对于可再生能源的分布式直流电源系统的控制策略.docx

Control strategy for a distributed DC power system with renewable energyThis paper deals with a DC-micro-grid with renewable energy. The proposed method is composed of a gearless wind power generation system, a battery, and DC loads in a DC distribution system. The battery helps to avoid the DC over-voltages by absorbing the power of the permanent magnet synchronous generator (PMSG) during line-fault. In addition, the control schemes presented in this paper including the maximum power point tracking (MPPT) control and a pitch angle control for the gearless wind turbine generator. By means of the proposed method, high-reliable power can be supplied to the DC distribution system during the line-fault and stable power supply from the PMSG can be achieved after line-fault clearing. The effectiveness of the proposed method is examined in a MATLAB/Simulink environment.IntroductionCurrently, for the greenhouse gas reduction, introduction of the renewable energies such as photovoltaics and wind energy is gaining popularity. When these renewable Distributed Generators (DGs) are connected to the power system, there is a concern about their harmful effects as most of their power fluctuate with weather conditions. Therefore, researchers have been working on practical application of micro-grids. Micro-grid is a small-scale power grid that has sources in certain areas and can supply power to a particular consumer. In the future, not only hospitals, banks and semiconductor factories, but also offices, shops and residential houses need high quality power. So, DC distribution systems are attracting attention in the world.The DC distribution system has the following advantages over the AC distribution system: (1) Each power generator connected to the DC distribution system can easily be operated in coordination because it controls only the DC bus voltage. (2) When the AC-grid system has fault conditions, the DC distribution system is disconnected from the AC grid, and then it is swi