It is well known that the cost performance of PAM SVG (Pulse Amplitude Modulation Static Var Generator) is better than that of PWM SVG (Pulse Width Modulation Static Var Generator) because of its low loss in operation and more compact size of equipment. Despite the advantage, the PAM SVG has been deprived of opportunities to show its effectiveness in power systems, having reputation for inferior of continuous operating performance under unbalanced-voltages and for slow response. In this paper, analogue simulation results show that decoupling control and proper amount of capacitor furnish the PAM SVG with great continuous operation ability and quick response, which suffice to improve power system stability.