基于卡尔曼滤波的波浪发电系统反步法最优功率跟踪控制

常规变速控制系统的精度不高,变换器晶闸管开关动作产生的高频纹波较大,为此提出一种基于卡尔曼滤波的反步控制方法。文章通过分析波浪能提取装置的受力及幅频特性,获取了波浪能转化效率最大化的控制条件,并搭建了一套基于卡尔曼滤波的波浪发电反步最优功率控制系统。通过仿真研究了3种控制方法的控制精度和有效性,仿真结果表明:低通滤波反步法存在相位延迟,不能满足最大功率捕获策略的相位条件,影响系统的最终有功功率输出;反步法的跟踪误差较大,导致系统输出的有功功率较低;卡尔曼滤波反步法的动态性能较好,跟踪电流的波形振幅较小,能保证系统全局收敛,在电机速度方向、幅值和频率突变的情况下,仍能快速准确跟踪给定信号,鲁棒性和抗干扰能力更好。     

Heavy Water Additive in Formamidinium: A Novel Approach to Enhance Perovskite Solar Cell Efficiency

Heavy water or deuterium oxide (D₂O) comprises deuterium, a hydrogen isotope twice the mass of hydrogen. Contrary to the disadvantages of deuterated perovskites, such as shorter recombination lifetimes and lower/invariant efficiencies, the serendipitous effect of D₂O as a beneficial solvent additive for enhancing the power conversion efficiency (PCE) of triple-A cation (cesium (Cs)/methylammonium (MA)/formaminidium (FA)) perovskite solar cells from ≈19.2% (reference) to 20.8% (using 1 vol% D₂O) with higher stability is reported. Ultrafast optical spectroscopy confirms passivation of trap states, increased carrier recombination lifetimes, and enhanced charge carrier diffusion lengths in the deuterated samples. Fourier transform infrared spectroscopy and solid-state NMR spectroscopy validate the N–H₂ group as the preferential isotope exchange site. Furthermore, the NMR results reveal the induced alteration of the FA to MA ratio due to deuteration causes a widespread alteration to several dynamic processes that influence the photophysical properties. First-principles density functional theory calculations reveal a decrease in PbI₆ phonon frequencies in the deuterated perovskite lattice. This stabilizes the PbI₆ structures and weakens the electron–LO phonon (Fröhlich) coupling, yielding higher electron mobility. Importantly, these findings demonstrate that selective isotope exchange potentially opens new opportunities for tuning perovskite optoelectronic properties.     

Wire-free electricity: Insights from a techno-futuristic exploration

Wireless Power Transmission is an emerging technology that enables the transmission of electricity without the use of artificial conducting mediums. Lack of significant technological breakthroughs widely affected its progress. In this paper, we analyze the early progress of WPT and attempt to forecast its growth using Pearl curve model. Fisher-Pry substitution model analysis indicates that technology substitution of wired transmission has just begun and half the substitution will be over by 2028. We conducted patent landscaping to identify hot domains and specific technology areas. Implications for technology developers and manufacturers, electric utility providers and national policymakers are also identified.     

An Improved Torque Sensorless Speed Control Method for Electric Assisted Bicycle With Consideration of Coordinate Conversion

In this paper, we propose an improved torque sensorless speed control method for electric assisted bicycle, this method considers the coordinate conversion. A low-pass filter is designed in disturbance observer to estimate and compensate the variable disturbance during cycling. A DC motor provides assisted power driving, the assistance method is based on the real-time wheel angular velocity and coordinate system transformation. The effect of observer is proved, and the proposed method guarantees stability under disturbances. It is also compared to the existing methods and their performances are illustrated through simulations. The proposed method improves the performance both in rapidity and stability.      

Wind power and photovoltaic power: How to improve the accommodation capability of renewable electricity generation in China?

China's wind curtailment and photovoltaic curtailment was one of the prominent issues in 2014, and the renewable curtailment worsened in 2015. With the rapid growth of renewables, the phenomenon of the insufficiency in renewable accommodation capability is becoming more and more serious in 2016. In that case, the problem of the insufficient accommodation capability is pointed out by analyzing China's development requirements. The renewable power generation scale, the renewable power consumption, and the restrictions on the renewable electricity generation are discussed from the China's market perspective. Meanwhile, the legal environment, the planning requirement, the institutional setting, and the policy tools are introduced from the perspective of governmental regulation. An empirical analysis, a cause analysis and a trend analysis are illustrated before explaining the problem of renewable curtailment and proposing a solution for enhancing the accommodation capability. According to the analysis results, the solution for addressing the wind curtailment and PV curtailment is offered with respect to the technology, the institution, the legislation, and the political aspect. Through the research, the research conclusions are drew finally and the corresponding policy recommendations are put forward.     

国内在役核电厂首例电气贯穿件更换改造

核电厂电气贯穿件作为安全壳上的关键设备，承担着核岛内外各种电力和信号传输以及保证安全壳压力边界完整性的重要功能。通过秦山核电厂一期工程30万千瓦机组第18次大修期间国产在役DDG-1型电气贯穿件更换改造项目的实施，分析了秦山核电厂一期工程在役电气贯穿件设备现状和改造的必要性；针对在役核电厂更换改造工期短和贯穿件密封性能验证难等问题，通过优化检验工序、制作专用检漏工装的方法，缩短了贯穿件改造的工期并验证了贯穿件密封性能。      

复杂岩基地质海上风电高桩承台基础关键技术研究及应用

本文针对福建海域复杂的地质特点,以岩基海床高桩承台基础为研究对象,对基础的承台选型、承台结构设计进行分析,结合基础的载荷计算、结构的内力建模、基础的实际监测数据,研究表明高桩中承台嵌岩基础满足设计规范要求。同时,以嵌岩基础施工为例,从桩基施工、承台施工2方面详细阐述了基础施工工艺,实践表明,采用打桩架固定式沉桩、整体式嵌岩平台、装配式预制钢套箱工艺可显著提高施工效率,满足工程建设要求。该高桩承台基础设计和施工方案可为东南沿海类似工程提供参考。     

泛在电力物联网在北京经济技术开发区的应用探索

泛在电力物联网是物联网在电力领域的具体体现，建设泛在电力物联网是推进"三型两网"建设的关键环节，也是实现能源转型的必要手段。阐述了泛在电力物联网的定义，从供电公司角度出发，根据北京经济技术开发区实际情况，讨论了依托地区特点的泛在电力物联网实施策略和实际应用场景，分析了可能遇到的问题。得出结论：随着泛在电力物联网的深入建设，供电公司能够为电力客户提供多元化服务，提高客户满意度；地市供电公司能够依托泛在电力物联网开展更多电力相关业务；泛在电力物联网的安全性、实用性、有效性是发展面临的首要问题。     

基于阶段注意力机制的电力线提取算法

电力系统维护是电力系统稳定运行的重要保障，应用智能算法的无人机电力巡检则为电力系统维护提供便捷。电力线提取是自主电力巡检以及保障飞行器低空飞行安全的关键技术，结合深度学习理论进行电力线提取是电力巡检的重要突破点。本文将深度学习方法用于电力线提取任务，结合电力线图像特点嵌入改进的图像输入策略和注意力模块，提出一种基于阶段注意力机制的电力线提取模型（SA-Unet）。本文提出的SA-Unet模型编码阶段采用阶段输入融合策略（Stage input fusion strategy， SIFS），充分利用图像的多尺度信息减少空间位置信息丢失。解码阶段通过嵌入阶段注意力模块（Stage attention module，SAM）聚焦电力线特征，从大量信息中快速筛选出高价值信息。实验结果表明，该方法在复杂背景的多场景中具有良好的性能。     

Adaptive robust control-based energy management of hybrid PV-Battery systems with improved transient performance

Energy management of hybrid photovoltaic (PV)-battery systems still serve as a challenging task owing to their complex and nonlinear characteristics, multicomponent structures, and the extensive range of environmental factors disturbing their nominal performance. The hybrid energy system developed in this study encompasses PV arrays, a battery component, one boost converter, and one bidirectional boost converter. In this paper, we propose a novel adaptive robust control framework for the optimal energy management of the PV-battery systems under many operating conditions and subject to unmodelled dynamics. An improved exponential-like adaptive integral sliding mode (EISM) control coupled to neural network approximator is introduced using a multi-rate convergence tweaking mechanism for the sliding surface to improve the transient performance of the closed-loop system. Furthermore, the entire dynamics of the hybrid energy system is considered unknown, unlike the previous studies that only assumed the parametric uncertainties. The global asymptotic stability of the system is guaranteed, and the effectiveness of this novel framework is compared to benchmark studies.