PhD student Temitope Amuda with Advisor A. Domínguez-García

We consider a data-driven frequency and voltage regulator for inverter-based power systems, specifically those integrating energy storage systems (ESSs) and photovoltaic (PV) arrays.  A key challenge addressed by this work is the practical limitation of having complete knowledge of the power system model, including the network admittance matrix, inverter dynamics, and PV array power-voltage characteristics.  To address this, we assume the power system model is not known.  The proposed control scheme employs two main components: an online recursive sensitivity estimator and a frequency and voltage controller.  The estimator determines the sensitivities of system frequency and critical bus voltages to the active and reactive power injections of the inverter-based resources (IBRs), while the controller leverages these sensitivities to adjust IBR power injections, minimizing deviations of system frequency and bus voltages from nominal operating conditions.

To validate the proposed control scheme, simulations were conducted on a modified IEEE 300-bus test system, designed to represent a large-scale, inverter-dominated power network.  The simulations focused on regulating system frequency and bus voltage magnitudes at critical buses by adjusting the active and reactive power injections of the IBRs, while subjecting the system to load fluctuations.  Major load changes were introduced at 3.5 seconds and 7 seconds.  Figure 22 demonstrated the controller’s ability to swiftly return the system frequency to its nominal value within one second following major load changes.  Furthermore, Figure 23 shows that the mean absolute error of the bus voltage magnitudes was reduced to below 10^(-4) after each substantial load variation, highlighting the controller’s effectiveness in maintaining voltage stability.  These results demonstrate the effectiveness of the proposed data-driven control scheme in addressing frequency and voltage regulation challenges in inverter-based power systems.

Figure 22. Trajectory of system frequency for the control scheme applied to the modified IEEE 300 test system.

Figure 23. Trajectory of the MAE of critical bus voltage magnitudes from their nominal values for the control scheme applied to the modified IEEE 300 test system.