Power plants require external sources of energy to power up. The grid is traditionally the default source of power; however, during a grid outage, the plant will need its own source of start-up power. This condition, when no grid power is available, is called a black start. For this project, a 12MWh Battery Energy Storage System (BESS) was developed to enable a black start of a generating station with multiple combustion turbine generators in combined cycle totaling 619MW. The additional project benefit of this BESS system is the use of a clean energy source for black start.
To black start the generating facility, multiple large induction motors must be started using the Battery Energy Storage System to provide auxiliary services needed to accelerate the primary production generators. The BESS must be capable of multiple generator black start attempts. When not in use, the BESS is charged from normal grid power. The system needs adequate margin to power its own operating loads, be able to grid form on command, power through the black start load profile, synchronize with the newly started turbine generator, and immediately transition into grid follow mode.
Nexus provided services directly to the owner to define scope, develop contract parameters with the BESS provider, and analyze the effects of a BESS configuration on the existing plant auxiliary system. Nexus’ intimate facility knowledge, along with black start and BESS experience, enabled a successful project. Nexus’s engineering support included initial system analysis, single line development, and review of construction documents and studies. We also provided assistance in the development of a high voltage generator sync scheme, procurement and construction support, and as-built / closeout documentation.