Technical Papers

Following are a few of our technical papers which will provide more detailed information on our products, as well as providing an introduction to some of the applications in which they are being implemented.

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Top 10 Reasons for Using Ultracapacitors in Your System Design
Discover 10 ways that Maxwell's ultracapacitors give system designers more freedom by allowing hybrid power system solutions that cost less and perform better than non-hybrid solutions.

Ultracapacitors Improve Reliability for Wind Turbine Pitch Systems
Examine the benefits offered by ultracapacitor technology for pitch control systems used in wind turbines. Pitch control systems are used to adjust the angle of attack for each blade on a wind turbine to maximize the efficiency of the energy capture system.

A Supercapacitor-Based Energy-Storage Substation for Voltage-Compensation in Weak Transportation By Alfred Rufer, David Hotellier, and Philippe Barrade
A supercapacitive-storage based substation for the compensation of resistive voltage-drops in transportation networks is proposed. It allows to feed as a current-source in any voltage conditions of the line. The system has been designed as a compensation-substation to be placed at weak points like end-of-line stations, instead of additional feeding substations. A dedicated power-electronic converter with an associated control system for the stabilization of the voltage level at the point of coupling in case of strong perturbations is proposed. Practical results are also presented, which have been recorded from a reduced-size prototype.

Ultracapacitors as Energy Buffers in a Multiple Zone Electrical Distribution System
A multiple zone electrical distribution system architecture augmented with local energy buffers is one method of addressing the need for redundancy that safety critical and security systems require. New introductions of x-by-wire functionality, idle-stop power trains, and electrified engine functions such as electro-mechanical engine valve actuation also benefit from modular and distributed local energy buffering offered by ultracapacitors. Ultracapacitors are non-Faradic surface effect storage devices that offer pulse power and power cycling capability far in excess of Faradic, bulk storage, electrochemical cells. Power management for safety critical systems such as steer, brake and drive by wire benefit from distributed energy modules that are positioned locally, are lower in mass, and are more energetic than batteries. Ultracapacitors have already found application in the propulsion system of conventional gasoline and diesel hybrid as well as fuel cell hybrid vehicles. The reason for the acceptance of ultracapacitors in vehicle propulsion systems is their high pulse power capability, fast transient response, and high efficiency during discharge and re-charging plus full charge cycling in excess of 100k cycles. The ultracapacitor is now proven to be an able augmentation to hybrid power trains as an electrical peaking unit. In this paper the application of ultracapacitors as distributed energy storage buffers in the vehicles electrical system is investigated.

Ultracapacitor Assisted Electric Drives for Transportation
Non-Faradic surface effect storage devices such as ultracapacitors offer pulse power and power cycling capability far in excess of Faradic, bulk storage, electrochemical cells for vehicular use. Vehicle applications for electric drives have been delayed due to technical inadequacy in these fiercely cost sensitive systems. Particularly in safety critical systems such as steer, brake and drive by wire where the cost of redundant systems would be prohibitive. Similarly for the vehicle power train where the demands for idle-stop and electrification of key functions such as engine cranking, electromechanical valve actuation and hybridization are concerned. In this paper both safety critical and power train systems are re-assessed within the context of distributed energy storage modules in the vehicle electrical distribution system to satisfy the requirements for power supply redundancy.

Ultracapacitor Applications in the Power Electronic World
There has been a lot of progress in control and motor design, due to the increasing power demand in electric applications, as well as ongoing pressures for more environmentally friendly and high efficiency solutions. However, designers and engineers have not been successful with regard to the electric power storage systems. This is due primarily to the fact that batteries are used to provide the power peaks in most of the currently developed solutions relying on a power storage system. The deficiencies of battery storage systems are many and they create a variety of design challenges for engineers. Batteries have a poor low-temperature performance, a very limited lifetime under extreme conditions - resulting in repeated replacement throughout the life of the system - and they are not designed to satisfy the most important requirements of power sources: To provide bursts of power in the seconds range over many hundreds of thousands of cycles.

Evaluation of Maxwell Technologies PC5 Ultracapacitor
The Parts Analysis and Assurance (PA&A) group at the Johnson Space Center (JSC) evaluated the PC5 Ultracapacitor from Maxwell Technologies and this evaluation reports on the results of the tests done. The PC5 is used in the International Space Station PEEK (Portable Electrical Equipment Kit). The PEEK hardware provides electrical power extension cables and outlets as well as 120 to 28Vdc converter units to power portable electrical hardware on the ISS.

Ultracapacitors, the New Thinking in the Automotive World
Due to the increasing power demand in future vehicles for comfort improvement, as well as ongoing pressures for more environmentally friendly means of transportation, automotive manufacturers are developing alternatives to existing fossil fuel-driven vehicles. Perhaps the most promising near-term alternative to fuel-cell vehicles, which will not be ready for volume production for at least a decade, is hybrid electric vehicle (HEV) technology. While progress has been made in control, engine and motor design, there has not been much success with regard to the electric power storage systems. This is due primarily to the fact that batteries are used to provide the power peaks in most of the currently developed hybrid electric vehicles. But the deficiencies of battery storage systems are multiple and they create many design challenges for automotive engineers.

Power Modules Enable Electric Drive Systems
Automotive technology is on the brink of a three-pronged revolution; the transition from heat engine propulsion to electric drive; 12 volts to 42 volts; and distributed electrical power. This free white paper explores how drivetrain and distributed power concepts will satisfy the two converging demands of environment and consumer which are driving this revolution.

Ultracapacitors and the Hybrid Electric Vehicle
Read about current Hybrid Electric Vehicle power solutions to learn how Maxwell's ultracapacitors can be used to improve vehicle performance and safety, while reducing costs, in this exciting new industry sector.

Ultracapacitor System Design: Optimizing Hybrid Electric Vehicles with Fuel Cell Power
The automotive industry's recent push towards developing electric and hybrid electric vehicles (EV and HEVs) is a direct response to the growing global pressure to improve the environment and has resulted in a search for significantly cleaner and more efficient vehicles.