Modeling of a nonlinear control method applied to an advanced static var compensator

The paper deals with the modeling and control of an advanced static VAR (Volt Amperes Reactive) compensator (ASVC) system with self controlled DC bus which employs a three phase Pulse Width Modulation (PWM) voltage source inverter. The ASVC system is modeled using the d-q transform and employs a programmed PWM voltage wave shaping pattern stored in an EPROM to simplify the logic software and hardware requirements. The inverter system can compensate leading and lagging reactive power supplied by the load connected to the supply. This model is used to design an efficient control strategy based on the control of the phase angle of the switching pattern. Simulated results obtained with Matlab are also presented and discussed to validate the model.