Level Doubling Network Based Multilevel Inverter for STATCOM Application

The Static Synchronous Compensator (STATCOM) is a well-known Flexible Alternating Current Transmission System (FACTS) device utilized in power grids to handle varying conditions. This paper introduced a Cascaded H Bridge Level Doubling Network based Static VAR Compensator (LDN-CHB-STATCOM) with different floating capacitor voltages. The asymmetric topology with a 1:5 asymmetry ratio is used to achieve high-resolution output while maintaining low converter losses. Additionally, reactive power flow control is implemented through the decoupled current control. The paper discusses the transition from reactive power injection to absorption using a proper closed-loop control, ensuring that capacitor balancing and power quality are not affected. Voltage stability and system reliability can be improved by STATCOMs employing LDN-based MLIs to quickly and precisely adjust reactive power. The concept is verified using MATLAB/Simulink.