PROJECT

Genesee 330P 500-kV Substation Expansion

Our team provided early engagement feasibility study, cost estimation, scope development, design, procurement, construction, commissioning and energization services for expansion of the Genesee 330P 500-kV Substation, which plays a vital role in Alberta’s lower-carbon future. The substation connects Genesee Generating Station, which provides 1,300 megawatts of baseload generation, to the Alberta Interconnected Electric System (AIES).

The existing Genesee 330P substation was a 500-kV, one-and-a-half-breaker bus configuration substation with three 500-kV transmission line connections from the generating station and three transmission line connections to the nearby 500-kV substations. The existing 138-kV switchyard was fed from 100 MVA coupling transformers providing backup power to the generation units and station service power to Sunnybrook Substation and a local mining facility.

The substation expansion was built 120 meters west of the existing switchyard and includes two incomplete one-and-a-half-breaker bus schemes, a new 500/138-kV 60/80/100 MVA power transformer, 500-kV live tank circuit breakers, 500-kV single-phase current transformers (CTs), single-phase bus and line capacitive voltage transformers (CVTs), disconnect switches, and a 37-meter-by-7-meter prefabricated control building. The control building houses protection and control relays, panels, SCADA, telecommunications, substation automation devices, security, battery banks and chargers, automatic transfer switches, and AC/DC service panels. The substation expansion included 138-kV double bus with five 138-kV transmission line connections. All 138-kV equipment was demolished from the exiting yard, which was retrofitted to install two 500-kV A-frames with slack spans, connecting the existing substation to the new substation.

The project required a complex outage cutover sequence that minimized outage durations and maintained reliability, requiring five existing 138-kV lines to be relocated from the existing substation to the new 138-kV outdoor switchgear in the new substation.

Client

EPCOR Distribution & Transmission Inc.

Location

Warburg, Alberta, Canada

Services

Electrical Transmission & Distribution

Electrical Transmission

Overhead Transmission

Substations

Industry

Power

Construction Solutions

Subsurface conditions at the new switchyard included areas of peat up to 4 meters thick. Rather than excavating and replacing the peat moss, an innovative civil design specified an engineered subgrade improvement section be constructed to bridge unsuitable material to minimize cost and schedule impacts.

Additional schedule challenges created by supply chain issues and delayed permitting were addressed by close management of procurement processes and resequencing of design and construction to offset severe winter conditions and minimize impacts.

After the discovery of an abandoned oil well, the substation yard was reengineered to place the oil well outside the substation footprint. This involved a comprehensive analysis of the rigid-bus design. A reduction in equipment spacing was achieved through examination of minimum clearances based on insulation coordination, considering factors such as lightning and switching surge studies. Maintenance access ways were also optimized to minimize the overall switchyard footprint.

Technology in Design

Our team completed a comprehensive 3D scan of the site to facilitate modifications to the substation site and transmission line configuration. This supported efficient desktop site reviews; allowed incorporation of existing infrastructure into designs; established connections with the current bus work, lines and equipment; and enabled verification of data against existing raster drawings.

Through building information modeling (BIM) software, the team was able to visualize the proposed yard equipment, bus work, buildings and other infrastructure on the site. The 3D model integrated the 3D scan data with civil grading models and transmission line models, facilitating interdisciplinary checks to identify conflicts and constructability issues early in the process. The 3D model also provides operations and maintenance crews with the ability to measure limits of approach distances and incorporate them into the work planning process.

The substation protection, automation and control (PAC) system uses IEC-61850 MMS protocol for station SCADA communication. IEC-61850 GOOSE messaging is being used extensively at the station bus level. Because of the physical separation between the two switchyards, the protection system uses a fiber-optic intertrip scheme to send and receive protection signals, eliminating the need for long and large-size control cables.

Project Scope

Rerouting of five 138-kV transmission lines

Construction of new 500-kV to 138-kV switchyard, including bus extensions, slack span installation and transformer installation

Rerouting of equipment connections for new switchyard

Addition of bus, switches, line terminations and disconnect switches

Disconnection of existing switches and transformer

New control building, protection relay and SCADA systems

Substation automation design and commissioning using 61850 protocols

Demolish existing 138-kV yard

Complex outage cutover sequence plan