fmincon finds local optima. However, I have the impression that interior point methods find global optima. I am not sure though. 1.Does matpower use fmincon in its source code to do a non-linear ACOPF? 2.Does matpower use interior point method for the non-linear ACOPF ? 3. Since DC-OPF is linear , is the optimum found a global optimum ? Thank you CC: [email protected] From: [email protected] Subject: Re: OPF on matpower Date: Tue, 23 Jul 2013 10:05:21 -0700 To: [email protected]
On Jul 23, 2013, at 9:42 AM, spyros gian <[email protected]> wrote: Dear Dr Zimmerman, Running an OPF in matpower means that 1. Bus types play no role (eg slack, PV, PQ etc) Yes. 2. All values for Real Power generation and reactive power generation are unknown Yes. 3. All values for bus_voltages and voltage phase angles in buses, are unknown as well The voltage angle of the reference bus is fixed and set to 0. 4. As a result, all values for real and reactive power flows are unknown. Yes. 5. Losses are unknown. Yes. What is known : 1. The resistance, reactance, admittance per unit / per conductor 2. Values for Real and Reactive demand at each bus 3. Limits on voltage magnitude , limits on real and reactive power generation 4. MVA limits on each line 5. Fuel cost for each generator. Yes for all So my question is a. Are the above correct for matpower ? b. Since matpower uses a non-linear optimisation, is the result a local minimum or a global minimum? (for the case of a cost-minimization OPF) ? i.e. the values for voltages, reactive powers etc, are globally optimum or perhaps other optimum values for all the unknown quantities exist ? I believe most of the optimization tools, such as fmincon in Matlab, find a local minimum. Shri Thank you, Spyros Gian
