Virtual-flux estimation and SVM based direct power control of a three-level NPC rectifier

Abstract

This paper discusses an existing Direct Power Control algorithms for three-phase three-level with neutral-point clamped (NPC) rectifiers. Direct Power Control, or DPC, implies the creation of the control algorithm in order to directly control both the active and reactive powers consumed by the rectifier, increasing the grid's power factor and reducing its current total harmonic distortion. Throughout this document, we will focus on one control algorithm directly related to DPC, through which we can achieve the rectifier control. The chosen method is the virtual flux based on DPC with space vector modulation. We will develop the mathematical model stemming from this algorithm and its operation under variable load. These tests and implementations will allow us to assert the superiority of virtual flux DPC with space vector modulation algorithm over conventional control techniques, verify the results obtained through the studied literature, and demonstrate the capacity of the algorithm to abide by the requirements and constraints. These tests will valorize, when working with medium to high power loads, the advantages of a multi-level inverter.