scholarly journals A Three-Phase Bidirectional Grid-Connected AC/DC Converter for V2G Applications

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Jingang Han ◽  
Xiong Zhou ◽  
Song Lu ◽  
Pinxuan Zhao

The smart grid and electric vehicles (EVs) are widely used all over the world. As the key role, the Vehicle-to-Grid (V2G) has been attracting increasing attention. The bidirectional grid-connected AC/DC converter is one of the indispensable parts in the V2G system, which can realize bidirectional power flow and meet the power quality requirements for grid. A three-phase bidirectional grid-connected AC/DC converter is presented in this paper for V2G systems. It can be used to achieve the bidirectional power flow between EVs and grid, supply reactive power compensation, and smooth the power grid fluctuation. Firstly, the configuration of V2G systems is introduced, and the mathematical model of the AC/DC converter is built. Then, for bidirectional AC/DC converters, the grid voltage feedforward decoupling scheme is applied, and the analysis of PI control strategy is proposed and the controller is designed. The system simulation model is established based on MATLAB/Simulink, and the experiment platform of the bidirectional grid-connected converter for V2G is designed in lab. The simulation and experiment results are shown, and the results evaluate the effectiveness of the model and the performance of the applied control strategy.

Energies ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2591
Author(s):  
Reza Sabzehgar ◽  
Yaser M. Roshan ◽  
Poria Fajri

A nonlinear sliding-mode controller for a three-phase converter, utilized in plug-in electric vehicles (PEVs), is proposed in this paper. The proposed controller enables the utilized converter to perform multiple functions during different operating modes of the vehicle, i.e., grid-to-vehicle (G2V) and vehicle-to-grid (V2G) modes. The bidirectional three-phase converter and the proposed controller operate as a power factor correction circuit, bridgeless boost converter, and rectifier during G2V mode (i.e., plug-in charging), and it operates as a conventional single-stage inverter during V2G mode. The stability analysis of the proposed controller is performed by defining a proper Lyapunov function. The functionality of the proposed nonlinear controller is first evaluated through simulation studies. The feasibility and effectiveness of the proposed control strategy is then validated using an industrial control card through a hardware-in-the-loop (HIL) experimental testbed.


Energies ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1240 ◽  
Author(s):  
Ângelo Casaleiro ◽  
Rodrigo Amaro e Silva ◽  
João Serra

Plug-in electric vehicles (PEVs) are expected to play a role as power grid ancillary service providers through vehicle-to-grid (V2G) chargers, enabling higher levels of renewable electricity penetration. However, to fully exploit the storage capacity of PEVs and fast responsiveness, it is crucial to understand their operational characteristics. This work proposes a characterization procedure for V2G systems providing grid services. It extends the existing literature on response time, AC/DC conversion and reactive power assessment. Illustrative results were obtained by implementing the procedure using a Nissan Leaf battery electric vehicle (BEV) connected to a remotely operated commercial V2G CHAdeMO charger. The V2G system was characterized as having a relative inaccuracy and variability of response inferior to 3% and 0.4%, respectively. Its average communication and ramping times are 2.37 s and 0.26 s/kW, respectively. Its conversion efficiency and power factor both showed degradation in the power values below 50% of the charger’s nominal power. Moreover, the proposed visualizations revealed that: i) the V2G system implements power requests for the DC power flow; ii) the power factor control algorithm was nonoperational; and iii) the acquired data can leverage statistical models that describe the operation of V2G systems (which is of extreme value for researchers and operators).


A reliable grid connected Photovoltaic (PV) system require effective control schemes for efficient use of solar energy. This paper presents a three-phase grid tied PV system with decoupled real and reactive power control to achieve desired power factor with Maximum Power Point Tracking (MPPT) controller to get maximum solar energy. The synchronous reference frame (dq) control along with decoupling concept is used to control the DC-AC inverter output, while the Phase Locked Loop (PLL) synchronization technique is used to monitor and synchronize the voltage and current at the grid side. The DC-DC converter with Incremental Conductance (InC) based MPPT model is also designed in this paper due to better accuracy compared to Perturb & Observe (P&O) algorithm. The simulation is performed in MATLAB/SIMULINK and a 31.5 kW PV system is modelled to get 30 kW power with the help of MPPT at Standard Test Conditions (STC). Any power factor value between 0.85 lagging to 0.9 leading can be obtained by changingreference q current in this inverter control strategy. The simulation results show that the change of reactive powerdoes not affecttheactive power values of the system, which verifies the effectiveness of the decoupled control strategy of the inverter.


Author(s):  
Maruf A. Aminu

This paper is presented in an attempt to validate the dynamic response of a microgrid to line-to-line short circuit. The microgrid components include two identical Wind Turbine Generators (WTGs) tied to a 100MVA, 13.8kV utility via a Point of Common Coupling (PCC). The utility-microgrid testbed is modeled in SIMPOWERSystems® using two Doubly-Fed Induction Generators (DFIGs) in the microgrid side. While in islanded operating mode, line-to-line short circuit fault is applied at 6.0s and withdrawn at 8.0s, obtaining a 50.0s dynamic response of the system for different fault locations, under voltage and reactive power control regimes of the wind turbine controller. For measurement purpose, the absolute value of the stator complex voltage is transformed to  reference frame. Bidirectional power flow between the two feeders is established in the study. The study also confirms that the microgrid composed of DFIGs offer reactive power management capability, particularly by presenting superior performance when stressed under Q control regime than under V control regime. Finally, the response of the testbed to line-to-line short circuit has been validated and shown to be consistent with established short circuit theory.


2012 ◽  
Vol 516-517 ◽  
pp. 1722-1727 ◽  
Author(s):  
Wei Jun Yun ◽  
Gang Yao ◽  
Li Dan Zhou ◽  
Chen Chen ◽  
Jun Min Pan

Nowadays Static Synchronous Compensator (STATCOM) has gradually become one of the representative techniques in the field of dynamic reactive power compensation in the power distribution system. This paper analyzed the topology and the voltage imbalance problem of the up and down capacitors on DC side of the three-phase four-wire STATCOM. In allusion to the imbalance problem of neutral point, a novel control strategy based on the control of zero-sequence current was proposed. By the triple close-loop control strategy, the STATCOM can achieve great control accuracy and dynamic performance. Simulation result proves that the proposed control method is effective.


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