【摘要】 针对传统分布式能源和微网中逆变器缺少惯性,以及当受到大功率扰动时缺乏稳定性的问题,提出了一种能够同时运行在孤岛、并网模式的非线性控制策略,且在电网并、离过程中不需要任何的预同步操作。首先,采用带储能的光伏系统向交流侧传输功率,稳定直流母线电压;在系统交流侧,引入模拟惯性和阻尼的同步电机转子摇摆方程,推导出相应的数学模型。其次,运用反步法设计控制器,针对反步法中计算膨胀和控制器饱和问题,采取指令滤波器处理。最后,利用Lyapunov稳定性定理验证系统的稳定性,并利用仿真观察控制器在不同模式下的运行状况。仿真结果表明,当系统受到突发性、强瞬变扰动时,所提出的控制方案能够在并网、孤岛和过渡模式下实现微网系统的稳定运行。更多还原

【Abstract】 In view of lacking of inertia of the inverter in traditional distributed energy sources and microgrid, and the stability of the inverter when subjected to large power disturbance, a backstepping control strategy that can run in both isolated and grid-connected modes is proposed, and no pre-synchronous operation is required during grid-departure. Firstly, the photovoltaic system with energy storage is adopted to transmit power to the AC side, and is able to stabilize the DC bus voltage. At the AC side of the system, the rotor mechanical equation of synchronous motor simulating inertia and damping is introduced, and the corresponding mathematical model is deduced. Secondly, the controller is designed by using the inverse step method, and the command filter is adopted to deal with the problem of calculating expansion and controller saturation in the inverse step method. Finally, Lyapunov stability theorem is used to verify the stability of the system, and simulation is used to observe the performance of the controller in different modes. When the system is subjected to sudden and strong transient disturbance, the simulation results are presented to show the effectiveness of the proposed control scheme in achieving stable and smooth operation of a microgrids system in grid-connected, islanding, and transition modes.更多还原