  This work investigates the impact of feeder bidirectional active power flow
on the operation of two cascaded step voltage regulators (SVRs) located at a
34.5 kV rural distribution feeder. It shows that, when active power flow
reversal is possible both by network reconfiguration and by high penetration
levels of distributed generation (DG), typical SVR control mode settings are
unable to prevent the occurrence of runaway condition, a phenomenon
characterized by loss of SVR voltage control capabilities. Such developments
are the basis for a DG pre-dispatch control strategy that aims to avoid the
adverse effects of the described power flow reversal scenarios, as well as to
ensure reliable operation of the utility distribution network.
