Medium Voltage Substations and Relaying

We designed a 69kV ringbus substation for an industrial plant that consisted of the following equipment and design: Two (2) 20MVA transformers, vertical break air switches with ground operators and interlocks, SF6 circuit breakers, aluminum rigid bus structure, structural supports, lightning protection, and grounding grid. The aluminum rigid bus structure was designed according to IEEE 605. The lightning protection was designed according to IEEE 998, and the ground grid was designed according to IEEE 80 using SKM Ground Mat software.

We provided design of the electromechanical relay replacement 100MW black start diesel plant, including all AC and DC control schematics, and three line diagrams to house the new Beckwith and SEL differential relays. The existing differential relay replaced proved to be particularly challenging. We specified and procured the relays, FT-1s, and other components. The project was performed in a phased approach so that only one generator was taken down at a time. Our team provided three months of professional engineering services for onsite construction support for the retrofit.

We were contracted to perform engineering, testing, and commissioning of a power station’s outdoor 66kV switchyard. There were two (2) separate scopes to this work. The first part consisted of the addition of a new switchyard for the combustion turbine generator repowering of the plant. The second part consisted of modifications to the existing switchyard to support the reuse of the existing plant steam turbine and plant equipment.

The project consisted of a 90MW natural gas plant utilizing two (2) step-up transformers and two (2) turbines that fed into a new 66kV substation. A third 30MW turbine powered by the steam heat recovery fed into the existing 66kV west bus. The existing switchyard substation consisted of 60MVA transformers, fiber optic communication with UGI electric utility, telephone line procurement, and coordination. PJM RTU design, assembly, and programming for Internet-based RTU using the ARCOM director was utilized for this project.