G. Marshall Molen

Modeling of a dc glow plasma loudspeaker

A plasma loudspeaker is a transducer that produces sound by means of an ionized gas channel rather than the voice coil of a conventional loudspeaker. Plasma loudspeakers characteristically have a flat frequency response at the higher acoustic frequencies because of their ‘‘massless’’ membrane; however, their low‐frequency response is limited. In this article, a comprehensive model for the electrical and thermodynamic operation of the electrical discharge is presented that explains the frequency‐dependent behavior of the discharge’s electrical impedance and acoustic response. The characteristic acoustic frequency response is shown to result from a spatial variation of the temperature relaxation time throughout the plasma channel due to the temperature dependence of that time constant. To support the model, electrical and sound‐pressure level measurements in helium, argon, and air are presented.

Simulation and hardware-in-the-loop evaluation of a GM Malibu

EcoCAR 2 is an Advanced Vehicle Technology Competition for collegiate level engineering students organized by Argonne National Laboratory (ANL) with the U. S. Department of Energy (DOE) and General Motors (GM) as the headline sponsors. The goal of the competition is to re-engineer a GM- donated 2013 Malibu Eco as a plug-in hybrid electric vehicle (PHEV) over the course of three years. Autonomie software developed by ANL and a mid-sized hardware-in-the-loop (HIL) system with rapid controller prototyping (RCP) controllers have been used for simulation of vehicle fuel economy and performance prior to the actual vehicle modification. The results of these simulations are compared to reported values for the Malibu Eco, and an analysis of the expected PHEV fuel economy is reported. Current ongoing work includes updating the HIL system plant model to represent the PHEV architecture and a vehicle control strategy using the RCP controllers for vehicle integration.

Design methodology for a range-extended PHEV

The range-extended PHEV is typically designed to operate in an all-electric mode where the batteries are initially charged from the electric power grid. Unlike the pure EV, the vehicles range is not limited by the battery capacity as an engine and generator are incorporated to sustain the battery once the state of charge has dropped to a minimal level. The effectiveness of the concept in terms of fuel economy and reduced emissions is dependent upon the optimal selection of components and a control algorithm that is appropriate for a specific drive cycle. A design methodology is presented that first provides guidelines for the development of the VTS and the various trade-offs that must be considered. A rigorous procedure is then presented for the design and later validation of the configuration and control algorithm using hardware-in-the-loop (HIL).

Reducing Vehicle Weight and Improving Security by Using Plastic Optical Fiber

Despite the extensive use of communication networks in todays vehicles, the mass of automotive electrical wiring has continued to increase as new technologies evolve. Approximately 100 kg of wire are used in a typical vehicle and the problem is exacerbated for electrified vehicles such as hybrids where additional electronic control circuitry is used along with high current cables for electric propulsion. Another consideration that is of increasing concern is the vulnerability of the network to security breaches where access to the network is illegally acquired or where the network integrity is compromised by electromagnetic interference. This paper describes the use of plastic optical fiber with Ethernet networks to alleviate many of these concerns.

An intelligent alternator control strategy for automotive applications

Intelligent peripheral control provides an opportunity for increased fuel efficiency and reduced emissions. Maximum benefit is achieved when combined with a hybrid vehicle architecture. A control strategy and related hardware are described that operate the 12-V alternator and accessories more efficiently than voltage regulator strategies that are currently employed by utilizing the energy storage of the 12-V battery in a mode that expands its functionality. This feature complements the energy savings in the high-voltage hybrid components of the vehicle. The results show that gains in fuel economy can be obtained through reduced high load accessory drag and lower idle losses.

A High Power Density, Full-Bridge Parallel Load Resonant ZVZCS DC-DC Converter

A full-bridge parallel loaded resonant zero current/zero voltage switching converter is developed for DC-DC voltage transformation. The power supply was used to condition power sourced by a 28volt 400A Neihoff alternator installed in a HMMWV delivered to a 5-kilowatt mobile radar. This design focuses on achieving maximum power density at reasonable efficiency (i.e. > 80%) by operating at the highest resonant and switching frequencies possible. A resonant frequency of 392kHz was achieved while providing rated power. The high resonant frequency was facilitated by the development of an extremely low inductance layout (< 20nH) capable of conducting the high resonant currents associated with this converter topology.