Xue Hua

Computation of unbalance factors for six-circuit transmission line on the same tower

The sequence parameters and unbalance factors of six-circuit transmission line with two shield wires on the same tower are computed. Firstly, sequence parameters of six-circuit transmission line are analyzed based on Carson model and image method correspondingly. Secondly, the unbalance factors of six-circuit transmission line are defined in detail. Finally, take a 110kV six-circuit transmission lines as an example, the sequence parameters and unbalance factors are computed using MATLAB. Through comprehensive comparison, the unbalance factors especially through-type electromagnetism unbalance factors for inverse phase sequence are smaller than others. Inverse phase sequence is recommended as the optimum arrangement.

Photovoltaic output power chaotic characteristic and trend prediction based on the actual measurement data

Based on the nonlinear dynamic modeling of photovoltaic power generation system output time sequences, parsing the kinetic characteristics of the output power of photovoltaic power generation system, the chaos characteristics of the photovoltaic power generation system output power is put forward. According to the phase space reconstruction theory, adding weight first order local prediction method is used for photovoltaic output power chaotic prediction. The actual measurement data of the output power acquired from the photovoltaic power generation system of a printing plant roof is used to verify the prediction method. Results show that the photovoltaic power generation system output power has chaotic characteristics, and it is feasible that the chaos prediction method apply to photovoltaic output power prediction, the method has a high accuracy for photovoltaic power ultra-short term prediction, it provide a new way for photovoltaic output power prediction.