三相光储发电系统并网电压穿越控制策略及其仿真分析

Grid Connection Voltage Crossing Control Strategy and Simulation Analysisof the Three-phase Optical Storage Power Generation System

为了提高逆变器电压控制精度,提出了一种三相光储发电系统并网电压穿越控制策略,并通过仿真测试分析了配电网正常工作状态下系统的控制方案。研究结果表明:储能系统需要根据光伏发电单元的功率变化对直流母线功率进行调整,由此实现整个发电系统保持恒定的输出功率状态。光伏系统输出功率达到0.4 s时从9.2 kW减小为5.3 kW,并在0.8 s时恢复正常光强,这时光伏输出功率也重新变为9.2 kW。锂电池保持恒定的SOC值,在光强减小到600 W/m^2时,形成了比并网功率更低的输出功率,引起直流母线出现功率波动的情况。通过储能单元来实现恒定的直流母线功率,并网电流与直流母线电压都处于稳定的状态。

In order to improve inverter voltage control accuracy,a grid connection voltage crossing control strategy was proposed for the three-phase optical storage power generation system,and the control scheme of the system under normal working state of the distribution network was analyzed through simulation test.The results showed that the energy storage system adjusted the DC bus power according to power changes of the photovoltaic power generation unit,so that the whole power generation system could maintain a constant output power.At 0.4 s,the output power of the photovoltaic system decreased from 9.2 kW to 5.3 kW,and normal light intensity was recovered at 0.8 s.At this time,the output power of the photovoltaic system was changed to 9.2 kW again.The lithium battery maintained constant SOC value.When the light intensity decreased to 600 W/m^2,the output power became lower than the grid-connected power,thus causing power fluctuation on the DC bus.Constant DC bus power was realized through the energy storage unit,and the grid-connected current and DC bus voltage were both in a stable state.