Protective equipment for a series-capacitor installation

A series-capacitor installation intended to be placed on a platform, insulated towards ground, for connection into a power line (L) for carrying a line current (IL) has a first and a second capacitor group (C 1 and C 2 , respectively). The capacitor groups are mutually parallel-connected and a non-linear voltage-limiting resistor (Z) is connected in parallel with the capacitor groups, the first capacitor group for carrying a first capacitor current (C 1 ) and the second capacitor group for carrying a second capacitor current (IC 2 ). Protective equipment is intended, in dependence on currents sensed in the installation and on chosen criteria for evaluation thereof, to initiate a protective measure for the installation under an abnormal operating condition. The protective equipment comprises means (T 1 and T 2, T 3, 9, respectively) for forming a first measured value (IMD) representing the difference between the first and second capacitor currents, and means ( 4, 5, 6 ) which, in dependence on said first measured value, initiate a protective measure for the installation for each of the abnormal operating conditions unbalance current between the first and second capacitor currents, overcurrent (IZ) through the voltage-limiting resistor, and a short-circuit fault in the series-capacitor installation.