Plug-in of An Extra Power Module into Parallel-Modules with Unknown Current Sharing Strategies

In commercial DC power systems, it is a common practice to parallel DC-DC converter modules with building block approach where the modules can be bought directly from power supply vendors. The internal circuits and parameters of these modules are unknown like black box, and backup modules are often required to ensure the reliability of the module-paralleled DC power supply system. However, when an original module fails and the backup module is absent, other new modules should be incorporated into the system. The mismatch may occur between the new power supply modules and the original system. And the normal operation of substitution modules in unknown systems can effectively broaden their application scopes. Therefore, it is important for substitution modules to adjust adaptively and coordinate with the original modules after being put into the system. In this paper, we simulated the process in which the optimal solution can be attained step by step when the conditions were unspecified, and then proposed a tentative control strategy. On the premise of ensuring compatibility between the substitution modules and the system, the operation effect of the system was further optimized. The load of each power module was distributed as evenly as possible, and the current sharing accuracy was controlled to guarantee the reliability of the system operation. Simulation results of MATLAB/Simulink verified the feasibility of the control strategy.