It is crucial to comprehend how the electric load reacts to changes in the supply voltage, especially when voltage reduction is now being utilized more often by utilities as means to reduce electric stress and demand response. After voltage reduction was implemented at a specific station, various engineering departments review the load change and compare the impact to their models and expectations. Often, the results don’t concur with their analysis, mainly due to the lack of modeling proper load coefficients. In the next paper, I can discuss the impact of voltage reduction on the substation transformers, sub-transmission feeders and the transmission system.
There are three types of loads, also known as load coefficients:
- Constant power load
- Constant current load
- Constant admittance (inverse of the impedance) load
Even though several load flow programs models the electric load as constant power only, the other two types play a key role as well. Most modern equipment is of a constant power load type. The main difference between these types is in their response to changes in voltage....(Read rest of "Load Coefficients"...)