Title

All-SiC ANPC Submodule for an Advanced 1.5 kV EV Charging System under Various Modulation Methods

Abstract

This work is focused on the design and experimental validation of the all-SiC active neutral-point clamped (ANPC) submodule for an advanced electric vehicle (EV) charging station. The topology of the station is based on a three-wire bipolar DC bus (±750 V) connecting an ac grid converter, isolated DC-DC converters, and a non-isolated DC-DC converter with a battery energy storage. Thus, in all types of power converters, the same three-level submodule may be applied. In this paper, a submodule rated at 1/3 of the nominal power of the grid converter (20 kVA) is discussed. In particular, four different modulation strategies for the 1.5 kV ANPC submodule, exclusively employing fast silicon carbide (SiC) MOSFETs, are considered, and their impact on the submodule performance is analyzed. Moreover, the simulation study is included. Finally, the laboratory prototype is described and experimentally verified at a switching frequency of 64 kHz. It is shown that the system can operate with all of the modulations, while techniques PWM2 and PWM3 emerge as the most efficient, and alternating between them, depending on the load, should be considered to maximize the efficiency. Furthermore, the results showcase that the impact of the different PWM techniques on switching oscillations, including overvoltages, can be nearly fully omitted for a parasitic inductance optimized circuit, and the choice of modulation should be based on power loss and/or other factors. View Full-Text

Keywords: ANPC converterEV chargingmultilevel converterPWM methodsSiC MOSFETs

Authors: Rafał Kopacz,Michał Harasimczuk,Bartosz Lasek,Rafał Miśkiewicz and Jacek Rąbkowski 

Date of publication: 6 September 2021


TITLE

Battery Charging System with Three-level ANPC Converter Operating at Variable Bipolar DC-link

Abstract

Three-level converters are an interesting solution for the input stage of EV charging systems as a number of advantages over two-level counterparts can be found, only to mention the better quality of the processed energy (lower harmonic distortion and EMI level). On the other hand, higher element count and power loss may be recognized as disadvantages. In such systems switching losses represent a significant part of the overall losses even if modern SiC power devices are applied. To resolve this issue, this paper focuses on the single-phase (1/3 PWM) modulation of the three-level Active Neutral-Point-Clamped (ANPC) converter. The system also contains a three-level DC/DC converter connected to the energy storage, which delivers variable DC-link voltage. A simulation study compares variable DC-link approach to other PWM strategies: carrier-based sinusoidal with 3 rd harmonic component and two-phase discontinuous modulation. For the investigated 20 kW charging system with the 1/3 modulation the semiconductor losses of the ANPC converter drop by 184 W (0,92% of nominal power). Operating conditions of the DC/DC converter are challenging due to required variable DC-link voltage but with a lower average value. This also leads to decreased switching loss. All in all, the total loss in selected SiC MOSFETs (C3M0015065K) semiconductors are reduced by 0,96% of nominal power.

Authors: Michał HarasimczukKrzysztof KalinowskiJacek Rąbkowski

Date of Conference: 13-16 October 2021


Conference

PCIM Europe 2022

TITLE

Three-level ANPC converter as an input stage of an EV charging system with bipolar DC link

Abstract

This paper presents a three-level ANPC AC/DC converter designed as an input stage on the grid side for an EV fast-charging system with a bipolar +/- 750 V DC-link. A 20 kVA prototype based on an universal All-SiC MOSFET ANPC submodule is shown. The focus is put on the design of the experimental model, along with the description of the control of the system, and its validation, both in simulation and experimental tests. The study shows that such a converter can be competitively employed as an input for such a system as it provides high flexibility of operation, good quality of the waveforms, and reasonable efficiency.

Authors: Michał Harasimczuk, Krzysztof Kalinowski, Rafał Miśkiewicz, Rafał Kopacz, Jacek Rąbkowski

Date of Conference: 10-12 May 2022


TITLE

Advanced charging system with bipolar DC-link and energy storage

Abstract

This paper presents a three-level ANPC AC/DC converter designed as an input stage on the grid side for an EV fast-charging This paper investigates an advanced electric vehicle fast-charging system with a bipolar DC-link rated at
+/- 750 V. The bipolar dc grid concept is known to provide lower on-state loss and much higher flexibility compared to conventional unipolar systems. However, multilevel structure  also requires a proper balancing mechanism. The system described in the article contains three types of bidirectional three-level converters based on 1200 V SiC power devices: active-neutral-point-clamped (ANPC) grid converter, non-isolated DC/DC converter for battery energy storage, and isolated dual active-bridge as interface with electric vehicles. All of the converters use the same submodule. The crucial part of the infrastructure is energy storage which enables managing power flow across the converters, thus providing more independence from the grid, such as exceeding maximal charging power from the grid or providing standalone work in case of grid failure. Moreover, bidirectional converters also enable to operate as grid backup energy storage or return energy from the vehicle batteries in vehicle-to-grid (V2G) operation. The study is focused on the various operation modes of the presented fast-charging station, grounded on the theoretical and simulation-based analysis.

Authors: Jacek Rąbkowski, Dimosthenis Peftitsis,  Radosław Sobieski, Michał Harasimczuk, Rafał Miśkiewicz, Kaushik Naresh Kumar, Rafał KopaczKrzysztof Kalinowski, Przemysław Trochimiuk

not available yet

Date of Conference: 27.06 – 01.07 2022


TITLE

Performance Evaluation of SiC-based Isolated Bidirectional DC/DC Converters for Electric Vehicle Charging

Abstract

In this paper, six 10 kW DC/DC isolated and bidirectional dual active bridge topologies, supplied by +750/0/-750V three-wire DC bus, are evaluated based on efficiency, loss distribution, volt-ampere semiconductors ratings and normalized cost of SiC MOSFETs for electric vehicle charging applications. The selected topologies are evaluated under the same voltage and power conditions, through electrothermal simulations and experiments. The simulation results were verified through experiments conducted on 5 kW prototypes of four of the considered topologies. The advantages and disadvantages of the topologies are discussed and analyzed based on the chosen performance metrics. It has been shown that series-resonant input-series output-parallel full-bridge DAB topology exhibits the highest efficiency while the active neutral point clamped (ANPC) DAB topology can be designed with the lowest cost. However, considering a fair trade-off between all the performance metrics, series-resonant ANPC DAB topology is shown to be the best design choice for the considered evaluation conditions.

Authors: Kaushik Naresh Kumar, Rafał Miśkiewicz, Przemysław Trochimiuk, Jacek Rąbkowski, Dimosthenis Peftitsis

Date of Conference: 5-9 September 2022


Conference

The 15th Conference Control in Power Electronics and Electric Drives – “SENE 2022”

TITLE

Three-Level Interleaved Non-isolated DC/DC Converter as a Battery Interface in an EV Charging System with Bipolar DC-Link

Abstract

This study presents a three-level, interleaved, non-isolated DC/DC converter designed as a battery interface for an EV fast-charging system with a bipolar +/- 750 V DC-link. A 20 kW prototype is exhibited based on a universal All-SiC MOSFET submodule for each leg. The core of the paper is the design of the experimental model, along with the description of the system’s control, as well as validation in simulation and in introductory experiments. It is shown that such a converter employing modularized power modules can properly operate as the DC/DC interface.

Authors: Rafał Kopacz, Michał Harasimczuk, Radosław Sobieski, Jacek Rąbkowski

not available yet

Date of Conference: 23-25 November 2022