Implementation of Redundant Vector Selector Logic of SVPWM for DC link balancing in Three Phase Three Level Neutral Point Clamped Multilevel Inverter

Advancements in Multilevel inverters are promising the future of several industries such as traction. Design and implementation of three phase three level neutral point clamped multilevel inverter(NPC) with redundant vector selection in space vector pulse width modulation for DC link balancing has been explained in this paper. Neutral point voltage unbalance issue is a common scenario while implementing the NPC. Redundant vectors in space vector Pulse width modulation method is analyzed along with characteristics of capacitors during each switching state is identified and sorted for implementing DC link unbalance issue. Harmonics can be improved by using this control method. DC link capacitor unbalance issue can be mitigated by selecting appropriate switching states among the redundant switching states in the Space vector pulse width modulation method. Capacitor voltages should be measured frequently and selection of redundant states are taken according to the measured capacitor voltages. Measured capacitor voltages are compared and the output is utilized for decision making in redundancy selection.