A new application of LQR controller with the ability of reference tracking for a multi modular converter with several cells is proposed. First, the mathematical model for the grid connected MMC is presented and then, the small signal state space model is obtained. MMC is a very complex MIMO system with several state variables and global control for this system is very important issue. Optimal advanced controller based on linear quadratic regulator with integral action is a very good candidate for controlling the AC signals and energy balancing in multi cells MMC system. The performance and validity of obtained model and designed linear controller are evaluated with non-linear model of MMC in SimPower System toolbox/Matlab. Simulation results are verified the excellent performance of the proposed approach in the transient and steady state operational conditions.