Siemens modernises Montenegro’s TPP Pljevlja

Siemens dd Zagreb in cooperation with Siemens doo Beograd completed the modernisation project for the 235MW thermal power plant Pljevlja in Montenegro. The HRK31.9 (US$5.4m) contract was signed with company Elektroprivreda Crne Gore dd in mid-2009. The project included the reconstruction of the entire electrical and automation system in the thermal power plant which is the main generation plant of the Montenegrin power system. The modernisation project was completed in only six months.

TPP Pljevlja is the only thermal power plant in the Montenegro power system powered by coal from the nearby coalmine. The thermal plant was commissioned in 1982 and it generates roughly 30 per cent of total power produced in Montenegro. The existing measuring, regulation and control equipment is Russian and has been used for 26 years. Increasing difficulties with the maintenance of the unit’s control equipment have brought about the need to install a new control system. Since the control equipment is outdated, it is hard to find spare parts for it. The concepts are also obsolete and, in terms of functionality, there are fewer options to use the block’s capacity. Therefore, the reconstruction of this unit was declared a project of special importance to Montenegro and the completion of works within agreed terms the main priority.

The modernisation project included the disassembly and the assembly of the entire existing automation and electrical equipment and the construction of the medium-voltage and low-voltage switchgear for temporary power supply. The Siemens consortium delivered to TPP Pljevlja a Distributed Control System (DCS) in the form of the SPPA T3000 automation system and boiler protection, as well as generator excitation system with a transformer, 220V direct current distribution utility, synchronisers, electrical protection for 6kV switchgears, generators and substations and electricity meters. With regard to electric power works, the modernisation included the installation of medium- and low-voltage switchgears, the installation of generator circuit breaker and measuring and regulation equipment in the field, which entailed construction works of a larger scope. The delivery included all necessary installation material, construction material and material for equipping the control room and the accompanying operator and staff rooms, air conditioning system for the control room and all rooms with electrical equipment and automation system cabinets, as well as the fire alarm system, including the auxiliary rooms and the administration building.

The scope of works and services constituted the main project for the complete modernisation, even for a part of electrical equipment not included in the scope of deliveries of the Siemens consortium. This particularly applied to medium- and low-voltage switchgear equipment. The installation works applied to complete modernisation, which also meant the installation of medium- and low-voltage switchgears, generator circuit breaker, measuring and regulation equipment in the field etc. The scope of contract for the most part also entailed construction works. Standard equipment testing, commissioning and optimisation of the measuring and regulation equipment were carried out. Technical personnel had both basic and additional training for working with the installed SPPA T3000 automation system. Siemens consortium provided complete support for the power plant during the trial run period.

After contract signing, the Main Project, including the specifications on equipment delivery, was prepared. The equipment was ordered and the preparations for its production began mid-July. Siemens dd Zagreb took over project coordination, engineering and commissioning.

Finally, over 35 subcontractors from the entire region came together to work on the project.
The implementation terms, first of all the terms for the making of the main project, production and delivery of the main equipment and material were unusually short. Disassembly of all existing automation and electrical equipment, as well as ordering and delivery of installation equipment and the construction of the medium- and low-voltage switchgear for temporary power supply began on July 20 and the work was completed in four weeks. The basic automation system equipment, equipment for generator excitation with a transformer and direct current distribution switchgear equipment were delivered approximately 15 days before the deadline. The engineering works were carried out by a team of 15 experts, while 30 associates (engineers and technicians) from Croatia, Serbia, Montenegro and Bosnia and Herzegovina worked on the commissioning activities. Installation works were carried out by over 120 additional workers provided by several hired subcontractors.

The Siemens consortium officially completed all planned equipment installation and testing works within the scope provided by November 13, 2009. The first successful grid synchronisation of the unit was carried out on December 16, 2009. After successful synchronisation there was a three-month trial run. A total of 201 days passed from the date of contract signing to the beginning of the TPP Pljevlja unit 1 exploitation.