Highly Efficient Interleaved Solar Converter Controlled with Extended Kalman Filter MPPT

Abstract

DC-DC power converters play an important role in the performance and control methods of solar power systems. Solar power converters are prone to high power losses due to intermittent irradiation and shading effects on solar photovoltaic (PV) modules. The device topology and control algorithm of a solar power converter are key factors to increase the total amount of harvested energy. In this paper, a solar power converter is proposed with a two−phase interleaved boost converter (IBC) topology and a novel maximum power point tracking (MPPT) method. The proposed MPPT controller is based on extended Kalman filtering (EKF) and it improves the tracking efficiency in both steady irradiation and partial shading conditions. The algorithm is improved with the prediction and estimation capabilities of the EKF algorithm. The proposed EKF MPPT is validated with simulations and experimentally validated by using the implemented two−phase IBC that is comprised of SiC MOSFETs. The proposed converter provides over 99% power conversion efficiency at 3 kW and over 96% MPPT tracking efficiency under partial shading conditions. The experimental studies verify that the proposed MPPT controller and two−phase IBC increase the overall efficiency both in steady-state and partial shading operations of a solar power converter.

Keywords

• interleaved boost converter
• solar converter
• partial shading
• extended Kalman filter
• maximum power point tracking (MPPT)
• SiC MOSFET