METHOD AND APPARATUS FOR LIMITING CURRENT IN A DIRECT VOLTAGE NETWORK OF A POWER TRANSMISSION SYSTEM

摘要

Apparatus and method for limiting current in a direct voltage network of a HVDC power distribution system. A direct voltage network is connected to an alternating voltage network through a VSC-converter. At least one parallel connection including a semiconductor switching element is connected in series with the direct voltage network. A surge diverter is connected in parallel with the semiconductor switching element. During a high current condition in the direct voltage network, the switching element is switched off interrupting the current flow which is then diverted through the surge diverter which reduces the current flowing in the direct voltage network. By inserting a plurality of parallel connections, and selectively turning off a number of said semiconductor switching elements, a number of different levels of over current conditions in said direct voltage network may be controlled.