Time delay compensation-based fast current controller for active power filters

Despite potential application of modern control techniques, conventional proportional-integral (PI) control technique is still a prefer choice for active power filters because of its good dynamic properties. However, the performance of the PI current controller is influenced by sampling and computation time delays under high di/dt operating conditions. In this study a conventional PI current controller is designed based on deadbeat control algorithm. The control system time delay is compensated by making use of a modified Smith predictor. The compensation of the reference current phase delay is also discussed in the study. Simulations have been carried out to demonstrate the performance of the designed active power filter with different control strategies. Experimental results show that the active power filter of the proposed current control scheme has achieved expected performance.