Input Reactor Unit (IRU) For transformerless installations in combination with a 6-pulse LSU. IRU comprises the input reactor as a current limiter and a terminal section for the power supply cables.•Active Rectifier Unit (ARU)6-pulse self commutated voltage source inverter•Inverter Unit (INU) 6-pulse self commutated voltage source inverter for power ratings of 3 and 5 MVA with control part and power cable termination incorporated in one cabinet.6-pulse self commutated voltage source inverter for power ratings of 7 or 9 MVA (parallel connection for higher output power possible).•Capacitor Bank Unit (CBU)Contains the DC link capacitors.•Terminal Unit (TEU)For power cable termination.•Control Unit (COU)•Water Cooling Unit (WCU)•Customer Interface Unit (CIU)Houses additional input and output interfaces.•Input Filter Unit (IFU)Harmonic filter for ARU, use depends on supply network configuration.•Voltage Limiter Unit (VLU)Dynamic DC voltage limiter•Resistor Braking Unit (RBU)DC chopper with integrated resistors•Braking Chopper Unit (BCU)DC chopper to be used in combination with external resistors•Isolator Unit (ISU)Disconnector for 2 CBUs only used in redundant configurations•Excitation Unit (EXU)6-pulse thyristor bridge or AC power controllerRefer to the detailed description of each unit in Chapter 5 - Description of Converter Units.