TY - JOUR
T1 - Generation characteristics and power quality control of a free piston linear generator considering system uncertainty
AU - Ma, Yuguo
AU - Feng, Huihua
AU - Jia, Boru
AU - Li, Jian
AU - Wei, Yidi
AU - Liu, Chang
AU - Wang, Jiayu
AU - Wei, Shuojian
N1 - Publisher Copyright:
© 2025
PY - 2025/6/1
Y1 - 2025/6/1
N2 - The free piston linear generator (FPLG) is a compact energy converter with high power density and multi-fuel adaptability, yet its practical application is hindered by system uncertainties and harmonic distortions caused by nonlinear piston dynamics. This study establishes an integrated thermodynamic-electromagnetic simulation model, validated against experimental data, to analyze generation characteristics. Results reveal that increasing operating frequency amplifies piston velocity harmonics, leading to high total harmonic distortion (THD >27 %) in induced voltages. Stochastic combustion perturbations further quantify system uncertainties, including fluctuating cylinder pressure, piston velocity, and compression ratio. Compared to uncontrolled rectification (voltage ripple: 40.89 %), controlled rectification significantly improves power quality, achieving minimal ripple (6.87 %) and near-unity power factor (0.985). To address these challenges, innovative control strategies are proposed: active disturbance rejection control (ADRC) replaces the voltage outer-loop PI controller for robust regulation under uncertainties, while dual-layer sequential model predictive control (SMPC) optimizes current tracking with a 63.86 % reduction in switching frequency. The ADRC-SMPC framework minimizes overshoot during abrupt load/voltage changes and maintains comparable stabilization time, demonstrating superior adaptability to dynamic operating conditions. These advancements establish a robust framework for stabilizing FPLG energy output, advancing its viability as a high-efficiency range extender for electric vehicles.
AB - The free piston linear generator (FPLG) is a compact energy converter with high power density and multi-fuel adaptability, yet its practical application is hindered by system uncertainties and harmonic distortions caused by nonlinear piston dynamics. This study establishes an integrated thermodynamic-electromagnetic simulation model, validated against experimental data, to analyze generation characteristics. Results reveal that increasing operating frequency amplifies piston velocity harmonics, leading to high total harmonic distortion (THD >27 %) in induced voltages. Stochastic combustion perturbations further quantify system uncertainties, including fluctuating cylinder pressure, piston velocity, and compression ratio. Compared to uncontrolled rectification (voltage ripple: 40.89 %), controlled rectification significantly improves power quality, achieving minimal ripple (6.87 %) and near-unity power factor (0.985). To address these challenges, innovative control strategies are proposed: active disturbance rejection control (ADRC) replaces the voltage outer-loop PI controller for robust regulation under uncertainties, while dual-layer sequential model predictive control (SMPC) optimizes current tracking with a 63.86 % reduction in switching frequency. The ADRC-SMPC framework minimizes overshoot during abrupt load/voltage changes and maintains comparable stabilization time, demonstrating superior adaptability to dynamic operating conditions. These advancements establish a robust framework for stabilizing FPLG energy output, advancing its viability as a high-efficiency range extender for electric vehicles.
KW - Active disturbance rejection control
KW - Controlled rectification
KW - Free piston linear generator
KW - Generation characterization
KW - Model predictive control
UR - http://www.scopus.com/pages/publications/105001546544
U2 - 10.1016/j.energy.2025.135861
DO - 10.1016/j.energy.2025.135861
M3 - Article
AN - SCOPUS:105001546544
SN - 0360-5442
VL - 324
JO - Energy
JF - Energy
M1 - 135861
ER -
