Finite control set model predictive control for grid-connected NPC converter with LCL filter and novel resonance damping method

This paper presents two implementations of finite control set model predictive methods applied to AC/DC converters with an LCL filter. The LCL filter in contrast to L filter offers higher level of harmonics attenuation. However, despite its advantages, LCL filter can cause a strong resonance in grid current. The proposed control strategy, i.e. PCi2uc-3L uses basic advantages of the MPC methods - multivariable control. On the contrary to active damping scheme, PCi2uc-3L ensures higher quality of grid current (low THDi value). The methods were also compared with a predictive control algorithm of an AC/DC converter with L filter. The control performance was tested in the simulation model and validated experimentally by measurements.