Designing of an Emergency Power Plant for Repowering and Black Starting of Combined-cycle Combined Heat and Power Plants

Abstract

Power system failures can lead to prolonged disconnection of thermal power plants from the power system and their subsequent autonomous start-up. The main difficulty of power plant black start is that it involves the need to have an independent power source, e.g., an emergency diesel power station for starting the motors of power plant auxiliaries. Given that the program for modernizing the Russian electric power industry for the period up to 2030 involves the widespread use of combined-cycle power units, determination of the conditions for starting combined-cycle combined heat and power plants (CCP-based CHPPs), which govern the choice of the type and required capacity of an emergency diesel power plant, is a topical issue.

The article considers the selection of diesel generator sets based not only on the load of power plant auxiliaries, but also on existing options of commercially available diesel generator sets.

In selecting the diesel-generator unit type and capacity for the PGU-450T combined cycle power unit, the processes of restoring power supply from an emergency diesel power station, the rapid start-up of a CCP-based CHPP and its connection to the grid after the restoration of its operation were taken as the subjects of study. A scheme for connecting an emergency diesel power station at the PJSC Mosenergo’s TETs-27 CHPP and a program of necessary switching operations have been developed.

Various CCP-based CHPP start-up modes were analyzed, as a result of which indicators have been determined that make it possible to consider such a start-up mode acceptable and successful, and recommend to set up an emergency diesel power station with the selected parameters for the PJSC Mosenergo’s TETs-27 CHPP for powering and performing black start of the PGU-450 power units.