Improving an Unjustified Common Practice in Ex Post LMP Calculation

A common practice for the Ex Post LMP calculation at a number of U.S. ISOs uses a small constant range, typically from -2.0 to +0.1 MW, as each generator's lower and upper bounds. This paper shows that this is an unjustified practice as the marginal units and LMP may change if the bounds are changed. A simple yet effective improvement is proposed.