基于功率频率分解孤立微电网储能容量优化配置-optimal allocation of energy storage capacity for isolated microgrid based on power frequency decomposition.docx

ABSTRACTWith the energy crisis and environmental pollution, new clean energy like wind power are highly valued. However, large-scale wind power will affect the security and stability of the grid due to its intermittence and volatility. It would reduce the impact on power system if the wind power was connected to the power system as a microgrid, storage system in microgrid can effectively reduce the fluctuations caused by the wind power. Storage system can stabilize the fluctuations of active power, which plays an important role in the stable operation of microgrid, reasonable configuration of energy storage is important to improve reliability and economy of microgrid. This paper was focused on the power balance analysis in isolated microgrid, reliability assessment considering energy storage and capacity optimization of hybrid energy storage system. The following work was carried out:To characterize the fluctuation of wind power and load in micro-grid including wind farm, micro turbine and energy storage, the definition of discrepancy power in microgrid was given, which is the difference between load and wind power fluctuations; According to the fluctuations of discrepancy power, the discrepancy power decomposition model using Discrete Fourier Transformation was established in microgrid, which is to decompose the discrepancy power into low frequency and high frequency components and the high frequency component was defined as imbalance power. Meanwhile, micro turbine was used to provide the low frequency component and energy storge system to balance the high frequency component, which is proposed as MT-ES joint operating strategy. Taking an island microgrid as a numerical example, the results showed that: Under the premise of meetting the load demand and without increasing fuel consumption, the proposed joint operating strategy can effectively reduce the storage system capacity configuration requirement.Based on the MT-ES joint operating strategy, a six-state energy