Estimation of equivalent inductance and resistance for adaptive control of three-phase PWM rectifiers

In this paper, an adaptive voltage-oriented control (VOC) for three-phase grid-connected pulse-width modulation (PWM) rectifier is developed. As the control loop behavior is affected by the PWM rectifier operating conditions, the effects associated to the PWM rectifier losses and uncertainty in the inductance should be inserted in the model. Thus, equivalent resistance and inductance are estimated online by means of an adaptive linear neuron (ADALINE). The proposed ADALINE estimator is inserted in the current control loop to perform an adaptive VOC scheme. Hence, an online updating of the decoupling terms and the current controller gains is achieved. The ADALINE capability to estimate accurately the equivalent inductance and resistance as well as the adaptive VOC scheme performances are finally evaluated by experiments. Experimental results show improved performances and accurate estimation.