Establishing the Value of Battery Energy Storage System in a dc Fast Charging Sta-tion

abstract: The objectives of this research project were to develop a model of real power demand from a dc fast charging station both with and without an integrated battery energy storage system (BESS). An optimal deterministic control strategy was devel-oped to perform load-shaping under various scenarios with various load-shaping goals in mind to establish the value for BESS’s with various power and energy capacities. To achieve these objectives, first a statistical model of electric vehicle drivers’ charging behaviors (home charging and dc fast charging) was constructed and simu-lated according to empirical charging data and several key findings about people’s charging habits in the literature. Data of private vehicles’ driving records was extracted from the National Household Travel Survey (NHTS), derived 42 statistical distributions that mathe-matically modeled people’s driving behaviors. From this start, two algorithms were developed to simulate driver behavior: one using a database sampling method (DSM) and another using probability distribution sampling method (PDSM) to simulate the electric vehicles’ driving cycles. Both methods used data and statistical distributions derived from NHTS. Next, a model of the EV drivers’ charging behavior was incor-porated into the simulation of the electric vehicles’ driving cycles, and then the ve-hicles’ charging behaviors were simulated. From these simulations, one can forecast the real-power demand of a typical dc fast charging station with six dc 50 kW fast chargers serving a population of 700 EVs. (The ratio of six dc fast chargers to 700 EVs was selected based on the current value of this ratio in the US.) Next, a BESS was integrated into the dc fast charging station demand model and the size and charging behavior was optimized to account for different criteria which were based on the goals of the different potential owners: SRP or a third-party owner. It was established when a BESS would become economically feasible using a simplified economic model. It was observed that the real-power demand shape is a function of the size of the BESS and the owner’s objective, i.e., flattening the demand curve or minimizing the cost of electricity.Dissertation/ThesisMasters Thesis Electrical Engineering 201

Indiana Electric Vehicle Infrastructure Implementation Update

2022 was a big year for EV infrastructure in Indiana. Starting with the approval of Indiana’s EV Implementation Plan in September 2022, INDOT and their team have been working fast and furiously to plan and deploy a network of DC Fast Charging Stations across the state. We will give an update on the plan implementation and next steps to inform stakeholders across the state on what they need to know for the next few years

Workload patterns of fast charging stations along the German Autobahn

We analyze daily charging demand patterns of electric vehicles at DC fast charging stations along the German autobahn for an average week in 2020. For this we develop an agent based simulation tool based on current empirical mobility data. Our results show that already in 2020 about 1,000 charging processes per charging location and day might be realistic. In order to avoid long waiting times these charging locations should be equipped with about 20 charging points. A utilization rate of up to 80% makes a profitable operation of these stations highly probable. A sensitivity analysis indicates main parameters which influence the throughput of electric vehicles significantly

A Novel MIMO Control for Interleaved Buck Converters in EV DC Fast Charging Applications

This brief proposes a new multiple input multiple output (MIMO) control for off-board electric vehicle (EV) dc fast chargers. The proposed feedback matrix design avoids multiple tuning of controllers in multiple and interconnected loops while improving the performance of interleaved dc buck converters over classical PI/PID controls. The innovative features of the presented strategy are the reference current monotonic tracking from any initial state of charge with an arbitrarily fast settling time and the fast compensation of both load variations and imbalances among the legs. Numerical results validate the performance improvements of the proposed discrete-time MIMO algorithm for interleaved buck converters over classical PI/PID controls. Full-scale hardware-in-the-loop (HIL) and scaled-down prototype experimental results prove the feasibility and effectiveness of the proposal

Design of DC Fast Charging Station for Light Electric Vehicles

The thesis is devoted to the design of a direct current fast charging station for light electric vehicles. The work consists of two parts. The first part is a theoretical study of existing technologies in the field of charging stations. The second part is the design of the charging station itself, which consists of the hardware and the software part. The hardware part of the project describes all the components of the device and the scheme of their connection. The software part presents a proprietary protocol for interaction between the charging station and an electric vehicle, an algorithm for controlling the station with a human-machine interface, and a variant of organizing remote control and monitoring of the station.The thesis is devoted to the design of a direct current fast charging station for light electric vehicles. The work consists of two parts. The first part is a theoretical study of existing technologies in the field of charging stations. The second part is the design of the charging station itself, which consists of the hardware and the software part. The hardware part of the project describes all the components of the device and the scheme of their connection. The software part presents a proprietary protocol for interaction between the charging station and an electric vehicle, an algorithm for controlling the station with a human-machine interface, and a variant of organizing remote control and monitoring of the station.

Charging strategies for economic operations of electric vehicles in commercial applications

When substituting conventional with electric vehicles (EV) a high annual mileage is desirable from an environmental as well as an economic perspective. However, there are still significant technological limitations that need to be taken into consideration. This study presents and discusses five different charging strategies for two mobility applications executed during an early stage long-term field test from 2013 to 2015 in Germany, which main objective was to increase the utilization within the existing technological restrictions. During the field test seven EV drove more than 450,000 km. For four out of five presented charging strategies the inclusion of DC fast charging is indispensable. Based on the empirical evidence five key performance indicators (KPI) are developed. These indicators give recommendations to economically deploy EV in commercial fleets. The results demonstrate that the more predictable the underlying mobility demand and the more technical information is available the better the charging strategies can be defined. Furthermore, the results indicate that a prudent mix of conventional and DC fast charging allows a high annual mileage while at the same time limiting avoidable harmful effects on the battery