In this paper, two new methods for load current control and capacitors voltage balancing in the three-level neutral point diode clamped inverters (3L-NPC) is presented which can be generalized to other control variables such as speed in electrical motors. In the first method after calculating the required reference voltage vector, K coefficient (with feedback from upper capacitor voltage) and virtual voltage vectors were used to control the capacitors voltage. Using K coefficient and virtual voltage vector in each sampling time, causes the entire sector surface includes the reference voltage vector, consists of voltage vectors that will have a positive effect or ineffective. In the second method, the zonning deatbeat model predictive control is introduced, which is based on the elimination of the voltage-based cost function in the simplified finite-set model predictive control. In fact, the closest voltage vector to the reference voltage vector is selected directly and without any cost function, which reduces the complexity and the computation burden. Therefore, using these two methods, there is no need for any cost function, modulators, weighting factor adjustment and capacitors voltage prediction. The validity of these two methods is confirmed by SIMULINK/MATLAB.

three-level inverters,switching,Finite control-set model predictive control (FCS-MPC)