Propulsion

About: Propulsion is a research topic. Over the lifetime, 24977 publications have been published within this topic receiving 200311 citations.

An Investigation of Electric Motor Drive Characteristics for EV and HEV Propulsion Systems

Abstract: The recent growing interest in electric vehicle (EV) and hybrid electric vehicle (HEV) demands for an efficient, reliable and economical motor drive for electric propulsion. However, searching for a suitable traction motor becomes quite involved when vehicle dynamics and system architecture are considered. This paper makes an in-depth investigation on two highly important traction motor characteristics, extended speed rangeability and energy efficiency, from vehicular system perspective. The influences of these two motor drive features on a pure EV, a post-transmission, and two pretransmission parallel HEV with 20% and 50% hybridization are studied in this paper. Two EV-HEV software packages ‘V-ELPH’ developed by Texas A&M University and ‘ADVISOR’ from NREL are used for simulation purposes. Based on the results in this paper, a systematic method is developed regarding the selection of traction drives for EV and HEV propulsion systems.

Microairplane propelled by laser driven exotic target

Abstract: We propose a propulsion concept to drive a microairplane by laser that can be used for observation of climate and volcanic eruption. Since it does not have to develop thrust for vertical takeoff, and it has no engine in the normal sense, the microairplane can be very light, with its payload consisting only of observation and communication equipment. In order to demonstrate the concept, we succeeded in flying a paper microairplane driven by a 590 mJ, 5 ns pulse yttrium–aluminum–garnet laser that impinges on a double-layer “exotic target.” The coupling efficiency agrees well with simulations and with experiments.

Propulsion Drive Models for Full Electric Marine Propulsion Systems

Abstract: Integrated full electric propulsion systems are being introduced across both civil and military marine sectors. Standard power system analysis packages cover electrical and electromagnetic components but have limited models of mechanical subsystems and their controllers. Hence, electromechanical system interactions between the prime movers, power network, and driven loads are poorly understood. This paper reviews available models of the propulsion drive system components: the power converter, motor, propeller, and ship. Due to the wide range of time constants in the system, reduced-order models of the power converter are required. A new model using state-averaged models of the inverter and a hybrid model of the rectifier is developed to give an effective solution combining accuracy with speed of simulation and an appropriate interface to the electrical network model. Simulation results for a typical ship maneuver are presented.

Numerical Study of the Effects of Engine Size on Rotating Detonation Engines

Abstract: Rotating detonation engines (RDE’s) represent an alternative to the extensively studied pulse detonation engines (PDE’s) for obtaining propulsion from the high efficiency detonation cycle. Since it has received considerably less attention, the general flow-field and effect of parameters such as stagnation conditions, combustion chamber sizing, and fuel mixture on specific impulse are less well understood than for PDE’s. In this paper we use a model developed previously for doing time-accurate calculations of RDE’s in two and three dimensions to examine the effect of different engine sizing parameters on mass flow rate, performance, and thrust. Specific sizing parameters that are discussed are area ratio of micro-injectors to head-end wall, combustion chamber diameter and length. Additionally, several three-dimensional simulations for small combustion chambers with different thicknesses are shown. Results indicate that for many of these parameters, the characteristics of the engine scale in predictable ways for high plenum pressures. At lower plenum pressures, the results are more difficult to interpret. Specific impulses varied from 3300 s (low-pressure, large chamber length) to 5500 s.

An EV Drive-Train With Integrated Fast Charging Capability

Abstract: This paper proposes a new class of on-board chargers for electric vehicles (EVs). Instead of being placed on-board as a separate unit, the three-phase (fast) chargers reutilize the existing components in EVs, which are already used for the propulsion. These are primarily the inverter and the machine, which however have to be multiphase (with more than three phases). The concept is valid for all multiphase propulsion drives with a prime number of phases higher than three and a single neutral point in motoring and is illustrated in detail for the five-phase inverter/five-phase machine configuration. During the charging mode, electromagnetic torque is not produced in the machine so that the rotor does not require mechanical locking. Hardware reconfiguration between propulsion and fast charging is required, but it is achieved with only two switches, which are the only two nonintegrated elements. The integrated topology is explained in this paper, together with the control scheme, and extension from five phases to higher phase numbers is illustrated using the seven-phase system as an example. Finally, the propulsion-mode operation with complete suppression of low-order harmonics, which map into the second plane, is achieved for the five-phase machine. Experimental verification of theoretical results and proposed control is provided for both charging and vehicle-to-grid mode of operation, as well as for propulsion.