Hydrogen is a key technology for the decarbonization of industrial sectors, such as steel industry. These industries requires large-scale electrolyzers, which are able to operate as flexible loads. This is thanks to the possibility of storing the hydrogen, and decouple the electricity consumption from the hydrogen demand. These flexible loads are an a essential tool to provide grid services, such as frequency regulation, in future power systems with a high share of renewable energies. However, to provide an overall fast response for frequency regulation, large-scale electrolyzers need to be combined with Energy Storage Systems (ESSs), such as battery systems, in Hybrid Hydrogen Systems (HHSs). Furthermore, the combination of different electrolyzer technologies, with Alkaline elec-trolyzers (AELs) and Proton Exchange Membrane Electrolyzers (PEMELs) as the dominant commercial technologies, can reduce the need and investment on ESSs. A power sharing control for frequency regulations using HHSs is proposed to achieve an overall fast system response, and maximize the advantages of the combination of AELs, PEMELs and ESSs. Simulations and experiments have been conducted to validate the effectiveness of the proposed control strategy for HHSs.