Static VAr compensator using packed U-cell based multilevel converter

The 5-level modified packed U-cell converter (MPUC5) is investigated in this paper to work as static VAr compensator (statcom). Main advantages of the MPUC5 include the reduced DC link voltages and having redundant switching states to balance those DC terminals. Such redundancies are analyzed to design an effective voltage balancing technique. The voltage balancing technique is integrated into switching algorithm in order to prevent further complexity. Since the DC link voltages are balanced through redundant switching states, a standard cascaded control is applied to control the injected reactive current and DC bus voltages without additional voltage regulators. Some simulations of MPUC5 statcom are performed and results are discussed. An intentional change in the amount of exchanging reactive power is made to ensure acceptable performance of the controller and proposed converter for STATCOM application.