Simulation Methods to Generate Time Series For Joint Wind and Photovoltaic Power Output Basede on Markov Chain and Copula Theory

For the planning, scheduling and control of power grid, it is significant to generate joint wind and photovoltaic (PV) power output time series by simulation method. Considering daily characteristics, whether characteristics and fluctuation properties of wind and PV power output, four simulation methods based on Markov chain and Copula theory to generate wind and PV power output time series were proposed. For the first method, the improved Markov Chain was utilized to generate two time series for wind power and PV power respectively and the two time series were superposed to obtain the joint wind and PV power output time series. As for the second method, the historical sequence of wind and PV power output were correspondingly added and the results were regarded as the historical data, then the improved Markov chain was utilized to directly generate the joint wind and PV power output time series. In the third method, to reduce the randomness due to the traditional sampling method, utilizing the combination of Markov chain with Copula theory, the joint wind and PV power output time series were generated. As for the fourth method, to seek a better method, the entropy weight method was used to carry out the combination simulation to generate the time series for wind and PV power output. Results of engineering practice show that all four proposed methods are correct and effective, and the fourth method, i.e., the combination generation method is more effective.