CONTROL AND VALIDATION OF THE SERIES
CONNECTED DGFACTS
ABSTRACT
A series voltage source connected between the supplier and the consumer of the
electric network supports the voltage in that line. If the voltage injected by this
series coupled system is likely to be controlled (mainly the angle with the current
on the line), the active power which fits the load consumption can be freely
matched between the network and the series device (sDGFACTS hereinafter).
Thus, the requirements for storing energy are reduced, or the time that the series
connected device continues to compensate voltage is increased. The introduced
power losses are the main problem of the series voltage compensation by means of
electronic devices when the line current flows through it. When the series con-
nected compensation device is injecting power, the losses can be assumed; but
when compensation is not needed, since the voltage stands within the limits, then it
is preferable to disconnect the series device. An interrupter is used to bypass the
series connected system. The connection or disconnection actions must be carefully
treated, in order to increase the durability of the device. A method to synchro-
nously connect or disconnect the system to or from the electricity network is pre-
sented.