Resolve Example 6.20, except with the generation at bus 2 set toa fixed value (i.e., modeled as off of AGC). Plot the variation inthe total hourly cost as the generation at bus 2 is varied between0 to 200 MW in 5-MW steps, resolving the economic dispatch at eachstep. What is the relationship between bus 2 generation at theminimum point on this plot and the value from economic dispatch inExample 6.20? Assume a load scalar of 1.0

Example 6.20: PowerWorld Simulator case Example 6_20 uses afive-bus, three-generator lossless case to show the interactionbetween economic dispatch and the transmission system (see Figure6.19). The variable operating costs for each of the units are givenby C1 = 10P1 + 0.016P 1 Square $yhr C2 =8P2 + 0.018P2 Square $yhrC4 = 12P4 + 0.018P 4 Square $yhr where P1, P2, and P4 are thegenerator outputs in megawatts. Each generator has minimum/maximumlimits of 100 <=P1 <=400 MW 150 <=P2 <= 500 MW 50 <=P4 <=300 MW In addition to solving the power flow equations,PowerWorld Simulator can simultaneously solve the economic dispatchproblem to optimally allocate the generation in an area. To turn onthis option, select Case Information, Aggregation,
Areas… to view a list of each of the control areas in a case (justone in this example). Then toggle the AGC Status field to ED. Nowanytime the power flow equations are solved, the generator outputsare also changed using the economic dispatchInitially, the case hasa total load of 392 MW with an economic dispatch of P1 =141 MW, P2= 181, and P4 = 70, and an incremental operating cost, l, of 14.52$?MWh. To view a graph showing the incremental cost curves for allof the area generators, right-click on any generator to display thegenerator’s local menu, and then select All Area Gen IC Curves(right-click on the graph’s axes to change their scaling). To seehow changing the load impacts the economic dispatch and power flowsolutions, first select Tools, Play to begin the simulation. Then,on the oneline, click on the up/down arrows next to the Load Scalarfield. This field is used to scale the load at each bus in thesystem. Notice that the change in the Total Hourly Cost field iswell approximated by the change in the load multiplied by theincremental operating cost. Determine the maximum amount of loadthis system can supply without overloading any transmission linewith the generators dispatched using economic dispatch.