Search Results (44)

This survey paper explores the cybersecurity certification requirements defined by the SunSpec Alliance for Distributed Energy Resource (DER) devices, focusing on aspects such as software updates, device communications, authentication mechanisms, device security, logging, and test procedures. The SunSpec cybersecurity standards mandate support for remote and automated software updates, secure communication protocols, stringent authentication practices, and robust logging mechanisms to ensure operational integrity. Furthermore, the paper discusses the implementation of the SAE J3072 standard using the IEEE 2030.5 protocol, emphasizing the secure interactions between electric vehicle supply equipment (EVSE) and plug-in electric vehicles (PEVs) for functionalities like vehicle-to-grid (V2G) capabilities. This research also examines the SunSpec Modbus standard, which enhances the interoperability among DER system components, facilitating compliance with grid interconnection standards. This paper also analyzes the existing SunSpec Device Information Models, which standardize data exchange formats for DER systems across communication interfaces. Finally, this paper concludes with a detailed discussion of the energy storage cybersecurity specification and the blockchain cybersecurity requirements as proposed by SunSpec Alliance. Full article

A multi-objective optimization is performed to obtain fueling conditions in hydrogen stations leading to improved filling times and thermodynamic efficiency (entropy production) of the de facto standard of operation, which is defined by the protocol SAE J2601. After finding the Pareto frontier between filling time and total entropy production, it was found that SAE J2601 is suboptimal in terms of these process variables. Specifically, reductions of filling time from 47 to 77% are possible in the analyzed range of ambient temperatures (from 10 to 40 °C) with higher saving potential the hotter the weather conditions. Maximum entropy production savings with respect to SAE J2601 (7% for 10 °C, 1% for 40 °C) demand a longer filling time that increases with ambient temperature (264% for 10 °C, 350% for 40 °C). Considering average electricity prices in California, USA, the operating cost of the filling process can be reduced between 8 and 28% without increasing the expected filling time. Full article

For electric vehicle (EV) charging in North America, three AC connectors are standardized, resulting in a proliferation of charging stations which can only charge one of the three types of EV. We propose a “Universal EV Outlet” that works with an EV “carry along” charging cable—one end of the cable has a connector specific to that user’s EV, the other a plug for the Universal EV Outlet. This proposal does not interfere with, nor require change to, any existing charging stations. It does not require any new types of inlets on EVs. The components are already standardized. Eight use cases are examined to illustrate the advantages, and some limitations, of the Universal EV Outlet. The use cases illustrate how this solution: resolves the problem of multiple AC charging connectors, makes today’s “EV Ready” building codes more adaptable, lowers capital and maintenance costs, creates a solution to curbside and urban charging, increases energy efficiency, enables higher power three-phase AC charging for heavy vehicles, and facilitates use of EVs for building backup power and for vehicle-to-grid. Finally, we propose a standards-based active cable used with the Universal EV Outlet, which would allow fast and secure EV identification for curbside or other shared charging locations, usable today without modifications to current EVs. Full article

This paper presents an advanced Wireless Power Transfer (WPT) system for electric vehicles (EVs) featuring Active Load Impedance Matching (ALIM) at the rectification stage. Unlike traditional synchronous rectification, ALIM dynamically adjusts load impedance, optimizing energy transfer efficiency and reducing thermal stresses, system costs, and mass. The system incorporates two circuits optimized for distinct frequency bands: one operates below 10 kHz using standard copper wiring for cost-effectiveness, and the other at 85 kHz, which significantly reduces the mass of the onboard coil and magnetic circuit while ensuring interoperability according to SAE J2954 standard. Our approach enhances charging efficiency across various operating conditions, improves thermal management, and minimizes maintenance costs. Additionally, it enables partial compensation for vehicle misalignment and ground assembly impedance, further boosting efficiency and interoperability. Experimental results demonstrate a notable increase in efficiency and reduction in system mass, confirming the superiority of the ALIM-equipped WPT system over conventional solutions. This paper underscores the potential of ALIM to advance the scalability, efficiency, and economic viability of wireless EV charging technology, promoting broader adoption and sustainability in EV infrastructures. By providing a comprehensive solution that addresses key challenges in wireless charging, our work paves the way for more efficient and cost-effective EV charging systems. Full article

This article compares potential revenue from electric storage in retail and wholesale electric markets. The retail value can be extracted when storage responds to time-of-day retail prices. The wholesale value is enabled by the recent US Federal Energy Regulatory Commission Order 2222, which requires regional transmission operators (RTOs) to allow distributed storage behind the meter to participate in wholesale electric markets. To quantify the value of these markets, we use realistic time-of-day rates and market prices in one RTO’s ancillary service market. Formulae are developed to estimate the value of behind-the-meter storage in wholesale and retail markets, using an example electric vehicle in a fleet setting. The formulae are also used to compare whether or not net metering is available and different charging rates. The aggregate national storage behind the retail meter is very large, given the projected growth of electric vehicles. Our findings indicate the revenue from wholesale markets can be significantly more than that of retail opportunities. However, the potential in either retail or wholesale markets is currently limited by both state policy and incomplete RTO implementation of FERC orders. Full article

Wireless charging (WC) has gained popularity for the charging of electric vehicles in recent years of research, particularly dynamic wireless charging systems (DWCSs). Among the different topologies of DWCSs, this paper focuses on an inductively coupled wireless charging system (ICWCS). In this ICWCS, double-D (DD) coils create horizontal and vertical flux components between different pad configurations, which show optimal features in contrast to circular pad coils. In this work, the three-dimensional (3D) finite element technique (FEM) is used to establish the proposed design to observe the coupling coefficient, while the system design’s performance is evaluated using a circuit simulator. In the simulation, the proposed DD coil configuration is used for both the transmitter and receiver sides. It provides the maximum coupling coefficient and efficiency at perfect alignment when using an in-between air gap of 166 mm and six I-type ferrite bars on the transmitter side and five I-type ferrite bars on the receiver side. The coupling coefficient and system parameters, such as power and efficiency, are considered for different misalignments in the proposed configuration. The results of this work satisfy the Society of Automotive Engineers (SAE) J2954 Class 3 criteria. The best results obtained are on account of optimizing the ferrite core, which is achieved by varying its length and width. While varying the ferrite core’s dimensions, 0.2451, as the optimal k value, is obtained at the effective width and length of 57.5 mm and 400 mm, respectively. The simulation results of the Ansys Maxwell 3D software prove the feasibility of the proposed structure. Full article

In urban intersections, the sensory capabilities of autonomous vehicles (AVs) are often hindered by visual obstructions, posing significant challenges to their robust and safe operation. This paper presents an implementation study focused on enhancing the safety and robustness of Connected Automated Vehicles (CAVs) in scenarios with occluded visibility at urban intersections. A novel LiDAR Infrastructure System is established for roadside sensing, combined with Baidu Apollo’s Automated Driving System (ADS) and Cohda Wireless V2X communication hardware, and an integrated platform is established for roadside perception enhancement in autonomous driving. The field tests were conducted at the Singapore CETRAN (Centre of Excellence for Testing & Research of Autonomous Vehicles—NTU) autonomous vehicle test track, with the communication protocol adhering to SAE J2735 V2X communication standards. Communication latency and packet delivery ratio were analyzed as the evaluation metrics. The test results showed that the system can help CAV detect obstacles in advance under urban occluded scenarios. Full article

Global navigation satellite systems (GNSSs) became an integral part of all aspects of our lives, whether for positioning, navigation, or timing services. These systems are central to a range of applications including road, aviation, maritime, and location-based services, agriculture, and surveying. The Global Positioning System (GPS) Standard Position Service (SPS) provides position accuracy up to 10 m. However, some modern-day applications, such as precision agriculture (PA), smart farms, and Agriculture 4.0, have demanded navigation technologies able to provide more accurate positioning at a low cost, especially for vehicle guidance and variable rate technology purposes. The Society of Automotive Engineers (SAE), for instance, through its standard J2945 defines a maximum of 1.5 m of horizontal positioning error at 68% probability ($1\sigma$), aiming at terrestrial vehicle-to-vehicle (V2V) applications. GPS position accuracy may be improved by addressing the common-mode errors contained in its observables, and relative GNSS (RGNSS) is a well-known technique for overcoming this issue. This paper builds upon previous research conducted by the authors and investigates the sensitivity of the position estimation accuracy of low-cost receiver-equipped agricultural rovers as a function of two degradation factors that RGNSS is susceptible to: communication failures and baseline distances between GPS receivers. The extended Kalman filter (EKF) approach is used for position estimation, based on which we show that it is possible to achieve 1.5 m horizontal accuracy at 68% probability ($1\sigma$) for communication failures up to 3000 s and baseline separation of around 1500 km. Experimental data from the Brazilian Network for Continuous Monitoring of GNSS (RBMC) and a moving agricultural rover equipped with a low-cost GPS receiver are used to validate the analysis. Full article

To increase the acceptance of electric vehicles (EVs), inductive charging technology can be an important tool because of the simplified charging process for the user. This paper presents the fundamentals of wireless power transfer (WPT) for EVs, while focusing on electromagnetic compatibility (EMC). This work deals with the investigation of the conducted and field-bound interference emissions using a WPT system with a max. input power of $3.6 \mathrm{k}\mathrm{W}$. During the research, a new frequency-tracking algorithm is developed, to find the optimal operating frequency at any coil misalignment. The impedance behavior as well as the possible interference paths are investigated, showing the great geometric influence of the test bench setup. The conducted interference currents are analyzed and subsequently filtered. The filter shows good performance in attenuating common mode currents. The measured radiated magnetic field is directly rated against the proposed limits of various standards. Finally, the EMC influence of the direct current (DC) power supply line to the inverter is examined, which is not defined precisely in the standard. This underlines the significance of a standardized test setup, since the limit values can be met under different geometric circumstances of the DC cable. Full article

In this study, the relationship between macro segregation and the equiaxed zone in high-carbon grades with continuous casting parameters was investigated and optimized at the İsdemir iron and steel plant. The work was conducted for the 1080 quality of the SAE J403 standard. In this study, some parameters, such as casting speed, secondary cooling, EMS current value and EMS frequency value, were examined. When the results of the experiments are examined, it can be observed that the equiaxed zone in the macrostructure decreases significantly with the reduction of the EMS frequency value. The decrease in casting speed and increase in EMS current value caused an increase in the equiaxed zone. The increment in secondary cooling led to a decline in the equiaxed zone. Once the macro segregation results are examined, it can be seen that it is very important to optimize the continuous casting parameters in order to reduce the macro segregation results of—especially—carbon, sulfur and phosphorus elements. It has also been determined that the macro segregation values of carbon, sulfur and phosphorus elements are low in casting conditions where casting speed is low, and the EMS current value and EMS frequency value are high. In addition, macro segregation measurements of manganese, silicon, chromium and vanadium elements are found to be low under similar casting conditions. It is critical to optimize the continuous casting parameters before production, especially in high-carbon grades to be used for prestressed concrete wire and cord wire applications. As a result of the work conducted using the İsdemir billet continuous casting machine for the 1080-grade SAE J403 standard, aiming to optimize macro segregation and the equiaxed zone, the effective results have been achieved by using process parameters of 2.8 m/min casting speed, 360 A EMS current, 5 Hz EMS frequency and low secondary cooling intensity. Full article

As a fuel for power generation, high-pressure hydrogen gas is widely used for transportation, and its efficient storage promotes the development of fuel cell vehicles (FCVs). However, as the filling process takes such a short time, the maximum temperature in the storage tank usually undergoes a rapid increase, which has become a thorny problem and poses great technical challenges to the steady operation of hydrogen FCVs. For security reasons, SAE J2601/ISO 15869 regulates a maximum temperature limit of 85 °C in the specifications for refillable hydrogen tanks. In this paper, a two-dimensional axisymmetric and a three-dimensional numerical model for fast charging of Type III, 35 MPa, and 70 MPa hydrogen vehicle cylinders are proposed in order to effectively evaluate the temperature rise within vehicle tanks. A modified standard k-ε turbulence model is utilized to simulate hydrogen gas charging. The equation of state for hydrogen gas is adopted with the thermodynamic properties taken from the National Institute of Standards and Technology (NIST) database, taking into account the impact of hydrogen gas’ compressibility. To validate the numerical model, three groups of hydrogen rapid refueling experimental data are chosen. After a detailed comparison, it is found that the simulated results calculated by the developed numerical model are in good agreement with the experimental results, with average temperature differences at the end time of 2.56 K, 4.08 K, and 4.3 K. The present study provides a foundation for in-depth investigations on the structural mechanics analysis of hydrogen gas vessels during fast refueling and may supply some technical guidance on the design of charging experiments. Full article

The charging station has a vital role in the electric vehicle sector. The charging station provides supply (AC or DC) to vehicles as per requirements. The charging station infrastructure includes software and hardware that ensure energy transfer and safety. Communication is mandatory to transmit messages that contain information from the battery management system and charger. This research focuses on implementing the communication between the charger controller and the battery management system. This paper adopts the controller area network (CAN) bus charger communication protocol based on the SAE J1939 standard from the Society of Automotive Engineers. The data are transmitted over a network to facilitate the information that is to be conveyed by an electronic control unit. The vehicle communicates via the battery management system to the charger controller using CAN communication. The charger power modules with AC to DC and DC to DC converters uses Modbus communication protocol. Therefore, this paper integrates CAN bus and Modbus communication protocols and implements the communication between charger and electric vehicle battery management system using a cost-effective Arduino UNO micro-controller. Using the CAN bus module (MCP2515) and Modbus module (MAX485), the distance between the electric vehicle and the charger is increased. Finally, the communication is validated using PCAN View software. Full article

The safety of hydrogen storage is essential for the development of fuel cell vehicles. A mathematical model for a compressed hydrogen storage tank is established based on the mass conservation equation, the energy conservation equation and the real gas equation of state. Using the Matlab/Simulink platform, a dual-zone lumped parameter model, which divides the tank into a hydrogen gas zone and a tank wall zone, is established. The initial conditions of the MC Default method hydrogen filling from SAE J2601 are utilized in the lumped parameter model for numerical simulation. Five cases are studied, including two different tanks. One case used the Lookup table for hydrogen refueling, and four cases used the MC Default method for fueling. The hydrogen gas temperature, wall temperature, pressure in the tank and state of charge are obtained during the fueling process. The simulated results show that the dual-zone lumped parameter model can well predict the temperature, pressure and state of charge (SOC) for Type IV tanks with volumes of 249 L and 117 L during refueling. By using the averaged heat transfer coefficient (80 W/(m²·K)) between gas and wall, and the constant heat transfer coefficient (20 W/(m²·K)) between wall and environment, the gas temperature and pressure of our dual-zone lumped parameter model show good agreement with the experiment. The maximum difference between simulated and experimental wall temperatures for five cases is around 2 °C. The experimental wall temperatures were measured on the external surface of the tank, while the simulated wall temperature of the dual-zone lumped parameter model is representative of a mean temperature averaged alone with the radial direction. Full article

In this study, an autonomous driving test was conducted from the perspective of FOT (field operational test). For data analysis and improvement methods, scenarios for FOT were classified and defined by considering autonomous driving level (SAE J3016) and the viewpoints of the vehicle, driver, road, environment, etc. To obtain data from FOT, performance indicators were selected, a data collection environment was implemented in the test cases, and driving roads were selected to obtain driving data from the vehicle while it was driven on an actual road. In the pilot FOT course, data were collected in various driving situations using a test vehicle, and the effect of autonomous driving-related functions on improving driving safety was studied through data analysis of discovered major events. Full article

This paper proposes a shielding sensor (SS) coil to solve the misalignment issue and the leakage magnetic field issue of the wireless power transfer (WPT) system for electric vehicles (EVs). The misalignment issue and leakage magnetic field issue must be solved because they can cause problems with power transfer efficiency reduction and electronic device malfunction. To solve these problems, the proposed SS coils are located over the Tx coil. The newly created mutual inductance between the Tx coil and the SS coil is used to detect the misalignment of the receiver in the Tx coil. In addition, the current phase of the SS coil is adjusted through impedance control of the SS coil to reduce the leakage magnetic field. The proposed SS coils were applied to the standard SAE J2954 model for the wireless charging of an EV. The WPT3/Z2 model of SAE J2954 with output power of 10 kW was simulated to compare the shielding effect according to the power transfer efficiency, and it was confirmed that a shielding effect of 76% was shown under the condition of a 3% reduction in the power transfer efficiency. In addition, the occurrence and direction of the misalignment between the receiver and the Tx coil were confirmed by using the tendency of mutual inductance between each SS coil and the Tx coil. In addition, as in the simulation result, the shielding effect and tendency were confirmed in an experiment conducted with the output power downscaled to 500 W. Full article