ispatch with Network and Ramping ints via Interior Point Methods

We describe an approach to the economic dispatch problem that combines both time-separated constraints (e.g., demand and network flow) and inter-temporal constraints (e.g., ramping) into a single optimization problem that can be solved efficiently by interior point methods. By including generator ramping limits as well as network line flow constraints, both economic and security issues are treated simultaneously, avoiding ad hoc post processing. We present several test cases, including dispatching six generators on the IEEE 30-bus network over 168 hours with line flow and ramping constraints. Computational effort as measured by iteration counts or execution time (CPU secs) varies only modestly with problem size.