Power Quality Enhancement of the Distribution Network by Multilevel STATCOM-Compensated Based on Improved One-Cycle Controller

There are several ways to reduce and compensate for voltage disturbances. One of the methods is to use a Multilevel STATCOM. Multilevel inverters are widely used in various parts of the power system and industry due to advantages, such as appropriate output waveform (voltage and current). There are numerous controllers for multilevel STATCOM control. One of the simple and economy controllers is the one-cycle controller, which is usually used in DC/DC and DC/AC converters. In this paper, a new structure is proposed to improve the performance of the one-cycle controller. Improvements include voltage sag and swell, voltage disturbances, harmonics, and short-term outages. To demonstrate the performance of the proposed controller, the multilevel STATCOM is also tested and compared with conventional PWM control. The simulation results show that multilevel STATCOM will correct the disturbances. Among the advantages of the proposed method are its simplicity, robustness, and flexibility, so that with one adjustment, the parameters of the control system can compensate for all the defects.