To lower the difficulty of fault protection,a doubly-fed induction machine based shipboard propulsion system(DFIM-SPS)that is partially power decoupled is presented.In such an intrinsically safe SPS architecture,a syn...To lower the difficulty of fault protection,a doubly-fed induction machine based shipboard propulsion system(DFIM-SPS)that is partially power decoupled is presented.In such an intrinsically safe SPS architecture,a synchronous generator(SG)is employed for power generation,and the accuracy of the parameters of power generation unit(PGU)plays an important role in SPS stable operation.In this paper,the PGU parameter deviations are studied to evaluate the effects on system performance.The models of salient-pole SG,type DC1A excitation system(EXS)and DFIM are illustrated first.Besides,the corresponding control scheme is explained.For the 16 important parameters of PGU,up to 40%of parameter deviations are applied to implement parameter sensitivity analysis.Then,simulation studies are carried out to evaluate the parameter deviation effects on system performance in detail.By defining three parameter deviation effect indicators(PDEIs),the effects on the PGU output variables,which are the terminal voltage and output active power,are studied.Moreover,the increasing rates of PDEIs with different degrees of parameter deviations for the key parameters are analyzed.Furthermore,the overall system performance is investigated for the two most influential PGU parameters.This paper provides some vital clues on SG and EXS parameter identification for DFIM-SPS.展开更多
在长期演进(long term evolution,LTE)系统中,移动终端需要定时更新同一小区和相邻小区的测量信息,以便于及时进行小区切换或重选。传统的接收信号功率测量算法虽然能够降低干扰和噪声对接收端信号的影响,然而在LTE无线环境下,参考信号...在长期演进(long term evolution,LTE)系统中,移动终端需要定时更新同一小区和相邻小区的测量信息,以便于及时进行小区切换或重选。传统的接收信号功率测量算法虽然能够降低干扰和噪声对接收端信号的影响,然而在LTE无线环境下,参考信号接收功率(reference signal receiving power,RSRP)常常受到时间同步和频偏影响,难以获得精确的测量结果。针对该问题,基于LTE系统结构和测量标准提出一种改良的接收信号功率测量算法。该算法对时间和频率同步要求低,且接收信号功率测量性能有所提升。该算法分别在频域和时域计算接收信号功率测量值,并选择两者中较大者作为小区最终接收信号功率值。仿真结果表明,在频偏不大于3 k Hz、定时偏差不大于30 ns时,所述接收信号功率测量算法,相对于传统算法有1 d B以上的平均测量误差的性能提升。展开更多
基金the National Natural Science Foundation of China under Grant 52007071 and 51907073the China Postdoctoral Science Foundation under Grant 3004131154 and 2020M672355the Applied Basic Frontier Program of Wuhan under Grant 2020010601012207。
文摘To lower the difficulty of fault protection,a doubly-fed induction machine based shipboard propulsion system(DFIM-SPS)that is partially power decoupled is presented.In such an intrinsically safe SPS architecture,a synchronous generator(SG)is employed for power generation,and the accuracy of the parameters of power generation unit(PGU)plays an important role in SPS stable operation.In this paper,the PGU parameter deviations are studied to evaluate the effects on system performance.The models of salient-pole SG,type DC1A excitation system(EXS)and DFIM are illustrated first.Besides,the corresponding control scheme is explained.For the 16 important parameters of PGU,up to 40%of parameter deviations are applied to implement parameter sensitivity analysis.Then,simulation studies are carried out to evaluate the parameter deviation effects on system performance in detail.By defining three parameter deviation effect indicators(PDEIs),the effects on the PGU output variables,which are the terminal voltage and output active power,are studied.Moreover,the increasing rates of PDEIs with different degrees of parameter deviations for the key parameters are analyzed.Furthermore,the overall system performance is investigated for the two most influential PGU parameters.This paper provides some vital clues on SG and EXS parameter identification for DFIM-SPS.
文摘在长期演进(long term evolution,LTE)系统中,移动终端需要定时更新同一小区和相邻小区的测量信息,以便于及时进行小区切换或重选。传统的接收信号功率测量算法虽然能够降低干扰和噪声对接收端信号的影响,然而在LTE无线环境下,参考信号接收功率(reference signal receiving power,RSRP)常常受到时间同步和频偏影响,难以获得精确的测量结果。针对该问题,基于LTE系统结构和测量标准提出一种改良的接收信号功率测量算法。该算法对时间和频率同步要求低,且接收信号功率测量性能有所提升。该算法分别在频域和时域计算接收信号功率测量值,并选择两者中较大者作为小区最终接收信号功率值。仿真结果表明,在频偏不大于3 k Hz、定时偏差不大于30 ns时,所述接收信号功率测量算法,相对于传统算法有1 d B以上的平均测量误差的性能提升。
