Direct Model Predictive Control Based Mitigation of Harmonics Using Active Power Filter

Abstract

Nowadays, model predictive control (MPC) techniques are gaining attention in the field of power electronics and its applications; due to the advancement of digital controllers. The performance of MPC techniques depends on many factors such as accuracy of the prediction model, optimization criteria, sampling times, etc. Specifically, under large sampling times, it is necessary to extrapolate the reference in order to avoid reference tracking delays. So far, Lagrange method, vector angle method and repetitive prediction method are presented in the literature. However, the influence of these methods on the compensation capabilities of shunt active power filter (SAPF) has not been investigated so far. In this paper, the performance of direct MPC is analysed and compared with hysteresis current control for SAPF application. The impact of extrapolation methods on the compensation capabilities of SAPF is also presented. One of the drawbacks of direct MPC technique is its spread switching frequency behaviour. To avoid this, a modulation method is applied in the control algorithm to operate the SAPF at fixed switching frequency.