The deregulation of the electricity market, however, has led
to major changes. The transmission grid is used as a transport
medium between producer A and consumer B, not necessarily
located in the same country. A and B have concealed a contract
Another problem that can occur is the uneven loading of
parallel transmission lines. The distribution of the power flow
between two parallel lines is dictated by their impedances [1].
The line with the smallest reactance carries the largest part
of the load. In most situations, one of the two lines will be
operating well below its nominal rating because otherwise the
parallel line would be overloaded.
In the two problems stated above, active power flow needs to
be controlled. The phase shifting transformer (PST) does just
that. Several countries have already installed or are planning to
install PST’s [2], [3], [4]. Although the technology is relatively