A large scale PWM solid state synchronous condenser

The description, steady-state analysis, and the closed-loop control design of a microcontroller-based large-scale pulsewidth-modulated solid-state synchronous condenser (PWM-SSSC) for reactive power compensation are presented. The key advantage of PWM-SSSC over its predecessors is the fact that large passive magnetic components are replaced by silicon. This provides a more compact and efficient systems at a cheaper price. A series of PWM switching patterns in the low-switching-frequency range (F/sub SW/<500 Hz), which are most suitable for high-power gate turn-off (GTO) thyristors, is presented. Formulations and solutions of the Newton-Raphson method for possible low-switching-frequency PWM patterns, performance comparisons for multiple solutions, different control strategies, and the filter design are presented. Cumbersome z-domain methods for pulsed stability analysis are completely avoided by using direct s-domain computations. A systematic approach for tuning the controller parameters is introduced by extending the concept of absolute stability.<>