Grid-Forming Control of Smart Solid-State Transformer in Meshed Network

Smart solid-state transformer (ST) is a promising solution to modernize the current electricity grid with high penetration of renewables, behaving as an energy hub/router. The ST-fed network can operate in either a radial or meshed configuration, due to the excellent power flow control capability. The power flow control scheme of ST is dependent on the ST-fed network configuration, (e.g., radial or meshed network), which is also impacted by the grid condition, i.e., grid faults. An universal power flow control scheme to allow the ST operating in both radial network and meshed network can avoid the transition caused by switching the control schemes. This paper proposes a grid forming control for the ST to fulfill aforementioned requirements and to ensure the dynamic performances under step change of the power setpoint. The simulation results based on the adapted Cigré LVac grid benchmark models are carried out in Matlab to validate the correctness of the proposed grid forming control of ST.