Method and Apparatus for Security Constrained Economic Dispatch in Hybrid Power Systems

摘要

The teachings herein disclose an advantageous method and apparatus for performing Security Constrained Economic Dispatch (SCED) for a hybrid power system that includes one or more AC grids interconnected with one or more multi-terminal High Voltage DC (HVDC) grids. The teachings include optimizing a non-linear objective function, subject to a set of constraints that include AC and DC grid constraints, for determining the SCED solution using successive linear approximation. The linear programming model used in the linear approximations is advantageously augmented with a DC grid portion in a manner that accounts for the effects of the DC grid on the AC grid, but which does not require exposing proprietary DC grid modeling details, and which conforms the resultant SCED solution to all applicable AC and DC grid constraints, including AC grid line flow constraints, AC grid power balance constraints, DC grid line flow constraints, and DC grid power balance constraints.

主权项

1. A method of determining a Security Constrained Economic Dispatch (SCED) solution for a hybrid power system comprising an Alternating Current (AC) grid interconnected with a multi-terminal High Voltage Direct Current (HVDC) grid at one or more Point-of-Common-Coupling (PCC) buses, said method comprising optimizing a non-linear objective function, subject to a set of constraints that include AC grid constraints and DC grid constraints, for determining the SCED solution using successive linear approximation, including:
computing a power balance sensitivity for the AC grid, based on calculating AC grid power flow according to a reasonably assumed dispatch solution and initialized power injection values for the PCC buses; determining an initial dispatch solution by solving a linear programming (LP) problem that linearly approximates the non-linear objective function, subject to a limited subset of the constraints and based on assumed power injection values; adopting the initial dispatch solution as the SCED solution when the initial dispatch solution does not result in any new constraint violations, as determined by performing an AC grid power flow analysis according to the initial dispatch solution, and otherwise performing an LP problem iteration, including:
calculating DC grid power flow in a DC grid power flow analysis, based on the injection values included in the current dispatch solution and correspondingly updating the DC grid constraints in the LP problem;solving the updated LP problem and adopting the resulting dispatch solution as the SCED solution if no new AC grid constraint violations are detected from repeating the AC grid power flow analysis, and otherwise adding a most-violated one of any newly-detected AC grid constraints to the LP problem and performing another LP problem iteration.