Design and Development of a Hybrid DC-DC Converter for Solar-Battery-Based Standalone Milk Vending Machine

2022 ◽  
pp. 110-144
Author(s):  
Aneeja K. J. ◽  
Bekkam Krishna ◽  
V. Karthikeyan

Dairying has become a major secondary source of income for several rural families. The easily perishable nature of milk increases the spoilage of the product and reduces the dairy farms' productivity in rural areas due to power supply shortage issues. In order to overcome the inaccessibility of proper preservation strategies, this chapter proposed a hybrid DC-DC converter for a solar battery-powered milk vending machine. This proposed system can work continuously and provides an uninterrupted power supply to maintain the milk quality at an optimum level. Moreover, the proposed system utilized a novel converter to reduce the number of power conversion stages and compact the system. Besides, the proposed converter can achieve a higher gain ratio with fewer components. Furthermore, a proper algorithmic-based control scheme has been implemented to maintain effective power flow management. Finally, to verify the feasibility and performance of the system, detailed results are obtained at different dynamic conditions, and various case studies are presented in this chapter.

2012 ◽  
Vol 263-266 ◽  
pp. 584-587
Author(s):  
Xu Guang Hou ◽  
Jian Yan ◽  
Jin Jin ◽  
Shun Liang Mei

Aiming at a three-axis stabilized microsatellite, a novel attitude control method, called magnetorquer based vertical damping, is proposed to avoid the occurrence of the worst situation that the non-solar-battery-plane spins towards the sun. DSP based simulation results based on DSP show that the vertical damping method outperforms the simple damping method when no orbit information is available, simultaneously the whole attitude control scheme is simple and effective. The proposed solution guarantees a stable power supply from the electrical source even under the extreme situation, which improves the reliability of the whole microsatellite system.


Author(s):  
Afef Hfaiedh ◽  
Ahmed Chemori ◽  
Afef Abdelkrim

In this paper, the control problem of a class I of underactuated mechanical systems (UMSs) is addressed. The considered class includes nonlinear UMSs with two degrees of freedom and one control input. Firstly, we propose the design of a robust integral of the sign of the error (RISE) control law, adequate for this special class. Based on a change of coordinates, the dynamics is transformed into a strict-feedback (SF) form. A Lyapunov-based technique is then employed to prove the asymptotic stability of the resulting closed-loop system. Numerical simulation results show the robustness and performance of the original RISE toward parametric uncertainties and disturbance rejection. A comparative study with a conventional sliding mode control reveals a significant robustness improvement with the proposed original RISE controller. However, in real-time experiments, the amplification of the measurement noise is a major problem. It has an impact on the behaviour of the motor and reduces the performance of the system. To deal with this issue, we propose to estimate the velocity using the robust Levant differentiator instead of the numerical derivative. Real-time experiments were performed on the testbed of the inertia wheel inverted pendulum to demonstrate the relevance of the proposed observer-based RISE control scheme. The obtained real-time experimental results and the obtained evaluation indices show clearly a better performance of the proposed observer-based RISE approach compared to the sliding mode and the original RISE controllers.


Author(s):  
Yiqi Xu

This paper studies the attitude-tracking control problem of spacecraft considering on-orbit refuelling. A time-varying inertia model is developed for spacecraft on-orbit refuelling, which actually includes two processes: fuel in the transfer pipe and fuel in the tank. Based upon the inertia model, an adaptive attitude-tracking controller is derived to guarantee the stability of the resulted closed-loop system, as well as asymptotic convergence of the attitude-tracking errors, despite performing refuelling operations. Finally, numerical simulations illustrate the effectiveness and performance of the proposed control scheme.


Author(s):  
Jun Zhou ◽  
Jing Chang ◽  
Zongyi Guo

The paper describes the design of a fault-tolerant control scheme for an uncertain model of a hypersonic reentry vehicle subject to actuator faults. In order to improve superior transient performances for state tracking, the proposed method relies on a back-stepping sliding mode controller combined with an adaptive disturbance observer and a reference vector generator. This structure allows for a faster response and reduces the overshoots compared to linear conventional disturbance observers based sliding mode controller. Robust stability and performance guarantees of the overall closed-loop system are obtained using Lyapunov theory. Finally, numerical simulations results illustrate the effectiveness of the proposed technique.


PEDIATRICS ◽  
1998 ◽  
Vol 102 (Supplement_1) ◽  
pp. 245-247
Author(s):  
Robert A. Hoekelman

The increase in population of the United States is occurring at a much more rapid rate than the increase in medical and nursing personnel available to maintain health services at an optimum level. Unless the pattern of furnishing health care, particularly to lower socioeconomic groups in both urban and rural areas, is drastically improved, these groups will suffer from increasingly inadequate health supervision. This paper describes an educational and training program in pediatrics for professional nurses (the “pediatric nurse practitioner” program), which prepares them to assume an expanded role in providing increased health care for children in areas where there are limited facilities for such care.


2021 ◽  
Vol 13 (4) ◽  
pp. 282-289
Author(s):  
I. V. Naumov ◽  
D. N. Karamov ◽  
A. N. Tretyakov ◽  
M. A. Yakupova ◽  
E. S. Fedorinovа

The purpose of this study is to study the effect of loading power transformers (PT) in their continuous use on their energy efficiency on a real-life example of existing rural electric networks. It is noted that the vast majority of PT in rural areas have a very low load factor, which leads to an increase in specific losses of electric energy when this is transmitted to various consumers. It is planned to optimize the existing synchronized power supply systems in rural areas by creating new power supply projects in such a way as to integrate existing power sources and ensure the most efficient loading of power transformers for the subsequent transfer of these systems to isolated ones that receive power from distributed generation facilities. As an example, we use data from an electric grid company on loading power transformers in one of the districts of the Irkutsk region. Issues related to the determination of electric energy losses in rural PT at different numerical values of their load factors are considered. A computing device was developed using modern programming tools in the MATLAB system, which has been used to calculate and plot the dependence of power losses in transformers of various capacities on the actual and recommended load factors, as well as the dependence of specific losses during the transit of 1 kVA of power through a power transformer at the actual, recommended and optimal load factors. The analysis of specific losses of electric energy at the actual, recommended and optimal load factors of PT is made. Based on the analysis, the intervals of optimal load factors for different rated power of PT of rural distribution electric networks are proposed. It is noted that to increase the energy efficiency of PT, it is necessary to reduce idling losses by increasing the load of these transformers, which can be achieved by reducing the number of transformers while changing the configuration of 0.38 kV distribution networks.


2022 ◽  
Vol 14 (1) ◽  
pp. 168781402110704
Author(s):  
Zhuang Dong ◽  
Jian Yang ◽  
Chendi Zhu ◽  
Dimitrios Chronopoulos ◽  
Tianyun Li

This study investigates the vibration power flow behavior and performance of inerter-based vibration isolators mounted on finite and infinite flexible beam structures. Two configurations of vibration isolators with spring, damper, and inerter as well as different rigidities of finite and infinite foundation structures are considered. Both the time-averaged power flow transmission and the force transmissibility are studied and used as indices to evaluate the isolation performance. Comparisons are made between the two proposed configurations of inerter-based isolators and the conventional spring-damper isolators to show potential performance benefits of including inerter for effective vibration isolation. It is shown that by configuring the inerter, spring, and damper in parallel in the isolator, anti-peaks are introduced in the time-averaged transmitted power and force transmissibility at specific frequencies such that the vibration transmission to the foundation can be greatly suppressed. When the inerter is connected in series with a spring-damper unit and then in-parallel with a spring, considerable improvement in vibration isolation can be achieved near the original peak frequency while maintaining good high-frequency isolation performance. The study provides better understanding of the effects of adding inerters to vibration isolators mounted on a flexible foundation, and benefits enhanced designs of inerter-based vibration suppression systems.


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