摘要
在光伏并网运行中,当电网电压不平衡时会导致电压、电流等的波动,从而影响电网电能质量及系统的稳定性。结合电压补偿控制等环节,提出了一种基于电压补偿控制的定直流电压、无功控制策略,将采集到的正、负序电压经电压补偿控制环节得到电压的不平衡系数,对电网电压的不平衡度进行补偿,并引入负序电流抑制环节。在PSCAD中分别设计搭建了改进前后的仿真模型,并对光伏并网发电系统的动态变化特性进行研究。仿真结果表明,在光照强度和温度阶跃扰动下,系统能够迅速做出响应并工作于最大功率点处,电压及电流波动幅度减小,电网电能质量得到明显改善,验证了MPPT算法及改进后控制策略的准确性及有效性。
In photovoltaic grid-connected operation,voltage and current fluctuations occur when the grid voltage is unbalanced,which affects the power quality of the grid and the stability of the system.Combined with voltage compensation control,a constant DC voltage and reactive power control strategy based on voltage compensation control is proposed.The voltage unbalance coefficient is obtained from positive and negative sequence voltages collected through voltage compensation control,and the unbalance degree of power grid voltage is compensated,and the negative sequence current suppression step is introduced.The simulation model before and after the improvement is designed and built in PSCAD respectively,and the dynamic change characteristics of photovoltaic grid-connected power generation system are studied and analyzed.The simulation results show that under the step disturbance of light intensity and temperature,the system can respond quickly and work at the maximum power point,the voltage and current fluctuation range is reduced,and the power quality of the power grid is significantly improved,which verifies the accuracy and effectiveness of the MPPT algorithm and the improved control strategy.
作者
陈斌
王俊江
王敬华
常鹏
李建宁
CHEN Bin;WANG Junjiang;WANG Jinghua;CHANG Peng;LI Jianning(School of Electrical and Electronic Engineering,Shandong University of Technology,Zibo 255049,Shandong,China;Shandong Kehui Electric Power Automation Co.,Ltd.,Zibo 255087,Shandong,China;Yanggu County Power Supply Company of State Grid Shandong Electric Power Co.,Ltd.,Yanggu 252300,Shandong,China)
出处
《电网与清洁能源》
北大核心
2022年第9期134-142,共9页
Power System and Clean Energy
基金
国家重点研发计划项目(2017YFB0902802,2017YFB0902800)。
关键词
光伏并网系统
改进控制策略
电压补偿控制
不平衡控制
动态变化特性
photovoltaic grid-connected system
improved control strategy
voltage compensation control
unbalance control
dynamic change characteristics
