Reconfigurability of the electrical network in a shipboard power system (SPS) after its failure is central to the restoration of power supply and improves survivability of an SPS. The navigational process creates a ...Reconfigurability of the electrical network in a shipboard power system (SPS) after its failure is central to the restoration of power supply and improves survivability of an SPS. The navigational process creates a sequence of different operating conditions. The priority of some loads differs in changing operating conditions. After analyzing characteristics of typical SPS, a model was developed used a grade III switchboard and an environmental prioritizing agent (EPA) algorithm. This algorithm was chosen as it is logically and physically decentralized as well as multi-agent oriented. The EPA algorithm was used to decide on the dynamic load priority, then it selected the means to best meet the maximum power supply load. The simulation results showed that higher priority loads were the first to be restored. The system satisfied all necessary constraints, demonstrating the effectiveness and validity of the proposed method.展开更多
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
针对感应式电能传输(inductive power transfer,IPT)系统偏移造成输出电压不稳定和效率低下的问题,提出一种强抗偏移的S/SP补偿IPT系统,该系统在变耦合变自感和变耦合不变自感两种情况下均能保证较小的输出电压波动和较高的传输效率。首...针对感应式电能传输(inductive power transfer,IPT)系统偏移造成输出电压不稳定和效率低下的问题,提出一种强抗偏移的S/SP补偿IPT系统,该系统在变耦合变自感和变耦合不变自感两种情况下均能保证较小的输出电压波动和较高的传输效率。首先,基于Maxwell有限元仿真,分析罐型磁心松耦合变压器的磁通分布和磁场分布特性,总结不同方向偏移的参数变化规律。然后,提出一种提高系统抗偏移能力的S/SP补偿参数设计方法,得到相应的磁耦合机构设计准则,并结合磁仿真数据,通过数值计算方式求得系统输出波动和输入阻抗角的变化规律。最后,通过实验验证文中采用罐型磁心和新型S/SP补偿拓扑实现多方向偏移下高效率、低波动无线电能传输的可行性。在额定负载下,系统沿纵向和水平方向偏移的输出电压波动分别为2.7%和3.1%,传输效率维持在90.8%~94.3%。展开更多
To verify the effectiveness and correctness of the protection settings in ring structure Shipboard Power System (SPS), a digital-physical hybrid simulation platform at China Ship Development and Design Center (CSDDC) ...To verify the effectiveness and correctness of the protection settings in ring structure Shipboard Power System (SPS), a digital-physical hybrid simulation platform at China Ship Development and Design Center (CSDDC) has been built, which aims to give double verification effect of design scheme and physical device. The platform consists of eMEGAsim digital simulator, signal power amplifiers and digital-analog interface equipments. With this platform, the multiple protection device of ring structure grid can be accessed to form a close-loop test system. Since eMEGAsim model-simulated faults and actual protection device actions are on real time, the tripping settings of each device as well as their coordinate performance between multiple devices can be verified in this close-loop test.展开更多
This paper examines the definition of MPT-SBSP and implementation model of such technology.It surveys the latest development and affirms the feasibility and a bright future of this technology,emphasizing the existing ...This paper examines the definition of MPT-SBSP and implementation model of such technology.It surveys the latest development and affirms the feasibility and a bright future of this technology,emphasizing the existing issues must be solved by more educated individuals and organizations for the early realization of this"beyond-the-realm-of-cost"technology.Because once this technology is successfully applied in large-scale,humans won’t have to worry about the energy crisis in the future.展开更多
S/SP非接触谐振变换器因为对系统参数变化尤其是变压器的耦合系数变化不太敏感,具有良好的应用前景。但该变换器中主要波形谐波含量较大,导致基波分析方法误差较大,直接影响到变换器的参数设计以及控制的有效性。为此论文对变换器的时...S/SP非接触谐振变换器因为对系统参数变化尤其是变压器的耦合系数变化不太敏感,具有良好的应用前景。但该变换器中主要波形谐波含量较大,导致基波分析方法误差较大,直接影响到变换器的参数设计以及控制的有效性。为此论文对变换器的时域特性展开研究。论文考虑谐波影响,推导谐振网络的通用等效电路,揭示谐波产生的原因,建立谐振腔各波形的定量表达式。在时域波形分析的基础上,论文进一步研究变换器的输出增益特性,推导精确的电压增益并指出基波分析方法结果偏大的原因。最后,设计一台1.5 k W的S/SP非接触谐振变换器,特征波形、电压增益的实验与分析结果吻合良好,验证了论文所采用的时域特性分析方法的正确性。展开更多
基波等效法是无线电能传输(wireless power transfer,WPT)技术的主要研究方法,该方法将整流性负载的基波阻抗等效为某一纯电阻,为系统的建模和分析提供基础。但该方法忽略整流性负载谐波阻抗的影响,使WPT系统的实际响应与理论分析结果...基波等效法是无线电能传输(wireless power transfer,WPT)技术的主要研究方法,该方法将整流性负载的基波阻抗等效为某一纯电阻,为系统的建模和分析提供基础。但该方法忽略整流性负载谐波阻抗的影响,使WPT系统的实际响应与理论分析结果存在较大的误差,从而影响系统的模型精度,限制WPT系统的进一步优化设计。该文以基于串/串并(series/series-parallel,S/SP)补偿网络的WPT系统为研究对象,分析利用基波等效法进行建模产生误差的原因,并提出一种基于迭代法的整流性负载基波以及各次谐波等效阻抗的精确计算方法。在此基础上,建立WPT系统的精确电路响应模型,所提模型可以有效表征发射线圈电流的畸变特性,并根据系统响应与补偿网络参数的关系获得系统逆变器开关损耗的优化设计方法。最后,搭建一台3kW的WPT系统样机,实验结果验证理论分析的正确性和可行性。展开更多
A simulation model of shipboard low voltage molded case circuit breaker (MCCB) is developed based on power system simulation software PSCAD/EMTDC. The motion characteristic of the magnetic instantaneous acting trip ba...A simulation model of shipboard low voltage molded case circuit breaker (MCCB) is developed based on power system simulation software PSCAD/EMTDC. The motion characteristic of the magnetic instantaneous acting trip based on electromagnetic characteristic analysis and Cassie arc model are applied into the simulation model to describe the dynamic behavior of the MCCB during short-circuit protection. The results of short-circuit interruption experiments verify the simulation model. It demonstrates that the simulation model has good prospect in optimizing the design and protection performance of MCCB.展开更多
Enrichment of bacteria capable of growing with electrochemical reducing power and CO2 was accomplished using a plate-type electrochemical bioreactor (PEB). A bacterial source obtained from wastewater treatment reactan...Enrichment of bacteria capable of growing with electrochemical reducing power and CO2 was accomplished using a plate-type electrochemical bioreactor (PEB). A bacterial source obtained from wastewater treatment reactant and forest soil was cultivated on carbonate-based mineral agar medium prepared in the PEB (PEB-carbonate agar). According to the pyrosequencing analyses, the abundance of Betaproteobacteria and Gammaproteobacteria at the phylum level, and Achromobacter, Alcaligenes, and Pseudomonas at the genus level were selectively increased after the electrochemical enrichment culture. Finally, one genus of bacterium that was autotrophically grown on the PEB-carbonate agar was identified as Alcaligenes. This bacterium may be useful to fix atmospheric CO2 with electrochemical energy obtained from the solar cell.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No.60704004the Fundamental Research Funds for the Central University under Grant No.HEUCFT1005
文摘Reconfigurability of the electrical network in a shipboard power system (SPS) after its failure is central to the restoration of power supply and improves survivability of an SPS. The navigational process creates a sequence of different operating conditions. The priority of some loads differs in changing operating conditions. After analyzing characteristics of typical SPS, a model was developed used a grade III switchboard and an environmental prioritizing agent (EPA) algorithm. This algorithm was chosen as it is logically and physically decentralized as well as multi-agent oriented. The EPA algorithm was used to decide on the dynamic load priority, then it selected the means to best meet the maximum power supply load. The simulation results showed that higher priority loads were the first to be restored. The system satisfied all necessary constraints, demonstrating the effectiveness and validity of the proposed method.
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.
文摘针对感应式电能传输(inductive power transfer,IPT)系统偏移造成输出电压不稳定和效率低下的问题,提出一种强抗偏移的S/SP补偿IPT系统,该系统在变耦合变自感和变耦合不变自感两种情况下均能保证较小的输出电压波动和较高的传输效率。首先,基于Maxwell有限元仿真,分析罐型磁心松耦合变压器的磁通分布和磁场分布特性,总结不同方向偏移的参数变化规律。然后,提出一种提高系统抗偏移能力的S/SP补偿参数设计方法,得到相应的磁耦合机构设计准则,并结合磁仿真数据,通过数值计算方式求得系统输出波动和输入阻抗角的变化规律。最后,通过实验验证文中采用罐型磁心和新型S/SP补偿拓扑实现多方向偏移下高效率、低波动无线电能传输的可行性。在额定负载下,系统沿纵向和水平方向偏移的输出电压波动分别为2.7%和3.1%,传输效率维持在90.8%~94.3%。
文摘To verify the effectiveness and correctness of the protection settings in ring structure Shipboard Power System (SPS), a digital-physical hybrid simulation platform at China Ship Development and Design Center (CSDDC) has been built, which aims to give double verification effect of design scheme and physical device. The platform consists of eMEGAsim digital simulator, signal power amplifiers and digital-analog interface equipments. With this platform, the multiple protection device of ring structure grid can be accessed to form a close-loop test system. Since eMEGAsim model-simulated faults and actual protection device actions are on real time, the tripping settings of each device as well as their coordinate performance between multiple devices can be verified in this close-loop test.
文摘This paper examines the definition of MPT-SBSP and implementation model of such technology.It surveys the latest development and affirms the feasibility and a bright future of this technology,emphasizing the existing issues must be solved by more educated individuals and organizations for the early realization of this"beyond-the-realm-of-cost"technology.Because once this technology is successfully applied in large-scale,humans won’t have to worry about the energy crisis in the future.
基金国家自然科学基金项目(5107706951377081)香港政府研究基金(Poly U 5274/13E)~~
文摘S/SP非接触谐振变换器因为对系统参数变化尤其是变压器的耦合系数变化不太敏感,具有良好的应用前景。但该变换器中主要波形谐波含量较大,导致基波分析方法误差较大,直接影响到变换器的参数设计以及控制的有效性。为此论文对变换器的时域特性展开研究。论文考虑谐波影响,推导谐振网络的通用等效电路,揭示谐波产生的原因,建立谐振腔各波形的定量表达式。在时域波形分析的基础上,论文进一步研究变换器的输出增益特性,推导精确的电压增益并指出基波分析方法结果偏大的原因。最后,设计一台1.5 k W的S/SP非接触谐振变换器,特征波形、电压增益的实验与分析结果吻合良好,验证了论文所采用的时域特性分析方法的正确性。
文摘基波等效法是无线电能传输(wireless power transfer,WPT)技术的主要研究方法,该方法将整流性负载的基波阻抗等效为某一纯电阻,为系统的建模和分析提供基础。但该方法忽略整流性负载谐波阻抗的影响,使WPT系统的实际响应与理论分析结果存在较大的误差,从而影响系统的模型精度,限制WPT系统的进一步优化设计。该文以基于串/串并(series/series-parallel,S/SP)补偿网络的WPT系统为研究对象,分析利用基波等效法进行建模产生误差的原因,并提出一种基于迭代法的整流性负载基波以及各次谐波等效阻抗的精确计算方法。在此基础上,建立WPT系统的精确电路响应模型,所提模型可以有效表征发射线圈电流的畸变特性,并根据系统响应与补偿网络参数的关系获得系统逆变器开关损耗的优化设计方法。最后,搭建一台3kW的WPT系统样机,实验结果验证理论分析的正确性和可行性。
文摘A simulation model of shipboard low voltage molded case circuit breaker (MCCB) is developed based on power system simulation software PSCAD/EMTDC. The motion characteristic of the magnetic instantaneous acting trip based on electromagnetic characteristic analysis and Cassie arc model are applied into the simulation model to describe the dynamic behavior of the MCCB during short-circuit protection. The results of short-circuit interruption experiments verify the simulation model. It demonstrates that the simulation model has good prospect in optimizing the design and protection performance of MCCB.
文摘Enrichment of bacteria capable of growing with electrochemical reducing power and CO2 was accomplished using a plate-type electrochemical bioreactor (PEB). A bacterial source obtained from wastewater treatment reactant and forest soil was cultivated on carbonate-based mineral agar medium prepared in the PEB (PEB-carbonate agar). According to the pyrosequencing analyses, the abundance of Betaproteobacteria and Gammaproteobacteria at the phylum level, and Achromobacter, Alcaligenes, and Pseudomonas at the genus level were selectively increased after the electrochemical enrichment culture. Finally, one genus of bacterium that was autotrophically grown on the PEB-carbonate agar was identified as Alcaligenes. This bacterium may be useful to fix atmospheric CO2 with electrochemical energy obtained from the solar cell.