Square of Voltage Out-Loop Based Feedback Linearization Control of Voltage Source Converter (VSC) in SMES

To improve the response characteristic of the VSC in SMES (Superconducting Magnetic Energy Storage) with wide load disturbance, a new square of voltage out-loop based feedback linearization control strategy is proposed for the control of VSC. The input variable was controlled by a combining of square of voltage out-loop based direct voltage control and current inner-loop control to achieve fast stabilization of DC bus voltage and accurate tracking of power of PCC. Stability and dynamic response characteristics of the system were verified by simulation results. It is shown that the proposed strategy can improve the DC bus voltage transient response with load step change, with simplified control variable expression and reduced calculating burden.