The dual three-phase PMSM(DTP-PMSM)drives have received wide attention at high-power high-efficiency applications due to their merits of high output current ability and copper-loss-free field excitation.Meanwhile,the ...The dual three-phase PMSM(DTP-PMSM)drives have received wide attention at high-power high-efficiency applications due to their merits of high output current ability and copper-loss-free field excitation.Meanwhile,the DTPPMSM drive provides higher fault-tolerant capability for highreliability applications,e.g.,pumps and actuators in aircraft.For high-power drives with limited switching frequencies and highspeed drives with large fundamental frequencies,the ratio of switching frequency to fundamental frequency,i.e.,the carrier ratio,is usually below 15,which would significantly degrade the control performance.The purpose of this paper is to review the recent work on the modulation and control schemes for improving the operation performance of DTP-PMSM drives with low carrier ratios.Specifically,three categories of methods,i.e.,the space vector modulation based control,the model predictive control(MPC),and the optimized pulse pattern(OPP)based control are reviewed with principles and performance.In addition,brief discussions regarding the comparison and future trends are presented for low-carrier-ratio(LCR)modulation and control schemes of DTP-PMSM drives.展开更多
有机磷农药(OPPs)已逐渐取代有机氯农药成为广泛应用的农药之一,其大量使用对环境构成威胁,了解环境领域中OPPs的研究动态与趋势,可为相关领域的科研工作和环境管理提供借鉴。运用文献计量学方法,对2000—2022年中国知网(CNKI)核心数据...有机磷农药(OPPs)已逐渐取代有机氯农药成为广泛应用的农药之一,其大量使用对环境构成威胁,了解环境领域中OPPs的研究动态与趋势,可为相关领域的科研工作和环境管理提供借鉴。运用文献计量学方法,对2000—2022年中国知网(CNKI)核心数据库和Web of Science(WoS)核心数据库收录的环境领域OPPs的相关文献进行了分析,系统梳理了该领域OPPs的研究现状,阐述了OPPs研究的发展态势及热点前沿,同时提出了未来重点研究方向。结果表明:2000—2022年,国内外关于环境领域OPPs的研究论文共3427篇,近10年来发文量呈显著上升趋势;环境领域OPPs的研究介质主要是水体和土壤,且对水体中OPPs的环境行为和特性探究更为深入;OPPs的检测手段以气相色谱法为主,毒死蜱[O,O-二乙基-O-(3,5,6-三氯-2-吡啶基)硫代磷酸酯]是OPPs研究中出现频率较高的目标污染物之一,且其在环境中的检出率较高;国内外关于OPPs在环境中的研究脉络基本相似,前期研究(2000—2010年)主要集中在环境中OPPs的萃取方法,中期研究(2011—2018年)主要集中在环境中OPPs的危害及对其的环境影响评价,近年来(2019—2022年)研究热点主要集中在OPPs的残留、环境检测以及高效去除等领域。未来建议加强OPPs降解产物的鉴定和环境毒性研究、OPPs复合暴露研究及环境修复研究,同时开发新型纳米材料和绿色农药替代方案等。展开更多
基金supported by the National Key Research and Development Program of China under the grant of 2022YFB3403100。
文摘The dual three-phase PMSM(DTP-PMSM)drives have received wide attention at high-power high-efficiency applications due to their merits of high output current ability and copper-loss-free field excitation.Meanwhile,the DTPPMSM drive provides higher fault-tolerant capability for highreliability applications,e.g.,pumps and actuators in aircraft.For high-power drives with limited switching frequencies and highspeed drives with large fundamental frequencies,the ratio of switching frequency to fundamental frequency,i.e.,the carrier ratio,is usually below 15,which would significantly degrade the control performance.The purpose of this paper is to review the recent work on the modulation and control schemes for improving the operation performance of DTP-PMSM drives with low carrier ratios.Specifically,three categories of methods,i.e.,the space vector modulation based control,the model predictive control(MPC),and the optimized pulse pattern(OPP)based control are reviewed with principles and performance.In addition,brief discussions regarding the comparison and future trends are presented for low-carrier-ratio(LCR)modulation and control schemes of DTP-PMSM drives.
文摘有机磷农药(OPPs)已逐渐取代有机氯农药成为广泛应用的农药之一,其大量使用对环境构成威胁,了解环境领域中OPPs的研究动态与趋势,可为相关领域的科研工作和环境管理提供借鉴。运用文献计量学方法,对2000—2022年中国知网(CNKI)核心数据库和Web of Science(WoS)核心数据库收录的环境领域OPPs的相关文献进行了分析,系统梳理了该领域OPPs的研究现状,阐述了OPPs研究的发展态势及热点前沿,同时提出了未来重点研究方向。结果表明:2000—2022年,国内外关于环境领域OPPs的研究论文共3427篇,近10年来发文量呈显著上升趋势;环境领域OPPs的研究介质主要是水体和土壤,且对水体中OPPs的环境行为和特性探究更为深入;OPPs的检测手段以气相色谱法为主,毒死蜱[O,O-二乙基-O-(3,5,6-三氯-2-吡啶基)硫代磷酸酯]是OPPs研究中出现频率较高的目标污染物之一,且其在环境中的检出率较高;国内外关于OPPs在环境中的研究脉络基本相似,前期研究(2000—2010年)主要集中在环境中OPPs的萃取方法,中期研究(2011—2018年)主要集中在环境中OPPs的危害及对其的环境影响评价,近年来(2019—2022年)研究热点主要集中在OPPs的残留、环境检测以及高效去除等领域。未来建议加强OPPs降解产物的鉴定和环境毒性研究、OPPs复合暴露研究及环境修复研究,同时开发新型纳米材料和绿色农药替代方案等。
