High Accurate Dual Loop Controller for Power Regulation in DAB DC-DC Converter for Solar PV Applications

In closed-loop control, dual phase shift (DPS) control provides a better power regulation with higher efficiency. However, owing to the presence of transformer leakage inductance and environmental conditions, the accuracy often deviates from the desired margin. It misleads the operation when dual active bridge (DAB) is interconnected with renewable energy systems, especially in solar PV applications. To overcome the above limitation, this paper proposes a highly accurate method of dual loop controller to regulate the power in the DAB DC-DC converter for solar Photovoltaic applications. The proposed approach has a dual loop algorithm which helps to obtain the accuracy over 99.50% for the entire power range. It also offers to achieve fast dynamic response during changes in solar PV power. To validate the proposed dual loop algorithm, it has been implemented using SPS, EPS, DPS and TPS modulation and verified with experimental results.