No abstract

Abstract:The Proportional Resonant (PR) current controller provides gains at a certain frequency (resonant frequency) and eliminates steady state errors. Therefore, the PR controller can be successfully applied to single grid-connected PV inverter current control. On the contrary, a PI controller has steady-state errors and limited disturbance rejection capability. Compared with the L-and LC filters, the LCL filter has excellent harmonic suppression capability, but the inherent resonant peak of the LCL filter may introduce instability in the whole system. Therefore, damping must be introduced to improve the control of the system. Considering the controller and the LCL filter active damping as a whole system makes the controller design method more complex. In fact, their frequency responses may affect each other. The traditional trial-and-error procedure is too time-consuming and the design process is inefficient. This paper provides a detailed analysis of the frequency response influence between the PR controller and the LCL filter regarded as a whole system. In addition, the paper presents a systematic method for designing controller parameters and the capacitor current feedback coefficient factor of LCL filter active-damping. The new method relies on meeting the stable margins of the system. Moreover, the paper also clarifies the impact of the grid on the inverter output current. Numerical simulation and a 3 kW laboratory setup assessed the feasibility and effectiveness of the proposed method. OPEN ACCESSEnergies 2014, 7 3935

No abstract

Summary The advancement and deployment of electric vehicle (EV) technologies are considered as an emergent solution to meet the current and future energy crises. The electrification of transportation systems is a promising approach to green the transportation systems and to reduce the issues of climate change. This paper investigates the present status, latest deployment, and challenging issues in the implementation of EV infrastructure, charging power levels, in conjunction with several charging power topologies, and analyzes EV impacts and prospects in society. In this study, the on‐board and off‐board categories of charging systems with unidirectional and bidirectional power flow comparison are addressed. Moreover, an extensive analysis of unidirectional and bidirectional chargers is presented. Unidirectional charging offers hardware limitation and reduces the interconnection issues. Bidirectional charging provides the fundamental feature of vehicle‐to‐grid technology. Furthermore, the beneficial and harmful impacts of EVs are categorized with remedial measures for harmful impacts and prolific benefits for beneficial impacts.

No abstract