Abstract: A voltage source converter, for interconnecting electrical networks, comprises a converter structure which includes a terminal for connection to the first electrical network and a terminal for connection to the second electrical network. The converter structure also includes at least one module that is connected between the terminals. The module includes at least one energy storage device and at least one switching element. The energy storage element and switching element are operable to selectively provide a voltage source. The converter structure still further includes an integrated passive fault current limiter that is configured to present a first impedance to a normal current flowing in the voltage source converter during normal operation of the voltage source converter, and is configured to present a second impedance to a fault current flowing in the voltage source converter during a fault condition. The first impedance is lower than the second impedance.