• Title/Summary/Keyword: Regenerative braking

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Design and Implementation of Modified Current Source Based Hybrid DC - DC Converters for Electric Vehicle Applications

  • Selvaganapathi, S.;Senthilkumar, A.
    • Transactions on Electrical and Electronic Materials
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    • v.17 no.2
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    • pp.57-68
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    • 2016
  • In this study, we present the modern hybrid system based power generation for electric vehicle applications. We describe the hybrid structure of modified current source based DC - DC converters used to extract the maximum power from Photovoltaic (PV) and Fuel Cell system. Due to reduced dc-link capacitor requirement and higher reliability, the current source inverters (CSI) better compared to the voltage source based inverter. The novel control strategy includes Distributed Maximum Power Point Tracking (DMPPT) for photovoltaic (PV) and fuel cell power generation system. The proposed DC - DC converters have been analyzed in both buck and boost mode of operation under duty cycle 0.5>d, 0.5<d<1 and 0.5<d for capable electric vehicle applications. The proposed topology benefits include one common DC-AC inverter that interposes the generated power to supply the charge for the sharing of load in a system of hybrid supply with photovoltaic panels and fuel cell PEM. An improved control of Direct Torque and Flux Control (DTFC) based induction motor fed by current source converters for electric vehicle.In order to achieve better performance in terms of speed, power and miles per gallon for the expert, to accepting high regenerative braking current as well as persistent high dynamics driving performance is required. A simulation model for the hybrid power generation system based electric vehicle has been developed by using MATLAB/Simulink. The Direct Torque and Flux Control (DTFC) is planned using Xilinx ISE software tool in addition to a Modelsim 6.3 software tool that is used for simulation purposes. The FPGA based pulse generation is used to control the induction motor for electric vehicle applications. FPGA has been implemented, in order to verify the minimal error between the simulation results of MATLAB/Simulink and experimental results.

An Off-line Maximum Torque Control Strategy of Wound Rotor Synchronous Machine with Nonlinear Parameters

  • Wang, Qi;Lee, Heon-Hyeong;Park, Hong-Joo;Kim, Sung-Il;Lee, Geun-Ho
    • Journal of Electrical Engineering and Technology
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    • v.11 no.3
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    • pp.609-617
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    • 2016
  • Belt-driven Starter Generator (BSG) differs from other mild hybrid systems as the crankshaft of vehicle are not run off. Motor permits a low-cost method of adding mild hybrid capabilities such as start-stop, power assist, and mild levels of regenerative braking. Wound rotor synchronous motor (WRSM) could be adopted in BSG system for HEV e-Assisted application instead of the interior permanent magnet synchronous motor (IPMSM). In practice, adequate torque is indispensable for starter assist system, and energy conversion should be taken into account for the HEV or EV as well. Particularly, flux weakening control is possible to realize by adjusting both direct axis components of current and field current in WRSM. Accordingly, this paper present an off-line current acquisition algorithm that can reasonably combine the stator and field current to acquire the maximum torque, meanwhile the energy conversion is taken into consideration by losses. Besides, on account of inductance influence by non-uniform air gap around rotor, nonlinear inductances and armature flux linkage against current variation are proposed to guarantee the results closer to reality. A computer-aided method for proposed algorithm are present and results are given in form of the Look-up table (LUT). The experiment shows the validity of algorithm.

A Study on Revising Train Departure Time for Reducing Electric Power Consumption (전력소비완화를 위한 전동열차 출발시간 조정에 관한 연구)

  • Kim, Kwang-Tae;Kim, Kyung-Min;Hong, Soon-Heum
    • Journal of the Korean Society for Railway
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    • v.14 no.2
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    • pp.167-173
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    • 2011
  • This paper considers the problem of revising train departure time to reduce electric power consumption of mass rapid transit (MRT) railways. The motion of a train running between stations is divided into three phases: traction, coasting, and deceleration phases. The traction phase requires high electric power to operate MRT railways. In the coasting phase, the train moves stably by consuming little or no power. The deceleration phase is a braking mode and produces some electric power called regenerated brake power owing to inertia force for the train generated In the traction and coasting phases. The regenerative energy can be used by other accelerating trains within a specific range from the train and thereby the power consumptions of train can be reduced. We developed a mixed integer programming model to solve the problem. To validate the suggested model, a computational experiment was conducted using real data from Korea Metropolitan Subway.

Research on Technical Trends of IGBT Gate Driver Unit for Railway Car (철도차량용 IGBT Gate Driver Unit 기술 동향 분석 연구)

  • Cho, In-Ho;Lee, Jae-Bum;Jung, Shin-Myung;Lee, Byoung-Hee
    • Journal of the Korean Society for Railway
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    • v.20 no.3
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    • pp.339-348
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    • 2017
  • Power supply for railway cars can be divided into propulsion system power supply and auxiliary power units (APU). The propulsion system power supply is for propulsion of railway cars, and regenerative braking; the APU provides power for the air compressor, lighting, car control and other auxiliary parts. According to high voltage and high current specifications, generally, an insulated-gate bipolar transistor (IGBT) is adopted for the switching component. For appropriate switching operation, a gate driver unit (GDU) is essentially required. In this paper, the technical trends of GDU for railway cars are analyzed and a design consideration for IGBT GDU is described.

A Study on Acquisition of Overhead Line Location Information of Pantograph for E-Highway (E-Highway를 위한 팬터그래프의 가공선 위치정보 취득에 관한 연구)

  • Gwang-Cheol Song;Jun-Jae An;Tuan-Vu Le;Seong-Mi Park;Sung-Jun Park
    • Journal of the Korean Society of Industry Convergence
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    • v.26 no.5
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    • pp.915-923
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    • 2023
  • As environmental regulations on carbon emissions are strengthened worldwide, the existing internal combustion engine-centered automobile industry is being reformed. In particular, large buses and large cargo trucks are pointed out as one of the main causes of environmental destruction due to excessive carbon emissions. The E-Highway power collection system, which has recently been proposed as a solution, uses the vehicle's battery as a backup power source or regenerative braking, depending on whether the pan head of the pentograph installed in the vehicle is in contact with the overhead line. It is used to store the excess energy generated. However, wear through contact due to continuous contact reduces the current collection effect and causes failure. In this paper, by using the current difference, the horizontal position information of the panhead in contact with the overhead line is acquired, thereby reducing the abrasion of the conductor and the panhead Make it possible to follow the overhead line. The position estimation method proposed in this paper simply configures a device that can detect the position of the overhead line of the pantograph by the difference in resistance. It is economical and has the advantage of reducing the volume. The characteristics of the pantograph estimating the location of overhead lines were analyzed using the difference between the two currents of the current collector, the feasibility of the positioning estimation system was verified through simulations and experiments.

Nano-scale Design of electrode materials for lithium rechargeable batteries

  • Gang, Gi-Seok
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2012.05a
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    • pp.72-72
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    • 2012
  • Lithium rechargeable batteries have been widely used as key power sources for portable devices for the last couple of decades. Their high energy density and power have allowed the proliferation of ever more complex portable devices such as cellular phones, laptops and PDA's. For larger scale applications, such as batteries in plug-in hybrid electric vehicles (PHEV) or power tools, higher standards of the battery, especially in term of the rate (power) capability and energy density, are required. In PHEV, the materials in the rechargeable battery must be able to charge and discharge (power capability) with sufficient speed to take advantage of regenerative braking and give the desirable power to accelerate the car. The driving mileage of the electric car is simply a function of the energy density of the batteries. Since the successful launch of recent Ni-MH (Nickel Metal Hydride)-based HEVs (Hybrid Electric Vehicles) in the market, there has been intense demand for the high power-capable Li battery with higher energy density and reduced cost to make HEV vehicles more efficient and reduce emissions. However, current Li rechargeable battery technology has to improve significantly to meet the requirements for HEV applications not to mention PHEV. In an effort to design and develop an advanced electrode material with high power and energy for Li rechargeable batteries, we approached to this in two different length scales - Atomic and Nano engineering of materials. In the atomic design of electrode materials, we have combined theoretical investigation using ab initio calculations with experimental realization. Based on fundamental understanding on Li diffusion, polaronic conduction, operating potential, electronic structure and atomic bonding nature of electrode materials by theoretical calculations, we could identify and define the problems of existing electrode materials, suggest possible strategy and experimentally improve the electrochemical property. This approach often leads to a design of completely new compounds with new crystal structures. In this seminar, I will talk about two examples of electrode material study under this approach; $LiNi_{0.5}Mn_{0.5}O_2$ based layered materials and olivine based multi-component systems. In the other scale of approach; nano engineering; the morphology of electrode materials are controlled in nano scales to explore new electrochemical properties arising from the limited length scales and nano scale electrode architecture. Power, energy and cycle stability are demonstrated to be sensitively affected by electrode architecture in nano scales. This part of story will be only given summarized in the talk.

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