Probabilistic load flow calculation of AC/DC hybrid system based on cumulant method

The operating conditions of the power system have become more complex and changeable. This paper proposes a probabilistic load flow based on cumulant method (PLF-CM) for voltage sourced converter high direct current (VSC-HVDC) hybrid containing photovoltaic grid-connected systems. Firstly, corresponding control mode is set converter, including droop master–slave control. unified iterative used to calculate conventional AC/DC flow. Secondly, basis probability model output, aforementioned results, use correlation coefficient matrix this will change relevant sample into independent sample, cumulants output are obtained; Then, density function (PDF) cumulative distribution (CDF) state variables obtained by using Gram-Charlie series expansion method. Finally, mean value standard deviation node line calculated modified IEEE 34-bus 57-bus transmission algorithm can reflect inherent uncertainty new energy sources, replace convolution operation, greatly improving calculation speed convergence.