BigPatents India

An improved back –to – back test circuit for high voltage direct current thyristor valve comprising a six pulse back – to – back test circuit having a six thyristor valve (7) connected to a converter transformer receiving power from a generator, said valve is connected to a valve for short circuit testing through two parallel smoothing reactor, said valve for short circuit testing is connected to a converter transformer receiving power from said generator through a current limiting reactor characterized in that an impulse generator is connected for VBO triggering to the level near to the ground in one of the valve of the bottom commutating group said impulse generator circuit comprises a transformer connected to a diode, a thyristor and an inductor in series with a capacitor in parallel connected between said diode and thyristor. (FIG.)nil