Current and Voltage Sensing Methods of BCBB Converter Used in Battery Interfacing System

As renewable energy sources are widely used not only in power systems, but also microgrids and self-powered equipment, a battery interfacing solution is critical for energy management and power flow control with PV or small wind turbine accordingly. Due to its broad input-output voltage range, the bidirectional cascaded buck-boost (BCBB) topology is widely employed in battery charging products and renewable energyinterfacing systems. However, achieving high-performance closed-loop control requires accurate current and voltage measurements, which leads to increased sensor usage and larger product volumes. To optimize the overall performance with the least number of sensors, initiated from a previous study on BCBB converter control [32], this paper proposes two novel sensing and reconstruction methods aligned with digital-power isolation requirements to address this hardware complexity while enhancing reliability. In scenarios without isolation, voltage and current values are detected using an embedded resistance network and shunt resistors within the BCBB circuit. In contrast, isolated voltage and current sensing utilize a hall current sensor and a coupled inductor winding. This approach not only offers cost-effectiveness but also enables shoot-through failure detection within each side half-bridge of BCBB converters., the paper Current and voltage reconstruction algorithms are derived based on a mode seamless modulation. Experimental results confirm the effectiveness of the proposed methods in simplifying the system while maintaining high accuracy.