Elimination of voltage violations in the Spanish electricity market: Part I: Theory

Abstract

The solution of voltage violations in the Spanish electricity market must consider: (a) the connection of off-line units (considering the active and reactive power injection effect), (b) the adjustment of the voltage control resources (generator voltages, transformer taps and shunt reactors and capacitors), (c) the preventive solution of the voltage violations under the occurrence of the postulated contingencies and (d) the start up cost internalized in the fixed income term of the generator offer. This start-up cost plays a key role in the solution of voltage violations since the coupled solution of the 24 hourly scenarios is different from the individual solution of each hourly scenario. This is the first part of a two-part paper. The objective of Part I is twofold. On one hand, the paper analyses the complexity of eliminating voltage violations proposing a simple methodology that includes the following steps: (a) contingency analysis (b) decoupled solution of voltage violations for each hourly scenario and (c) daily coupled solution of voltage violations. On the other hand, the paper describes the mathematical formulation of a set of mixed-integer optimization algorithms designed to obtain the hourly decoupled solution and the daily coupled solution of voltage violations in the Spanish electricity market. In Part II the methodology and performance of the algorithms will be illustrated and compared using an actual example of the Spanish electricity market.