MV Grid Reactive Power Compensator Based on a Four Level NPC Converter

Abstract

The present research study is focused on the design, development and validation of a device based on multilevel converter for medium voltage distribution networks. It regulates the reactive power exchanged with the grid (up to 3 MVAR), allowing to achieve the following objectives: Network voltage regulation, reactive power compensation and power factor control. The device is composed by an IGBT based 4 level NPC (neutral point clamped) converter. The adopted modulation strategy is the space vector modulation and it takes into account the bus capacitor voltage balancing. The reactive power regulation will be carried out by a vector control technique. The correct behavior of the electronic system connected to a radial distribution network is validated in simulation. Firstly the behavior of the system is analyzed under normal operation conditions. After that, its robustness is analyzed when sudden network voltage changes occur