Circuit Synthesis of Electrochemical Supercapacitor Models

This paper is concerned with the synthesis of RC electrical circuits from physics-based supercapacitor models describing conservation and diffusion relationships. The proposed synthesis procedure uses model discretisation, linearisation, balanced model order reduction and passive network synthesis to form the circuits. Circuits with different topologies are synthesized from several physical models. This work will give greater understanding to the physical interpretation of electrical circuits and will enable the development of more generalised circuits, since the synthesized impedance functions are generated by considering the physics, not from experimental fitting which may ignore certain dynamics

Integration between Super-capacitors and ZEBRA Batteries as High Performance Hybrid Storage System for Electric Vehicles

Abstract This paper presents experimental evaluations on the performance of a hybrid energy storage system to supply urban electric vehicles. The paper starts with a description of nickel chloride batteries and electric double layer capacitors with details on their related advantages. Then, a laboratory test bench is presented to experimentally evaluate the performance of the realized hybrid storage system, obtained through a controlled DC/DC bidirectional power converter, supplying an electric power-train in real operative conditions on standard driving cycles. The main results of this study shows the importance of using that power converter to take advantage of the power characteristics of the super-capacitor and to easily implement on board energy management strategies to increase the whole vehicle performance

Dynamic Behavior and Management Strategy of Hybrid Wind/Fuel Cell System

Abstract: hybrid generation system is considered as a solution for the uncontrolled energy production from such dispersed sources as wind generation. In this paper, modeling and control of wind/FC system is proposed. Dynamics models for the main system components, namely, wind energy conversion system (WECS), fuel cell, electrolyses, power electronic interfacing circuits, hydrogen storage tank and ultra-capacitor are developed. Also, a variable speed wind generation maximum power point tracking (MPPT) based on Adaptative Neuro-Fuzzy Inference system (ANFIS) is presented. Based on the dynamic component model, a simulation model for the proposed hybrid energy system has been developed using Matlab/Simulink and the power flows management strategy are proposed. The result shows that this system can tolerate the rapid changes in wind speed and/or power demand. This results shows also that, the overall power management strategy is effective and the power flows among the different energy sources and the load demand is balanced successfully

Comparison of Ultracapacitor Electric Circuit Models

Due to ultracapacitors\u27 unique features, the electrical performances and reliabilities of electrical systems using ultracapacitors can be improved. It is important to have a good ultracapacitor model for simulation and assisting electrical system design and product development. Several kinds of ultracapacitor models are given these years. Especially, electric circuit models are the interested ones for electrical engineers. This paper concentrates on the electric circuit model. Three basic RC network models are discussed in detail, including modeling ideas, circuit formation, linear/nonlinear factors and evaluations of each model. The general electric circuit model considering the inductance and leakage current effects are given. Model selection depends on the specific applications of ultracapacitor. Based on the analysis in this paper, recommendations of ultracapacitor selection strategies are provided

Various analytical models for supercapacitors: a mathematical study

Supercapacitors (SCs) are used extensively in high-power potential energy applications like renewable energy systems, electric vehicles, power electronics, and many other industrial applications. This is due to SCs containing high-power density and the ability to respond spontaneously with fast charging and discharging demands. Advancements in material and fabrication techniques have induced a scope for research to improve the application of SCs. Many researchers have studied various SC properties and their effects on energy storage and management performance. In this paper, various fractional calculus-based SC models are summarized, with emphasis on analytical studies from derived classical SC models. Study prevails such parameterized resistor- capacitor networks have simplified the representation of electrical behavior of SCs to deal with the complicated internal structure. Fractional calculus has been used to develop SC models with the aim of understanding their complicated structure. Finally, the properties of different SC models utilized by various researchers to understand the behavior of SCs are listed using an equivalent circuit

Underground Wireless Channel Bandwidth and Capacity

The UG channel bandwidth and capacity are vital parameters in wireless underground communication system design. In this chapter, a comprehensive analysis of the wireless underground channel capacity is presented. The impact of soil on return loss, bandwidth, and path loss is discussed. The results of underground multi-carrier modulation capacity are also outlined. Moreover, the single user capacity and multi-carrier capacity are also introduced with an in-depth treatment of soil texture, soil moisture, and distance effects on channel capacity. Finally, the chapter is concluded with a discussion of challenges and open research issues