Hourly solution of voltage constraints in the Spanish electricity market

The solution of voltage constraints in each hourly scenario of the Spanish electricity market must take into account: (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) and (c) the preventive solution of the voltage violations under the occurrence of the postulated contingencies. This paper describes two algorithms that optimize the solution of voltage constraints in each hourly scenario, overcoming the limitations of existing optimal power flow algorithms to comply with the required features in the Spanish electricity market. The performance of both algorithms is illustrated considering the solution of voltage constraints of an actual hourly scenario of the Spanish electricity market. In addition, their solution is compared from an economic and technical point of view.