Analysis, design and control of two-level voltage source converters for HVDC systems

The Voltage Source Converter (VSC) is replacing the conventional line commutated current source converters in High Voltage DC (HVDC) transmission systems. The control of a two-level voltage source converter and its design dealt with HVDC systems and various factors such as reactive power, power factor, and harmonics distortion are discussed in detail. Simulation results are given for the two-level converter and designed control is used for bidirectional power flow. The harmonics minimization is taken by extending the 6-pulse VSC to multipulse voltage source converters. The control is also tested and simulated for a 12-pulse voltage source converter to minimize the harmonic distortion in AC currents