Optimal Tuning of Fast P Support in Multi-area HVDC-HVAC Power Systems with Electrolyzers

Abstract

HVDC-HVAC power systems dominated by power electronic converter interfaced elements are exposed to frequency instability risk due to low levels of system inertia and ineffective primary frequency control. Hence, significant research is devoted to new control concepts to enable fast active power (P) - frequency support by power electronic converters. Furthermore, when multiple elements attempt to arrest P imbalances, a coordinated strategy is required to avoid adverse consequences of concurrent and interfering control actions such as steep rate-of-change-of-frequency and over/under frequencies during the frequency containment period. To tackle this issue, in this paper, three different optimization strategies are formulated aiming at a cooperative reaction of fast P controllers attached to the outer control layer of modular multilevel converters (MMCs) applied in HVDC links and proton exchange membrane (PEM) electrolyzers. Each formulation is implemented by combining DIgSILENT PowerFactory 2024 SP2 as a power system simulation tool with a Python-based optimization solver that adopts the mean variance mapping optimization algorithm (MVMO). A comparative analysis performed on a multi-area multi-energy hybrid HVAC-HVDC power system to evaluate the proposed formulations in terms of their applicability, effectiveness according to P reserve availability, optimization convergence rate, and the suitability of the frequency response due critical sudden P imbalances.