Electric Power   A HVDC backtoback station with a maximum transmission rate of  megawatts was built at Broken Hill in  It consists of  static inverters working with a voltage of  kV After this station was operational the two other power stations closed and their equipment was gradually removed  An HVDC backtoback station merely connects two stations either on different frequencies or at least not phaselocked  It does not produce any power  The first part of the section on Electric Power implies that by the s there were only two stations left and states that these were connected as a grid ie phaselocked and directly connected  What stations did the HVDC backtoback system connect and which stations were then demolished