Stability Analysis of Magnetically Controlled Reactor for Reactive Power Compensation Based on Small-Signal Model

Magnetically controlled reactors (MCRs) provide a flexible way of regulating reactive power. However, the stability of the MCR for reactive power compensation has not been researched deeply due to switching nonlinearity and ferromagnetic nonlinearity that are inherent in MCR. In this paper, a small-signal model of the MCR for reactive power compensation is established by means of a piecewise linearization-method. Based on the derived small-signal model, the stability boundaries of some key parameters are analyzed. It is found that the most possibly unstable operating point corresponds to a specific saturation degree when the compensating reactive power changes. The analysis results in this paper will play an important role in designing MCR for reactive power compensation. Finally, simulations and experiments are performed to validate the stability analysis results.