A New Kalman-Filter-Based Harmonic Current Suppression Method for the Virtual Oscillator Controlled Voltage Source Converters with LCL Filter

Virtual Oscillator Control (VOC) is a new control strategy applied to grid-connected inverters, which can achieve fast dynamics and low harmonics in island mode. This paper proposes a new harmonic currents elimination strategy for virtual oscillator controller (VOC)-based voltage source converters (VSC) connected to a distorted electrical grid. In order to achieve the control goal, the Kalman filter is used to replace the traditional band-pass filter to extract the harmonic components of the grid voltage at the common coupling point (PCC). From the impedance-based analysis, the equivalent output impedance of the DC/AC inverter has been significantly enhanced at the selected low harmonic frequency. It is worth noting that the system can remain stable within a considerable range of equivalent grid impedance. Simulation results in MATLAB/Simulink have verified the effectiveness of the proposed method.