Nonlinearity and Linearization of Hysteresis PWM Study and Analysis for HAPF

Abstract

AbstractThis chapter presents a hysteresis pulse width modulation (PWM) study for three-phase four-wire hybrid active power filter (HAPF). As the coupling inductor and capacitor (LC) impedance yields a nonlinear inverter current slope, this can affect the controllability of using the conventional hysteresis control method and generate unexpected trigger signals to the switching devices. This results in deteriorating the system operating performances. Based on the proposed modeling, the linearization of the hysteresis control for the HAPF is first studied, investigated, and compared with the linear active power filter (APF). Two limits are proposed in this work that divides the HAPF into nonlinear, quasi-linear, and linear operation regions. The design criteria of hysteresis band and sampling time can then be derived. Single-phase simulation and experimental results are given to verify the hysteresis control study of HAPF compared with APF. Finally, representative simulation and experimental results of a three-phase four-wire center-split HAPF for power quality compensation are presented to demonstrate the validity of the hysteresis linearization study.KeywordsActive Power FilterCoupling LCHybrid Active Power FilterHysteresis PWMLinearizationNonlinear Inverter Current Slope