Applying single phase shift (SPS) control to a dual active bridge converter will introduce considerable return power, which reduces power transmission efficiency and increases current stress to the power switches. While for a DAB cluster with input-serial-output-parallel (ISOP) configuration, the inevitable parameter mismatch among all the modules will cause uneven power distribution, resulting in uneven healthy condition and life-span of its power modules. In order to solve those problems, we propose a power balance control based on return power optimization, which ensures good power balance, evidently reduces the return power and improves the dynamic response of the system. Finally, its effectiveness is verified via simulation data at different working conditions. The results confirm that the proposed solution considerably outperforms the traditional technique in terms of return power and current stress reduction with faster control dynamics.