Input-output linearization of DC-DC converter with discrete sliding mode fuzzy control strategy

The major thrust of the paper is on designing a fuzzy logic approach has been combined with a well-known robust technique discrete sliding mode control (DSMC) to develop a new strategy for discrete sliding mode fuzzy control (DSMFC) in direct current (DC-DC) converter. Proposed scheme requires human expertise in the design of the rule base and is inherently stable. It also overcomes the limitation of DSMC, which requires bounds of uncertainty to be known for development of a DSMC control law. The scheme is also applicable to higher order systems unlike model following fuzzy control, where formation of rule base becomes difficult with rise in number of error and error derivative inputs. In this paper the linearization of input-output performance is carried out by the DSMFC algorithm for boost converter. The DSMFC strategy minimizes the chattering problem faced by the DSMC. The simulated performance of a discrete sliding mode fuzzy controller is studied and the results are investigated

Perbaikan Unjuk Kerja Boost Converter untuk Panel Surya Menggunakan Sliding Mode Controller

Salah satu cara memanfaatkan sumber energi terbarukan adalah dengan menggunakan sel surya yang mengubah energi cahaya matahari menjadi energi listrik. Sebuah converter umumnya diperlukan untuk menyesuaikan tegangan keluaran sel surya dengan kebutuhan aplikasinya. Salah satu jenis konverter yang dapat digunakan yaitu konverter boost, yang dapat menghasilkan tingkat tegangan pada keluarannya lebih tinggi dari masukannya. Keluaran dari sel surya yang bervariasi tergantung pada perubahan iradiasi cahaya matahari menjadi masukan bagi konverter. Pada penelitian ini metode pengendalian sliding mode control (SMC) dimanfaatkan untuk mengurangi osilasi pada tegangan keluaran konverter boost. Penelitian dilakukan dengan cara simulasi menggunakan MATLAB/Simulink pada kondisi sistem pengendalian loop terbuka dan loop tertutup. Nilai settling time dan selisih tegangan keluaran saat sebelum terjadi gangguan dan setelah terjadi gangguan berupa tegangan masukan yang bervariasi dan beban yang bervariasi dianalisis

Técnicas de control para la mejora de la estabilidad en redes eléctricas DC con convertidores operando a potencia constante

Some electrical devices in direct current (DC) networks, under certain operating characteristics, behave as constant power loads (CPLs). This behavior is defined by presenting negative incremental resistance, compromising the stability of the supply networks. The current evolution of electrical networks favors the proliferation and increase of this unstable behavior. In this research, a stability analysis method is presented that allows verifying a sufficient condition for the local stability of linear and time invariant DC circuits with CPLs, for all possible equilibria of the system that arise when varying the power consumed by the CPLs. Furthermore, this method is expressed by linear matrix inequalities that can be verified by convex programming. It is also proposed to connect a stabilizing device in parallel, given an accessible connection port in the electrical network, which through an adequate control law, allows ensuring the local stability of linear and time-invariant DC networks with CPLs. The techniques used to obtain the control law have been H8 control, self-tuning control, and non-linear control. In addition, it is shown that the proposed solution meets the objectives established a priori, based on the worst-case regarding the system stability, through numerical results in simulation and experimental results obtained in a prototype plant designed and built within the framework of this research.Algunos dispositivos eléctricos de las redes de corriente continua (DC), bajo determinadas características de funcionamiento, se comportan como cargas de potencia constante (CPLs). Este comportamiento, se define por presentar resistencia incremental negativa, comprometiendo la estabilidad de las redes de suministro. La evolución actual de las redes eléctricas, favorece la proliferación y aumento de este comportamiento inestable. En esta investigación, se presenta un método de análisis de estabilidad que permite comprobar una condición suficiente para la estabilidad local de circuitos de DC lineales e invariantes en el tiempo con CPLs, para todos los posibles equilibrios del sistema que surgen al variar la potencia consumida por las CPLs. Además, este método se expresa en forma de desigualdades matriciales lineales que pueden ser verificadas mediante programación convexa. También se propone la conexión de un dispositivo estabilizador en paralelo, dado un puerto de conexión accesible en la red eléctrica, que mediante una ley de control adecuada, permita asegurar la estabilidad local de redes de DC lineales e invariantes en el tiempo con CPLs. Las técnicas utilizadas en la obtención de la ley de control han sido control H8, control autosintonizado y control no lineal. Además, se demuestra que la solución propuesta cumple los objetivos establecidos a priori, basados en el peor caso respecto a la estabilidad del sistema, mediante resultados numéricos en simulación y resultados experimentales obtenidos en una planta prototipo diseñada y construida en el marco de este trabajo de investigación.Postprint (published version

Challenges of Inductive Electric Vehicle Charging Systems in both Stationary and Dynamic Modes

Inductive power transfer as an emerging technology has become applicable in wide power ranges including Electric Vehicle, Electric Aircraft, wheelchair, cellphone, scooter and so on. Among them, inductive Electric Vehicle (EV) charging has gained great interest in the last decade due to many merits namely contactless technology, more convenience, full automotive charging process. However, inductive EV charging systems could bring about so many issues and concerns which are addressed in this dissertation. One of the critical challenges addressed in this dissertation is a virtual inertia based IPT controller to prevent the undesirable dynamics imposed by the EVs increasing number in the grid. Another adverse issue solved in this dissertation is detecting any metal object intrusions into the charging zone to the Inductive Power Transfer (IPT) systems before leading to heat generation on the metal or risk of fire. Moreover, in this dissertation, a new self-controlled multi-power level IPT controller is developed that enables EV charging level regulation in a wide range of power; suitable for different applications from golf-cart charging system (light duty EV) to truck (heavy duty EV). The proposed controller has many merits including easy to be implemented, cons-effective, and the least complexities compared to conventional PWM methods. Additionally, in this dissertation, the online estimation of IPT parameters using primary measurement including coupling factor, battery current and battery voltage is introduced; the developed method can find immediate applications for the development of adaptive controllers for static and dynamic inductive charging systems. Finally, the last objective of this research is physics-based design optimization techniques for the magnetic structures of inductive EV charging systems for dynamic application (getting charged while in motion). New configuration of IPT transmitting couplers with objective of high-power density, low power loss, low cost and less electromagnetic emission are designed and developed in the lab

Modeling and Control of a 7-Level Switched Capacitor Rectifier for Wireless Power Transfer Systems

Wireless power continues to increase in popularity for consumer device charging. Rectifier characteristics like efficiency, compactness, impedance tunability, and harmonic content make the multi-level switched capacitor rectifier (MSC) an exceptional candidate for modern WPT systems. The MSC shares the voltage conversion characteristics of a post-rectification buck-boost topology, reduces waveform distortion via its multi-level modulation scheme, demonstrates tank tunability via the phase control inherent to actively switched rectifiers, and accomplishes all this without a bulky filter inductor. In this work, the MSC WPT system operation is explained, and a loss model is constructed. A prototype system is used to validate the models, showing exceptional agreement with the predicted efficiencies. The modeled MSC efficiencies are between 96.1% and 98.0% over the experimental power range up to 20.0 W. Two significant control loops are required for the MSC to be implemented in a real system. First, the output power is regulated using the modulation of the rectifier\u27s input voltage. Second, the switching frequency of the rectifier must exactly match the WPT carrier frequency set by the inverter on the primary side. Here, a small signal discrete time model is used to construct four transfer functions relating to the output voltage. Then, four novel time-to-time transfer functions are built on top of the discrete time model to inform the frequency synchronization feedback loop. Both loops are tested and validated in isolation. Finally, the dual-loop control problem is defined, closed form equations that include loop interactions are derived, and stable wide-range dual-loop operation is demonstrated experimentally