Artificial Intelligence And Its Applications In Wind-Photovoltaic Hybrid Power Systems

As two kinds of abundant, clean and renewable energy sources, wind and solar energy will make tremendous contribution to energy structure adjustment and environmental protection. According to research at home and abroad, wind-photovoltaic hybrid power (WPHP) is better than wind power or photovoltaic power independently, which has drawn attention all over the world. At present, research on WPHP is mainly focused on wind turbine manufacture and control, photovoltaic power unit manufacture and control, and also the optimization design of wind-photovoltaic hybrid power farm (WPHPF). There is less report about energy management and control of WPHPF, which is vital to the popularization and application of this new green energy.Based on colleting, analyzing, generalizing material about WPHP at home and abroad, this dissertation makes an intensive study of energy management and control of WPHPF. The main contents of this dissertation are as follows:(1) Research on particle swarm optimization (PSO).A new PSO is presented. It uses uniform designs (UD) to initialize particles, which makes some particles stay at or near the position where the global optimal solution stays with more probability. So the new PSO can find global optimal solution with more probability and more speed. Particles can keep diverse through mutating inertia particle with the probability of 1 in the process of evolution, which makes the new PSO find more precise solution. The results of experiments verify that the new PSO can find more precise solution with higher speed than the standard one.(2) Research on control systems of WPHPFThere are many power devices in large size WPHPF, which scatter all over the power farm. According to this circs, the architecture of control systems of WPHPF is constructed using distributed artificial intelligence-Agent theory and technology. It not only dovetails nicely with the controlled objectives, but has many merits such as strong adaptivity, good openness and fault-tolerance. This dissertation builds agent models, and introduces functions of each module and relationship among them. Propose an advanced contract-net protocol, which simplifies agents' negotiation procedure, solves the problem of task decomposition.(3) Research on the frequency control of wind-photovoltaic hybrid power systems (WPHPS)With the aim of minimum generation cost, this dissertation establishes a frequency optimizing control mathematical model of WPHPS under conditions of the assigned reactive flow dispatches. This model takes into account WPHPS frequency safety and stability, and the operation economical efficiency. The optimized result by the improved PSO shows that the mathematical model controls WPHPS frequency effectively, and makes WPHPS run economically. With the size of WPHPF enlarging, the number of control variable becomes more, thus the speed of optimization becomes slower, which doesn't meet the strong real-time demand of frequency control. To solve this problem, multi-agent collaborative optimization is adopted. The result of experiment shows it is more effective than sole population PSO. An automata model of frequency control subsystem of WPHPS is made. The experimental result shows it controls the variety of frequency of WPHPS well. It also confirms the robustness of this automata model.(4)Research on the voltage control of WPHPSWith the aim of minimum voltage deviation and active power loss, a mathematical model used to control voltage variety of WPHPS is built under conditions of determined active power. The results gotten by the advanced PSO and multi-agent cooperative optimization show the mathematical model controls voltage of WPHPS effectively, and reduces active power loss. An automata model of voltage control subsystem of WPHPS is made. The experimental result shows it controls the variety of voltage of WPHPS effectively. Also the correctness of this automata model is verified.At the end of this dissertation, the main research is summarized. It makes out the points of innovation and main research results, also points out the further researches.