Systematic Turbine Compressor Controls Employ High Performance Modules

Russian Remote Automation
By Michael Rosemeyer, Siemens AG | May 2012, Vol. 239 No. 5

The Supervisory Control System of Systema-Service is based on SIMATIC WinCC from Siemens in a server-client architecture.

On its long journey from extraction to the consumer, natural gas has to be compressed repeatedly to maintain the required discharge pressure in the pipelines. Russia's leading supplier of automation equipment for the gas turbine compressors used for this purpose places its trust in the proven "made in Germany" control technology. This ensures reliable long-term operation as well as maximum supply quality and reliability during natural gas transport.

Natural gas pipelines are the equivalent of the veins of civilization, which supply the material that warms us and increasingly also drives our vehicles, mostly from very inhospitable areas. The pipelines often run thousands of kilometers across borders and continents and are subjected to extremely harsh climatic conditions. This makes their operations management a very challenging task, in addition to their construction and maintenance.

For example, the natural gas has to be transported through the pipeline at the appropriate flow rate to ensure that the amount being transported is sufficient. However, the pressure decreases during transport due to the internal friction of the molecules in the gas flow and the external friction of the gas flow against the inner walls of the piping. For this reason, compressor stations are installed every 100-200 km along the pipelines running from northern Siberia to the west, south and east, in which several turbo compressors compensate the pressure drop. The pressure, flow volume and temperature of the natural gas are measured and controlled to the specified values in one or more passes.

Sound Basis For Maximum Reliability
Since failures would result in extremely high costs, in particular at compressor stations far away from civilization, there are one or two reserve turbo compressors in each station. The auxiliary units feature redundant automation and high availability to some extent. Important process parameters are monitored and controlled continuously.

The ZAO Systema-Service, a closed joint-stock company (Закрытое Акционерное Общество, ЗАО) headquartered in St. Petersburg, is one of the largest suppliers, worldwide, of control and automation systems for gas turbine compressors and power plants. The company, which has been an autonomous entity for 16 years, has its origins in a scientific research institute and has been active in the automation of such stations for more than 30 years (see sidebar). As a service provider, the system vendor also has the scientific and technological knowledge required for reliable long-term operation of highly complex plants that are often subjected to extreme environmental temperatures ranging from -60°C to +50°C.

With Siemens AG, which has held a stake in Systema-Service for several years, the St. Petersburg company has a partner that for its part produces gas turbines of the type required for such compressor stations. It was therefore natural to use the latest Siemens automation technology in the course of the MSKU 5000 innovation round – the current seventh generation of the multiprocessor-based control and operations management system for the stations. At the same time, however, Dr. Simon D. Altshul, general director of Systema-Service, stresses the performance-oriented nature of the close cooperation: “Our systems have to fulfill the highest demands with the maximum possible reliability. That requires not only the most efficient automation technology, but also a sound understanding of the challenges faced."