Iman, First of all, you should get exactly the same maximum lambda when you vary the load at a specific bus, because the lambda is relative to system MVA base (ie, baseMVA). I just did some testing in the way you mentioned and the results did come out exactly the same.
The reason you got different and higher maximum lambda is probably related to the way you changed load. If you only double the active power of a load and kept the reactive power as it was, the power factor would be much higher. And you will likely see higher loadability, ie, maximum lambda. Please note that, in the CPF program, both active and reactive power at the specified bus will be varied in order to keep the initial power factor as implied in the case file. Also note that load variations at multiple buses are currently not supported, and I have been evaluating approaches of implementing that piece. If you have any other specific needs regarding CPF enhancement, please feel free to contact me off-list. Rui (Ray) Bo, Ph.D, SMIEEE Regulatory and Economic Studies Department Midwest ISO 1125 Energy Park Drive St.Paul, MN 55108 Phone: (651) 632-8447 Email: [email protected], [email protected] From: iman Sent: Monday, October 08, 2012 05:54 To: MATPOWER discussion forum Subject: CPF Dear all, I have done CPF for IEEE 30 case and got lamda max as 1.26 .Then I doubled all loads and got lamda max as 3.17.How that is possible?Am I be doing something wrong? Since generators are kept constant logically by doubling all loads, maximum loadability (lamda max) should decrease.Shouldn't it? Thanks Iman
