具有改进瞬态响应的新型电池-超级电容储能系统拓扑用于快速直流母线恢复

Supercapacitors are pivotal in battery-supercapacitor energy storage systems (BScESS) to enhance the stability of the DC link. However, conventional BScESS configurations exhibit significant limitations, leading to sluggish DC link voltage recovery under varying load profiles. These challenges are mainly attributed to the existence of phase lag zero frequency (PLZF) in the system, which restricts the control bandwidth and reduces the phase margin, leading to oscillations and instability in the DC link. Further, a decrease in supercapacitor voltage negatively impacts the voltage control bandwidth and phase margin of the BScESS. To address these challenges, this article proposes a new BScESS topology with enhanced transient performance, enabling quick DC link voltage restoration in response to sudden changes in load. The proposed topology effectively eliminates the destabilizing effect of PLZF, thereby facilitating wide bandwidth without compromising the phase margin. This results in quick restoration, i.e., with a time span of approximately 20-22 milliseconds for a substantial step change in load current, with minimal oscillation behaviour. Furthermore, reduction in supercapacitor voltage does not affect the bandwidth and phase margin of the system. The proposed system also supports high-current operation, providing improved system performance across a range of operational scenarios. To validate the effectiveness of the proposed BScESS, a scaled-down prototype for 960 W is presented and operated using an FPGA Artix-7 microcontroller board.