Designing an integral LQR controller for DC-DC X-converter based on enhanced shuffled frog-leaping optimization algorithm

Abstract EN

Power Electronics DC-DC converter plays an important role in different applications, for example, electric vehicles, wind generation and PV systems.

This paper addresses the design of DC-DC X-converter with optimal LQR controller combined with integral gain action.

Therefore, the proposed controlling scheme for DC-DC converter is very important to make the system stable under different conditions.

In order to achieve high performance for DC-DC converter system, the current controller was made first as an inner loop and then an output voltage controller was designed as an outer loop.

The behavior of an LQR controller design with integral action is characterized by two parameters: state and control weighting matrices.

The problem of finding the semi-optimum weighting matrices has been formulated as an optimization problem.

Standard Shuffled Frog-Leaping (SSFL) optimization algorithm is introduced to optimize the selection of the controller's weighting matrices.

Furthermore, an Enhanced SFL Optimization Algorithm (ESFLA) is proposed to improve the stability performance of the considered system.

The performances of both SSFLA and ESFLA are evaluated in terms of speed of convergence to the global optimum and algorithm accuracy, based on a set of ten benchmark test functions.

The simulation results demonstrate that the DC-DC X-converter based on LQR with integral gain tuned by ESFLA outperforms other designs incorporating SSFLA in terms of control effort, stability performance as well as transient response specifications.