Abstract: An apparatus for testing a thyristor valve includes: a current source circuit that provides an electric current when a thyristor valve as a test target is turned on; a voltage source circuit that provides a reverse voltage or a forward voltage when the thyristor valve is turned off; and a first auxiliary valve provided between a connection point between the thyristor valve and the voltage source circuit and the current source circuit, and that insulates the current source circuit from the voltage source circuit to protect the current source circuit from a high voltage of the voltage source circuit.

Abstract: An apparatus for testing a thyristor valve includes: a current source circuit that provides an electric current when a thyristor valve as a test target is turned on; a voltage source circuit that provides a reverse voltage or a forward voltage when the thyristor valve is turned off; and a first auxiliary valve provided between a connection point between the thyristor valve and the voltage source circuit and the current source circuit, and that insulates the current source circuit from the voltage source circuit to protect the current source circuit from a high voltage of the voltage source circuit.

Abstract: A DC power transmission system of a voltage source converter using a pulse-interleaving auxiliary circuit is disclosed. The converter system comprises an IGBT converter for converting an AC power to a DC power or the DC power to the AC power; an open Y-Y transformer and a Y-? transformer for stepping up or stepping down the AC power having a predetermined magnitude; a capacitor for dividing a DC voltage; and a DC Auxiliary circuit composed of a normal transformer and half-bridge for overlapping a pulse type input voltage to increase the number of pulses of an output waveform. In using a DC auxiliary circuit composed of normal transformer and 3-level half-bridge to increase the number of pulses of the output waveform by superposing the voltage in the form of the pulse, a normal transformer may be used instead of the tapped transformer to reduce the size thereof and to obtain an accurate transformer ratio, and a 3-level half-bridge may be used instead of the H-bridge to reduce the switching loss.

Abstract: A DC power transmission system of a voltage source converter using a pulse-interleaving auxiliary circuit is disclosed. The converter system of the present invention comprises an IGBT converter for converting an AC power to a DC power or the DC power to the AC power; an open Y-Y transformer and a Y-? transformer for stepping up or stepping down the AC power having a predetermined magnitude; a capacitor for dividing a DC voltage; and a transformer and a half-bridge auxiliary circuit for overlapping a pulse type input voltage to increase a number of pulses of an output waveform. In accordance with the present invention, the normal transformer is used instead of a tapped transformer to reduce the size thereof and to obtain an accurate transformer ratio, the 3-level half bridge is used instead of the H-bridge to reduce the switching loss in order to increase the number of pulses of the output waveform by superposing the voltage in the form of the pulse using the auxiliary transformer and the bridge circuit.