Abstract

In using a neutral point clamped (NPC) converter, in addition to the control method, it is necessary to balance the voltage of DC-link capacitors. If the capacitors in this converter are not balanced, the output voltage and current will not be properly controlled. There are several methods for balancing the voltage of capacitors, which are mostly based on the measurement of the voltages of the capacitors. Voltage sensor-based balancing methods increase the total cost and the measurement error due to the use of voltage sensor interface circuits. Also, the use of the finite-set model predictive control (FS-MPC) method will increase the computational burden. In this paper, current sensors are used instead of voltage sensors. Besides, redundancy switching is used to balance the voltages of the capacitors. To reduce the computational burden, the triangular zoning method is used, in which only three candidates are included in the cost function. The proposed method is evaluated using simulation.