The interconnection between Colombia and Panamá has been the object, since 2003, of a series of feasibility studies, cooperation agreements and financing approaches for a project which is intended to be a great contributor to the electrical markets integration of the Andean and Central America regions.
Both countries have confirmed their interest in developing a power interconnection; Panamá is looking mainly for a more competitive electrical energy market, a diversified electrical energy matrix, in order to guarantee the permanent availability of the electrical energy while Colombia wants to exploit its electrical energy exporting potential. The line is important not only for Colombia and Panamá, but for the regional integration as well.
HVDC technology was chosen for the development of the interconnection since it offers complete control over the power flow while decoupling the two networks. Additionally, HVDC lines, towers, and rights of way can be smaller than a comparable AC system, reducing the line’s environmental footprint which is very critical for this project. Based on several studies of resource planning and regional market pricing simulations (that take into account the future power supply and demand and also the capacity of the Central America power interconnection - SIEPAC), it was found that a capacity between 300 and 400MW was optimum to carry the power exchanges between the two systems.
Studies have been performed by the authors for the optimization of the HVDC OHTL and the terminal stations in order to minimize the investment and O&M costs within a secure and reliable performance of the planned link. On the base of two different hypotheses for the power transfer (300 and 400MW) the optimum system voltage and conductor have been chosen in order to minimize the overall cost; all this within the technical limits defined for voltage drop, maximum conductor temperature and corona effects.
Special attention has been paid on insulation coordination requirements to withstand the operating voltages, the overvoltages on the sound pole due to a fault on the other pole, the lightning performance and the surface insulation for the main portion of the line and for the line session close to the sea.
To maximize the reliability of the system, an insulated dedicated metallic return (DMR) has been considered and placed in an appropriated position in order to minimize the line cost. The insulation study of the DMR and the adoption of a metallic return transfer breaker (MRTB), to ground temporarily the neutral of one of the HVDC stations, are reported along with the philosophy of intervention to allow the minimum interruptions of power transfer in both bipolar and emergency monopolar operation.