Greenfield and Brownfield Substation Projects

Bangalore, December 11, 2017: Whether designing greenfield substation projects from the ground up or performing brownfield design associated with existing substation infrastructure, intelligent 3D substation design employing BIM processes and reality modeling demonstrates cost and time saving benefits. In a greenfield project in Cambodia, PESTECH undertook a project for Diamond Power Limited for the conceptual design through commissioning of the 230-kilovolt Kratie and Kampong Cham Substation and Transmission System. The project will support the growing population and tourism industry. The Kratie 230/22-kilovolt substation will connect with the Sesan hydropower plant, which is under construction in the upper Mekong area, and also serve as a major collection center of power from several mini hydropower plants, connecting to the national power grid of Cambodia.

Visualization of the3D substation design was essential to prepare and plan work before and duringconstruction. The site was located far from the town within forest and hillyroads and visualization of the design with accurate dimensions was asignificant challenge, which was successfully overcome using Bentley Substationand Bentley Navigator. ProjectWise was used for collaboration acrossdepartments on-site and offsite including procurement, management, engineering,and construction. The project is expected to be completed in November 2017 andPESTECH will also be responsible for operating the power transmission systemfor a concession period of 25 years.

The design of pastprojects was done manually, via hand-drawn and manual calculation of componentsand third-party CAD software. This approach was prone to human error, timeconsuming, and resulted in inconsistent quality. PESTECH’s engineering teamreported many benefits of Bentley Substation from the unified designenvironment facilitating cross-discipline collaboration, automated designdrawing and reports, enforcement of engineering standards, and more. Theseincluded cost savings in procurement, reduction in errors, and substantial timesavings. A detailed analysis comparing the use of Bentley applications withprevious methods estimated time savings of up to 70 percent wereachieved. 

In contrast,approximately 95 percent of Pacific Gas & Electric’s (PG&E) annual USD1 billion substation budget is spent on existing brownfield substations. Since2016, PG&E has been pioneering the use of a combination of aerial equipmentsuch as man lifts, unmanned aerial vehicles (UAVs), and on-ground photoequipment to capture images of existing substations. Bentley’s ContextCaptureis used to process these images and produce accurate 3D reality meshes, whichcan be referenced into Bentley Substation to complete the entire substationdesign in 3D. ContextCapture models allow effective collaboration between theTransmission Line, Land Planning and Zoning, and the Electrical and CivilSubstation Engineering departments. ProjectWise is used to manage the modelsand facilitate collaboration. With up-to-date 3D models, all stakeholders canclearly see the impact of each department on the project, avoiding costlyconflicts in the field and allowing for more streamlined, effective, andsustainable long-term planning.

For community andgovernment relations, this method can be used to capture and retain historical infrastructurein 3D before new construction takes place. In areas where thick ballistic wallsfor security are required by the Federal Energy Regulatory Commission’s (FERC),realistic renderings of the existing substation and new security walls in 3D helpsto gain community acceptance. 3D models generated by ContextCapture can also beutilized as a mesh to generate quick and low-cost digital terrain models andenables PG&E to identify and categorize existing substation assets forcondition-based maintenance substation asset inventories.

PG&E expects toreduce cost spent on recreating existing substation equipment in 3D by 50percent, a reduction from 120 hours to less than 60 hours on average. Improvingcaptured 3D model’s accuracy to within inches will eliminate field measurementson cleared and energized equipment. PG&E also expects a 50 percentreduction of substation personnel travels to and from substation facilities.

Ralph Hansen,construction supervisor, PG&E, said, “Having a complete 3D model at the timeof constructability review allows us to measure electrical and physicalclearance in real time, which helps eliminate costly conflicts during theconstruction phases. With today’s increasing substation complexity anddecreasing substation footprint, having a 3D model is a must.”

The South Street115/11.5/23-kilovolt Indoor Substation project executed by TRC for NationalGrid involved rebuilding South Street Substation in Providence, Rhode Island,converting the existing three 115-kilovolt overhead line supply circuits tounderground cable circuits, and re-routing the existing 23- and 11.5-kilovoltunderground feeder getaway facilities. To complete the project on time and onbudget required TRC to integrate existing conditions to the new construction whilethe substation remained in operation. This project was also in a highly visibleand congested area, which caused concern over the aesthetics of the site andbuilding.

The project had avery complicated building design and required incorporating a large number ofsubcontractor files in third-party formats to a single master design model forcross-discipline checking. These files were placed in ProjectWise and provided anindisputable record of what was received from subcontractors. BentleySubstation was used to integrate these different formats into the BentleySubstation models by TRC staff in design centers across the country. As aresult, TRC identified issues before construction or fabrication that wouldhave led to delays at the site and cost overruns. Bentley Substation was usedto do full 3D client walkthroughs for interior and exterior design reviews andthe 3D models were also used in the renderings for the planning board and forpublic comment. 

Jason Poissonnier,TRC ProjectWise administrator, said, “Bentley Substation along with ProjectWisewas instrumental in successfully completing the South Street project, which wasin a congested, highly visible area. TRC utilized resources from severaloffices who collaborated on over 2,000 CAD files as well as Excel, Word,PowerPoint, Outlook, PDF, TIFF, and other files. The ability to incorporatedifferent types of design files from subcontractors into the 3D model made thedesign reviews truly all-encompassing and resulted in identifying many areasthat needed redesign, thereby avoiding costly changes later duringconstruction.” 

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