During a heavy load voltage schedule action, which voltage levels should increase MVAR output?

In the context of the PJM Transmission Practice, when addressing heavy load voltage schedule actions, it's important to understand how MVAR (MegaVolt-Ampere Reactive) output is influenced by voltage levels. Increasing MVAR output is typically necessary to maintain voltage stability, particularly during higher load conditions.

The selection of voltage levels that should increase MVAR output during these conditions relates to how reactive power is supplied to the system. Lower voltage levels, such as 230 kV and below, are more susceptible to voltage drops during heavy loading, as they operate closer to their reactive power limits. In these situations, increasing MVAR output from generators or other reactive power sources supports voltage levels, helping to stabilize the grid and avoid voltage collapse.

Higher voltage levels, such as those above 345 kV or at 500 kV, typically have a stronger voltage profile and can manage reactive power in a different manner. They are often more resilient to the voltage fluctuations caused by load changes, making them less reliant on MVAR output increases during heavy load scenarios.

Thus, focusing on the lower voltage levels aligns with the operational strategies of maintaining voltage stability in the grid under heavy load, making the identification of the 230 kV or lower levels as the appropriate choice for increasing