Dynamic reactive power control. Static devices

Today's reactive power compensation devices are typically based on thyristors. They provide a satisfactory response to the problems of unbalance compensation, network voltage regulation with respect to reactive power fluctuations, and power factor regulation. Reactive power absorbers range from a few megavars to several hundred megavars. There are two families of static reactive energy compensators (RECs): network RECs and furnace RECs. Their effectiveness depends on two main factors:

• sizing or the ratio between the power of the disturbance equipment and the reactive power of the capacitor bank and absorber;

• the control device for the adjusting element, whose speed is a key factor.

This speed aspect is currently limited by the thyristor components used. In the coming years, it is likely that blockable components such as GTOs (Gate-Turn-Off), IGCTs (Insulated-Gate-Commutated-Thyristor) or high-power IGBTs (Insulated-Gate-Bipolar-Transistor) will greatly enhance the dynamic performance of Reactive Energy Compensators, especially as these modern actuators could also act as active filters...

The article "Static reactive power compensators" is the subject of four booklets:

• D 4 315 Voltage fluctuations and flicker. Evaluation and mitigation (part 1) D 4 316 Voltage fluctuations and flicker. Evaluation and mitigation (part 2)D 4 317 Dynamic reactive power control. Static devicesDoc. D 4 318 Static reactive power compensators. For further information

Subjects are not independent of each other

Readers will need to refer back to the other issues often enough.

The fourth fascicule [Doc. D 4 318] places voltage fluctuations in the general context of electromagnetic compatibility. Relevant normative references and bibliography are included.