Hourly Power Grid Variations, Electric Vehicle Charging Patterns, and Operating Emissions

Innovative Bidirectional Isolated High-Power Density On-Board Charge for Vehicle-to-Grid

This paper deals with developing and implementing a bidirectional galvanically isolated on-board charger of a high-power density. The power density of the new charger was 4 kW/kg and 2.46 kW/dm³, and the maximum efficiency was 96.4% at 3.4 kW. Due to the requirement to achieve a high-power density, a single-stage inverter topology was used. Regarding switching losses, due to the topology of the circuit with so-called hard switching, the switching frequency was set to 150 kHz. A laboratory prototype was built to verify the properties and operating principles of the described charger topology. The on-board charger has been tested in a microgrid test platform. Due to the parasitic properties of the transformer and other electronic components, overvoltage with subsequent oscillations occurred on the primary side of the transformer and damped resonance on its secondary side. These parasitic properties caused interference and especially voltage stress on the semiconductor elements. These undesirable phenomena have been eliminated by adding an active element to the charger topology and a new transistor control strategy. This new switching control strategy of transistors has been patented.

Well-to-wheel greenhouse gas emissions of electric versus combustion vehicles from 2018 to 2030 in the US

CONCISE ABSTRACT

Electric vehicles (EVs) can reduce transportation-related greenhouse gas (GHG) emissions, given the planned electric grid decarbonization. Regulations can also reduce internal combustion engine vehicle's (ICEVs) emissions by mandating increased fuel economies or ethanol-gasoline mixes. Factors such as fuel economy, electricity grid mix, vehicle choice, and temperature affect EV GHG emissions relative to ICEVs, and successfully decarbonizing the transportation sector depends on understanding their combined effects. We use life-cycle assessment to compare the EV and ICEV well-to-wheel GHG emissions in the United States and four other states from 2018 to 2030. We found lower emissions for EVs than ICEVs in most conditions considered. In New York state, where natural gas power plants replace nuclear energy, GHG emissions of electricity generation increase over time after 2020. Future ICEVs can have comparable emissions to EVs due to fuel economy increase. Therefore, EV and ICEV can together lower transportation GHG emissions at a faster pace.

EXTENDED ABSTRACT

Transportation-related greenhouse gas (GHG) emissions can be reduced by (a) increasing the share of electric vehicles (EVs) and (b) reducing GHG emissions of internal combustion engine vehicles (ICEVs) by mandating increased fuel economies or ethanol-gasoline mixes. Factors, such as fuel economy, electricity grid mix, vehicle choice, and temperature affect EVs' relative GHG emissions compared to ICEVs, and understanding their combined effect is necessary for a successful decarbonization of the transportation sector. We used life-cycle assessment to evaluate the simultaneous effect of the above-mentioned factors on the well-to-wheel GHG emissions of EVs and ICEVs from 2018 to 2030. The analysis was performed for the United States (US) average and state-level for Arizona, California, New York, and Oregon. Our results showed lower GHG emissions for EVs than ICEVs for most conditions considered. GHG emissions are expected to decrease in the US on average by 5% for EVs and 27% for ICEVs in 2030 compared to 2018. In 2030, the ICEV well-to-wheel GHG emissions were comparable to those of the EVs in the US average and Arizona. EVs perform best in California and Oregon throughout the considered period. In regions, such as New York, EVs driven 2021 and after will have higher GHG emissions than ICEVs, as natural gas power plants are replacing nuclear energy. While EV GHG emissions decrease over time due to grid decarbonization, future ICEVs can lower the GHG emissions, especially for larger vehicles, where EVs might not be the best option. Therefore, EV and ICEV can together lower transportation GHG emissions at a faster pace.

An Integrated Assessment of Emissions, Air Quality, and Public Health Impacts of China's Transition to Electric Vehicles

Electric vehicles (EVs) are a promising pathway to providing cleaner personal mobility. China provides substantial supports to increase EV market share. This study provides an extensive analysis of the currently unclear environmental and health benefits of these incentives at the provincial level. EVs in China have modest cradle-to-gate CO2 benefits (on average 29%) compared to conventional internal combustion engine vehicles (ICEVs), but have similar carbon emissions relative to hybrid electric vehicles. Well-to-wheel air pollutant emissions assessment shows that emissions associated with ICEVs are mainly from gasoline production, not the tailpipe, suggesting tighter emissions controls on refineries are needed to combat air pollution problems effectively. By integrating a vehicle fleet model into policy scenario analysis, we quantify the policy impacts associated with the passenger vehicles in the major Chinese provinces: broader EV penetration, especially combined with cleaner power generation, could deliver greater air quality and health benefits, but not necessarily significant climate change mitigation. The total value to society of the climate and mortality benefits in 2030 is found to be comparable to a prior estimate of the EV policy's economic costs.

Solar-Powered Charging Networks for Electric Vehicles

The cost of solar-generated electricity and battery costs have been decreasing significantly. These developments can be combined to introduce solar-powered charging networks with demand management prices (DMP) to enable electric vehicle (EV) customers to help utilities to manage renewable energy. As solar-generated electricity becomes the cheapest source of power, the need to increase demand for electricity during the day can be met by charging EVs at an attractive DMP in parking lots with solar panels and charging stations that are connected to the electrical grid. The demand for electricity can be managed and controlled by the utility with the goal of increasing demand for power as needed so that all electricity that is generated can be sold. The proposal is to introduce a new DMP rate that is only implemented when the utility wants to increase demand and sell power at this low rate in order to make full use of the supply. As utilities strive to reach 100% renewable electrical power to serve a society transported by EVs, cooperative plans to make good use of batteries in EVs for managing the electrical grid will become more important.

Design Patterns and Electric Vehicle Charging Software

The development and maintenance of complex software systems, with ever-changing requirements has benefited from the implementation of design patterns, which ensure a higher degree of maintainability. The present article illustrates the essential role of design patterns in sketching the software architecture for an electric vehicle charging management platform. We have integrated a series of design patterns to create a solid base structure for the API (Application Programming Interface). Furthermore, we have explored cloud design patterns in the deployment process to ensure a proper multi-tenant cloud application with the best possible tenant isolation for the cost. The aim of this paper is to offer readers an introduction in the case study theme, to describe a complex platform development through design patterns. With proper examples from real projects debated in the industry. The paper demonstrates the design patterns applicability from software level to cloud resources plan and advocates for a high-quality solution in every segment of project development. In conclusion, the results are promising, and the functionality of the established methods on this type of platforms will be evaluated during the implementation period. Overall, design patterns have proven to be essential in the development process, ensuring effective team communication and the delivery of qualitative software solutions.