Modelling of large‐sized electrolysers for real‐time simulation and study of the possibility of frequency support by electrolysers

Abstract

Hydrogen as an energy carrier holds promising potential for future power systems. An excess of electrical power from renewables can be stored as hydrogen, which can be used at a later moment by industries, households or the transportation system. The stability of the power system could also benefit from electrolysers as these have the potential to participate in frequency and voltage support. Although some electrical models of small electrolysers exist, practical models of large electrolysers have not been described in literature yet. In this publication, a generic electrolyser model is developed in RSCAD, to be used in real-time simulations on the Real-Time Digital Simulator (RTDS). This model has been validated against field measurements of a 1-MW pilot electrolyser installed in the northern part of the Netherlands. To study the impact of electrolysers on power system stability, various simulations have been performed. These simulations show that electrolysers have a positive effect on frequency stability, as electrolysers are able to respond faster to frequency deviations than conventional generators.

Analytical Modeling and Control of Grid-Scale Alkaline Electrolyzer Plant for Frequency Support in Wind-Dominated Electricity-Hydrogen Systems

“…In [24], the authors present a techno-economic model of a 25 MW PEM electrolyzer offering FCR service, but without considering second-level dynamic frequency regulation. Reference [25] investigates the modeling and converter control of a PEM electrolyzer providing frequency support, but lacks an analytical model to quantify the contributions of electrolyzer's frequency regulation to improving system inertia and specific frequency performances (e.g. RoCoF and steady-state deviations).…”

Importance of Model Fidelity of Power to X Devices in Energy System Analysis

“…These studies use simplified representations, such as equations with constant relation between the power input and energy output. Some use generic models that highly depend on manufacturer's data [8]- [10], where performance is measured in ideal conditions, and often performance metrics are averaged over testing periods of a year (such as with heat pump coefficient of performances). In reality, performance of a PtX highly depends on operational conditions such as ambient temperature, pressure conditions within the device, etc.…”

Dynamic Frequency Support for Low Inertia Power Systems by Renewable Energy Hubs with Fast Active Power Regulation

“…In this way, the natural inertia that could have been extracted from the wind turbine cannot be fully and promptly deployed [8]. Furthermore, the VSC units belonging to HVDC systems [9], or responsive demand (e.g., large-size electrolyzers [10]), could be involved in fast active power-frequency control. Nevertheless, the active power set points required to fulfil the required power transfer may restrict the headroom and speed of active power adjustment.…”