Grid-forming (GFM) inverters are recognized as a viable solution to increase the penetration of renewable energy in bulk power systems. However, they are physically different from synchronous generators in terms of overcurrent capability. To protect the power semiconductor devices and support the power grid under severe symmetrical disturbances, the GFM control systems should be able to achieve the following requirements: current magnitude limitation, fault current contribution, and fault reco

This paper proposes a novel configuration of a dual UPQC supplied by a dual photovoltaic (PV), hereinafter referred to as 2UPQC-2PV,to improve the power quality performance of a single-phase 220 V/50 Hz distribution system. The 2UPQC-2PV configuration is proposed to anticipate the possible failure of both inverters in one of the UPQC circuits. The PV array replaces the DC-link capacitor to maintain its voltage connected to the DC-link of the UPQC constant while at the same time supplying active

This paper presented an overview of the characteristics of GFM inverters by comparison with those of traditional grid-following inverters, and the recent innovations in GFM inverter technologies were highlighted, summarizing the benefits and opportunities of GFM inverters for grid interactive operations under different scenarios.1.The functions of GFM inverters. GFM inverters are generally designed as voltage sources that regulate their voltages and frequencies in synergy with power grids thr

A novel PET for a distribution grid called a flexible power distribution unit is proposed in this paper, and the energy exchange mechanism between the network and the load is revealed. A 30 kW 600 VAC/220 VAC/110 VDC medium-frequency isolated prototype is developed and demonstrated. This paper also presents key control strategies of the PET for electrical distribution grid applications, especially under grid voltage disturbance conditions. Moreover, stability issues related to the grid-connected