Akademik Veri Yönetim Sistemi
International Journal of Circuit Theory and Applications, 2025 (SCI-Expanded, Scopus)
This paper presents a Lyapunov control method to regulate the uninterruptible power supply (UPS) dynamics. The single-phase full-bridge inverter is considered for UPS application, and the converter dynamics are controlled under unknown load conditions. UPS systems operate under specific output voltage characteristics. The current drawn from the UPS varies depending on the load connected to the UPS output. The model of the load is usually unknown, and the information for the load current is necessary to obtain a well-regulated closed-loop implementation. The Lyapunov control strategy uses the energy function to determine the control input. The determination of the control signal is based on the stability criterion of the Lyapunov control method; the selection of the control signal must ensure the asymptotic stability rule. However, the information on the load current is mandatory to achieve a fully regulated energy conversion operation. Thus, the load current is measured in most applications for simplicity. This paper proposes a Lyapunov control strategy using a model-based reference generator and load current observer. The proposed method uses the state observer to estimate the load current under unknown load conditions. The model-based reference generator produces the inductor current reference, and an inner Lyapunov regulator controls the inductor current. The mathematical concepts are verified using the real single-phase full-bridge prototype. The proposed control algorithm is implemented using STM32H743 digital signal processor (DSP). The performance of the Lyapunov regulator, load current estimator, and the model-based reference generator is experimentally investigated. According to the experimental results, the proposed control approach provides a robust and suitable UPS operation under unknown load conditions.