Virtual Inertia Implementation in Dual Two-Level Voltage Source Inverters

In this paper, the implementation of virtual inertia in a dual two-level voltage source inverter (DTL VSI) configuration is investigated. The derivative control method is employed to provide virtual inertia. The virtual synchronous generator (VSG) topology is presented, and its elements are introduced. According to the frequency changes, the active power reference is generated. Moreover, the control structure is designed and presented to control the DTL VSI properly. By means of the derivative control method, the DTL VSI participates in the frequency regulation, and the frequency oscillations during contingencies are confined. The results show that the controller follows its reference in all cases. The potentiality of the proposed controller is confirmed through MATLAB simulations. Compared to the conventional DTL VSI, the rate of change of frequency (ROCOF) and frequency nadir are reduced during disturbances.