Antriebe und Energiesysteme von morgen 2022

Chapter grid access:

The dynamics of EV registration numbers are increasingly felt as a time burden in the grids and by the processors. In order to efficiently manage customer requests in the grid access teams, efficient tools for the automated processing of grid requests are being introduced. This so-called digital grid access is demonstrated by means of a real example (source: vorarlberg netz).

Chapter Technical further development of fixed and mobile charging points:

After the introduction of a standardised switching contact in A-CH-CZ, further development steps are presented with a view to supporting the voltage and frequency stability of the grids.

The “Bürgerladenetz BW”, a federal state funded project, enables 20 citizens and small businesses to set up a community based EV-charging infrastructure as pilot customers in rural Baden-Württemberg. The project partners offer the necessary hardware and software for implementation. The wallbox model B3200WFE from the manufacturer EV Plug Technologies Ltd. was supplemented with an IoT device before delivery to the participating pilot customers of the project. Based on this hardware, IoT edge software enables wallbox control by a dashboard, which serves as a user interface to the wallbox operator. A mobile app for wallbox users enables credit card payments for shared use of the e-charging station. In addition, self-use and roaming with RFID cards and chips is possible. While the use of EV charging stations via credit card payment is only slowly increasing, a significant increase in use is expected from the recently implemented roaming option. As part of the project, first power grid simulations on the effects of e-mobility were carried out. The results show that even in a very rural power distribution network with increased power consumption by 13% in 2030, no bottlenecks were identified even if all e-charging was bundled at one time. The next steps are to integrate the future results of the pilot phase into the calculations and to update the underlying assumptions to recent political developments, e.g. the political goal of 15 Mio EVs in 2030. The biggest challenge of the project are the main legal and regulatory barriers, which currently make sharing of charging stations less attractive for wallbox operators. Such hurdles should be removed for functioning peer-to-peer energy supply solutions. Nevertheless, the project has shown, that a community based EV charging infrastructure can be part of the solution in rural areas and will therefore be expanded due to the project’s success.

The ramp up of battery electric vehicles (BEVs) could lead to severe grid issues but also enables flexibility. This paper provides an overview of the challenges and potentials of integrating BEVs in urban and rural power grids. Three charging strategies were modelled on four use cases and six low voltage grids for urban and rural areas. Especially in rural areas, where many cars charge at home overnight, the charging strategy significantly affects grid issues. Purely market-oriented strategies can lead to high load peaks and thus to transformer and line overloading, while even a relatively simple, balanced charging strategy can significantly reduce grid issues.

By 2030, at least 15 million electric vehicles are to be registered in Germany and one million charging points installed. The automotive industry is promoting the development of the charging infrastructure in particular in order to make electromobility more attractive. For example, Volkswagen is increasingly installing charging points in employee parking lots. Most of these charging points are accessible to everyone and some are directly connected to the low-voltage level of the industrial grid, which also supplies the production facilities. Previous studies already show that charging electric vehicles generates harmonics. Industrial grids often contain harmonics due to electronic components in the production facilities. Additionally charging electric vehicles in the industrial grid can lead to further deterioration of the power quality. Therefore, three different electric vehicles are integrated into an industrial grid and simulations are performed. By means of different scenarios, the effects of the electric vehicles with regard to voltage harmonics on the industrial grid are analyzed.

Power generation and distribution to electric vehicle charging points requires investment in the energy sector and infrastructure. Studies show that the expansion is technically and financially possible. The prerequisite is that charging infrastructure and electric vehicles support intelligent and dynamic load management. A communication system that connects all partners in the system supports the implementation of the functions for successful grid integration: charging and load management, authorization, payment systems, bidirectional charging, e-roaming and value-added services. For all interfaces existing in the overall e-mobility system, there are standards for communication protocols that support the above functions through the specified messages and data elements. In this way, tariff tables, maximum possible charging power can be transmitted and the desired scheduling for the charging process can be communicated by the vehicle. Efficient solutions for intelligent load management take into account local as well as temporary conditions, e.g. residential area/parking garage, temporal availability of green electricity. Optimizations can be implemented locally through suitable parameterization. Availability and demand of electricity are in balance.

The aim of this paper is to investigate how supply chains in the German automotive industry are changing against the backdrop of short-term disruptions (using the Covid-19-pandemic as an example) and long-term changes due to the transformation to electric mobility, and how the global supply chains can be made more resilient in the future. For the first time, geomaps are used to depict and quantify the shift in value creation networks for conventional and electric vehicles from Germany to Asia. This can be shown exemplarily for different German manufacturers in the premium and volume segments. The paper highlights the international interdependencies of the automotive industry with Baden-Württemberg as an example, the effects of the Covid-19-pandemic, corporate strategies including product and platform strategies in the transformation to electric mobility and their consequences for value creation networks, as well as recommendations for the design of resilient supply chains for companies and policymakers.

CO₂ assessment over the whole life cycle supports a better understanding for the pathway to net zero CO₂. Therefore, engineering and design of components and powertrains increasingly focus on balancing cost and CO₂ optima for all technology options.

The paper will discuss the latest findings and trends in life cycle assessments of raw material, production, use and end of life for the technology pathways of ICE-hybrid, battery electric and fuel cell electric. For the battery electric pathway, CO₂ reduction effects on battery aging and second life are discussed. The methods and tools for CO₂ engineering are introduced by various examples and sensitivity evaluations. In addition, the future options and reduction potentials in the design to CO₂ developments are laid out. Finally, the scaling effects from the single vehicle over the fleet to the eco system are summarized.

MAHLE, in co-operation with PRETTL, developed a charging plaza, with 2.4 MW rectifier power following a centralized approach, fully flexible distribution of power to up to 20 charging points, with up to 750 kW charging power each, controlled by an intelligent load and tariff management system. With up to 12 charging points this system fulfills the “Deutschlandnetz” tender requirements. To operate the system within the limits of its grid connection, the system will be dynamically configured by big data strategy, and consumers can choose the tariff and thereby the power level based on travel plans and vehicle capabilities.

Electric vehicles represent a promising technology for a sustainable transport sector with reduced CO₂ emissions, especially if the vehicles can be charged with electricity from renewable energy sources. The present work describes an intelligent charging load management system for electric vehicles with integrated charging optimization, which prevents the overloading of operating resources in buildings during multiple simultaneous charging processes and considers local renewable energy sources like PV or biogas fired CHP units. The developed charging load management system can be easily adapted to site-specific conditions and offers an intuitive web-based observation, monitoring and remote maintenance tool for charging infrastructure operators. The intelligent load management avoids in many cases the need for cost-intensive building connection or grid expansions. To make active use of electricity from onsite renewable energy systems, prioritized charging has been developed for a charging load management system. Based on a ramp-up or ramp-down algorithm, a deterministic integer optimization takes place, which also includes a phase-accurate power distribution. The utilization of local renewable electricity increases the general cost effectiveness and in Germany brings additional financial income for public and semi-public charging point operators due to an increased GHG quota from greenhouse gas trading. Furthermore, prioritized charging can be used to react on flexible electricity prices to further minimize costs.

A developed simulation model has been coupled with the control software in a software in the loop environment, to analyze the implemented functionalities of the intelligent charging load management. Input parameters include real vehicle data, generator profiles of a photovoltaic system and a building load profile to obtain realistic simulation results. For electric car charging, measured charging curves have been used. As part of the validation, the functionalities of standard charging load management, the integration of renewable energies, prioritized charging and interactions of different charging modes could be successfully investigated. Initial tests proved how the integrated load management works in real operation.

Vehicle-to-Grid (V2G) technology connects the transportation and power sectors and supports the transition of electrical power generation to renewable energy sources. This can make a valuable contribution to stabilizing the electric grid and integrating renewable sources. Furthermore, the bidirectional energy transfer between battery electric vehicles and the grid enables new revenue streams. This can be made possible through high utilization of local energy resources and participation in the energy and ancillary service markets. Appropriate load shifting strategies and usage of dynamic tariffs can further lower the energy costs for consumers. Evaluating these potentials is crucial for the success of new market actors deploying their business models.

In this context, the paper addresses the automatic aggregation and analysis of market- and environment-related data from various publicly accessible servers. This helps smart energy management strategies to plan V2G capacities in a cost-optimized way. As an example, the revenue opportunities of a parking lot are investigated. The simulation results show that energy costs can be significantly reduced by integrating several revenue streams up to the participation in balancing markets. It is shown that for the investigated use case charging costs can be reduced by up to 72% when utilizing all intelligent charging algorithm measures compared to state-of-the-art grid compliant charging.

With their ability to feed back the electrical energy stored in their batteries, bidirectional electric vehicles can actively contribute to making our power supply system more flexible. However, the actual utilization of the flexibility potential of mobile battery storage requires an intelligent interaction of electric vehicles, charging infrastructure and the overall energy system. In the research project “Bidirectional Charging Management—BDL” such an approach is therefore being developed and tested in a pilot operation with 50 BMW i3 on the basis of various use cases. However, in order to be able to actually fully utilize the energy system-related added value of millions of individual mobile battery storage units, not only the technical development of electric vehicles and charging infrastructure is required, but also the regulatory framework must be adapted and further developed to reflect the requirements of the new flexibility options. In this article, regulatory hurdles and possible solutions for the provision of ancillary services from electric vehicles with bidirectional charging management are shown for three exemplary vehicle-to-grid use cases. In particular, Frequency Containment Reserve as well as for congestion management redispatch services and local network services in accordance with Section 14a of the EnWG are considered.

The research project “Bidirectional Charging Management” (BCM) tests bidirectional charging applications in a comprehensive field trial to demonstrate the customer benefits and value of this technology. Various data are collected for the evaluation of the field trial and the assessment of the different use cases. This study gives an overview of first results while focusing on the private customers. The functionality of the increase of self-consumption use case is described and key values are presented. Due to the delayed start of the field trial, only the unfavorable winter months with less solar radiation could be analyzed so far. Nevertheless, the data show that customers with a large PV system, high household power consumption and connection time during the night as well as a low target State of Charge (SoC) reach the best results in this use case. Furthermore, the own consumption rate and self-sufficiency are compared to different charging methods and the efficiency of the system is evaluated.