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排序方式: 共有156条查询结果,搜索用时 31 毫秒
1.
本文提出了并行求解问题时所应征用MPP系统中临界处理器数的选择方法,该方法根据问题图中每一结点的时间特征进行选择,可操作性好,易于实现,特别适用于基于互连网络的MPP系统和分布式系统。 相似文献
2.
自适应路由器是MPP研究领域中的一个重要研究课题。本文实现了一个路由器模型系统,介绍了几种自适应无死锁路由算法,并利用模型系统对路由算法进行了测试。 相似文献
3.
论述了MPP系统中节点机的通信结构,以及在主控机与节点机之间实现的Message Passing通信及其通信协议。 相似文献
4.
Influenced by partial shade, PV module aging or fault, there are multiple peaks on PV array's output power–voltage (P–V) characteristic curve. Conventional maximum power point tracking (MPPT) methods are effective for single peak P–V characteristic under uniform solar irradiation, but they may fail in global MPP tracking under multi-peak P–V characteristics. Existing methods in literature for this problem are still unsatisfactory in terms of effectiveness, complexity and speed. In this paper, we first analyze the mathematical model of PV array that is suitable for simulation of complex partial shade situation. Then an adaptive MPPT (AMPPT) method is proposed, which can find real global maximum power point (MPP) for different partial shade conditions. When output characteristic of PV array varies, AMPPT will adjust tracking strategies to search for global peak area (GPA). Then it is easy for conventional MPPT to track the global MPP in GPA. Simulation and experimental results verify that the proposed AMPPT method is able to find real global MPP accurately, quickly and smoothly for complex multi-peak P–V characteristics. Comparison analysis results demonstrate that AMPPT is more effective for most shade types. 相似文献
5.
Toward multiple maximum power point estimation of photovoltaic systems based on semiconductor theory
Jen‐Cheng Wang Yu‐Li Su Kun‐Chang Kuo Jyh‐Cherng Shieh Joe‐Air Jiang 《Progress in Photovoltaics: Research and Applications》2015,23(7):847-861
Environmental conditions, such as temperature, non‐uniform irradiation, and solar shading, deeply affect the characteristics of photovoltaic (PV) modules in PV‐assisted generation systems. Several local maximum power points (MPPs) are found in the power–voltage curve of PV systems constructed by series/parallel‐connected PV modules under partially shaded conditions. The characteristics of PV systems change unpredictably when multiple MPPs occur, so the actual MPP tracking (MPPT) becomes a difficult task. Conventional MPPT methods for the PV systems under partially shaded conditions cannot quickly find the actual MPP such that the optimal utilization of PV systems cannot be achieved. Based on the p–n junction semiconductor theory, we develop a multipoint direct‐estimation (MPDE) method to directly estimate the multiple MPPs of the PV systems under partially shaded conditions and to cope with the mentioned difficulties. Using the proposed MPDE method, the multiple MPPs of the PV systems under partially shaded conditions can be directly determined from their irradiated current–voltage and power–voltage characteristic curves. The performances of the proposed MPDE method are evaluated by examining the characteristics of multiple MPPs of PV systems with respect to different shading strengths and numbers of the shaded PV modules and also tested using the field data. The experimental results demonstrate that the proposed MPDE method can simply and accurately estimate the multiple MPPs of the PV systems under partially shaded conditions. The optimization of MPP control models and the MPPT for PV systems could be achieved promisingly by applying the proposed method. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
6.
Juan Manuel Enrique Jos Manuel Andújar Eladio Durn Miguel Angel Martínez 《Progress in Photovoltaics: Research and Applications》2015,23(12):1940-1955
This paper presents a new, simple, accurate, and inexpensive practical methodology and experimental solution for the modeling of conventional (domestic and commercial facilities) photovoltaic generators (PVG), so that they can work at their maximum power point (MPP). The PVG may be a panel, an array of panels, or a photovoltaic field. As a starting restriction (actual) it has to be assumed that it is not possible to isolate the PVG variables dependence (mainly current, voltage, and hence power) with solar radiation and temperature, because they are highly correlated. This methodology proposes the modeling facility on its MPP by its MPP resistance (RMPP = VMPP/IMPP), being VMPP and IMPP the voltage and current of the PVG, respectively, at its MPP. The analysis shows, by simulation first and then experimentally, that RMPP does not present significant temperature dependencies, at least in the usual range. This important result allows us to model the PVG only in terms of solar radiation. From a set of experimental data, different models to estimate RMPP are proposed. The obtained results are very accurate. These models allow an immediate practical application that it is also developed in the paper: MPP tracker (MPPT) design by the calculation of the DC/DC converter duty cycle which places the PVG at its MPP directly and continuously. This new methodology and experimental system has been registered in the Spanish Patent and Trademark Office with the number P201530352. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
7.
Traditional reliability-based design optimization (RBDO) requires a double-loop iteration process. The inner optimization loop is to find the reliability and the outer is the regular optimization loop to optimize the RBDO problem with reliability objectives or constraints. It is known that the computation can be prohibitive when the associated function evaluation is expensive. This situation is even worse when a large number of reliability constraints are present. As a result, many approximate RBDO methods, which convert the double loop to a single loop, have been developed. In this research, an engineering problem with a large number of constraints (144) is designed to test RBDO methods based on the first-order reliability method (FORM), including single- and double-loop methods. In addition to the number of constraints, this problem possesses many local minimums. Some original authors of the RBDO methods are also asked to solve the same problem. The results and the efficiencies for different methods are published and discussed. 相似文献
8.
PVM与网络并行计算 总被引:2,自引:0,他引:2
松散耦合的异构型并行处理系统近年来又有较大的发展,这种只能支持粗粒度并行的计算环境,由于通讯硬件的更新和软件环境的开发,其性能已经能够与某些MPP机相媲美,因而形成并行处理领域一个强有力的分支-网络计算,本文围绕PVM,讨论网络计算的软件环境,概述其特色和发展,并与其它基于消息传递的软件环境相比较,最后预测PVM未来可能面临的问题和发展方向。 相似文献
9.
10.
LS MPP编程语言研究 总被引:1,自引:1,他引:0
为了方便开发运行于LS MPP系统的应用程序,文章研究了LS MPP编程语言.首先,分析了现有LS MPP计算机的体系结构,以及作为其未来发展方向的图像处理器的概念模型.然后,介绍了对应该概念模型的中间语言和中间表示.最后,详细分析了该概念模型对应的高级语言扩展部分.分析表明,高级语言对概念模型描述的并行计算机性能的提高非常有益,使程序员的编程更加方便,并且降低了编译器的复杂性. 相似文献