Thermal - electric cooperative control of solid oxide electrolytic cell stack considering system efficiency optimization

Solid oxide electrolysis cell holds great potential for large-scale hydrogen production. However, achieving high efficiency and fast and safe dynamic response is difficult due to the complex physical and chemical processes involved in the system, as well as the variable power input that the system may experience. To address these issues, this study aims to develop a thermo-electric coordinated control scheme that overcomes different timescales to optimize the efficiency and dynamic response of a 3 kW solid oxide electrolysis cell system. The scheme combines parameter sweep analysis with Pareto front-based optimization to explore the temperature and electrical performance of the solid oxide electrolysis cell system across the entire parameter space and obtain the optimal steady-state operating points under different input current conditions. Furthermore, the optimal operating parameters are used as feedforward in conjunction with the neural network predictive control algorithm to achieve voltage and temperature control of the solid oxide electrolysis cell stack. Under simulated photovoltaic input conditions, the proposed control scheme maintains system efficiency between 73.75 and 82.08% and achieves a rapid and minimal overshoot voltage response to reach a new steady state. These indicates that the proposed control scheme ensures high system efficiency under steady-state conditions and safety with fast response during dynamic operations.