A transient performance improved strategy based on virtual inertia and its allocation for PV-storage DC Microgrid

Owing to the wide-scale application of renewable energy generation, DC microgrid (DCMG) is regarded as an indispensable part in the future energy landscape. However, DCMG is featured with low inertia as it is highly penetrated with power electronic converters. In order to increase the system inertia and decrease the transient voltage drop of the system, this paper first proposes a virtual inertial control method, i.e., analogous virtual synchronous generator (AVSG) and analyze it from three aspects: initial dynamic response, stability and parameter sensitivity. Further, on the basis of the proposed VIC method, an inertia allocation control (IAC) method was presented to improve the transient characteristics of each energy storage unit (ESU) in the distributed energy storage system (DESS), the maximum output power of ESU and system’s requirement for the virtual inertia are two principles of IAC. Finally, the result of simulations verifies the effectiveness of the proposed control strategy.