Future T&D Technology

Power Electronics has evolved over the past 20 years to be the main method of power conversion in terms of equipment volume, efficiency and cost. In power transmission and distribution systems power electronics does not compare in efficiency and cost and only provides support where conventional technology is not incapable of performing the task. With the promise of Silicon Carbide (SiC) based IGBTs rated at 10kV to be realised within the next year the paper examines what effect this might have on the role of Power Electronics within Power Transmission. In particular values of efficiency, weight and size are developed for 300MW PWM based HVDC converter equipment operating with both a 50Hz transformer and at 1kHz and 20kHz and concludes that with Silicon Carbide devices the cost of VSC-HVDC stations will reduce by about 30%. Changing to high frequency conversion using frequencies of up to 20kHz will result in comparable efficiencies and volumes with Si based VSC-HVDC stations, however the overall cost will increase by about 30%.