Privacy-Preserving Predefined-Time Secondary Control for Networked Microgrid With CPLs: An Auxiliary Variable Encryption Approach

As networked microgrids (NMGs) expand in scale, they face growing challenges in privacy security and control performance, including demands for enhanced dynamic response, accuracy, and robustness. This is particularly critical in the DC NMG with high-penetration constant power loads (CPLs), as their negative impedance characteristics can trigger oscillations and instability. To address these issues, this study proposes a privacy-preserving predefined-time secondary control strategy by integrating auxiliary variable-based data encryption with a CPL stability compensation mechanism. An active damping mechanism based on decoupled voltage feedback is proposed to suppress CPL-induced instability with rigorous stability conditions. OPAL-RT experiments are set up to demonstrate the strategy’s effectiveness in privacy protection, fast convergence, low steady-state error, and CPL tolerance level.