A Modular Multilevel Interface for Transformerless Grid Integration of Large-Scale Infrastructure for Wireless Electric Vehicle Charging

Giuseppe Guidi,Salvatore D"Arco,Jon Are Suul,Ryosuke Iso,Jun-Ichi Itoh 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5

This paper presents a system configuration for transformer-less grid integration of large-scale charging infrastructures for electric vehicles (EVs) with wireless inductive charging. The proposed configuration relies on a Modular Multilevel Converter (MMC) topology as the grid interface of the charging infrastructure, where one wireless EV charger can be supplied from each individual module. This system topology could provide significant reduction in footprint and complexity of cable installations by allowing for transformer-less connection and direct integration with the medium voltage distribution grid. The requirements for power flow management when charging EVs that are unevenly distributed within the infrastructure are evaluated analytically. On this basis, a control strategy is presented for ensuring horizontal and vertical energy balancing among the MMC arms, and voltage balancing among the modules of each arm. Time-domain simulations demonstrate how the system can operate with severe unbalances resulting from different number and location of charging EVs.

Driving Performance Experimental Analysis of Series Chopper Based EV Power Train

Kawamura, Atsuo,Guidi, Giuseppe,Watanabe, Yuki,Tsuruta, Yukinori,Motoi, Naoki,Kim, Tae-Woong The Korean Institute of Power Electronics 2012 JOURNAL OF POWER ELECTRONICS Vol.12 No.6

In this paper, the series chopper based power train for electric vehicle is proposed for aiming the increase of one battery charge driving distance. Both the motor test bench based experiments and the chassis dynamo based experiments are tested and then analyzed for EV driving performance that the proposed power train with SAZZ chopper and Quasi-PAM control scheme is compared with or without the series chopper. It is confirmed through two kinds of experimental analyses that the series chopper power train for EV can be useful to extend the driving distance if the high efficiency and the low weight of chopper are satisfied.

Driving Performance Experimental Analysis of Series Chopper Based EV Power Train

Atsuo Kawamura,Giuseppe Guidi,Yuki Watanabe,Yukinori Tsuruta,Naoki Motoi,Tae-Woong Kim 전력전자학회 2012 JOURNAL OF POWER ELECTRONICS Vol.12 No.6

In this paper, the series chopper based power train for electric vehicle is proposed for aiming the increase of one battery charge driving distance. Both the motor test bench based experiments and the chassis dynamo based experiments are tested and then analyzed for EV driving performance that the proposed power train with SAZZ chopper and Quasi-PAM control scheme is compared with or without the series chopper. It is confirmed through two kinds of experimental analyses that the series chopper power train for EV can be useful to extend the driving distance if the high efficiency and the low weight of chopper are satisfied.

Four quadrant SAZZ-1 Chopper for EV and HEV power train

Yukinori Tsuruta,Martin Pavlovsky,Giuseppe Guidi,Atsuo Kawamura 전력전자학회 2011 ICPE(ISPE)논문집 Vol.2011 No.5

This paper discusses four quadrant SAZZ-1 chopper (Snubber Assisted Zero Voltage and Zero Current Switching) and its direct application to a EV (Electric Vehicle) power train. The performance of SAZZ-1 chopper is demonstrated on several prototypes. The first prototype is a 25 ㎾, 50 ㎑ SAZZ-1 with efficiency in the range between 96 % and 97 %. This was further improved by a redesigned SAZZ-1 chopper which reached even higher efficiency in the range of 97 % to over 98 %. Further on, a new mid-power 30 ㎾ water cooled SAZZ-1 chopper was constructed for KAST (Kanagawa Academy of Science and Technology) advanced EV project. This prototype was used and fully tested in an EV prototype named KAST-EVKana. As discussed, SAZZ-1 topology proved to be well performing in direct EV application.

Virtual Synchronous Machine-based Control of a Single-phase Bi-directional Battery Charger forProviding Vehicle-to-Grid Services

Jon Are Suul,Salvatore D"Arco,Giuseppe Guidi 전력전자학회 2015 ICPE(ISPE)논문집 Vol.2015 No.6

This paper presents a single-phase Virtual Synchronous Machine (VSM) and its possible application for providing Vehicle-to-Grid (V2G) services from domestic battery chargers of Electric Vehicles (EVs). In a VSM, the power converter is controlled to emulate the inertia and the damping effect of a synchronous machine. Thus, a VSMbased EV charger can contribute to the spinning reserve and frequency regulation of the power system. In case of grid outages, the VSM can seamlessly establish an islanded grid and supply local loads from the battery onboard the EV. In order to avoid the influence on the virtual inertia from power oscillations associated with a single phase circuit, the proposed control scheme relies on a virtual twophase system for calculating active and reactive powers. The proposed VSM implementation is described in detail and its dynamic performances in grid-connected as well as standalone operation are demonstrated by numerical simulations and by laboratory experiments.

Influence of a Regular, Standardized Meal on Clinical Chemistry Analytes

Gabriel Lima-Oliveira,Gian Luca Salvagno,Giuseppe Lippi,Matteo Gelati,Martina Montagnana,Elisa Danese,Geraldo Picheth,Gian Cesare Guidi 대한진단검사의학회 2012 Annals of Laboratory Medicine Vol.32 No.4

Background: Preanalytical variability, including biological variability and patient preparation, is an important source of variability in laboratory testing. In this study, we assessed whether a regular light meal might bias the results of routine clinical chemistry testing. Methods: We studied 17 healthy volunteers who consumed light meals containing a standardized amount of carbohydrates, proteins, and lipids. We collected blood for routine clinical chemistry tests before the meal and 1, 2, and 4 hr thereafter. Results: One hour after the meal, triglycerides (TG), albumin (ALB), uric acid (UA), alkaline phosphatase (ALP), Ca, Fe, and Na levels significantly increased, whereas blood urea nitrogen (BUN) and P levels decreased. TG, ALB, Ca, Na, P, and total protein (TP) levels varied significantly. Two hours after the meal, TG, ALB, Ca, Fe, and Na levels remained significantly high, whereas BUN, P, UA, and total bilirubin (BT) levels decreased. Clinically significant variations were recorded for TG, ALB, ALT, Ca, Fe, Na, P, BT, and direct bilirubin (BD) levels. Four hours after the meal, TG, ALB, Ca, Fe, Na, lactate dehydrogenase (LDH), P, Mg, and K levels significantly increased, whereas UA and BT levels decreased. Clinically significant variations were observed for TG, ALB, ALT, Ca, Na, Mg, K, C-reactive protein (CRP), AST, UA, and BT levels. Conclusions: A significant variation in the clinical chemistry parameters after a regular meal shows that fasting time needs to be carefully considered when performing tests to prevent spurious results and reduce laboratory errors, especially in an emergency setting. Background: Preanalytical variability, including biological variability and patient preparation, is an important source of variability in laboratory testing. In this study, we assessed whether a regular light meal might bias the results of routine clinical chemistry testing. Methods: We studied 17 healthy volunteers who consumed light meals containing a standardized amount of carbohydrates, proteins, and lipids. We collected blood for routine clinical chemistry tests before the meal and 1, 2, and 4 hr thereafter. Results: One hour after the meal, triglycerides (TG), albumin (ALB), uric acid (UA), alkaline phosphatase (ALP), Ca, Fe, and Na levels significantly increased, whereas blood urea nitrogen (BUN) and P levels decreased. TG, ALB, Ca, Na, P, and total protein (TP) levels varied significantly. Two hours after the meal, TG, ALB, Ca, Fe, and Na levels remained significantly high, whereas BUN, P, UA, and total bilirubin (BT) levels decreased. Clinically significant variations were recorded for TG, ALB, ALT, Ca, Fe, Na, P, BT, and direct bilirubin (BD) levels. Four hours after the meal, TG, ALB, Ca, Fe, Na, lactate dehydrogenase (LDH), P, Mg, and K levels significantly increased, whereas UA and BT levels decreased. Clinically significant variations were observed for TG, ALB, ALT, Ca, Na, Mg, K, C-reactive protein (CRP), AST, UA, and BT levels. Conclusions: A significant variation in the clinical chemistry parameters after a regular meal shows that fasting time needs to be carefully considered when performing tests to prevent spurious results and reduce laboratory errors, especially in an emergency setting.

Minimization of dead time effect on bridge converter output voltage quality by use of advanced gate drivers

Havard Lefdal Hove,Ole Christian Spro,Dimosthenis Peftitsis,Giuseppe Guidi,Kjell Ljøkelsøy 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5

This paper presents a voltage-controlled multistage gate driver topology for delay time minimization that improves the converter output voltage quality while supplying a motor load. Three gate driver topologies for SiC MOSFETs are compared based on their dead time requirement in a bridge leg converter. Experimental results of the gate driver delay times are reported and are used as input to a simulated motor drive application. Results show that turn-off delay times can be reduced by up to 74% for the multistage driver compared to the conventional counterpart when the rate of change for the converter voltage output is limited to 10 V/ns. Furthermore, minimizing the dead time increases the linearity region of the output voltage from the converter by 1.8% to 3.8% and reduces the current THD in the linear region by up to 7.7% when switching at 15 kHz.