SEMICONDUCTOR SWITCHING CIRCUIT

SEMICONDUCTOR SWITCHING CIRCUIT A semiconductor switching circuit (10), for use in a HVDC power converter, comprises: a main current branch (12) including a main semiconductor switching element (16) and through which current flows when the main semiconductor switching element (16) is switched on; an auxiliary current branch (14) connected in parallel or inverse-parallel with the main current branch (12), the auxiliary current branch (14) including an auxiliary circuit (18), the auxiliary circuit (18) including a plurality of active auxiliary semiconductor switching elements (22) connected to form an active switching bridge, the auxiliary current branch (14) further including an energy storage device (24) and/or an impedance device (20), the active switching bridge having a control unit (26) operatively connected therewith, the control unit (26) being configured to switch the active switching bridge to connect the auxiliary circuit (18) into and out of circuit with the main current branch (12) and thereby selectively create an alternative current path via the auxiliary current branch (14) whereby current flowing through the main current branch (12) is diverted to flow through the alternative current path to regulate one or more of current flowing through the main semiconductor switching element (16) and voltage appearing across the main semiconductor switching element (16), wherein the control unit (26) is configured to switch the active switching bridge to arrange the alternative current path to selectively pass through the energy storage device (24) and/or impedance device (20). (Figure 1) L'invention concerne un circuit de commutation à semi-conducteurs (10), destiné à être utilisé dans un convertisseur de courant continu à haute tension (HVDC pour High Voltage Direct Current), ledit circuit comprenant : une branche de courant principale (12) comprenant un élément principal de commutation à semi-conducteurs (16) et à travers laquelle le courant circule lorsque l'élément principal de commutation à semi-conducteurs (16) est activé ; une branche de courant auxiliaire (14) raccordée en parallèle ou parallèle inverse à la branche de courant principale (12), la branche de courant auxiliaire (14) comprenant un circuit auxiliaire (18), le circuit auxiliaire (18) comprenant une pluralité d'éléments de commutation à semi-conducteurs auxiliaires actifs (22) raccordés de sorte à former un pont de commutation actif, la branche de courant auxiliaire (14) comprenant en