Analyzing Frequency Characteristics: The Role of Traditional and Virtual Inertia in Power Systems

The widespread application of wind and solar energy has led to a significant integration of power electronic devices into the power system, resulting in a reduced level of system inertia. Consequently, the frequency stability of power systems has garnered extensive attention in both academia and industry. Currently, virtual inertia is widely utilized in the control of inverters to compensate for the lack of system inertia. To compare the frequency stability of power systems with virtual inertia against traditional power systems, it is necessary to establish models for simulation analysis. This paper establishes single-machine infinite models for both the synchronous generator and the Virtual Synchronous Generator (VSG), ensuring that the basic parameters of the two models are the same. Taking into account the stiffer external characteristics and control strategies of the inverter, virtual impedance technology is incorporated to smooth the control process. The frequency waveforms obtained from the MATLAB/Simulink simulation model validate the consistency of the frequency characteristics between traditional inertia and virtual inertia.