, a second interface for receiving data on the current state of primary connections, a database of updated data on primary connections, a unit for extracting calculated segments of the primary connection circuit, a calculation unit balances and damage localization, while the output of the first interface is connected to the first input of the unit for calculating balances and damage localization, output One of the second interface is connected to the input of the database of updated data on primary connections, the output of which is connected to the second input of the block for calculating balances and localizing damages through the block for allocation of calculated segments of the primary connections. 2. The device according to claim 1, in which the warning signal generation unit and the archive of balances and damage, equipped with an external access interface, are connected to the output of the balance calculation and damage localization unit. 3. The device according to claim 2, into which a configuration module equipped with external access means is inserted, the outputs of which are connected to the installation inputs of the balance calculation and damage localization unit, the warning signal generation unit, the primary connection circuit allocation segment allocation unit, the balance and damage archive.