This paper addresses the transient stability of grid-forming (GFM) inverters when transitioning from islanded to grid-connected mode. It is revealed that reconnection GFM main grid can be equivalent a step change active power reference, whose impact closely related with local load, reference inverter, and short-circuit ratio (SCR) grid. Such disturbance may cause lose synchronism To avoid loss ...

Grid connected voltage source inverters (VSIs) are essential for the integration of the distributed energy resources. Hysteresis current control (HCC) is a commonly employed method for power control of VSIs. This control method, in contrast with voltage control, provides good dynamics, good stability and implicit over current protection. However, the most important concern of digital implementa...

In this paper, a review of PV inverters is reported based on converter characteristics as the number of energy processing stages, the presence of a transformer (high-frequency or 50Hz transformer), and the adopted configuration of the PV field. In particular, the considered solutions have been evaluated depending on efficiency, input current ripple and life-time of the capacitors coupling with ...

This letter proposes a decentralized control scheme for grid-connected cascaded modular inverters without any communication, and each module makes decisions based on its own local information. In contrast, the conventional methods are usually centralized control and depend on a real-time communication. Thus, the proposed scheme has advantages of improved reliability and decreased costs. The ove...

An improved control strategy for grid-connected inverters within microgrids is presented in this paper. The strategy is based on the classical P-ω and Q-V droop method. The improvement in the proposed control strategy is twofold: Firstly, the transient response of the droop controller is improved by replacing the traditional method of measuring average power, which is based on using a first ord...

This study explores the integration issues of next-generation high-penetration photovoltaic (PV) systems, where the grid is becoming more decentralised and vulnerable. In that case, the PV systems are expected to be more controllable with higher efficiency and reliability. Provision of ancillary and intelligent services, such as fault ride-through and reactive power compensation, is the key to ...

This paper develops a Lyapunov approach to control design for grid connected inverter. The control objective is to track a reference current which is proportional to the fundamental harmonic of the grid voltage. By using the internal model principle, the grid voltage and the reference current are described as the outputs of an autonomous linear oscillatory system. The state of this oscillatory ...

Under weak grid conditions and in microgrids, the gird impedance is often large has a highly varying nature. In such scenario, stabilizing grid-connected inverters with an LCL output filter could be challenging task. The control delay that comes from sampling PWM may contribute to worsen this condition. particular, mentioned causes critical frequency at one-sixth of (f <sub xmlns:mml="http://ww...