A Extended State Observer Based Backstepping Control for Improving Stability of DC-DC Boost Converters with Constant Power Loads

In DC microgrid, constant power loads are connected to the DC main bus through the Boost converter, and these constant power loads introduce negative impedance, making it difficult to stabilize the DC bus voltage. In order to improve the stability of the system, this paper proposes a composite controller that combines backstepping control (BSC) with extended state observer (ESO) for Boost converter. First, the system model is transformed to the Brunovsky’s canonical form by exact feedback linearization. Second, in order to improve the robustness of the system, the external disturbances, model uncertainty and aggregate uncertainty term disturbances are estimated and compensated by extended the state observer. Then, the use of backstepping control ensures fast voltage tracking while solving the non-minimum phase problem of the Boost converter. Finally, the simulation was verified in MATLAB/Simulink. The results show that the proposed controller is capable of global tracking and fast response of voltage in the face of reference voltage variations, power fluctuations, and inaccuracies in circuit component parameters.