Performance Evaluation of Homogeneous and Heterogeneous Droop-Based Systems in Microgrid—Stability and Transient Response Perspective

Proportional load sharing and stability are two main issues for the parallel operation of inverter-based distributed generators (DGs) in microgrids. To address these issues, many novel control techniques like conventional droop control, generalized droop control, inverse droop control, transient droop control, virtual synchronous machines, etc. are proposed in the literature. Majority of the work presented in the literature assumes a homogeneous mixture of these inverters, i.e., same type of control in all the generators. However, integration of inverter-based DGs manufactured by different vendors into the system operating on different droop laws makes the system more heterogeneous. Such systems are prone to have stability and transient issues. In the present paper, stability and transient response of distributed generators characterized by various droop control techniques in an islanded microgrid with homogeneous and heterogeneous mix is evaluated through mathematical analysis, simulation, and experiments.