12,823 research outputs found
Detection and emotional evaluation of an electric vehicleâs exterior sound in a simulated environment
Electric vehicles are quiet at low speeds and thus potentially pose a threat to pedestriansâ safety. Laws are formulating worldwide that mandate these vehicles emit sounds to alert the pedestrians of the vehiclesâ approach. It is necessary that these sounds promote a positive perception of the vehicle brand, and understanding their impact on soundscapes is also important. Detection time of the vehicle sounds is an important measure to assess pedestriansâ safety. Emotional evaluation of these sounds influences assessment of the vehicle brand. Laboratory simulation is a new approach for evaluating exterior automotive sounds. This study describes the implementation of laboratory simulation to compare the detection time and emotional evaluation of artificial sounds for an electric vehicle. An Exterior
Sound Simulator simulated audio-visual stimuli of an electric car passing a crossroad of a virtual town at 4.47 ms-1 (10 mph), from the perspective of a pedestrian standing at the crossroad. In this environment, 15 sounds were tested using experiments where participants detected the car and evaluated its sound using perceptual dimensions. Results show that these sounds vary significantly in their detection times and emotional evaluations, but crucially that traditional metrics like dB(A) do not always relate to the detection of these sounds. Detection time and emotional evaluation do not have significant correlation. Hence, sounds of a vehicle could be detected
quickly, but may portray negative perceptions of the vehicle. Simulation provides a means to more fully evaluate potential electric vehicle sounds against the competing criteria
Architecture of a network-in-the-Loop environment for characterizing AC power system behavior
This paper describes the method by which a large hardware-in-the-loop environment has been realized for three-phase ac power systems. The environment allows an entire laboratory power-network topology (generators, loads, controls, protection devices, and switches) to be placed in the loop of a large power-network simulation. The system is realized by using a realtime power-network simulator, which interacts with the hardware via the indirect control of a large synchronous generator and by measuring currents flowing from its terminals. These measured currents are injected into the simulation via current sources to close the loop. This paper describes the system architecture and, most importantly, the calibration methodologies which have been developed to overcome measurement and loop latencies. In particular, a new "phase advance" calibration removes the requirement to add unwanted components into the simulated network to compensate for loop delay. The results of early commissioning experiments are demonstrated. The present system performance limits under transient conditions (approximately 0.25 Hz/s and 30 V/s to contain peak phase-and voltage-tracking errors within 5. and 1%) are defined mainly by the controllability of the synchronous generator
European White Book on Real-Time Power Hardware in the Loop Testing : DERlab Report No. R- 005.0
The European White Book on Real-Time-Powerhardware-in-the-Loop testing is intended to serve as a reference document on the future of testing of electrical power equipment, with speciïŹ c focus on the emerging hardware-in-the-loop activities and application thereof within testing facilities and procedures. It will provide an outlook of how this powerful tool can be utilised to support the development, testing and validation of speciïŹ cally DER equipment. It aims to report on international experience gained thus far and provides case studies on developments and speciïŹ c technical issues, such as the hardware/software interface. This white book compliments the already existing series of DERlab European white books, covering topics such as grid-inverters and grid-connected storag
Integration of a mean-torque diesel engine model into a hardware-in-the-loop shipboard network simulation using lambda tuning
This study describes the creation of a hardware-in-the-loop (HIL) environment for use in evaluating network architecture, control concepts and equipment for use within marine electrical systems. The environment allows a scaled hardware network to be connected to a simulation of a multi-megawatt marine diesel prime mover, coupled via a synchronous generator. This allows All-Electric marine scenarios to be investigated without large-scale hardware trials. The method of closing the loop between simulation and hardware is described, with particular reference to the control of the laboratory synchronous machine, which represents the simulated generator(s). The fidelity of the HIL simulation is progressively improved in this study. First, a faster and more powerful field drive is implemented to improve voltage tracking. Second, the phase tracking is improved by using two nested proportionalâintegralâderivativeâacceleration controllers for torque control, tuned using lambda tuning. The HIL environment is tested using a scenario involving a large constant-power load step. This provides a very severe test of the HIL environment, and also reveals the potentially adverse effects of constant-power loads within marine power systems
Space benefits: The secondary application of aerospace technology in other sectors of the economy
Benefit cases of aerospace technology utilization are presented for manufacturing, transportation, utilities, and health. General, organization, geographic, and field center indexes are included
Modelling of reduced GB transmission system in PSCAD/EMTDC
Energy and environmental issues are two of the greatest challenges facing the world today. In response to energy needs and environmental concerns, renewable energy technologies are now considered the future technologies of choice. Renewable energy is produced from natural sources that are clean and free; however, it is widely accepted that renewable energy is not a solution without challenges. An example of this can be seen in the UK, where there is much interest amongst generation developers in the construction of new large scale onshore and offshore wind farms, especially in Scotland. The stability of electric power systems is also an important issue. It is important to have full knowledge of the system and to be able to predict the behaviour under different situations is an important objective. As a result, several industrial grade power system simulator tools have been developed in order to estimate the behaviour of the electric power system under certain conditions. This paper presents a reduced Great Britain (GB) system model for stability analysis using PSCAD/EMTDC. The reduced model is based upon a future GB transmission system model and, hence, contains different types and mix of generation, HVDC transmission lines and additional interconnection. The model is based on the reduced DIgSILENT PowerFactory model developed by National Grid
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Space-Based Capstone: Public-Private-Academic Partnership in the Making
The Electronic Systems Engineering Technology (ESET) Program at Texas A&M University provides a recognized undergraduate program with an emphasis in electronics, communication, embedded systems, testing, instrumentation and control systems. The program combines engineering and industrial knowledge and methods to develop, design, and implement new innovative products through a two-semester long Senior Capstone Project.
Capstone is designed to prepare future engineers by bridging the gap between the classroom and industry. Students are required to form teams of two to six members which allows them to develop the skills necessary to succeed in a diverse industry setting. Each team is required to use their knowledge and skills to design, develop, document, and deliver a real-world project equivalent to the assignments they will soon receive as professional engineers.
Following NASAâs approval for funding the development of a research facility named Hermes, a Capstone team, named Microgravity Automated Research Systems (MARS), was sponsored by T STAR, a local space commercialization company, to develop the electronics portion of the facility. Hermes will reside on the International Space Station for five years in the hopes of streamlining the development of experiments that require extended periods of time in microgravity environments.
The Hermes facility will host and manage up to four experiments at a time while allowing for the downlink of experiment data to an Earth station, and the uplink of commands to change experiment parameters. Experiments will adhere to a power budget and communication standard established by MARS so that experiments can be swapped out during the facilityâs lifetime. MARS will work with the Mobile Integrated Solutions Laboratory (MISL), an undergraduate applied research lab, in order to prepare them to maintain support for Hermes in the future.Cockrell School of Engineerin
A methodology for the efficient computer representation of dynamic power systems : application to wind parks
This contribution presents a methodology to efficiently obtain the numerical and computer solution of dynamic power systems with high penetration of wind turbines. Due to the excessive computational load required to solve the abc models that represent the behavior of the wind turbines, a parallel processing scheme is proposed to enhance the solution of the overall system. Case studies are presented which demonstrate the effectiveness and applications of the proposed methodology
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