Design of Controller for VSC-HVDC Systems with the alpha beta Stationary Frame

A novel proportional resonant (PR) controller in the VSC-HVDC systems is proposed in the paper. The technique took full advantage of the characteristic of PR controller which can realize zero steady-state error in AC input signal under α-β coordinate. In the method, the active and reactive current component in the vector control strategy are transformed in the stationary frame to achieve the target of keeping the DC-link voltage constant, and decoupling the active and reactive power. Compared with the common double close-loop proportional integral (PI) controller, the PR technique is better in harmonic compensation without the complex coordinate transformation and the couple of feedback voltage. Also the control algorithm is easy to be realized while the robustness and power quality is improved.