A multi-stack fuel cell hybrid power system (MFCHS) consists of multiple sources with various characteristics. The power distribution between different sources influences the performance of the system, which involves many factors. To distribute the power effectively and enhance the efficiency and fuel economy of a single-stack fuel cell system, this study proposed a hierarchical energy management strategy (EMS) for MFCHS. An MFCHS configuration that included three fuel cell systems and a battery was presented. An MFCHS model that incorporated the effect of altitude was constructed, and an efficiency analysis of the multi-stack fuel cell system (MFCS) was performed. The hierarchical EMS of MFCHS was composed of a bottom control layer and a top management layer. The bottom control layer utilized a coordinated optimal distribution strategy based on the maximum efficiency range of MFCS to realize optimal power allocation between the different fuel cells in MFCS. The top management layer used EMS under multiple operating conditions to realize the effective distribution of the demand power between MFCS and the battery. Results demonstrate that the proposed strategy improves the average efficiency of MFCS by up to 5.2% and 8.9% compared with those of the equal distribution and daisy chain strategies, respectively. The proposed strategy also displays good performance in terms of the hydrogen consumption of MFCS, which saved 1% and 3% hydrogen compared with the equal distribution and daisy chain strategies, respectively. The proposed strategy results in promising improvements in the overall performance of the system. This study provides a good reference for developing EMS for MFCHS. Keywords: Fuel cell, Multi-stack fuel cell hybrid power system, Energy management strategy, Coordinated optimal distribution, Maximum efficiency range Un sistema de potencia híbrido de pilas de combustible multipila (MFCHS) consta de múltiples fuentes con diversas características. La distribución de potencia entre las distintas fuentes influye en el rendimiento del sistema, en el que intervienen muchos factores. Para distribuir la potencia eficazmente y mejorar la eficiencia y el ahorro de combustible de un sistema de pila de combustible monopila, este estudio propone una estrategia jerárquica de gestión de la energía (EMS) para MFCHS. Se presenta una configuración MFCHS que incluye tres sistemas de pilas de combustible y una batería. Se ha construido un modelo de MFCHS que incorpora el efecto de la altitud y se ha realizado un análisis de la eficiencia del sistema de pilas de combustible multipila (MFCS). El EMS jerárquico del MFCHS está compuesto por una capa de control inferior y una capa de gestión superior. La capa de control inferior utiliza una estrategia de distribución óptima coordinada basada en el rango de eficiencia máxima del MFCS para realizar una asignación de potencia óptima entre las distintas pilas de combustible del MFCS. La capa de gestión superior utiliza EMS bajo múltiples condiciones de funcionamiento para realizar la distribución efectiva de la potencia demandada entre el MFCS y la batería. Los resultados demuestran que la estrategia propuesta mejora la eficiencia media del MFCS hasta un 5,2% y un 8,9% en comparación con las estrategias de distribución equitativa y en cadena, respectivamente. La estrategia propuesta también muestra un buen rendimiento en cuanto al consumo de hidrógeno del MFCS, que ahorra un 1% y un 3% de hidrógeno en comparación con las estrategias de distribución equitativa y conexiones en cadena, respectivamente. La estrategia propuesta produce mejoras prometedoras en el rendimiento global del sistema. Este estudio proporciona una buena referencia para el desarrollo de EMS para MFCHS.

A steady-state compressor relation can misattribute a lagged temperature response during load changes to a change in estimated efficiency. Motivated by the monitoring of near constant-speed, single-shaft gas turbines, this study evaluates a thermal inertia-inspired correction that couples one effective temperature state to an efficiency parameter through an extended Kalman filter (T-EKF). Controlled tests distinguish spurious efficiency excursions from imposed slow degradation. The original 18 cases are supplemented with 30 new noise realizations in each of six prescribed conditions, comparing seven methods over 60–600 s. Across these 180 additional realizations, the median efficiency root-mean-square error is 0.001658 for T-EKF, compared with 0.008402 for the steady-observation EKF and 0.005194 for causal smoothing. A same-structure unscented Kalman filter obtains nearly identical errors, whereas a three-state EKF with the known two-pole reference structure obtains a lower median error of 0.0007099. Time-constant and covariance sensitivity, thermodynamic parameter mismatch, and innovation diagnostics characterize the limits of the low-order approximation. Archived industrial records provide a separate temperature-output diagnostic, with a slight improvement in March and a slight deterioration in April, after parameter freezing. The approach provides a compact correction for dynamic mismatch under the tested assumptions; it does not demonstrate physical efficiency improvement or independently validated field efficiency accuracy.