Research on Fuzzy Self-Tuning PI Control Strategy for ISOP Converters
High-voltage DC conversion technology is widely applied in power systems, rail transit, long-distance power transmission systems and other fields. The Input Series Output Parallel (ISOP) combined converter can effectively reduce the voltage stress of each module through the series-parallel connection of standard modules, while achieving high-power current output. However, the ISOP system has strict requirements for input voltage sharing and output current sharing, that is, it needs to have strong anti-interference ability. On the basis of fixed PI parameter adjustment, this paper introduces fuzzy control logic to real-timely tune the PI parameters, which ensures the control stability and achieves better dynamic performance. Compared with the traditional PI control, the proposed method has a 47% faster response time. To verify the effectiveness of the strategy, an experimental platform with 180W and 15KHz was built, and the recovery time of the output voltage for sudden load changes is only 26ms.