Transient voltages on the power system can be measured
using power quality monitors. These devices are designed to
measure a range of power quality phenomena, including;
harmonics, inter-harmonics, voltage sags, voltage swells,
negative phase sequence unbalance, and transients. At
voltages below 600V [1], power quality monitors may be
connected directly to the power system. At higher voltages,
the power quality monitor needs to be connected via a voltage
transformer (VT), as shown in Figure