Abstract: A fuzzy-logic controlled super-capacitor to improve the load frequency control (LFC) of an interconnected power system is proposed in this paper. The load perturbation unbalances the generation output power and load demand power, the primary target of interconnected power system load frequency control is to maintain the frequency and tie-line exchange power in normal range. In the proposed method, the frequency deviation is used as the input of the fuzzy-logic controller, the super-capacitor in each area is interfaced with a bidirectional Buck-Boost converter, which is used to control super-capacitor to charge or discharge. When the load suddenly changes, the super-capacitor will release or absorb power from the system to ensure the power system stable. The simulation results show that the fuzzy-logic controller can suppress frequency deviation caused by load power fluctuation, thus the load frequency control targets can be satisfied, and this method also has good robust and dynamic characteristic.

Key words: Super-capacitor, interconnected power system, load frequency control, fuzzy control

摘要： 针对负荷频率控制系统具有不确定性问题，提出了一种基于超级电容的两区域互联电力系统负荷频率模糊控制方法。互联电力系统的负荷频率控制的首要目标是保证系统频率和联络线交换功率维持在合理的范围内，而负荷的突然变化会使发电功率和需求功率之间不平衡导致系统的频率和联络线交换功率出现偏差。该方法以区域偏差量作为模糊控制器的输入，采用双向Buck-Boost变换器和模糊控制来对超级电容进行充放电控制。仿真结果表明，在满足各种负荷扰动情况下，所提方法可有效地跟踪功率波动所引起的频率偏差，满足负荷频率控制指标，具有更强的抗干扰性和鲁棒性。

关键词: 超级电容, 互联电力系统, 负荷频率控制, 模糊控制