开发基于Matlab的Stand-Alone软件

Matlab语言是国际上使用最为广泛的科学与工程计算软件工具,但是由Matlab生成的代码不能脱离Matlab环境运行。如何令Matlab代码能够完全脱离Matlab环境独立运行,对于各专业人员借助Matlab语言快速开发出具备强大计算功能的专业应用软件具有重要的意义。本文在分析了Matlab软件的优缺点的基础上,给出了使包含Matlab代码的应用软件能够脱离Matlab环境运行的具体步骤和方法。

Optimal Configuration for Design of Stand-Alone PV System

This paper presents a design for a stand-alone photovoltaic (PV) system to provide the required electricity for a single residential household in rural area in Jordan. The complete design steps for the suggested household loads are carried out. Site radiation data and the electrical load data of a typical household in the considered site are taken into account during the design steps. The reliability of the system is quantified by the loss of load probability. A computer program is developed to simulate the PV system behavior and to numerically find an optimal combination of PV array and battery bank for the design of stand-alone photovoltaic systems in terms of reliability and costs. The program calculates life cycle cost and annualized unit electrical cost. Simulations results showed that a value of loss of load probability LLP can be met by several combinations of PV array and battery storage. The method developed here uniquely determines the optimum configuration that meets the load demand with the minimum cost. The difference between the costs of these combinations is very large. The optimal unit electrical cost of 1 kWh for LLP = 0.049 is $0.293;while for LLP 0.0027 it is $0.402. The results of the study encouraged the use of the PV systems to electrify the remote sites in Jordan.

Stand-alone XLIF治疗退变性脊柱侧凸

目的评估Stand-alone XLIF(即不使用螺钉内固定的单纯极外侧入路椎间融合术)治疗退变性脊柱侧凸(DS)的临床疗效。方法回顾性分析南部战区总医院采用Stand-alone XLIF治疗的15例DS患者的临床资料,其中单节段8例、双节段4例、三节段1例、四节段2例,共27个节段。采用腰椎Oswestry功能障碍指数(ODI)、日本骨科学会(JOA)评分和腰腿痛视觉模拟量表(VAS)评分评估患者的临床疗效;测量术前和末次随访时腰椎冠状面Cobb角和椎间孔高度,观察随访期间植骨融合及并发症发生情况。结果随访时间1~9年,平均随访时间4.2年。末次随访时腰椎ODI、JOA评分和VAS评分均较术前改善(P<0.05),术前、末次随访腰椎冠状面Cobb角和椎间孔高度分别为(28.1±5.8)°、(11.7±3.6)°和(16.3±2.5)、(19.2±2.7)mm,手术前后比较,差异有统计学意义(P<0.05)。术后1年24个节段(89%)获植骨融合,3个节段植骨延迟愈合。术后4例出现腹胀,5例出现腹股沟区一过性麻木或疼痛。随访期间未有内固定松动、感染并发症发生。结论在合理选择适应证的前提下,Stand-alone XLIF具有微创、术后恢复快的优势,可有效治疗DS。

Jaya Learning-Based Optimization for Optimal Sizing of Stand-Alone Photovoltaic,Wind Turbine,and Battery Systems

Renewable energy sources(RESs)are considered to be reliable and green electric power generation sources.Photovoltaics(PVs)and wind turbines(WTs)are used to provide electricity in remote areas.Optimal sizing of hybrid RESs is a vital challenge in a stand-alone environment.The meta-heuristic algorithms proposed in the past are dependent on algorithm-specific parameters for achieving an optimal solution.This paper proposes a hybrid algorithm of Jaya and a teaching–learning-based optimization(TLBO)named the JLBO algorithm for the optimal unit sizing of a PV–WT–battery hybrid system to satisfy the consumer’s load at minimal total annual cost(TAC).The reliability of the system is considered by a maximum allowable loss of power supply probability(LPSPmax)concept.The results obtained from the JLBO algorithm are compared with the original Jaya,TLBO,and genetic algorithms.The JLBO results show superior performance in terms of TAC,and the PV–WT–battery hybrid system is found to be the most economical scenario.This system provides a cost-effective solution for all proposed LPSPmax values as compared with PV–battery and WT–battery systems.

A Summary of Optimal Methods for the Planning of Stand-alone Microgrid System

This paper describes the characteristics and optimal methods for the planning of stand-alone microgrid system, in order to improve the power supply reliability, increase the coefficient of utilization of renewable energy and reduce the cost of investment and operation. Next, the problems in the optimal planning for a stand-alone microgrid system are summarized, including the unique operational control targets, the flexible combination approaches and the operation strategies of distributed generation energy supply system, and the special requirements of the reliability of power supply quality factor from the different users. And then, centering on the operational control and the advanced energy management strategy, the optimal mathematical models and the solving methods, the reliability assessment approaches and the improvement measures of a stand-alone microgrid system, an overview of the general situation of the recent research at home and abroad and the limitations of the study are summarized. Finally, several problems, existing in the optimal planning of stand-alone microgrid system, to be urgently solved, are put forward.

A Case Study to Determine Optimal Capacity of a Stand-Alone Wind/PV/Battery System

In this paper, a stand-alone hybrid microgrid consisting of wind turbines, photovoltaic (PV) arrays and storage battery banks is developed for use in Qinghai Province, China. With the help of Software Homer and Matlab, different variables such as annual average wind speed, annual average load demand, and annual capacity shortage are considered. The net present value is then used during an entire project lifetime for the optimization solution.

Optimal planning of stand-alone microgrids incorporating reliability

This paper proposes a new method for the planning of stand-alone microgrids.By means of clustering techniques,possible operating scenarios are obtained considering the daily patterns of wind and load profiles.Then,an approximate analytical model for reliability evaluation of battery energy storage system is developed in terms of the diverse scenarios,along with multistate models for wind energy system and diesel generating system.An optimal planning model is further illustrated based on the scenarios and the reliability models,with the objective of minimizing the present values of the costs occurring within the project lifetime,and with the constraints of system operation and reliability.Finally,a typical stand-alone microgrid is studied to verify the efficiency of the proposed method.

Stand-along OLIF植入3D打印解剖型融合器治疗退行性腰椎管狭窄症32例临床分析

目的分析无内固定单纯斜外侧入路椎间融合术(Stand-along OLIF)植入自制3D打印解剖型融合器(3D anatomical type Cage)治疗退变性腰椎管狭窄症(Degenerative lumber spinal stenosis,DLSS)的临床疗效.方法32例退变性腰椎管狭窄症患者均行Stand-along OLIF手术,并采用视觉评分表(VAS)、Oswestry功能障碍指数(oswestry disability index,ODI)、SF-36生活质量量化表评价临床疗效;术前、术后1周、术后3个月、术后6个月、术后12个月及末次随访对手术节段的前缘椎间隙高度(DH)、后缘椎间隙高度(VH)、椎间孔高度(FH)及宽度(FW)、椎管前后矢状径(APD)、椎管横截面积(CSA)等参数进行影像学对比.结果32例患者术后1周至末次随访VAS评分和ODI指数均显著降低,SF-36显著增高(P<0.05);术后1周至末次随访DH、VH、FH、FW、APD及CSA均显著提高(P<0.05).结论Stand-alone OLIF植入3D打印解剖型融合器治疗DLSS具有创伤小、术后康复快、有效改善患者临床症状的优势.

A Sliding Mode Controller Based on Robust Model Reference Adaptive Proportional-integral Control for Stand-alone Three-phase Inverter

This paper proposes a sliding mode controller based on robust model reference adaptive proportional-integral(RMRA-PI)control for a stand-alone voltage source inverter(SA-VSI).The proposed controller has two control loops where the coefficients of PI controller are regulated by the adaptive sliding law.This method is used to regulate the output voltage of the inverter under different load conditions and uncertainty,and adapts the output to the reference model to reduce the total harmonic distortion(THD).In this paper,the stability of the proposed controller is proven by using Lyapunov's theory and Barbalet’s lemma.The proposed controller performs well in voltage regulation such as low THD under sudden load change and uncertainty.Also,the results of the proposed controller are compared with PI controller to show the effectiveness of the presented control system.

Control Strategy of Wind Turbine Based on Permanent Magnet Synchronous Generator and Energy Storage for Stand-Alone Systems

This paper investigates a variable speed wind turbine based on permanent magnet synchronous generator and a full-scale power converter in a stand-alone system.An energy storage system(ESS)including battery and fuel cell-electrolyzer combination is connected to the DC link of the full-scale power converter through the power electronics interface.Wind is the primary power source of the system,the battery and FC-electrolyzer combination is used as a backup and a long-term storage system to provide or absorb power in the stand-alone system,respectively.In this paper,a control strategy is proposed for the operation of this variable speed wind turbine in a stand-alone system,where the generator-side converter and the ESS operate together to meet the demand of the loads.This control strategy is competent for supporting the variation of the loads or wind speed and limiting the DC-link voltage of the full-scale power converter in a small range.A simulation model of a variable speed wind turbine in a stand-alone system is developed using the simulation tool of PSCAD/EMTDC.The dynamic performance of the stand-alone wind turbine system and the proposed control strategy is assessed and emphasized with the simulation results.

Micro-perforated structures as stand-alone sound absorbers

1 Introduction Early attempts to create a sound absorber which would function without the involvement of any fibrous or porous damping material go far back to K. A. Veliszhanina, S. N. Rschevkin and others as was outlined in Ref. [1]. 30 years ago, D. Y. MAA[2] was first in proposing a practicable design concept and calculation model for Micro-Perforated Absorber （MPA） prototypes which still forms the basis for various applications. During the past 12 years the Fraunhofer IBP developed a whole family of MPA products in close cooperation with 8 or more industrial partners operating in a variety of widely differing market segments. Meanwhile a large number of MPA modules and surface elements have evolved from MAA＇s creative pioneer work. More and more ambitious acousticians have, more recently, caught on this attractive idea of employing absorbers made of non-fibrous, non-abrasive materials with non-polluting, almost closed and optically attractive surfaces. MPA structures have played an important part in a long-standing and on-going effort at IBP to establish novel Alternative Fibreless Absorber （ALFA） tools for a better noise control and acoustic comfort.

某医院大型医用设备单机数据的CT和MRI使用绩效分析

目的打通现有医院业务系统,获取单机大型医用设备的绩效数据,对比分析医院7台电子计算机断层扫描(computed tomography,CT)设备、7台磁共振成像(magnetic resonance imaging,MRI)设备的2020年指标数据。方法开发数据接口,打通业务系统,利用关键字段,获取单机大型医用设备的结构化数据;基于指标数据,运用SPSS 26.0进行正态性检验、独立样本t检验分析,对7台CT、7台MRI的指标数据进行统计学分析。结果2020年CT品牌成本收益率排名前3位分别为UCT510、SOMATOM、Edge258,MRI品牌成本收益率排名前3位分别为3.0T HDX TWINSP、1.5T HDX UPG、Creator1.5T,CT、MRI的成本收益率差异具有统计学意义(P<0.05)。结论研究运用信息技术手段,打通业务系统,实现了大型医用设备单机数据的精确快捷获取,并尝试从成本收益角度出发进行分析,追踪其使用情况和投资回收情况,一定程度上反映单机大型医用设备的绩效产出,如CT设备成本收益率更高,国产CT设备表现亮眼,为大型医用设备的更新配置提供了数据支撑。

A Preliminary Assessment of Load Consumption and Solar Power Potential at Kota Belud,Sabah

This paper presents a detailed preliminary assessment of load consumption and solar power potential at the Eco-Tourism Centre of Liogu Ku Silou-Silou(EPLISSI),Kota Belud,Sabah.This initial investigation assessed the feasibility of an off-grid solar PV system at EPLISSI with a suitable solar panel system for project installation and commissioning purposes.Due to the absence of an electrical grid and power supply,no pre-existing electrical appliances could be found in EPLISSI.Hence,an excel-based software,the ESCoBox,was used to produce the load profiles.The input data for this software came from a list of required electrical appliances(LED lights,fans,and phone chargers)and the historical frequency of visitors to EPLISSI.Meanwhile,to assess the solar power potential at EPLISSI,an online simulator known as Global Solar Atlas version 2.3 or GSA 2.3 was used.As an input for the GSA 2.3,the initial solar panel system capacity was set for 0.5 kWp,and then an increment of 0.1 kWp was entered until specific criteria were met.The selection of the suitable size is made when the system can satisfy the daily total average load demand and a specific load fulfillment demand.As a result,it was found that the site requires a total average demand and a total peak demand of 4.60 and 11.87 kWh/day,respectively.From the GSA 2.3 generated report,an off-grid solar PV system with the capacity of 2.50 kWp solar PV can satisfy the daily total average load demand of this area,where the average PV energy output is within the range of between 7.74–9.80 kWh/day or an average of 8.72 kWh/day.In conclusion,this preliminary assessment indicates that installing an off-grid solar PV system in this area is possible.

Performance Analysis of PV Energy System in Western Region of Saudi Arabia

The potential implementation of photovoltaic (PV) energy system in western region of Saudi Arabia was analyzed in this paper. HOMER (hybrid optimization model for electric renewable) software was used to perform the technical feasibility of the system. The feasibility of PV energy system was analyzed based on solar irradiances. Stand-alone PV systems with battery storage element will be evaluated and discussed. The analysis will be addressed to the impact of PV and battery storage on electric energy production.

Reliable off-grid power supply utilizing green hydrogen

Green hydrogen produced from wind,solar or hydro power is a suitable electricity storage medium.Hydrogen is typically employed as mid-to long-term energy storage,whereas batteries cover short-term energy storage.Green hydrogen can be produced by any available electrolyser technology[alkaline electrolysis cell(AEC),polymer electrolyte membrane(PEM),anion exchange membrane(AEM),solid oxide electrolysis cell(SOEC)]if the electrolysis is fed by renewable electricity.If the electrolysis operates under elevated pressure,the simplest way to store the gaseous hydrogen is to feed it directly into an ordinary pressure vessel without any external compression.The most efficient way to generate electricity from hydrogen is by utilizing a fuel cell.PEM fuel cells seem to be the most favourable way to do so.To increase the capacity factor of fuel cells and electrolysers,both functionalities can be integrated into one device by using the same stack.Within this article,different reversible technologies as well as their advantages and readiness levels are presented,and their potential limitations are also discussed.

Reliable planning of isolated Building Integrated Photovoltaic systems

In this paper,two probabilistic reliability indices are presented to define the effect of clouds on different types of Building Integrated Photovoltaic(BIPV)systems.Existing indices do not match the main features of photovoltaic(PV)sources,such as variability,uncertainty and dependency on weather conditions.In addition,they are time indicators that describe the percentage of total failure time per year without any indication about power or energy mismatch.By using the available Geographic Information System solar-irradiation database,the proposed indices consider a similar pattern of expected daily solar irradiation as a model of PV systems.Two different models are studied for diverse building loads:an energy model for flexible loads and a constant-power model for critical loads.A comparative study is implemented for six different locations:Cairo,London,Berlin,Beijing,Madrid and Riyadh.Moreover,three types of BIPV systems are studied:fixed,double-axis-tracking and concentrated PV systems.The presented results show the effects of clouds,PV type and locations on the system performance.