PROJECT TITLE :

Nonminimum Phase Compensation in VSC-HVDC Systems for Fast Direct Voltage Control

ABSTRACT:

Newly developed VSC-HVDC systems are reaching power levels of up to one thousand MW. At this power level, the nonminimum part behavior of the VSC-HVDC systems’ dc plant becomes a threat to the soundness of the direct voltage for quick dc control-loop dynamics. This paper presents a novel compensation theme, referred to as RHP-zero shifting+damping, designed to deal with the nonminimum part dynamics of the dc plant by adding extra compensation loops to this controller of the VSC-HVDC system. The compensation scheme will work together with linear controllers and permits the closed-loop bandwidth of the direct voltage controller to be increased without affecting the direct voltage stability of high-power VSC-HVDC systems. Thence, the direct voltage variations are significantly reduced throughout power changes within the ac or dc network. The performance of the compensation theme is evaluated through simulations and corroborated in a very one-kW experimental take a look at bed.