风柴独立微电网频率H_2/H_∞优化控制研究

Frequency H_2/H_∞ optimal control for isolated wind-diesel hybrid micro-grid

受风能和负荷不断变化的影响,风柴互补的独立孤岛型微电网会出现频率的大幅度波动。为保证微电网的正常运行,设计了一种H_2/H_∞控制器对柴油发电机进行有功功率调节,平衡由于风能和负荷的变化而引起的功率偏差,实现微电网的频率控制。H_2/H_∞控制器综合了两种性能指标的优点,其中,采用H_2性能指标使系统获得较好的动态性能,采用H_∞性能指标提高系统抑制随机干扰的能力,使系统对风电及负荷扰动等随机干扰既有较强的鲁棒性,又保证具有较好的动态性能。仿真结果表明,加入了H_2/H_∞控制后,微电网的频率变化能够控制在要求的范围内,避免了因负荷、风电相互作用而引起的频率波动,保障了微电网的安全、稳定运行。

Affected by change of wind and load, large islands wind-diesel complementary micro-grid. In order frequency fluctuation will occur in independent to ensure the normal operation of the micro-grid, an H2/H∞ controller was designed to adjust the active power of diesel generators, and the power variation caused by wind and load was balanced, so the frequency control of micro-grid was achieved. H2/H∞ controller combined the advantages of two kinds of performance index. H2 performance index was adopted to get good dynamic performance, and H∞ performance index was adopted to improve the ability of system to suppress random disturbance. So the system had strong robustness for the random disturbance such as wind power and load, and good dynamic performance had got. Simulation results show that after an H2/H∞ eontroller being added, the frequency change of micro-grid can be controlled within the range required , the frequency fluctuations was avoided caused by the interaction of wind and load, and the safety and stable operation of the micro-grid was protected.