A Method for Stabilizing Dual Active Bridge-Based Energy Storage Systems

Dual Active Bridge (DAB)-based energy storage systems are the key to integrating renewable energy sources into the power grid. However, because of the well-known negative impedance characteristic of constant power loads (CPLs), the DAB converters are prone to become unstable, destabilizing the overall system. Therefore, a stability enhancement method is proposed using the concept of variable inductance to guarantee and expand the converter stability region that overcomes the risk of destabilization from fast-acting transients. Full-order continuous-time average modeling and dynamic analysis of DAB converters with CPLs are studied to analyze the stability of these systems. The proposed method significantly improves the stability region of the system and is verified using simulation results.