Verso Corporation, Wisconsin Rapids Mill, Steam Turbine K1
Wisconsin Rapids, WI
600 4th Avenue North
Wisconsin Rapids, WI 54495
The L&S Electric Advanced Excitation System (AES) static excitation system was selected to replace the existing Basler Shunt Static Exciter (SSE) Regulator at the Verso Corporation, Wisconsin Rapids Mill’s Steam Turbine K1 synchronous generator. Verso Corporation choose the AES for its advanced monitoring and control features, the comfort they felt in L&S Electric’s excitation engineering expertise, the L&S Electric provided 24/7 product support, the two (2) year warranty, the AES’s competitive price, and the commercially available spare parts.
The Steam Turbine K1 synchronous generator’s rated output is 20 MW at 13.8kV and has field requirements of 428 amperes, 250 volts at rated load and 0.85 power factor. The input power to the AES was provided from an excitation power transformer (EPT) with ratings of 250kVA, 13,800/320 volts AC, 3-phase, 60 hertz, wye-delta with ±2x2½% primary taps and one (1) RTD in the center winding for over-temperature protection.
The Verso exciter is a LS-AES-FS-EXC-DT-600 Static Exciter System. The exciter included the AES’s standard features; a digital excitation controller, a 800-amp, full wave rectifier bridge assembly with redundant fan-cooling, an AC input breaker, AC field flashing, a crowbar with a linear field discharge resistor for over excitation protection, an AC filter, a DC filter, a holding resistor, shaft voltage suppressor, Ethernet IP communications, redundant 24Vdc power supplies, dual power source and a 15-inch color touchscreen (OIT), all in a 2-door, climate controlled, NEMA 12 enclosure with forced ventilation.
The Verso exciter also included the optional excitation redundant protection (SEL-700G relay), field ground monitoring and detection (64F) capabilities and Power System Stabilizer (PSS2B).
Additionally, the L&S Electric project provided services including the design and supply of the AES excitation elementary diagrams, the wiring diagrams, the assembly diagrams, operation & maintenance manual, installation engineering (cut-ins), installation supervision services, and the AES commissioning with onsite AES training.
The unit was installed May 2018.