This paper formulates a generic DC approximation of the full active-reactive AC power flow problem. This novel approximation includes a novel linear reactive DC model than can be used to estimate bus voltage magnitudes and MVAr flows (DC-Q model). In addition, the combination of the DC-P and DC-Q models also provides a better estimation of network power losses, improving the accuracy of the well-known DC-P model. This novel DC-Q model is based on a change of variables, where the bus voltage module is substituted by its natural logarithm, and presents the same advantages recognized in the DC-P model. Due to this fact, it can be easily integrated into any software application that is already using the DC-P model. Using a small size 2-bus system and actual real-time scenarios of the Spanish electric power system, the precision performance of the DC-Q model is assessed, and the accuracy of the DC-P and DC-Q models are also compared.
Keywords: DC power flow, contingency analysis, voltage security assessment.
Registration date: 2016-07-21