摘要
近年来新能源发电并网系统中多次发生了次同步振荡问题,其中直驱风电并网系统出现了新型的次同步振荡问题,迫切需要开展这种次同步振荡机理研究。该文基于同步参考坐标系,推导了直驱风机动态模型和输入导纳模型,分析了输入导纳实部及虚部(电导及电纳)的频率特性,提出了直驱风机网侧输入导纳在次同步频率范围的负电导特性是次同步振荡的重要表现形式,进一步分析了前置滤波、电流内环、直流电压外环及锁相环控制参数和接入系统强度对负电导特性影响;最后,采用传递函数的极点分析和时域仿真验证了所提出机理的正确性。
The subsynchronous oscillation （SSO） has occurred several times in grid-connected renewable energy generation systems in recent years, including a new type of SSO issue occurred in direct-drive wind power generation system （WPGS）. To address this issue, there is an urgent need to develop SSO mechanism and characteristics. In this paper, an input-admittance modeling approach based on synchronous reference frame was presented at first. An explanation of SSO mechanism based on the real and imaginary （conductance and susceptance） frequency characteristic analysis of the input-admittance was proposed： the input-admittance at grid side appears as a negative conductance in subsynchronous frequency range, which is an important form of SSO. Moreover, the influence factors of negative conductance were analyzed, including power grid strength and the control parameters of prepositive filter, inner current loop, outer direct voltage loop, and phase-locked loop. At last, the SSO mechanism and characteristics was verified using pole analysis of transfer function and time-domain simulation.
出处
《中国电机工程学报》
EI
CSCD
北大核心
2017年第16期4662-4670,共9页
Proceedings of the CSEE
基金
国家重点研发计划项目(2016YFB0900605)
国家电网公司科技项目(SGXJ0000KXJS500669)~~
关键词
新能源
直驱风电
次同步振荡
输入导纳
接入系统强度
机理与特性
renewable energy
direct-drive wind power generation system
subsynchronous oscillation （SSO）
input-admittance
power grid strength
mechanism and characteristics
