Error Storage Based Online Linearization of the Nonlinear Transfer Function of a High Power Dual Active Bridge

This paper introduces an error storage based online
linearization method for the reduction of the nonlinearity inher-
ent in the current transfer function of a Dual Active Bridge in
order to increase the possible dynamics of current and voltage
control. The proposed algorithm autonomously learns deviations
from the ideal current transfer function based on previous
operational data of the current controller. This approach enables
real-time compensation through the implementation of an error
storage system, resulting in an effective online compensation
method. Furthermore, this method is not limited to Dual Active
Bridges but can also be used for any other time invariant system
with repeating operation points and nonlinear transfer charac-
teristics. The algorithm is implemented on a Field Programmable
Gate Array and experimentally verified on a 40 kW test bench.
Experimental measurements affirm the practical feasibility and
effectiveness of this algorithm.