CONTROL DESIGN OF STATCOM USING FIVE LEVEL NEUTRAL POINT CLAMPED CONVERTER AND ITS APPLICATION TO REACTIVE POWER

This paper deals with multilevel neutral point clamped (NPC) converter voltage source inverter applied as STATCOM. The proposed control with space vector modulation (SVM) switching and decoupled current control with IP controllers have been tested to prove the advantages of the proposed control. The effectiveness and validity of the controller system is supported by computer simulation. Simulation results obtained confirm that the controller has a very good performance, allowing compensation of capacitive or inductive. The simulation of the proposed system is developed using MATLAB, Simulink. Benefits of reactive power compensation are well known: increased stability, increased transmission capacity over existing lines, better voltage profile and decreased losses. The management of reactive power by traditional means has its drawbacks, depending on compensation technique used. These include a possibility of resonance, slow response, introduction of harmonics, rotational instability or management of reactive power which can be done only in discrete steps. Moreover, if capacitor banks are used (with or without thyristors), they occupy a considerable amount of real estate. The new generation of static compensator based on multilevel inverters have become an effective and practical solution for increasing power and reducing harmonics of ac waveforms. They are used for driving highpower medium-voltage induction motors and var compensation in flexible ac transmission systems (FACTS). The main advantages of multilevel PWM inverters are the following: