Overview of current development in electrical energy storage technologies and the application potential in power system operation

The science and technology of ultracapacitors are reviewed for a number of electrode materials, including carbon, mixed metal oxides, and conducting polymers. More work has been done using microporous carbons than with the other materials and most of the commercially available devices use carbon electrodes and an organic electrolytes. The energy density of these devices is 3¯5 Wh/kg with a power density of 300¯500 W/kg for high efficiency (90¯95%) charge/discharges. Projections of future developments using carbon indicate that energy densities of 10 Wh/kg or higher are likely with power densities of 1¯2 kW/kg. A key problem in the fabrication of these advanced devices is the bonding of the thin electrodes to a current collector such the contact resistance is less than 0.1 cm2. Special attention is given in the paper to comparing the power density characteristics of ultracapacitors and batteries. The comparisons should be made at the same charge/discharge efficiency.

Ultracapacitors: Why, How, and Where is the Technology

This paper reviews the current status and implementation of battery chargers, charging power levels, and infrastructure for plug-in electric vehicles and hybrids. Charger systems are categorized into off-board and on-board types with unidirectional or bidirectional power flow. Unidirectional charging limits hardware requirements and simplifies interconnection issues. Bidirectional charging supports battery energy injection back to the grid. Typical on-board chargers restrict power because of weight, space, and cost constraints. They can be integrated with the electric drive to avoid these problems. The availability of charging infrastructure reduces on-board energy storage requirements and costs. On-board charger systems can be conductive or inductive. An off-board charger can be designed for high charging rates and is less constrained by size and weight. Level 1 (convenience), Level 2 (primary), and Level 3 (fast) power levels are discussed. Future aspects such as roadbed charging are presented. Various power level chargers and infrastructure configurations are presented, compared, and evaluated based on amount of power, charging time and location, cost, equipment, and other factors.

/pdf/review-of-battery-charger-topologies-charging-power-levels-85yy2igx2w.pdf

Review of Battery Charger Topologies, Charging Power Levels, and Infrastructure for Plug-In Electric and Hybrid Vehicles

http://ieeexplore.ieee.org/iel5/5610941/5624686/05624745.pdf

Power electronics

Solid-state switch-mode rectification converters have reached a matured level for improving power quality in terms of power-factor correction (PFC), reduced total harmonic distortion at input AC mains and precisely regulated DC output in buck, boost, buck-boost and multilevel modes with unidirectional and bidirectional power flow. This paper deals with a comprehensive review of improved power quality converters (IPQCs) configurations, control approaches, design features, selection of components, other related considerations, and their suitability and selection for specific applications. It is targeted to provide a wide spectrum on the status of IPQC technology to researchers, designers and application engineers working on switched-mode AC-DC converters. A classified list of more than 450 research publications on the state of art of IPQC is also given for a quick reference.

/pdf/a-review-of-single-phase-improved-power-quality-ac-dc-2pm6h4zjxq.pdf

A review of single-phase improved power quality AC-DC converters

A novel power-factor-corrected single-stage alternating current/direct current converter for inductive charging of electric vehicle batteries is introduced. The resonant converter uses the current-source characteristic of the series-parallel topology to provide power-factor correction over a wide output power range from zero to full load. Some design guidelines for this converter are outlined. An approximate small-signal model of the converter is also presented. Experimental results verify the operation of the new converter

Power-Factor-Corrected Single-Stage Inductive Charger for Electric Vehicle Batteries

In this paper, simplified EV power train models are developed for new and existing production vehicles. The models are developed based on published vehicle parameters and range information for the Nissan Leaf and the Tesla Roadster. The models are compared with published manufacturer specifications for range under various route and driving conditions, and for various drive cycles. The models are additionally validated against test results for the Nissan Leaf and Tesla Roadster vehicles, where the test route topography is modeled using Google Earth and a GPS-based smart-phone application. Excellent correlations are demonstrated between the experimental results and manufacturer data and the vehicle models. Impacts of battery degradation with time and vehicle HVAC loads are considered in the study.

Simplified electric vehicle power train models and range estimation

A full bridge DC-DC series-resonant power converter is operated at a constant switching frequency using a phase delay between the transistor legs of the bridge to control the output voltage. All power semiconductor devices switch on and switch off at approximately zero volts while operating at a constant switching frequency which is above the resonant frequency of the resonant tank circuit. Zero-voltage switching increases the efficiency of the power converter and allows high frequency operation which minimizes component volumes. Constant frequency operation simplifies design of the magnetic components, confines the EMI spectrum to known frequencies and simplifies EMI design, and reduces the voltage and current excursions and thus reduces the peak component stress.

Constant frequency resonant power converter with zero voltage switching

A novel power-factor-corrected single-stage AC-DC converter for inductive charging of electric vehicle batteries is introduced. The resonant converter uses the current-source characteristic of the series-parallel topology to provide power factor correction over a wide output power range from zero to full load. Some design guidelines for this converter are outlined. An approximate small-signal model of the converter is also presented Experimental results verify the operation of the new converter.

Power-factor-corrected single-stage inductive charger for electric-vehicle batteries

The present invention comprises a power-factor-corrected, single-stage inductive charger that may be used to charge a load, such as batteries of an electric vehicle. The inductive charger system is a single stage inductive charger compatible with the Society of Automotive Engineers inductive charging standard SAE J-1773. The single stage power processing provided by the inductive charger system includes both power factor correction and output power regulation using a relatively low parts count. The inductive charger system is fully soft switched over the line voltage and power range, resulting in high efficiency. The inductive charger system uses the current source operation of a series-parallel resonant converter feeding the SAE J- 1773 interface to provide voltage gain for power factor correction over the full AC line cycle. The operating frequency of the converter is modulated around the current-source frequency to regulate the output power from zero to full load.

John G. Hayes

Papers

Power-Factor-Corrected Single-Stage Inductive Charger for Electric Vehicle Batteries

Simplified electric vehicle power train models and range estimation

Constant frequency resonant power converter with zero voltage switching

Power-factor-corrected single-stage inductive charger for electric-vehicle batteries

Power-factor-corrected single-stage inductive charger