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This paper discusses electrical insulation characteristics of liquid nitrogen (LN2) / polypropylene (PP) laminated paper composite insulation system for the practical electrical insulation design of high temperature superconducting (HTS) cables. Partial discharge (PD) inception, propagation and breakdown (BD) characteristics under ac voltage application were obtained and discussed at atmospheric and pressurized conditions. Experimental results were analyzed quantitatively and revealed that void-type discharge was categorized as an important form of discharge to characterize the transition of PD activity leading to BD. [ABSTRACT FROM AUTHOR]

Partial discharge (PD) inception and breakdown (BD) characteristics of liquid nitrogen (LN2) / polypropylene (PP) laminated paper composite insulation system for high temperature superconducting (HTS) cables are presented. In this paper, we measured PD inception characteristics under lightning impulse and ac voltage applications by electrical, optical and acoustic methods. The impulse PD inception characteristics were compared with those under ac voltage application, and the PD generation mechanisms are discussed. Experimental results reveal that PD detection sensitivity under lightning impulse voltage application is as small as 6 pC. PD inception at the lower stress was verified to be generated not only in the butt gaps but also in micro gaps between PP laminated paper layers under both lightning impulse and ac voltage applications. After PD inception, PD activity could be developed in the butt gaps at the higher stress, finally leading to BD. [ABSTRACT FROM AUTHOR]

The monolithic integration of a GaInP-based high-power red laser for DVD ± R/RW/RAM and an AlGaAs-based high-power infrared laser for CD-R was successfully achieved for the first time. The monolithic device provides reliable output power of 200 mW for red lasers and 240 mW for infrared lasers, allowing writing speeds of 12× for DVD-R and 48× for CD-R. The kink power of AlGaInP DVD lasers is dramatically improved up to 300 mW from 220 mW even at the high temperature of 85°C, due mainly to the reduction of the lateral leakage current. The beam separation is precisely controlled to be within 110±1 μm despite forming separately two ridge stripes. [ABSTRACT FROM PUBLISHER]