Stability Analysis of Triple Active Bridge Converter with Hybrid Loads and Different Control Strategies

This article investigates the stability of triple active bridge (TAB) converter with different types of loads. In this paper, port2 of TAB converter adopts voltage control to supply a constant power load (CPL), and port3 uses voltage control to supply a resistor or uses current control to supply a battery. Then, an extra element theorem-based ...

An Adaptive Virtual Impedance Control for Reactive Power Sharing in Microgrids

In multi-inverter parallel connected islanded micro-grids, reactive power sharing is challenged by the differences in feeder impedance and various controller parameters. In order to address this issue, a virtual impedance reshaping strategy based on the consensus algorithm is proposed in this paper. The proposed method facilitates adaptive...

Stability Enhanced Design of EV Chargers for Weak Grid Connection

Reinforcement of the legacy grid infrastructure will be very costly and thereby unrealistic. Consequently, weak grid connection of electric vehicle (EV) chargers will sooner or later be the case. It may however bring instability issues since the EV chargers that can work well in strong grid conditions usually do not fit the weak grid...

Virtual Impedance Control for Load Sharing and Bus Voltage Quality Improvement

This paper proposes a virtual impedance reshaping strategy to share active and harmonic power while promoting the PCC voltage quality. Moreover, the suggested method is resilient to cyber-attacks and immune to communication interruption and delay. Furthermore, it significantly reduces the communication burden. Experiments verify the...

Critical Short Circuit Ratio of an EV Charging System

The critical short circuit ratio (CSCR), as an important metric for grid stability evaluation, is not clearly defined in the literature. Aimed at clarifying the misunderstandings, the paper compares the different CSCR definitions. Moreover, CSCR reduction-oriented design is studied for electric vehicle chargers. Simulations verify the analysis.

Detection of cyber attack in smart grid: A Comparative Study

Smart grid steady control relies heavily on the communication infrastructure among sensors, actuators, and control systems, which makes it vulnerable to cyber-attacks. Accurate acquisition of dynamic state information is deemed vital for efficient detection of these cyber-attacks on a smart grid. However, several popular state estimation...

Review on Power Quality Issues in EV Charging

Electric vehicles (EVs) are playing a crucial role in achieving the carbon neutral goal. To make the charging experience comparable with the refueling of the gasoline cars, more and more chargers are installed and connected to the grid. Meanwhile, the charging power is going up. As a result, more and more power quality issues associated with EV...

An Adaptive Cyber Security Scheme for AC Microgrids

Distributed secondary control is deemed necessary to restore the state of AC micro-grids to set points. However, for its limited global information, the power electronic system is vulnerable to cyber-attacks that aim to desynchronize converters or even cause a shutdown of micro-grids by unnecessarily triggering the protection schemes. To this...

Harmonic Emission Modelling of Electric Vehicle Chargers

In emerging fast-charging stations, DC fast chargers (DCFCs) are employed which rely on power electronics and control to achieve the required performance. Harmonic emission induced by the complex system behavior is of great concern in the DCFC system. This paper proposes a harmonic emission model for the typical electric vehicle charger...

Multi-timescale Modeling of Fast Charging Stations for Power Quality Analysis

To accurately simulate the harmonic emission of EV DC fast chargers (DCFCs) and the harmonic voltage of the power grid to which the chargers are connected, a small time-step, i.e., typically smaller than 10μs, is required. However, for harmonic assessment, a long timescale, typically a day, is required. A conflict between accuracy and time...

Design, modelling and evaluation of a GaN based motor drive for a solar car

In recent years, electrical vehicle (EV) starts showing its unique advantages that the conventional combustion vehicles do not have. Together with the increasing interests on EV, the motor drive with higher efficiency and lighter weight also becomes more attractive. A promising solution is to apply the wide band gap (WBG) components including...