If both manually controlled shunt capacitors and automatically controlled generator MVAR are available, which should be used first?

The use of shunt capacitors to increase generator dynamic reactive reserve is preferred first in this scenario because shunt capacitors provide a quick and effective means of supplying reactive power to the grid. They are designed to enhance the voltage support and improve system stability, especially during dynamic conditions. By deploying shunt capacitors first, the system can achieve a more immediate response to changes in load or generation, which can be critical in maintaining system reliability during transient events.

When shunt capacitors are used, they can quickly discharge or absorb reactive power, thus helping to stabilize voltage levels without causing delays associated with the starting or adjusting of automatically controlled generator MVAR. Furthermore, prioritizing shunt capacitors allows for the generators to maintain their rotor angle stability, as it does not intervene with the core functionality of the generators which may already be operating under dynamic conditions.

In contrast, automatically controlled generator MVAR response may be necessary when there's a requirement for a more extensive adjustment or if the system's real power supply is tight. However, as a first step in managing reactive reserves, shunt capacitors can provide a more immediate and easily manageable solution. This prioritization supports the efficient and reliable operation of the electric grid, ensuring that the voltage levels are adequately maintained before