Power System Study for a large campus electrical upgrade project. The main campus 15KV Switchgear was analyzed as well as (2) double ended dry-type unit substations. Total substation capacity was 10MVA. The campus facility included 4 buildings, (3) exterior generators, and approximately 360 panels. Electrical studies included fault current evaluation, load flow analysis, system protection & coordination, Arc Flash Evaluation, and motor starting transient analysis. We were able to assist the engineer of record by helping to solve NEC required selective coordination problems associated with the life safety and elevator systems. We provided a code analysis of the existing system to assist the contractor and USDA in correcting several existing system deficiencies.
Project Challenges:
Determining the existing medium voltage relay characteristics as well as CT ratios without causing an outage on the campus.
Existing legacy substations were specified with the incorrect primary winding ratios. We made recommendations on adjusting the taps as needed to obtain correct voltages and compensating for load flow voltage drop.
Integration of (2) existing solar PV systems into the model. Total system capacity was 2.2 MW. Due to long distances of the transmission cables, medium voltage transformers were used to step up the voltage for transmission to the facility.
Extensive invasive survey was needed to obtain the field data. Freestate Electric assisted BKM in removing equipment covers for this data acquisition. BKM wore all appropriate PPE per NFPA 70E.
Recommendations were required in an effort to properly protect new and existing transfer switches. We assisted the engineer of record in selecting the proper over current protection to properly protect the new and existing transfer switches. We were able to protect the switches such that expensive and large 30 cycle switches were not required. They would not have fit in the space allocated.
