Variable-speed generators(VSG)offer numerous benefits over fixed-speed generators.These advantages include significant fuel savings,reduced noise emissions,and extended engine lifespan.However,VSGs have a major drawba...Variable-speed generators(VSG)offer numerous benefits over fixed-speed generators.These advantages include significant fuel savings,reduced noise emissions,and extended engine lifespan.However,VSGs have a major drawback:their high manufacturing cost owing to the expensive permanent-magnet generators(PMGs)commonly used in these generators,as well as the large size of the power electronics section,which has the same power rating as the generator itself.Asolution to reduce the initial investment cost by introducing a two-regime generator(TRG)is proposed.The first mode operates at a constant speed for loads exceeding 50%,without the need for a converter.The second mode operates at variable speeds for loads below 50%using a converter that reduces its power by 50%,thus decreasing the investment cost.Additionally,the cost can be further reduced by replacing the PMG with a brushless synchronous generator.The controller employed in thisstudy is a two-loop proportional-integral-derivative controllerthat exhibits favorable dynamics and compensates for dead times and parameter variations.TRG have shown a significant reduction in cost compared to VSGwhile retaining the advantages of the latter.展开更多
This study examines regional competition in China by considering the spatial correlation and spillover effect of construction land price distortion using a two-regime Spatial Durbin Model to investigate the patterns a...This study examines regional competition in China by considering the spatial correlation and spillover effect of construction land price distortion using a two-regime Spatial Durbin Model to investigate the patterns and trends of the competition between 285 cities in China from 2006 to 2015. The study finds:(i) price distortion of construction land is a common phenomenon but the distortion index generally shows a declining trend;(ii) regional competition through construction land price distortion shows a weakly intensified pattern, although the competition patterns in the four regions of China varied;and (Hi) the intensity of competition between regions was lower during the 12th Five-year Plan compared to the 11th Plan. The intensity of competition between cities was also lower inside than outside urban agglomerations. These results provide policy implications for remedying the price distortion of construction land and promoting regional coordinated development.展开更多
文摘Variable-speed generators(VSG)offer numerous benefits over fixed-speed generators.These advantages include significant fuel savings,reduced noise emissions,and extended engine lifespan.However,VSGs have a major drawback:their high manufacturing cost owing to the expensive permanent-magnet generators(PMGs)commonly used in these generators,as well as the large size of the power electronics section,which has the same power rating as the generator itself.Asolution to reduce the initial investment cost by introducing a two-regime generator(TRG)is proposed.The first mode operates at a constant speed for loads exceeding 50%,without the need for a converter.The second mode operates at variable speeds for loads below 50%using a converter that reduces its power by 50%,thus decreasing the investment cost.Additionally,the cost can be further reduced by replacing the PMG with a brushless synchronous generator.The controller employed in thisstudy is a two-loop proportional-integral-derivative controllerthat exhibits favorable dynamics and compensates for dead times and parameter variations.TRG have shown a significant reduction in cost compared to VSGwhile retaining the advantages of the latter.
基金the research achievement of the Human Resource Management Research Base in Jiangsuthe Fundamental Research Funds for the Central Universities (No. NJ2018030)+1 种基金the Postgraduate Research and Practice Innovation Program of Jiangsu Province (No. K.YCX 18-0238)the Social Science Foundation of Jiangsu Province (No. 18GLB014).
文摘This study examines regional competition in China by considering the spatial correlation and spillover effect of construction land price distortion using a two-regime Spatial Durbin Model to investigate the patterns and trends of the competition between 285 cities in China from 2006 to 2015. The study finds:(i) price distortion of construction land is a common phenomenon but the distortion index generally shows a declining trend;(ii) regional competition through construction land price distortion shows a weakly intensified pattern, although the competition patterns in the four regions of China varied;and (Hi) the intensity of competition between regions was lower during the 12th Five-year Plan compared to the 11th Plan. The intensity of competition between cities was also lower inside than outside urban agglomerations. These results provide policy implications for remedying the price distortion of construction land and promoting regional coordinated development.
