摘要
随着电网光伏渗透率逐渐提高,迫切需要光伏发电系统主动参与电网频率调节,然而目前光伏发电系统多以最大功率跟踪方式并网,不具备有功调频能力。针对上述问题,提出一种基于变步长功率跟踪的有功备用式光伏发电系统,利用变步长功率跟踪使系统运行在有功备用模式,当电网频率扰动时通过修正直流侧电容电压调节光伏阵列的有功输出来参与一次调频。网侧逆变器采用改进下垂控制策略,通过引入角频率的微分负反馈虚拟惯量控制和直流侧电容储能特性模拟转子惯量环节弥补故障初期一次调频出力不足的问题,减小频率的跌落深度。通过仿真分析验证了所提控制策略无论在故障初期的动态作用还是一次调频过程中都可以提供更多的功率支撑,可以一定程度上替代同步发电机调频效果。
With the gradual increase of photovoltaic permeability,the photovoltaic power generation system is urgently needed to participate actively grid frequency regulation.However,the present photovoltaic power generation system is connected to power grid by the maximum power tracking mode and does not possess active power frequency modulation ability.In view of above issue,a kind of active standby photovoltaic power generation system based on variable step power tracking is proposed.The variable step power tracking is used to make the system operate in the active standby mode.In case of grid frequency disturbance,the active power output of the photovoltaic array is adjusted by way of correcting capacitive voltage of DC side so to participate the primary frequency modulation.The improved droop control strategy for the grid-side inverter is adopted.The differential negative feedback virtual inertia control of angular frequency simulation rotor inertia of the capacitive capacitor energy storage characteristic at DC side are introduced to make up for the issue of insufficient primary frequency modulation output at the beginning of fault so to reduce the depth of frequency drop.It is verified by the simulation analysis that the proposed control strategy can provide much power support either at the dynamic action at the initial fault or during the primary frequency modulation,which can,to some extent,replace the frequency modulation effect of the synchronous generator.
作者
何伟
陈拓新
赵伟哲
李佳
熊俊杰
何昊
HE Wei;CHEN Tuoxin;ZHAO Weizhe;LI Jia;XIONG Junjie;HE Hao(Electric Power Research Institute,State Grid Jiangxi Electric Power Co.,Ltd.,Nanchang 330096,China;Electric Power Dispatch Control Center,State Grid Jiangxi Electric Power Co.,Ltd.,Nanchang 330077,China)
出处
《电力电容器与无功补偿》
2021年第5期251-259,共9页
Power Capacitor & Reactive Power Compensation
基金
国家重点研发计划项目(2016YFB0900100)
国网江西省电力有限公司科技项目(面向综合能源服务的风/光功率预测及调度支撑技术研究与应用,52182018001F)。
关键词
光伏发电
有功备用
变步长
下垂控制
photovoltaic power generation
active standby
variable step
droop control
