A Novel Passivity-Based Control Algorithm for Single-Phase Active Power Filter Using Euler-Lagrange Model

The performance and application of active power filter(APF) in power system is closely linked to the selection of control strategies.The paper proposes a novel passivity-based algorithm for single-phase APF based on its Euler-Lagrange(EL) averaged model.Firstly,the EL averaged model of single-phase APF with the presence of feeder impedance and nonlinear loads is established in terms of substitution theorem.Then,according to passivity theory and EL averaged model,the passivity-based indirect control law is acquired so that asymptotically tracking control objectives are achieved.In order to overcome the difficulty in estimating the ripple component on dc-side capacitor reference voltage,the modified control algorithm is proposed by ignoring the ripple component.Furthermore,the relation between control performance and damping coefficient is researched.In addition,the reasons of voltage source converter(VSC) inner-loop control overmodulation are also analyzed.Based on the relation between control performance and VSC inner-loop input saturation,damping coefficient is adjusted on-line by fuzzy logic reasoning so that the trade-off between control accuracy and limitation of VSC inner-loop control overmodulation is solved preferably.Lastly,simulation results are presented to verify the validity of the proposed control algorithm.