Modeling and Control of a V2G Charging Station Based on Synchronverter Technology

This paper proposes an idea for modeling and con-trol of a V2G charging station(CS)for electric vehicles(EVs)by using synchronverter technology.First,the architecture of the CS is introduced.Then,a T-S fuzzy controller is designed to decide the reference real power of the synchronverter by considering the grid frequency.Due to the inner frequency-and voltage-drooping mechanisms of the synchronverter,the input and output real and reactive power of the CS will be automatically adjusted on the basis of the reference value according to the degree of deviation from the nominal value of the grid frequency and voltage.To ensure the safety of this operation,an adaptive frequency droop coefficient mechanism is designed to adapt the change of the total energy storage of a CS unit by changing the slope of the P-f control characteristic of the synchronverter.The performance of the CS with the proposed control strategy is investigated with EVs of different battery states,different users’sets and under different grid status.Simulation results demonstrate that the proposed strategy can not only effectively perform controlled charging/discharging of each single electric vehicle inside the CS,but also improve the performance of the electricity grid in terms of efficiency,stability and reliability.

Fuzzy Logic Controller-based Synchronverter in Grid-connected Solar Power System with Adaptive Damping Factor

In recent years,renewable energy sources,specifically solar power systems,have developed rapidly owing to their technological maturity and cost effectiveness.However,its grid integration deteriorates frequency stability because of insufficient rotating masses and inertial response.Hence,a synchronverter,which is an inverter that mimics the operation of a synchronous generator,is crucial to interface solar power in a power grid.It stabilizes the power grid by emulating a virtual inertia.However,a conventional proportional-integral(PI)-based synchronverter is not equipped with an adaptive damping factor(Dp)or a digitalized smart controller to manage fast-responding solar inputs.Hence,a novel fuzzy logic controller(FLC)framework is proposed such that the synchronverter can operate in a grid-connected solar power system.In this study,Dp is controlled in real time using an FLC to achieve balance between speed and stability for frequency error correction based on frequency difference.Results of four case studies performed in Matlab/Simulink show that the proposed FLC-based synchronverter can stabilize the grid frequency by reducing the frequency deviation by at least 0.2 Hz(0.4%),as compared with the conventional PI-based synchronverter.

Integration of Photovoltaic Energy to the Grid,Using the Virtual Synchronous Generator Control Technique

Renewable energy is becoming more popular due to its benefits for both economic and environmental reasons.Therefore,having a fault free system will enhance efficiency and proper delivery of power.This paper presents the design,modelling and simulation of a Synchronverter,analyzing its fault and response of the system during integration.A synchronous frequency regulator for grid connection is proposed to improve quick recovery,power quality enhancement and good system performance after a fault occurrence.The swing equation provides the inertia and the damping for stability,swift system integration of photovoltaic energy to the grid and an overall effective performance.The effectiveness of the proposed model was simulated in MATLAB/Simulink to analyze the system’s response during and after a fault occurrence and photovoltaic integration comparing load change at different times.Simulation results and analysis are presented to validate proposed controller.