Stability analysis of a non-inverting synchronous buck-boost power converter for a solar power management system

[[abstract]]This paper presents the stability analysis of a non-inverting synchronous buck-boost DC/DC power converter for a solar power management system. The system can operate in buck, buck-boost or boost mode according to the condition of the supply voltage. The variation of the supply voltage arises from the rapid changes of the atmospheric condition or sunlight incident angle. The stability margins of each individual operation mode for different system parameters (inductor, capacitor) and load conditions are analyzed first. The results show that the stability margins depend on the inductor and capacitor selected for the converter and depend on the load conditions also. The systems are then modeled as Markov jump systems for evaluating the mean square stability of the systems. With careful selection of the system parameters, adequate stability margins of each individual operation mode and mean square stability of the jump system can be assured. The buck-boost converter is incorporated into the solar power battery management system to maximize the utility of the available solar power drawn from the solar panel.[[conferencetype]]國際[[conferencedate]]20081124~20081127[[iscallforpapers]]Y[[conferencelocation]]Singapor

A Study on the Fuzzy-Logic-Based Solar Power MPPT Algorithms Using Different Fuzzy Input Variables

[[abstract]]Maximum power point tracking (MPPT) is one of the key functions of the solar power management system in solar energy deployment. This paper investigates the design of fuzzy-logic-based solar power MPPT algorithms using different fuzzy input variables. Six fuzzy MPPT algorithms, based on different input variables, were considered in this study, namely (i) slope (of solar power-versus-solar voltage) and changes of the slope; (ii) slope and variation of the power; (iii) variation of power and variation of voltage; (iv) variation of power and variation of current; (v) sum of conductance and increment of the conductance; and (vi) sum of angles of arctangent of the conductance and arctangent of increment of the conductance. Algorithms (i)–(iv) have two input variables each while algorithms (v) and (vi) use a single input variable. The fuzzy logic MPPT function is deployed using a buck-boost power converter. This paper presents the details of the determinations, considerations of the fuzzy rules, as well as advantages and disadvantages of each MPPT algorithm based upon photovoltaic (PV) cell properties. The range of the input variable of Algorithm (vi) is finite and the maximum power point condition is well defined in steady condition and, therefore, it can be used for multipurpose controller design. Computer simulations are conducted to verify the design.[[notice]]補正完畢[[journaltype]]國外[[incitationindex]]EI[[ispeerreviewed]]Y[[booktype]]電子版[[countrycodes]]CH

Circuit Simulation for Solar Power Maximum Power Point Tracking with Different Buck-Boost Converter Topologies

[[sponsorship]]MDPI[[conferencetype]]國際[[booktype]]電子版[[iscallforpapers]]Y[[conferencelocation]]http://sciforum.net/conference/ece-

Fuzzy Controller for a Voltage-Regulated Solar-Powered MPPT System for Hybrid Power System Applications

[[abstract]]This paper presents the design of a fuzzy-logic-based voltage-regulated solar power maximum power point tracking (MPPT) system for applications involving hybrid power systems. The system contains a solar power system and battery as the primary and secondary power sources, respectively. The solar system alone supplies power to the electric motor and maintains the output voltage at a predetermined level when it has sufficient power. When the solar power is insufficient, the solar system is operated at its maximum power point (MPP) and the battery is engaged to compensate for the insufficiency. First, a variant of the incremental conductance MPP condition was established. Under the MPP condition, the voltage-regulated MPPT system was formulated as a feedback control system, where the MPP condition and voltage regulation requirements were used as the system inputs. Next, a fuzzy controller was developed to perform the voltage-regulated MPPT function for the hybrid power system. A simulation model based on Matrix laboratory (MATLAB)/SIMULINK (a block diagram environment for multi-domain simulation and model-based design) and a piecewise linear electric circuit simulation (PLECS) tool for controlling the dc motor velocity was developed to verify the voltage-regulated solar power MPPT system.[[notice]]補正完畢[[journaltype]]國外[[incitationindex]]SCI[[ispeerreviewed]]Y[[booktype]]電子版[[countrycodes]]CH

Attitude Determination Using a MEMS-Based Flight Information Measurement Unit

Obtaining precise attitude information is essential for aircraft navigation and control. This paper presents the results of the attitude determination using an in-house designed low-cost MEMS-based flight information measurement unit. This study proposes a quaternion-based extended Kalman filter to integrate the traditional quaternion and gravitational force decomposition methods for attitude determination algorithm. The proposed extended Kalman filter utilizes the evolution of the four elements in the quaternion method for attitude determination as the dynamic model, with the four elements as the states of the filter. The attitude angles obtained from the gravity computations and from the electronic magnetic sensors are regarded as the measurement of the filter. The immeasurable gravity accelerations are deduced from the outputs of the three axes accelerometers, the relative accelerations, and the accelerations due to body rotation. The constraint of the four elements of the quaternion method is treated as a perfect measurement and is integrated into the filter computation. Approximations of the time-varying noise variances of the measured signals are discussed and presented with details through Taylor series expansions. The algorithm is intuitive, easy to implement, and reliable for long-term high dynamic maneuvers. Moreover, a set of flight test data is utilized to demonstrate the success and practicality of the proposed algorithm and the filter design

Characterization of membranous and cytoplasmic EGFR expression in human normal renal cortex and renal cell carcinoma

Metastatic renal cell carcinoma (RCC) is highly resistant to conventional systemic treatments, including chemotherapy, radiotherapy and hormonal therapies. Previous studies have shown over-expression of EGFR is associated with high grade tumors and a worse prognosis. Recent studies suggest anticancer therapies targeting the EGFR pathway have shown promising results in clinical trials of RCC patients. Therefore, characterization of the level and localization of EGFR expression in RCC is important for target-dependent therapy. In this study, we investigated the clinical significance of cellular localization of EGFR in human normal renal cortex and RCC. RCC and adjacent normal kidney tissues of 63 patients were obtained for characterization of EGFR expression. EGFR protein expression was assessed by immunohistochemistry on a scale from 0 to 300 (percentage of positive cells × staining intensity) and Western blotting. EGFR membranous staining was significantly stronger in RCC tumors than in normal tissues (P < 0.001). In contrast, EGFR cytoplasmic staining was significantly higher in normal than in tumor tissues (P < 0.001). The levels of membranous or cytoplasmic EGFR expression in RCC tissues were not correlated with sex, tumor grade, TNM stage or overall survival (P > 0.05). These results showed abundant expression of membranous EGFR in RCC, and abundant expression of cytoplasmic EGFR in normal tissues. EGFR expression in RCC was mostly located in the cell membrane, whereas the EGFR expression in normal renal tissues was chiefly seen in cytoplasm. Our results suggest different locations of EGFR expression may be associated with human renal tumorigenesis

An Autopilot Design for the Longitudinal Dynamics of a Low-Speed Experimental UAV Using Two-Time-Scale Cascade Decomposition

[[abstract]]This paper discusses a cascade decomposition method for two-time-scale systems. We decompose the two-time-scale system into slow and fast subsystems connected in cascade form. With the proposed decomposition method, fast and slow low-order subsystems can be easily extracted from the two-time-scale full order system. The longitudinal dynamics of a low speed experimental UAV is used to illustrate the proposed method. An altitude hold control structure is constructed to allow sequential designs based on the lower order fast and slow models using classical designs. The structure contains two control loops. The inner loop is for altitude rate regulation. In this control loop, we use combination of altitude rate and pitch angle as the feedback signals. A fast controller is designed to satisfy the high frequency requirements using the fast model. Following the results of the fast design, three control gains are designed to satisfy the low frequency requirements using the slow models. The design results of the inner loop are used to design the outer altitude control loop. Frequency domain analysis and computer simulations confirm the success of the proposed decomposition method and verify the effectiveness of the control law using the proposed control structure.[[incitationindex]]SCI[[incitationindex]]EI[[booktype]]紙

Design of a MEMS-Based Flight Information Measurement Unit for UAV Application

[[abstract]]Obtaining precise attitude information is essential for aircraft navigation and control. This paper presents the results of the attitude determination using an in-house designed low-cost MEMS-based flight information measurement unit. This study proposes a quaternion-based extended Kalman filter to integrate the traditional quaternion and gravitational force decomposition methods for attitude determination algorithm. The proposed extended Kalman filter utilizes the evolution of the four elements in the quaternion method for attitude determination as the dynamic model, with the four elements as the states of the filter. The attitude angles obtained from the gravity computations and from the electronic magnetic sensors are regarded as the measurement of the filter. The immeasurable gravity accelerations are deduced from the outputs of the three axes accelerometers, the relative accelerations, and the accelerations due to body rotation. The constraint of the four elements of the quaternion method is treated as a perfect measurement and is integrated into the filter computation. Approximations of the time-varying noise variances of the measured signals are discussed and presented with details through Taylor series expansions. The algorithm is intuitive, easy to implement, and reliable for long-term high dynamic maneuvers. Moreover, a set of flight test data is utilized to demonstrate the success and practicality of the proposed algorithm and the filter design.[[notice]]補正完畢[[journaltype]]國外[[booktype]]紙本[[countrycodes]]GB

Design of a Solar Power Management System for an Experimental UAV

[[abstract]]本論文探討無人飛行載具太陽能電力電源管理系統之設計，目的為提供機載電腦系統之電力需求。此電源管理系統主要包含太陽能電池與最大功率追蹤、電池管理與電力轉換三級。太陽能電池與最大功率追蹤，主要目的是用來收集太陽能，並且追蹤太陽能板隨著溫度與照度而改變的最大功率點，以得到最佳效率。電池管理監視及控制鋰高分子聚合物電池之充∕放電流程管理。電力轉換則將供電電壓轉換為+5V與±12V，以提供系統及機載電腦之所需。[[abstract]]The design of a solar power management system (SPMS) for an experimental unmanned aerial vehicle (UAV) is summarized. The system will provide power required for the on-board electronic systems on the UAV. The power management system mainly consists of the maximum power point tracking (MPPT), the battery management, and the power conversion stages. The MPPT stage attempts to obtain the maximum power available from the solar cell panels. The battery management stage monitors and controls the charge and discharge processes of the Li-ion polymer battery modules. The last stage is for power conversion that consists of dc/dc synchronous buck converters to generate +5 V and +12 V powers for the on-board computers and other electronic circuitries.[[incitationindex]]SCI[[incitationindex]]EI[[booktype]]紙本[[booktype]]電子