Variable-Speed PICO Hydel Energy Storage With Synchronverter Control to Emulate Virtual Inertia in Autonomous Microgrids

Autonomous microgrids are potential alternative to grid connectivity for powering remote communities around the globe. A sustainable microgrid with renewables and energy storage having minimum operation and maintenance routines is the most sought option. Batteries are predominantly used to support the stochastic behavior of renewables in such microgrids. However, they are prone to frequent failure and require periodic maintenance, which demands an alternative. Thus, in this article, the renewable powered irrigation system in India was configured to form sustainable pico hydel energy storage (PHES). To enhance the inertia of the microgrid with static sources, virtual inertia capability was induced into PHES by modified synchronverter technology. First, the small-signal modeling approach was presented to derive the closed-loop transfer function of the system. Subsequently, the effect of control parameter variation on system stability and the interaction between the governor and the synchronverter was investigated using eigenvalue analysis. Next, the performance of synchronverter was compared with the established vector control through time-domain simulations in MATLAB/Simulink. The simulation results revealed that the proposed strategy improved the inertial response of PHES and outperformed vector control by reducing peak overshoot, settling time, and steady-state error.