Dynamic analysis and control design for the gas distribution and storage system of the tritium fuel cycle in EU-DEMO

Neural network control and optimization for fuel cell hydrogen supply system

Design and Performance Analysis of a Type-2 FLC Controller for a Fuel Cell Electric Vehicle Powertrain

PEMFC‐System Model for BOP Configuration Analysis

A suitable design for the balance of plant (BOP) of fuel cell systems is essential and depends on the specific requirements of the stack, or stacks, as well as the application. System models can help to analyze the feasibility of different system designs during the preliminary design phase and offer the basis to derive the requirements for the different components making up the final system design. This paper will present the development of such a system model for a stationary fuel cell system, which will be built up in the project H2OptiLifeCycle. The system model is a coupling of the individual component models, with a focus on the fuel cell stack model and the humidifier models. A 1D finite element model of a fuel cell membrane electrode assembly (MEA) is simplified to a Simscape‐Block to model the behavior of the MEA, including reaction kinetics, diffusion, ionic conductivity, and water transport. This model is also the starting point for the development of the humidifier models, which are then validated against measurement data from the manufacturer. This system model is subsequently used to study three different designs regarding the humidification of the stack. The reference system design uses a single humidifier in the cathode subsystem of the stack, while the second configuration consits of two humidifiers, where the anode humidifier is supplied with a portion of the cathode exhaust in order to humidify the fuel flow to the stack. Finally, the third configuration uses only one humidifier in the anode subsystem. All three configurations are tested in simulation with the Autostack Industry load cycle, to confirm that the achieved humidification of the fuel cell is sufficient. Furthermore, the efficiency of all three configurations is evaluated.

Coordinated Dynamic Operation of Integrated Electrolyzer-Compressor Systems

The increasing interaction between power and hydrogen sectors highlights the importance of coordinated operation of electrolyzers and electric-driven compressor stations (EDCSs). This becomes particularly of higher importance under transient disturbances. However, coordinated dynamic interactions of these coupled subsystems remain largely unexplored. This article addresses such gap by developing a dynamic model for an integrated electrolyzer-EDCS system and designing appropriate PID control schemes to address the potential disturbances affecting either component. To this end, linearized models of the electrolyzer and EDCS are first derived to enable systematic controller design. Then, two PID controllers, representing conservative and fast-tracking designs, are developed to coordinate the system response. The developed coordinated model is examined and verified under four different cases. The results demonstrate the effectiveness of the proposed model under disturbances from the compressor driver or the electrolyzer. Controlling the electrolyzer flow in response to EDCS disturbances coordinates system dynamics and mitigates undesirable transient fluctuations. Conversely, under electrolyzer disturbances, regulating the EDCS torque eliminates inconsistent responses in pressure, flow, and rotational speed, while preventing hazardous transient undershoots and overshoots. Overall, the proposed framework guarantees transient stability and operational reliability of the integrated electrolyzer-EDCS system.

Experimental demonstration of reactor-relevant adaptive density control on the DIII-D tokamak with coordinated gas and pellet fueling

Precise regulation of plasma density is crucial for achieving and maintaining fusion-relevant conditions in reactor-grade tokamaks. Tokamak reactors will utilize both gas puffing and pellet injection as standard fueling mechanisms. However, the coordinated use of gas puffing and pellet injection within feedback control frameworks is largely unexplored, underscoring the necessity to develop and validate dedicated strategies on existing machines. These strategies must address the various challenges associated with both actuators, including actuation delays, unknown fueling efficiencies, and the coexistence of continuous-time and discrete-time dynamics. To overcome these challenges, which surpass the capabilities of traditional empirically tuned proportional-integral-derivative (PID) control, an indirect adaptive control algorithm is proposed in this work for the regulation of the line-averaged electron density through coordinated gas puffing and pellet injection. After initial validation in simulations with a multi-reservoir global particle model, the controller was successfully implemented and tested on the DIII-D tokamak. Experimental results demonstrate robust density tracking under reactor-relevant scenarios, showcasing the controller’s ability to seamlessly coordinate actuators while handling disturbances and evolving actuator constraints. This work provides a critical step forward in the control of future fusion reactors.

Study of the influence of directed gas-dynamic oscillations on the operation of a fuel cell in a shipboard power plant

The paper presents a comprehensive analysis of existing active and passive methods for water management in fuel cells. The study aims to experimentally evaluate the effect of directed gas-dynamic oscillations in the audible frequency range on the performance of a single fuel cell, as well as to develop recommendations for improving such systems for shipboard power plants. The configuration of the developed laboratory test bench for in situ testing under electrochemical reaction conditions is described using a prototype cell with an active area of 25 cm² and an external gas-dynamic generator. It was found that gas-dynamic excitation at the fundamental frequency of 1.68 kHz increases the power density of the studied cell by more than 25% due to the intensification of mass transfer processes and the efficient removal of excess moisture. The obtained results experimentally confirm the prospects for integrating gas-dynamic control systems into shipboard fuel cell power plants. A distinctive feature of this study compared with similar studies is the implementation of in situ tests using an external gas-dynamic generator operating in the audible frequency range. For the first time in the Russian scientific literature, the resonant mechanism of gas-dynamic action on gaseous reactants and the membrane electrode assembly is experimentally substantiated, and the possibility of a significant increase in fuel cell output power using the proposed method is demonstrated. The relevance of the study is determined by the need to decarbonize waterborne transport in accordance with the requirements of the International Maritime Organization, as well as by the absence of active gas-dynamic water management systems for shipboard fuel cell power plants in Russia. The results obtained can be used as a basis for developing adaptive moisture removal systems operating under actual operating conditions.