The aim of recording is to identify emerging disturbances and interferences. A high level of them may cause failure states. A failure in a power system may have unexpected effects and their removal may be expensive. Disturbance recorders enable to detect and analyze irregularities appropriately early. These devices and resistant to harsh environmental conditions in power substations.
Disturbances are signals measured with high frequency. The SMT-102/103 device is able to record them with the frequency of 2 500 000 samples per second. The speed of voltage fluctuations triggering an oscillogram record is up to 2000 kV/µs. Basing on a knowledge database and identified premises, appropriate alarms and notifications are generated, associated with prompts and explanations for maintenance and dispatching staffs.
The SO-52v11-eMR device is intended for recording disturbances in the low-, medium- and high-voltage power distribution boxes. Depending on the number of signals subject to registration, individual recorders can be combined into a network, creating a hardware layer of the station, distributed recording system and interference analysis.
The SO-52v11-R disturbance recorder performs records of disturbance and operation courses in switchings substation bays of all voltage levels. Depending on the number of signals which are to be recorded, single recorders may be connected into a network, creating the hardware aspect of a substation distributed system for disturbance recording and analyzing. Gathered data is sent to a superior system and processed by specialized software in order to identify causes of failures.
The modules and connected and supplied by the internal LVDS bus. In its maximal configuration, the recorder may be equipped with 4 modules of the MWS-201w.200 type and a redundant MZA-210 power supply module.
Basic functions of the recorder are performed by the MPA-351-1R measurement-communication module. It continuously measures currents and voltages. If conditions for recording initialization are met, courses and analog and binary signals are recorded with appropriate advance and delay times. Parameters of recording initialization and its duration time are defined during configuration of recorder parameters.
The communication-measurement module realizes also transmission with external communication devices and other systems using the MODBUS, DNP 3.0, IEC1850, TFTP and other protocols, defined while designing a given application.
An outstandingly interesting device is our specialized measurement transducer, SMT-101, equipped with a set of measurement probes, designed for bushing monitoring. The implementation of this device has given us extraordinary "power" experience when we have successfully recorded courses of discharges and short-circuits on an 110 kV line in the Zakład Remontowy Energetyki [Power Renovation Company] in Czerwonak.
The transducer records connection and storm overvoltages on the primary and secondary sides of a transformer. It detects dynamic changes of bushing capacities and long-term changes, which indicate a rapid or slow degradation of dielectric layers. Measurements are transmitted to the SYNDIS ES system, our expert software, which is able to determine the change of the bushing loss rate. Appropriate messages and notifications are generated on the basis of change trends.
We believe, that systematic statistic of recorded atmospheric overvoltages, including their measured values, provides valuable information about lightning protection on a substation.
During exploitation of the transducer it has appeared to record also voltage disturbances connected with failures in a power system as well! Such records may be applied for additional verification of operation of disturbances recorders and some protection devices.