Optimal Sizing and Power Losses Reduction of Photovoltaic Systems Using PVsyst Software

This paper presents a method for optimizing a grid-connected photovoltaic system through an LCL filter. An algorithm based on particle swarm optimization (PSO) is used to determine the number of batteries, the number of panels in series and in parallel, as well as to evaluate the joule losses due to cable heating and the switching losses of the multilevel inverters. This system is applied to a village named YAGOUA, located in the far north of Cameroon. The evaluation of the Joule effect and the switching losses as well as the regulation of the voltage level at the point of common coupling (PCC) are carried out in PVsyst and Matlab software, then at IEEE 33 bus. This algorithm reduced the Joule losses to 1.2% and the switching losses to 2.2%. A power of 210.4 MWh is produced, to be injected in the electrical network via an LCL filter. The THD calculation gave a rate of 3.015% in accordance with the 519 standards. Synchronization through the Phase Locked Loop (PLL) is performed. After the power was injected into the grid, the voltage and current remained in phase, showing the power factor correction and the efficiency of the filter. According to NASA meteorological data, the locality of YAGOUA gives the global solar irradiation forecast of 6.8 kW/m2.

Combined Novel Gate Level Model and Critical Primary Input Sharing for Genetic Algorithm Based Maximum Power Supply Noise Estimation

A gate level maximum power supply noise （PSN） model is defined that captures both IR drop and di/dt noise effects. Experimental results show that this model improves PSN estimation by 5.3% on average and reduces computation time by 10.7% compared with previous methods. Furthermore,a primary input critical factor model that captures the extent of primary inputs＇ PSN contribution is formulated. Based on these models,a novel niche genetic algorithm is proposed to estimate PSN more effectively. Compared with general genetic algorithms, this novel method can achieve up to 19.0% improvement on PSN estimation with a much higher convergence speed.

An optimal method for prediction and adjustment on gasholder level and self-provided power plant gas supply in steel works

An optimal method for prediction and adjustment on byproduct gasholder level and self-provided power plant gas supply was proposed.This work raises the HP-ENN-LSSVM model based on the Hodrick-Prescott filter,Elman neural network and least squares support vector machines.Then,according to the prediction,the optimal adjustment process came up by a novel reasoning method to sustain the gasholder within safety zone and the self-provided power plant boilers in economic operation,and prevent unfavorable byproduct gas emission and equipment trip as well.The experiments using the practical production data show that the proposed method achieves high accurate predictions and the optimal byproduct gas distribution,which provides a remarkable guidance for reasonable scheduling of byproduct gas.

Topology Optimization for Steady-State Navier-Stokes Flow Based on Parameterized Level Set Based Method

In this paper,we consider solving the topology optimization for steady-state incompressibleNavier-Stokes problems via a new topology optimization method called parameterized level set method,which can maintain a relatively smooth level set function with a local optimality condition.The objective of topology optimization is to􀀀nd an optimal con􀀀guration of theuid and solid materials that minimizes power dissipation under a prescribeduid volume fraction constraint.An arti􀀀cial friction force is added to the Navier-Stokes equations to apply the no-slip boundary condition.Although a great deal of work has been carried out for topology optimization ofuidow in recent years,there are few researches on the topology optimization ofuidow with physical body forces.To simulate theuidow in reality,the constant body force(e.g.,gravity)is considered in this paper.Several 2D numerical examples are presented to discuss the relationships between the proposed method with Reynolds number and initial design,and demonstrate the feasibility and superiority of the proposed method in dealing with unstructuredmesh problems.Three 3D numerical examples demonstrate the proposedmethod is feasible in three-dimensional.

A Novel Serial Hybrid Three-level NPC Topology for Multi-MW Medium Voltage Wind Power Converters

提出一种新型的串联混合三电平中点钳位（neutralpoint clamped,NPC）拓扑,该拓扑是基于传统三电平NPC拓扑的改进和优化,引入大功率IGBT的串联应用。该新型拓扑中,桥臂的两个外管分别用两个低压IGBT串联,两个内管均用高压IGBT。在多兆瓦级中压风电变流器中,大功率IGBT的开关损耗很大,从而限制了开关频率。提出的新型拓扑通过低压IGBT的串联来减小功率器件的损耗,从而提高开关频率,同时可减小输出滤波器的尺寸。通过传统三电平拓扑和新型串联混合三电平拓扑IGBT损耗的对比,说明新拓扑的优势。通过改变门极驱动电阻实现串联IGBT的均压,对新拓扑的应用具有重大意义。最后通过新拓扑的单相样机验证新拓扑的正确性和可行性。

Low power and high speed explicit-pulsed double-edge triggered level converting flip-flop

Variable supply voltage-clustered voltage scaling （VS-CVS） scheme can be very effective in reducing power consumption of CMOS circuits without degrading system performance. Level converting flip-flops （LCFFs） are key elements in the CVS scheme. In this paper, a new explicit-pulsed double-edge triggered level converting flip-flop （nEP-DET-LCFF） is proposed, which employs double-edge triggering technique, dynamic structure, explicit pulse generator, conditional discharge technique and proper arrangement of stacked nMOS transistors to efficiently perform latching and level converting functions simultaneously. The proposed nEP-DET-LCFF combines merits of both conventional explicit-LCFFs and implicit-LCFFs. Simulation shows the proposed nEP-DET-LCFF has improvement of 19.2% -46% in delay, and 19.4% - 52.9% in power-delay product （PDP） as compared with the published LCFFs.

Optical power limiting of ultrashort hyper-Gaussian pulses in cascade three-level system

Propagation of strong femtosecond hyper-Gaussian pulses in a cascade three-level molecular system is studied by solving numerically the Maxwell–Bloch equations by the iterative predictor-corrector finite-difference time-domain method.Optical power limiting behavior induced by strong nonlinear two-photon absorption is observed for different orders of the femtosecond hyper-Gaussian pulses. Pulses of a higher order temporal profile are found to have a wider power range of optical limiting but a larger output saturation intensity. Both the output saturation value and the damage threshold of optical power limiting decrease with pulse duration increasing. The decrease of the pulse area along the pulse propagation is much slower than that obtained from the two-photon area theorem due to invalidity of the slowly varying amplitude approximation and the monochromatic field hypothesis.

Philosophy of GodForm:Power Authorities, Functional Position Levels, Religion and Science

In this work,author expressed new R-Synthesis specifically.Good and/or correct perspective that must be behind the definitions and administration generally expressed.New perspective of the philosophy explained generally.Philosophy of GodForm is defined and expressed as connected/related with the following concepts:(a)basic principles,(b)17 upper constructional philosophies,(c)14 lower constructional philosophies,(d)eight basic philosophies.As special cases,Philosophy of Engineering and Technology,Philosophy of Wireless Administration and others defined as hybrid philosophies.17 specific components/units which can be considered to define the basic principles of the related formation,are proposed to be designed by GodForm and defined by the author.Philosophy of GodForm and its relation with Values and Positions specifically defined.New Era Theory and New Era Belief explained generally.Some specific religions/beliefs are defined as variants/forms of the Progressive Religion.Good and/or correct power authorities(R-Power Authority)are defined due to 29 categories.Functional position levels defined for the R-Power Authorities with a unique table.As result of the R-Synthesis,functional position levels of some philosophers,some scientists,and of Prophet Jesus,Prophet Mohamed,Prophets Mouses,Buddha,and of Confucius generally/specifically defined.Integration and past/present effects of some R-Power Authorities in 5 x 5 Ideal Political Construction specifically explained.New Era Belief,Concepts of GodX and Science relation explained with the following concepts:(1)Religion of GodForm,(2)Knowledge of GodX,(3)Nature of GodX.With this respect,some other characteristics of 7 GodX power authorities expressed with details as complementary information.Following concepts/systems defined to arrange and solve some/most/all religious problems,which are determined with R-Synthesis:(a)Religious Responsibilities and Positions,(b)Ideal Religious Administration,(c)Sustainable/Continuable Political Administration System,(d)Community Values Council/Authority for each world country,(e)Progressive Councils.15 general religious position categories defined to express their good and/or correct meanings/values/responsibilities in the religious system.21 general/specific cases/programs defined due to New Era Belief to solve possible past/present/future community values problems,to have continuous,judicious,and progressive administration about the 36 kinds of community values.Progressive Councils,which are related with the CUS-WW-HO,are defined.Progressive Religion Council and some of the related religious responsibilities expressed for the kind progressive religion studies due to the Philosophy of Progressive Religions.

Design of Low Power Level Shifter Circuit with Sleep Transistor Using MultiSupply Voltage Scheme

New low-power Level Shifter (LS) circuit is designed by using sleep transistor with Multi Threshold CMOS (MTCMOS) technique for robust logic voltage shifting from sub-threshold to above- threshold domain. MultiSupply Voltage Design (MSVD) technique is mainly used for energy and speed in modern system-on-chip. In MSVD, level shifters are required to allow different voltage supply to shift from the lower power supply voltage to the higher power supply voltage. This new low-power level shifter circuit is also used for fast response and low leakage power consumption. This low leakage power consumption can be achieved through insertion of sleep transistor and proper transistors sizing. The proposed design efficiently converts 100 mv input signal into 1 v output signal and achieves the power of 2.56 nW by using 90 nm technology.

Comparison of the Sound Power Levels of an Aerodynamically Designed EGV and a State-of-the-Art EGV

Within previous EU projects, possible modifications to the engine components have been investigated, that would allow for an optimised aerodynamic or acoustic design of the EGV （exit guide vanes） of the TEC （turbine exit casing）. However, the engine weight should not be increased and the aerodynamic performance must be at least the same. This paper compares the sound power level of a state-of-the-art TEC （reference TEC） with typical EGVs with an aerodynamically optimised TEC configuration for the engine operating point approach. It is shown that a significant weight reduction （only bladings considered） and reduction in engine length can be achieved but the sound power level for the fundamental tone （lst blade passing frequency） for this acoustically important operating point is increased. It is also shown that the losses of the aerodynamical optimised EGVs are higher for this off design point but significantly lower at the aero design point. Measurements were conducted in the STTF （subsonic test turbine facility） at the Institute for Thermal Turbo machinery and Machine Dynamics, Graz University of Technology. The inlet guide vanes, the LPT （low pressure turbine） stage, and the EGVs have been designed by MTU Aero Engines.

Adaptive Sub-Threshold Voltage Level Control for Voltage Deviate-Domino Circuits

Leakage power and propagation delay are two significant issues found in sub-micron technology-based Complementary Metal-Oxide-Semiconductor(CMOS)-based Very Large-Scale Integration(VLSI)circuit designs.Positive Channel Metal Oxide Semiconductor(PMOS)has been replaced by Negative Channel Metal Oxide Semiconductor(NMOS)in recent years,with low dimen-sion-switching changes in order to shape the mirror of voltage comparator.NMOS is used to reduce stacking leakage as well as total exchange.Domino Logic Cir-cuit is a powerful and versatile digital programmer that gained popularity in recent years.In this study regarding Adaptive Sub Threshold Voltage Level Control Pro-blem,the researchers intend to solve the contention issues,reduce power dissipa-tion,and increase the noise immunity by proposing Adaptive Sub Threshold Voltage Level Control(ASVLC)-based domino circuit.The efficiency and effec-tiveness of the domino circuit are demonstrated through simulation results.The suggested system makes use of high-speed broad fan-gate circuits,occupies mini-mum space,and consumes meagre amount of power.The proposed circuit was validated in Cadence simulation tool at a supply voltage of 1V,frequency of 100 MHz,and an operating temperature of 27°C with 64 input OR gates.As per the simulation results,the suggested Domino Gate reduced the power dissipa-tion by 17.58 percent and improved the noise immunity by 1.21 times in compar-ison with standard domino logic circuits.

Radioactivity level of the ambient environment of Anren bone-coal power station

The radioactivity level of the ambient environment of Anren Bone-coal Power Station (BCPS) was investigated systematically. The γ radiation dose rate level in the environment, the content of 238U and 226Ra in the ambient soil and the farmland in the direction of downwind, the concentrations of 238U. 232Th. 226Ra 40K and 222Rn as well as α potential energy in air, and the concentrations of natural U and Th in effluent are all higher than the corresponding values of the reference site. The additional annual effective dose equivalent to the residents living in the houses made of bone-coal cinder brick is 2.7 mSv.

考虑大规模风光分层接入的配电网多层协调无功优化方法

大量风光新能源分层、多点接入给配电网运行带来了电压越限等负面影响,增加了不同电压等级无功协同优化的难度。兼顾不同电压等级调节需求,从模型降维等值的角度,提出了基于等值模型的配电网多层协调无功优化方法。该方法分别针对含有无功调节设备及没有无功调节设备的两种台区系统,利用神经网络对大量台区相关运行数据进行训练得到台区拟合模型,形成不可控和可控两种类型的台区等值模型,并用这两类拟合模型分别代替两类台区系统的物理模型,使台区以数据驱动的方式参与配电网无功优化,形成馈线物理模型和台区拟合模型组成的单一电压等级物数混合优化调度模型。将原多层无功优化问题转换为单层系统优化问题,再对该单层系统无功优化调度问题进行求解。该方法可降低配电网系统优化计算规模,从而减小计算量,以无功优化数学模型与数据驱动方法相结合的方式,实现配电网馈线-台区多层协调无功优化。通过算例验证了所提方法对于解决分布式风光分层接入所导致电压越限问题的可行性、有效性和优越性,能够保障配电网的经济安全稳定运行。

PD Power-Level Control Design for MHTGRs

Due to its inherent safety feature, the modular high temperature gas-cooled reactor (MHTGR) has been seen as one of the best candidates in building next generation nuclear plants (NGNPs). Since the MHTGR dynamics has high nonlinearity, it is necessary to develop nonlinear power-level controller which is not only beneficial to the safe, stable, efficient and autonomous operation of the MHTGR but also easy to be implemented practically. In this paper, based on the concept of shiftedectropy and the physically-based control design approach, it is proved theoretically that the simple proportional-differential (PD) output-feedback power-level control can provide globally asymptotic closed-loop stability. Numerical simulation results verify the theoretical results and show the influence of the controller parameters to the dynamic response.

碳中和背景下我国电力碳排放水平分析

电力低碳化转型对我国实现碳中和目标具有全局性战略意义。在总结我国近10年电力低碳化发展历程的基础上,以人口、城市化、经济总量与经济结构为边界条件和驱动力,分析预测未来40年电力增长过程和阶段性发展目标;以系统安全、供需平衡为约束,分析了化石电力占比、终端电力消费比重、核电发展规模以及碳捕集、利用及封存(CCUS)等因素对碳排放水平的影响;预计电力碳排放峰值将出现在2035年前后,达到60~65亿吨,随后逐年降低,到2060年降至10亿吨以内,辅以CCUS技术,可实现电力零排放。最后,针对需求持续增长与低碳转型长期并存的矛盾,提出未来电力发展须以安全供给为前提,优先开发可再生能源电力、多能发展、更大范围多能互补协调开发和互补运行的建议。

风光热储互补发电系统容量配置技术研究

针对无常规电源支撑的风光热储互补发电系统,协调规划装机容量对提高发电系统运行经济性和利用率具有重要意义。提出了一种双层优化配置方法,上层以最小度电成本及弃电率为目标,确定系统装机容量;下层以新能源发电消纳最大为目标,解决功率分配问题。通过反复迭代寻优,得到系统容量配置;然后;通过纳什谈判对优化结果进行选择;最后,对甘肃河西地区数据进行仿真分析。结果表明:风光热储互补发电系统最优容量配置下的度电成本为0.3064元/(k W·h);风电场加光伏电站装机容量与光热电站装机容量的最优比为6:1,对比相同装机容量的风光互补发电系统,风光热储互补发电系统具有更高的稳定性。

一类三电平伪图腾柱无桥PFC变换器

针对传统二极管钳位型三电平整流器在单相电源前级功率校正(power factor correction,PFC)电路应用场景下全控开关器件数量多的问题,该文基于3种传统无桥PFC电路进行三电平电路拓扑设计,提出一类三电平伪图腾柱PFC电路(single-phase three-level pseudo totem-pole PFC circuit,STPT-PFC),该类三电平PFC具有双电感支路桥臂,两者相互配合工作为输入电流提供路径,在正负半周两电感支路桥臂工作于不同模态可有效降低分别流过两电感的电流;基于该类PFC的一个代表性电路,从工作电流路径过程、关键波形和调制脉冲分配等方面对其进行工作原理分析,并对其它电路进行电路特性总结,推导桥臂对地电压电平特性与开关脉冲分配的数学关系式。另外,该类STPT-PFC共有5种结构,结合该类STPT-PFC结构特点,提出统一区间判断条件的双层载波调制技术,该类STPT-PFC具有相同开关器件不同拓扑结构可采用同一调制方案的特点,便于该类调制技术移植。最后,基于STPT-PFC-I电路设计1台额定功率1 kW、直流输出电压400 V的实验样机,从稳态及动态两方面进行实验分析,实验结果验证所提出一类三电平伪图腾柱PFC电路的可行性和三电平统一双层调制方法的有效性。

中原城市群文化软实力综合评价及空间分异研究

基于文化吸引力、文化展示力、文化传播力、文化创新力、文化事业投入力和文旅融合力6个维度构建文化软实力评价指标体系,运用空间分类、核密度分析、空间自相关等方法,分析中原城市群文化软实力的空间特征并解析其影响因素。结果表明:(1)从综合实力差异看,高、较高文化软实力城市数量少且主要分布在核心区,中等实力城市仅有3个,半数城市为低和较低实力。空间上具有明显的东西差异,西半壁呈现以郑汴为引领的中心外围格局,东半壁则表现为亳州、阜阳引领的极化特征,且在东西半壁之间形成聊城至驻马店的低值连绵带。(2)从分维度空间差异看,文化吸引力子系统、文化展示力子系统与综合实力格局类似,而文化事业投入力子系统呈现“西北高、东南低”的格局。此外,文化传播力子系统、文化创新力子系统呈现与前3个子系统完全不同的格局,表现为以郑汴为核心的低值包围高值的分布结构。(3)从空间集聚和关联看,中原城市群分别围绕郑州和亳州形成了“一主一副”的双核集聚态势,且主核区附近形成了显著的高-高集聚群。其中,文化吸引力子系统与综合实力的集聚格局基本一致,文化展示力子系统的集聚在郑州减弱而在亳州得到加强,文化传播力子系统和文化创新力子系统仅在中部形成集聚核心,文旅融合力子系统则在综合格局的基础上在东南部形成两个集聚核心。(4)从影响因素看,市区GDP对城市文化软实力的影响最强,第三产业增加值次之,交通设施、科教文卫单位数和城镇化率的影响作用不明显。

风氢耦合系统参与现货市场的竞标策略及优化调度方法

为解决高比例风电市场竞标能力弱、市场消纳困难的问题,提出高比例风电耦合氢储能系统联合参与现货市场竞价的双层Stackelberg博弈模型。首先,研究风氢耦合系统内部能量转换关系,揭示风氢耦合系统的能量“时空平移”机理,在综合考虑风氢耦合系统收益和成本的基础上,建立风电投标和氢储能充放电决策模型;其次,兼顾风氢耦合系统和独立系统运营商的利益诉求,基于Stackelberg博弈建立以火电机组、风氢耦合系统为主体的市场出清模型;最后,针对双层模型求解困难的问题,运用KKT条件和强对偶理论将双层模型转换为易于求解的单层混合整数规划模型。仿真结果表明,所提策略对高比例风电的市场消纳起到了积极作用。