光储联合发电系统的功率振荡特性分析与控制

高渗透光储并网发电系统功率振荡将因缺乏阻尼能力而威胁系统的动态稳定。首先分析通过调节光储系统的有功、无功增加系统阻尼的原理,并在光储联合系统并网功率控制的基础上,提出光储系统基于有功、无功控制的附加阻尼控制策略。该控制策略通过检测光伏侧直流电压变化,实现功率振荡过程中光伏并网逆变器和蓄电池储能系统的控制模式切换,使联合系统具备持续调节注入系统有功、无功功率的能力,并改善电网的阻尼特性。最后,基于渗透率约为30%的光储并网发电仿真系统,验证在系统出现振荡后,光储系统在所提控制策略下,具备通过快速功率调节抑制功率振荡的能力,从而实现多电源协调改善发电系统阻尼的控制目标。

Analysis and control of power oscillation characteristics based on photovoltaic energy storage system

Due to the lack of damping in the system, the power oscillation in the energy storage based grid-connected photovoltaic power generation system with high permeability will threaten the dynamic stability of the system.In this paper, the control principle of active power and reactive power increasing system damping is analyzed firstly.Then, on the basis of grid connected power control of photovoltaic energy storage system, a novel control strategy of additional active and reactive power modulation is proposed, thus, the power oscillation is effectively suppressed.The proposed strategy can realize the control mode switching of the PV grid connected inverter and the battery energy storage system in the process of power oscillation by detecting DC voltage variation in the PV side.Meanwhile, it also can make the joint system have the ability to inject active and reactive power, so as to improve the damping characteristic of the system.Finally, a typical power system based on 30% permeability rate of grid-connected photovoltaic system is used to validate the proposed control strategy.Simulation results demonstrate that the proposed control method damp the power oscillation sufficiently and it achieves the goal of improving the damping of power generation system with multi-power coordination.