THE "VEGA-TSG" AUTOMATED TELEMETRY SYSTEM COMPLEX
The main task of the system for telemetry of gas distribution facilities is monitoring technological parameters: inlet and outlet gas pressure, filter pressure drops, activation of safety fittings, etc. Emergency signals should be generated with minimum delay to ensure continuous facility status monitoring and prompt response in event of failures.
Equipping gas distribution networks with telemetry systems enables receiving valid information online from a big number of territorially remote facilities, and improving substantially the safety and operational reliability of the gas supply system by enhancing real-time control and prevention of emergencies.
The facilities being modernised:
Gas control units (GCU) and gas control stations (GCS) are one of the most critical components of the gas distribution system because they have a direct inpact on safe and economical combustion of gas fuel. Incidentally, the latter factor, with account of the current gas situation in Ukraine, is the one that conditions the need to use advanced automated monitoring and metering instrumentation. Its functioning shall ensure maximum savings along with improving the reliability and safety of operating the gas distribution system.
All GCU and GCS (with few exceptions) are built to standard projects. Therefore, the transition to a new automatics system should be, on the one hand, integrated, and on the other hand, a standard one to use the same equipment with minimum setup to the features of a specific facility.
With this in view, JV RADMIRTECH has started developing and executing the project “Automated complex for the VEGA-TSG telemetry system”.
The main task was making a reliable system for controlling the values of gas parameters, signalling and transmission of data to the central dispatcher station over a wireless communication channel. The latter condition was obligatory because the GCU are territorially remote and using wire communication lines is challenging.
Structural diagram of the VEGA-TSG telemetry system:
The system comprises the following:
- Equipment located in an explosion-hazardous area:
- Absolute (excess) pressure transducers (up to 5 pcs.),
- Pressure difference transducers (up to 5 pcs.),
- Temperature transducers (up to 3 pcs.),
- Door opening sensors,
- Safety valve detectors (blow-off and shutoff, up to 5 pcs.),
- Gas pollution sensor,
- Control unit (CU),
- Discrete signals controller (DSC),
- Equipment in the explosion-proof area
- Telemetry system communication module (installed in the mounting box):
- cable with a galvanic decoupler (up to 15 m),
- communicator with an external antenna,
- gas pollution detector power controller and DSC (with a built-in galvanic decoupler),
- power supply with switching devices,
- storage battery.
The control unit (CU) of the VEGA-TSG telemetry system is intended for collecting information about gas parameters over a digital channel from analog absolute (excess) pressure transducers, pressure difference transducers and temperature transducers. The CU also receives information through the discrete signals controller (DSC) from sensors detecting door “open-closed” conditions in GCU rooms, blow-off and shutoff valve detectors, and room gas pollution sensors. The built-in keyboard panel is used to display information on the CU screen on the status of each analog and discrete detector, read archived information, and view the status of the built-in power battery, current time, date, and other data. The CU keyboard is also used for entering the operator authentication password.
A cable with a galvanic decoupler is used for providing power supply to the CU and for transmitting received information to the communicator for subsequent data transmission through wireless networks to the enterprise server.
The dedicated enterprise server processes the data received from GCU (GCS) in the packet GPRS channel over the GSM standard digital cellular radio communication network, and enters it to the database.
The Web portal on-line “Vega–WEB” service is used to access industrial process information from GCU (GCS) and compile reports on the side of the enterprise dispatcher station.
Special software “nVEGA_G” installed on a PC is used for adjustment and set-up of components in the VEGA-TSG telemetry system, and for reading data at the facility.
Software “Set_RTV” is used for set-up of the communicator built-in GPRS modem.
The VEGA-TSG telemetry system components are powered from an a.c. mains 220 V through a power supply controller and the communicator. The power supply circuits are decoupled. In the event of an external power supply failure, the system is powered from a storage battery capable of supplying the system up to 6 months without recharging. The storage battery is part of the delivery set.
Basic system functions:
- Polling controlled units on request or to a specified schedule (by the dispatcher);
- Displaying all controlled units on the PC monitor with their visualisation on Google maps;
- For the selected controlled unit, displaying on the PC monitor the current readings of all analog and discrete detectors, and real-time, per hour and daily parameter values in graphical or tabular form;
- Online display on the PC monitor of information about occurrence of incidents (off-range readings of detector settings, unauthorised opening of doors, emergency actuation of valves, excess methane concentration in a room, etc.);
- Archiving and printing all received data;
- Display of current system parameters: time on CU and built-in GPRS modem, GSM signal level, storage battery and mains voltage levels, information about the life of built-in CU and GPRS modem batteries, etc.;
- System setup at the facility or remotely using “nVEGA_G” software.