Since the advent of 5G network, polymeric low dielectric constant (low‐k) materials have been indispensable for high speed and stable signal transmission at microwave frequency. Herein, the low‐k composites of 1,2‐polybutadiene/styrene‐butadiene‐styrene triblock copolymer/ethylene‐propylene‐dicyclopentadiene (1,2‐PB/SBS/EPDM) were prepared with cured organic peroxide. Two structurally different organic peroxides, namely dicumyl peroxide (DCP) and bis(1‐(tert‐butylperoxy)‐1‐methylethyl)‐benzene (BIPB), were used as free‐radical initiators. The composites with highly efficient initiator—BIPB exhibited considerably enhanced conversion rate, thermal stability, and cross‐link density compared with the DCP system. Furthermore, the increased cross‐link density contributed to dielectric stability over a broad range of frequency (3‐15 GHz) and superior mechanical properties. The cross‐linked composites possessed the typical low polarity group of C─C single bond with suppressed dielectric constant (Dk) and loss (Df). Especially, the average Dk of 2.36 and average Df of 0.0054 were obtained for the composite containing 4 part‐by‐weight (pbw) BIPB. This work demonstrated that the 1,2‐PB/SBS/EPDM composite with 4 pbw BIPB is a good candidate for high‐frequency substrate materials.
Recently, a new type of motor, synchronous reluctance motor (SRM), has attracted wide attention from academia and industry because of its potential applications in fans, pumps, and elevator traction systems. Compared with traditional motors, these motors have lower eddy-current loss, less torque ripple, reduced noise, smaller moment of inertia, and faster dynamic response, and they provide a greater operating efficiency and safety and are simpler and easier to maintain. However, the ontology design and operation control of SRMs continue to be significant hurdles that must be overcome prior to practical implementation. In order to facilitate the practical application of SRMs in industry, at the invitation of an elevator company, we designed a large SRM for elevator traction. Herein, we describe the design of the proposed system and present a theoretical analysis of the system. Furthermore, we fabricate a real prototype and the corresponding control system and perform an experimental test under the rated operating conditions and 1.5× overload conditions in order to verify the SRM's performance. The results of the experimental testing were satisfactory and consistent with the theoretical calculations. At present, we have entered the stage of small-batch trial production and we expect to ultimately implement this novel design. Further, the approach to ontology design and operation control in this study can be used to inform the future development of novel SRMs.
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