PSTI has designed/ upgraded relay protection and fabricated panels for nine 230/115kV transmission substations. Powerserve Technologies assisted in the installation of the panels in four substations.

Brookridge-Crystal River 230 kV Line
PSTI completed protective relay upgrades of a 230kV transmission line for Progress Energy. We replaced the existing electromechanical line protection with a SEL-321-3 relay as the primary protection and a SEL-311C relay as the secondary protection. Pilot tripping is performed via Progress Energy's fiber optic network. The design required significant interfacing with existing electromechanical protective and control schemes including SCADA.

Intercession City
PSTI is in the process of relay system upgrades for Progress Energy. All of the 69kV circuit breakers are being replaced and a new autotransformer is being added at their Intercession City substation. We redesigned the breaker controls and breaker failure schemes for all the circuit breakers using SEL-351S relays. We then designed the transformer protection for the new 230/69kV autotransformer using SEL-351S, SEL-387 and SEL-587 relays. The addition of the autotransformer required a redesign of the source side 230kV bus differentials using SEL-487 relays.

Dade Corners
PSTI prepared the feasibility study as well as the complete engineering and coordination of a three-stage transmission project involving 6 - 230kV lines that intertwined at one location as system grew. The project consisted of the reconfiguration/ swapping of some of the existing lines, additional storm strengthening work for some structures, and replacement of some old structures to bring them up to code. Phase 1 completed successfully and the full project is expected to be completed by 2009.