Thyristor Switched Capacitor Bank
Thyristor switched capacitor banks equipped with a fast control are designed to support the line voltage and to compensate the reactive power of the load. Thyristor switches make possible that a fast response is achieved without any mechanical wear, noise or excessive transient associated with contactor switching. A control signal can be brought from the compensated equipment and so it is achieved reactive power compensation almost without delay. All steps of the capacitor bank are switched on during one network period. Each step of the bank consists of a capacitor unit with a blocking reactor. These form a series resonant circuit tuned to a frequency below that of the lowest harmonic.
Capacitor bank is chosen to be suitable for load according to the control system, compensation power and load switching. The compensated equipment can be symmetrical or unsymmetrical for main or phase voltage switched loads.