TRACTION NETWORK MONITORING AND PROTECTION SYSTEM SMTN-3
Traction network monitoring and protection system, series SMTN-3 is provided for:
- traction network protection against short circuit current and harmful overloads;
- traction network parameters monitoring;
- data acquisition for the following analysis of emergency processes.
Traction networks protection is provided by monitoring of traction network voltage and current dynamics change.
In case of protective functions preset parameters exceed the system issues a command to open high speed circuit breaker.
SMTN-3 provides the following operation capabilities:
- measurement of traction network voltage and current value and shape in different modes, including short-circuit in line;
- protection of traction network against short-circuit currents, including remote short circuits low currents and overloads;
- oscillography and long-term memory record of voltage and current value and shape under short circuits (one of emergency process protections detection in traction network);
- waveforms storage and display, as well as data for further analysis transfer to upper level system (or PC);
- software-based internal configuration setting (protections input, protective characteristics selection, number of protection stages, etc.);
- local and remote input, storage and display of protection settings;
- storage of two setting sets and switching of setting sets by external
- information on the number and time of protections operation storage
- analysis of current distribution between incoming panels.
SMTN-3 is designed as a set of separate modules, fixed on DIN-rail and connected with each other:
- measuring module with voltage divider is located in high voltage area (busbar compartment);
- processing module is located in low voltage area (control compartment).
Measuring and processing modules are interconnected with optic cable that provides transmission of information between modules, as well as galvanic isolation between high voltage measuring circuits and secondary circuits.
Measuring module is directly connected to voltage and current measurement primary sensors. Current sensor is a resistive element of power circuit (shunt). Voltage sensor is a resistive voltage divider located inside measuring module. It is provided for the measured voltage reduction to the level suitable for further processing in the electronic modules.
Current rate of rise protection
SMTN-3 provides smooth and reliable operation of the system, as well as filtering against false tripping. It performs the following protection functions:
- instantaneous overcurrent;
- overcurrent protection;
- current rate of rise protection;
- current increment directional
- overvoltage protection;
- undervoltage protection;
- thermal protection;
- breaker failure.
Optionally, the system is equipped with the following systems (modules) that extend functional range of the system as a whole:
• line measuring impedance system;
• cable insulation control system.
Line impedance measuring system allows to determine line impedance before high-speed circuit breaker closing. In case if line impedance is lower then the setting parameter, the system issues a prohibition to close high-speed circuit breaker.
Cable insulation control system continuously monitors cable insulation resistance and gives a warning signal in case of insulation degradation. A signal to open high-speed circuit breaker is given in case of cable insulation fault.
SMTN-3 system provides the following methods of parameters setting, both of the system itself and protection functions parameters:
• local «Human Machine» interface based on LCD touch screen;
• remote «Human Machine» interface based on WEB- technologies;
• remote access to device using ModBusTCP/IP protocol, for upper level systems and power management systems, etc.
Remote «Human Machine» interface based on WEB- technology is an integrated WEB- server in each SMTN-3 processing module. It does not require any additional software installation on computer. This interface is used to configure, display and analysis of data acquired by SMTN-3 system.
Communication with SMTN-3 WEB- server can be fulfilled via Ethernet cable or by wireless connection via PC, tablet or smartphone. Only WEB-browser installed on the device is needed to work with SMTN-3 WEB-server.
«Human Machine» interface is in English and Russian languages. The interface can also be implemented in other languages.
Configuring through user WEB-interface
EVENTS AND PARAMETERS LOGGING
SMTN-3 generates and stores the following records:
• events log;
• failures log;
• emergency oscillograph records.
The records are stored on nonvolatile solid data storage medium, that guarantees high reliability and data storage in case of devices power supply interruption.
SMTN-3 system provides generation and storage of emergency oscillograph records. Emergency oscillograph record generation is performed when one of protective functions operates. Two records of emergency oscillograph are generated and saved when one of the protection functions operates: • «Fast track»; • «Slow track».
SMTN-3 stores up to 200 records of emergency processes. When the limit is exceeded, a new record will be saved instead of the oldest one.
Emergency records can be viewed using WEB-interface, read by upper level system via Ethernet or saved on external USB-disk for later analysis using a PC.
SMTN-3 system also logs maximum values of current and voltage. When newly measured current or voltage values exceed the previously logged ones, new values are recorded instead of old ones. Comparison is made independently for current and voltage channels.
Remote viewing of fault records