Damping of input LC filter resonance based on virtual resistor for matrix converter

An inductor-capacitor (LC) filter is normally required at the input of the matrix converter, to assist in the commutation of switching devices and to mitigate input current harmonics. However, its presence, in turn, often results in degradation of dynamic performance and instability of the system. This paper gives a simple procedure to select the input filter parameters for the matrix converter and four conventional methods to employ real resistors to damp filter oscillation. Then, an effective damping method is proposed by using a virtual resistor that can be connected in parallel with the filter capacitor. And it only changes the calculation of the modulation index of the space vector modulation strategy for matrix converter. This method is suitable for the microcontroller implementation without sacrificing the power efficiency. Simulation and experiment results are included to verify the proposed method.