基于模糊理论的并网型含光伏微电网功率控制

Fuzzy Theory Based Grid-Connected Power Control of Microgrid Containing Photovoltaic System

微网中风、光等可再生能源在接入电网后,其随机性和波动性等特点会对电网产生不利影响,为此提出一种基于模糊理论的利用分布式发电系统出力来平滑微电网与电网间联络线功率的控制方法。以光伏与柴油机组成的系统为例,建立了控制理论模型,利用光照强度以及联络线功率差作为模糊运算的输入量,经过模糊建模过程,输出一个对光伏逆变器进行有功控制的PWM控制波形,从而控制输向负荷的光伏系统出力。仿真结果表明联络线上的交换功率得到了有效抑制,同时意味着储能设备的使用有所减少,保证了能源的利用效率,在与电网互联时能够保证将对大电网的功率冲击控制在较小的范围内。

Randomness and fluctuation of renewable energy resources such as wind farm and photovoltaic （PV） generation included in grid-connected microgrid bring negative influence to power grid. For this reason, a fuzzy theory based control method, in which the output of distributed generation systems is used to smooth the power in tie line connecting microgrid with power grid, is proposed. Taking a system composed of PV generation and diesel generator as example, a theoretical control model is established, in which the intensity of illumination and the power difference of the tie line are regarded as input variables of fuzzy operation and through the fuzzy modeling a PWM control waveform is output, which controls the active power of PV inverter. Thus the output of PV system transmitted to load is controlled. Simulation results show that the exchanged power in the tie line can be effectively suppressed, and it means that the employment of energy storage devices is somewhat decreased, so the utilization of renewable energy sources can be ensured. Therefore, when the microgrid is connected to power grid the power impact from microgrid to power grid can be controlled within a lighter extent.