Expert technology
The time-proven technology applied to high capacity motor drives at steel plants brought PLASPO’s full-power converters into the wind power industry. Highly reliable AlSiC IGBTs and self-healing polypropylene type capacitors are used to enhance over all system stability. Especially the all-in-one multi-layered bus-plates that we developed on our own are strong against salinity of off-shore wind turbines and vibration of nacelles, therefore, no additional snubber circuits needed. Resonance frequency avoidance algorithm is applied to eliminate unstable factors which can be caused by resonance amplification from towers, drive-trains or blades from wind power systems through optimal resonance compensation, and realize stable power output. Active damping technique applied to LCL filters for PWM output voltage filtering results in reducing size & cost compared to L filters and enhancing power quality to the grid.

Design efficiency
3D structural designing creates products of compact size and high power density of 2.5MW/㎥ at the core power conversion parts, which go into nacelles. Simple connection of liquid-cooling system maximizes space use and minimizes errors caused by the heat generated. Fastidious criteria of selecting core components consequently guarantee 20-year life-cycle of the whole system and, therefore, efficiency in maintenance and repair.

Full-power converters
The full-power converters for PMSG type variable speed wind turbines control to generate maximum power according to the turbine characteristics at the optimum level of wind and rotation speed. As the capacity of a wind turbine is getting bigger and wind power connection to the grid is dramatically increasing, full-power converters are fast becoming a trend fulfilling grid operators requirements for stable operations of the power grid.

Parallel structures
It is possible to reduce the output current THD to the half without increasing filter values when parallel construction. Modular 1MW & 2MW units can make 3M or 5MW full-power converters for on/off-shore wind turbines.

Grid codes & voltage dip test equipment
Complying with grid codes of E.ON, NGET, FERC, Elkraft/Eltra, etc., LVRT(Low voltage ride through) and HVRT(High voltage ride through) functions are more focused. 3MVA voltage dip test equipment is under development for the LVRT test of 750kW, 1.5MW, 2MW, 2.5MW and 3MW wind turbines. Soon the turbine makers in Korea or nearby countries will enjoy the time-and-money saving by using the voltage dip test equipment within an easy access for their LVRT certification.

750kW and 2MW models are applying for UL certification according to UL1741 standard & Subject 6141 and IEEE1547 standard.