A V2G Enabled Bidirectional Single/Three-Phase EV Charging Interface Using Modular Multilevel Buck PFC Rectifier

Abstract

The battery charging power electronics interface of an electric vehicle (EV) must be capable of bidirectional power flow to enable both grid-to-vehicle (G2V) and vehicle-to-grid (V2G) operations. In the presence of a single/three-phase AC supply, the front-end of the EV charger employs a power factor correction (PFC) rectifier, which should have the bidirectional capability to facilitate V2G mode. A conventional active rectifier functions in boost mode while performing PFC and voltage regulation. In most of the currently available EVs, however, the battery nominal voltage is low and, hence, a downstream high step-down DC-DC converter and high voltage DC bus capacitor are required in the charging interface. To overcome these issues, this work proposes a bidirectional AC-to-DC buck rectifier topology that can operate in G2V and V2G modes, both in single- and three-phase versions. The proposed topology utilizes the switched capacitors principle to achieve self-balancing of voltages in the capacitors. In addition, it is highly modular in structure. This paper describes the proposed topology, its working and modulation and its applications. The hardware proto model is used to validate the proposed power converter and the control approach to achieve PFC and voltage regulation. In addition, a comparison with other topologies is presented to demonstrate its competence.

Analysis of Optimal Operation of Charging Stations Based on Dynamic Target Tracking of Electric Vehicles

“…P rep (t) ≥ αP total (t) (10) where P rep is the new energy generation power at moment t; P total is the total demand load of the charging station at moment t; and a is the minimum self-generation rate of the charging station system.…”

“…Many scholars have studied the dynamic target tracking and economic operation of charging stations, and the literature [8,9] uses the Monte Carlo method to extract the driving characteristics of electric vehicles, considering the autonomy of the user in terms of driving time. The literature [10] proposes a bi-directional alternating current-direct current (AC-DC) buck rectifier topology for a charging station interface that can operate in grid-to-vehicle (G2V) and vehicle-to-grid (V2G) modes, including single-phase and three-phase versions. The literature [11] also proposes an optimal EV charging regulation method to analyze the impact of PV charging stations on the economic operation of the grid, as well as carbon emissions, by comparing the disorderly charging situation.…”

New combined control strategy of on-board bidirectional battery chargers for electric vehicles

“…In [7] a new non-isolated integral bidirectional onboard EV charger was proposed with benefits such as a longer motor lifespan and soft switching to enhance effectiveness and minimize filter size. In [8], it was suggested to use a flexible multilevel buck PFC rectifier to support the G2V and V2G modes of single-and three-phase chargers. Proposes a novel five-level single-phase active neutral point clamp (ANPC) that makes use of a DC/DC dual-active half-bridge converter for improved the quality of power and efficiency [9].…”

Bidirectional Power Converters for EV Battery Chargers

“…A modular multilevel buck PFC rectifier enabling the use of the G2V and V2G modes of a single/three-phase EV charger was proposed in [6]. As an added value, the proposed topologies permitted operation in the G2V and V2G modes in both the single-phase and three-phase structures.…”