Current tracking control strategy for mine chain STATCOM

In view of problems of strong interaction effect between STATCOM and power grid under weak power, the power voltage feed-forward control strategy is not effective in resisting power grid voltage distortion due to the delay, a current tracking control strategy for mine chain STATCOM considering control delay was proposed. The control strategy is based on the traditional proportional resonance control strategy, and compensation link is added in power grid voltage feed-forward link. The compensation link is equal to reciprocal of product of sample delay and control delay transfer function. The approximation expression of compensation link available to meet the requirements is derived through McLaughlin expansion. The compensation strategy added compensation link can eliminate control delay and avoid influence of grid voltage distortion, so that the STATCOM can still work normally when power grid voltage harmonics are large. The simulation results show that the control strategy has strong ability to resist power grid voltage disturbance and good control effect of current tracking.