An Optimal Collocation Strategy for the Key Components of Compact Photovoltaic Power Generation Systems

Abstract

The objective of this study was to develop an optimal evaluation system for collocating photovoltaic (PV) modules and power conditioners by using the extension engineering method. The matter-element model and correlation functions of the extension theory were adopted as the basis of the proposed extension evaluation system, which was then used to develop a multilevel evaluation model for PV modules and PV power conditioners. The extension evaluation system was used to evaluate and test numerous PV modules and power conditioner products that are commonly employed and commercially available in Taiwan. First, a PV module matter-element model was established based on price, power temperature, size, and weight, and a PV power conditioner matter-element model was established based on input voltage range, maximum power point tracking (MPPT) voltage range, number of MPPT units, minimum operating voltage, and maximum input current. Second, the weighting values of the various characteristics in the extension method were determined according to numerous consideration factors of the PV modules and power conditioners. Finally, the values of the degree of correlation between numerous user preferences and the various PV modules and power conditioner brands were calculated using correlation functions to determine the key components of PV power generation systems (PV-PGSs) that corresponded to user preferences. The test results confirmed that the proposed extension evaluation system can determine the optimal collocation for the key components of the PV-PGSs under different user preference settings.

Fault Diagnosis and Tolerant Control of Three-Level Neutral-Point Clamped Inverters in Motor Drives

“…It features (1) the idea of changing contradictory problems into compatible ones and (2) creates matter-element theory to provide new ways of solving contradictory problems with matter-element transformation based on the extensibility of matter elements. Extension theory also (3) creates extension set theory, giving quantitative descriptions of quantitative change to qualitative changes in the extension domain and critical elements, thus realizing quantitative extension mathematics in the extension theory based on extension sets [26][27][28][29][30].…”

“…In contrast, extension theory-based methods do not require large data quantities for training as they feature models of matter-elements, the coupling of qualification and quantification, and non-closure [26][27][28][29][30], while the distances and rank values makes it possible to establish correlation functions for fault types, and the correlation degrees can be used to identify fault types, thus reducing the learning process and making determination easier, faster, and more accurate. Hence, this study proposes an intelligent fault-tolerant control system based on extension theory for locating faults in a three-level NPC-type inverter.…”

Design and Control of Brushless DC Motor Drives for Refrigerated Cabinets

“…To determine the command value of the rotational speed, the two characteristic values of the rotational speed difference and the rate of change in rotational speed difference are classified into several zones according to their magnitude ranges. Then, the classical domain and the neighborhood domain of the extension theory [8] are used to build an extension model and the weights are defined according to the importance of the two characteristics [9,10]. The correlation degree of each rotational speed difference and each change in rate of rotational speed difference to the zone categories is computed.…”

Simulation and Analysis of Perturbation and Observation-Based Self-Adaptable Step Size Maximum Power Point Tracking Strategy with Low Power Loss for Photovoltaics

“…For example, increasing the temperature results in a slight increase in the short-circuit current and a significant decrease in the open-circuit voltage, which reduces the maximum output power. maximum output point called the maximum power point (MPP) [7,[11][12][13][14][15][16][17][18][19][20][21][22]. For the PV system operated with higher efficiency, an MPP tracking (MPPT) controller is indispensable; the tracking methodologies are introduced in detail in the MPPT section of this report.…”

“…For the PV system operated with higher efficiency, an MPP tracking (MPPT) controller is indispensable; the tracking methodologies are introduced in detail in the MPPT section of this report. For a PV system with an MPPT controller, the structure can be depicted as consisting of a PV panel, a power converter [7,8,16,[19][20][21][22][23][24][25][26][27][28][29][30][31][32][33], an MPPT controller, and a load (including but not limited to motors, batteries, heaters, energy-storage systems, and other electric appliances). The structure of the PV system is shown in Figure 1.…”