Applications Grid Dynamics Power Quality Voltage Regulation Earth Fault Detection Active and reactive power control by REGSysTM Normally a voltage regulator REG-D(A) is responsible for the constant voltage on the secondary side of a transformer. The main task is to find the correct balance between good voltage inside the tolerance band (bandwith) on the one side and less movements of the tap-changer on the other side. Additionally another firmware feature, PQCtrl, is available on REG-D(A) devices. This has been designed for the regulation of Phase Shifting Transformers, so called Quad Boosters, and other customer-specificapplications. In case of PQCtrl the desired value will be the active- or the reactive power instead of the voltage, which is like explained used for standard voltage regulation.

Main characteristics of the special feature PQCtrl • It is a software feature which can be activated with regard to the hardware on all REG-D(A) devices independent from the date of delivery. Depending on the existing firmware version it may be necessary to do a firmware update. • Four desired values (setpoints) will be available: Two voltage values (first and second setpoint), one value for active power (third setpoint) and one value for reactive power (fourth setpoint). • The general functionality of the regulator REG-D(A) - voltage, active - or reactive power control - can easily be changed...

Regulation of phase shifting transformers Phase shifting transformers or more simple Quad boosters are special constructions of transformers used to control the power flow in three-phase transmission grids. For an alternating current transmission line the power flow through the line is proportional to the sine of the difference in the phase angle of the voltage between the transmitting end and the receiving end of the line. Where parallel circuits with different capacity between two points in a transmission grid (for example, an overhead line and an underground cable) exist, direct manipulation...

Other Applications Regulation of a generator transformer Minimizing of reactive power flow on network feeding points Under normal operation conditions the generator controls the voltage of the power plant grid. The generator transformer is also equipped with a tapchanger to regulate the voltage during maintenance periods or in emergency situations. With this tap-changer it is also possible to transform the impedance of the grid during normal operation. This transformation influences the reactive power flow from or to the grid. In some grids it is possible to use only some big transformers or...