Time sequence three-phase probabilistic power flow calculation for power system including traction station load of high-speed railway.

• The time sequence probabilistic model of traction station load of high-speed railway considering the spatial correlation is proposed by applying the diffusion-based kernel density estimator (DKDE). • The model of time sequence three-phase probabilistic power flow (3PPF) calculation for power system connected with traction load is proposed through the port transformation of traction power supply system (TPSS). • The algorithm of time sequence 3PPF calculation model based on the three-point estimation method (3PEM) owned both the accuracy and the computational efficiency. • The time sequence probability density curves of voltage amplitude and three phase voltage unbalance degree of grid are obtained under the impact of the asymmetry and spatiotemporal of traction load of high-speed railway. The increasing traction station load of high-speed railway with single-phase, high-power, spatiotemporal mobility, and uncertainty has brought major impacts and challenges to the power system. The non-negligible characteristics are the spatial distribution of traction stations on high-speed railway lines, the time sequence of traction load moving with EMUs, as well as the nonparametric probabilistic features and correlation of traction load. A method of time sequence three-phase probabilistic power flow (3PPF) calculation for power system including traction station load of high-speed railway is proposed in this paper. Firstly, through the port transformation of traction power supply system (TPSS), the three-phase equivalent model of TPSS is established to construct an unbalanced three-phase power flow calculation model of grid with traction station load. Secondly, considering the spatial correlation, time sequence and non-parametric probabilistic feature of traction load, the time sequence probabilistic models of multiple traction station loads are built based on diffusion-based kernel density estimator (DKDE). Then, the algorithm of time sequence 3PPF calculation based on three-point estimation method (3PEM) is applied to deal with the computational efficiency and accuracy problems of 3PPF considering correlation and timing. Finally, the two modified three-phase power systems are employed for case studies in combination with the measured data of traction station of a high-speed railway. The validity and computing efficiency of the proposed method are verified. [ABSTRACT FROM AUTHOR]