A novel direct-drive type wind power generation system based on hybrid excitation synchronous machine（HESM）is introduced in this paper.The generator is connected to an uncontrollable rectifier,and a fully controlled...A novel direct-drive type wind power generation system based on hybrid excitation synchronous machine（HESM）is introduced in this paper.The generator is connected to an uncontrollable rectifier,and a fully controlled voltage-sourceinverter is used to connect the system to utility grid.An intermediate DC bus exists between the rectifier and inverter.A new control strategy is proposed which achieves the maximum power point tracking（MPPT） with the control of excitation current of HESM and stabilizes the DC link voltage with the control of inverter output current simultaneously.Specially-designed buck circuit is used to control the excitation current of HESM,and grid voltage-oriented vector control strategy is employed to realize the decoupling of the inverter output power.Simulation results and experiment in 3 kW lab prototype show an excellent static and dynamic performance of the proposed system.展开更多
A new dimmer using a mental-oxide-semiconductor field-effect transistor (MOSFET) for alternating-current (AC) directly driven light-emitting-diode (LED) lamp was presented. The control method of proposed dimmer is pul...A new dimmer using a mental-oxide-semiconductor field-effect transistor (MOSFET) for alternating-current (AC) directly driven light-emitting-diode (LED) lamp was presented. The control method of proposed dimmer is pulse width control (PWM) method. Compared with the conventional phase-controlled dimmer, the proposed PWM dimmer can produce sine wave and did not cause harmonics problem. Furthermore, the proposed control method did not amplify the light flicker due to the independence of input voltage. Therefore, the PWM dimmer can be used as the dimmer of the AC LED lamp instead of the conventional phase-controlled dimmer. The experimental result shows that the proposed PWM dimmer has good performances.展开更多
A new method of switched reluctance wind power generation position sensorless based on DFNN by FEA was proposed, Through current and magnetic linkage to get the angle of SRG rotor position, the nonlinear mapping of cu...A new method of switched reluctance wind power generation position sensorless based on DFNN by FEA was proposed, Through current and magnetic linkage to get the angle of SRG rotor position, the nonlinear mapping of cur- rent-magnetic linkage-angle was built, By training these sample data from FEA, the angle of SRG rotor position was replaced by the output of DFNN to achieve SRG position sensorless. Simulation results show that the error between actual rotor position and estimate rotor position is small; SRG can commutate with great accuracy; and the output voltage of SRG wind power system under variable wind speed is essentially constant.展开更多
目的探讨成果导向教育(outcome based education,OBE)理念下任务驱动教学法在儿科护生带教中的作用。方法根据随机数表法,将2022年3月—2022年6月在重庆医科大学附属永川医院儿科见习的76名护生分为观察组、对照组,各38名。对照组采用...目的探讨成果导向教育(outcome based education,OBE)理念下任务驱动教学法在儿科护生带教中的作用。方法根据随机数表法,将2022年3月—2022年6月在重庆医科大学附属永川医院儿科见习的76名护生分为观察组、对照组,各38名。对照组采用常规教学法,观察组采用OBE理念下任务驱动教学法。比较2组考核成绩、自我导向学习能力(self-rating scale for self-directedness in learning,SRSSDL评分)、核心能力(competency inventory for registered nurse,CIRN评分)与批判性思维(critical thinking disposition inventory‐Chinese version,CTDI-CV评分)、教学评价以及护理质量(service quality,SERVQUAL评分)。结果教学结束后,与对照组相比,观察组考核成绩、SRSSDL评分、CIRN评分、CTDI-CV评分以及SERVQUAL评分均较高,差异有统计学意义(P<0.05)。观察组教学好评率与对照组教学好评率对比,差异无统计学意义(P>0.05)。结论应用OBE理念下任务驱动教学法不仅能有效提升护生的综合素养,培养其自我导向学习能力,锻炼其核心能力与批判性思维,还有助于儿科护理质量的提升,且深受护生认可。展开更多
针对现有测向系统多信号适应能力弱、测向精度低的问题,提出一种基于数据驱动的高精度阵列测向新方法。该方法提取单信号入射时的输入特征向量,基于卷积神经网络构建单信号测向网络框架。利用信号的独立性,将多信号测向问题转化为单信...针对现有测向系统多信号适应能力弱、测向精度低的问题,提出一种基于数据驱动的高精度阵列测向新方法。该方法提取单信号入射时的输入特征向量,基于卷积神经网络构建单信号测向网络框架。利用信号的独立性,将多信号测向问题转化为单信号测向问题,在单信号训练网络的基础上实现多信号来波方向估计。仿真实验与理论分析结果表明,该方法有效减少了输入特征维数和网络训练样本数目,在多信号同时入射及阵列互耦效应条件下均获得了高精度的到达方向(Direction of Arrival,DOA)估计的测向结果。展开更多
基金Project supported by Delta Power Electronic Science and Education Development (Grant No.DRES2007002)
文摘A novel direct-drive type wind power generation system based on hybrid excitation synchronous machine（HESM）is introduced in this paper.The generator is connected to an uncontrollable rectifier,and a fully controlled voltage-sourceinverter is used to connect the system to utility grid.An intermediate DC bus exists between the rectifier and inverter.A new control strategy is proposed which achieves the maximum power point tracking（MPPT） with the control of excitation current of HESM and stabilizes the DC link voltage with the control of inverter output current simultaneously.Specially-designed buck circuit is used to control the excitation current of HESM,and grid voltage-oriented vector control strategy is employed to realize the decoupling of the inverter output power.Simulation results and experiment in 3 kW lab prototype show an excellent static and dynamic performance of the proposed system.
文摘A new dimmer using a mental-oxide-semiconductor field-effect transistor (MOSFET) for alternating-current (AC) directly driven light-emitting-diode (LED) lamp was presented. The control method of proposed dimmer is pulse width control (PWM) method. Compared with the conventional phase-controlled dimmer, the proposed PWM dimmer can produce sine wave and did not cause harmonics problem. Furthermore, the proposed control method did not amplify the light flicker due to the independence of input voltage. Therefore, the PWM dimmer can be used as the dimmer of the AC LED lamp instead of the conventional phase-controlled dimmer. The experimental result shows that the proposed PWM dimmer has good performances.
基金Supported by the National Natural Science Foundation of China （50977080） the Science ＆ Technology Department Project of Hunan Province （2010F J3116） the Education Department Project of Hunan Province （ 10A 114）
文摘A new method of switched reluctance wind power generation position sensorless based on DFNN by FEA was proposed, Through current and magnetic linkage to get the angle of SRG rotor position, the nonlinear mapping of cur- rent-magnetic linkage-angle was built, By training these sample data from FEA, the angle of SRG rotor position was replaced by the output of DFNN to achieve SRG position sensorless. Simulation results show that the error between actual rotor position and estimate rotor position is small; SRG can commutate with great accuracy; and the output voltage of SRG wind power system under variable wind speed is essentially constant.
文摘目的探讨成果导向教育(outcome based education,OBE)理念下任务驱动教学法在儿科护生带教中的作用。方法根据随机数表法,将2022年3月—2022年6月在重庆医科大学附属永川医院儿科见习的76名护生分为观察组、对照组,各38名。对照组采用常规教学法,观察组采用OBE理念下任务驱动教学法。比较2组考核成绩、自我导向学习能力(self-rating scale for self-directedness in learning,SRSSDL评分)、核心能力(competency inventory for registered nurse,CIRN评分)与批判性思维(critical thinking disposition inventory‐Chinese version,CTDI-CV评分)、教学评价以及护理质量(service quality,SERVQUAL评分)。结果教学结束后,与对照组相比,观察组考核成绩、SRSSDL评分、CIRN评分、CTDI-CV评分以及SERVQUAL评分均较高,差异有统计学意义(P<0.05)。观察组教学好评率与对照组教学好评率对比,差异无统计学意义(P>0.05)。结论应用OBE理念下任务驱动教学法不仅能有效提升护生的综合素养,培养其自我导向学习能力,锻炼其核心能力与批判性思维,还有助于儿科护理质量的提升,且深受护生认可。
文摘针对现有测向系统多信号适应能力弱、测向精度低的问题,提出一种基于数据驱动的高精度阵列测向新方法。该方法提取单信号入射时的输入特征向量,基于卷积神经网络构建单信号测向网络框架。利用信号的独立性,将多信号测向问题转化为单信号测向问题,在单信号训练网络的基础上实现多信号来波方向估计。仿真实验与理论分析结果表明,该方法有效减少了输入特征维数和网络训练样本数目,在多信号同时入射及阵列互耦效应条件下均获得了高精度的到达方向(Direction of Arrival,DOA)估计的测向结果。
基金Supported by State Key Program of National Natural Science Foundation of China （60834001） and National Natural Science Foundation of China （60774022）.Acknowledgement Authors would like to thank NSFC organizers and participants who shared their ideas and works with us during the NSFC workshop on data-based control, decision making, scheduling, and fault diagnosis. In particular, authors would like to thank Chai Tian-You, Sun You-Xian, Wang Hong, Yan Hong-Sheng, and Gao Fu-Rong for discussing the concept on design model shown in Fig. 12, the concept on temporal multi-scale shown in Fig. 8, the concept on fault diagnosis shown in Fig. 14, the concept on dynamic scheduling shown in Fig. 15, and the concept on interval model shown in Fig. 16, respectively.
