ELD-OSG Control of a Battery-Based Electronic Load Controller for a Small Hydro Energy Conversion System

To provide clean and cheap electricity in remote and hilly areas, where the availability of the utility grid is of concern, small hydro generation possesses a promising solution. This article focuses on the utilization of a small hydro energy conversion (SHEC) system. An enhanced Lyapunov's demodulator (ELD)-based orthogonal signal generator technique is utilized for the extraction of active and reactive components of the load currents in the standalone mode. Moreover, synchronization of the SHEC system is required with the utility grid for smooth power transfer, henceforth the ELD scheme is used for the estimation of frequency whose range complies with the IEEE 1547-2018 std. The system is investigated for both standalone as well as seamless transfer to grid-connected operation and serves the major concerns, i.e., in the standalone mode, it regulates the frequency and terminal voltage to their nominal values at the point of interconnection (PoI). Besides, it mitigates the harmonics injected into the system on account of nonlinear load, which distorts the voltages and currents at the PoI in both modes. Finally, it rectifies the unbalance in the voltages and currents of the hydrogenerator due to the presence of unbalanced loads at the PoI. A comparative analysis of the ELD scheme with other algorithms is provided, which depicts the robustness of the control algorithm. Moreover, comparative performance of estimation of frequency extracted from the ELD approach with other control is also given. A hardware prototype is developed and test results are presented to validate the above-mentioned features. The power quality results depict the total harmonic distortion of the voltages and currents to comply with the IEEE-519 std.