摘要
含分布式能源的直流微网惯性低、母线电压易受负荷功率波动影响,而风电机组的转子中蕴含着大量动能,可改变风机侧变流器的控制策略,使发电机转子释放或储存动能,为直流电压提供惯性支撑。首先,通过类比交流电网中的虚拟同步发电机控制,提出了一种适用于直流微网中风电机组的类虚拟同步发电机惯性控制策略。其次,引入与转子旋转动能、变流器可调容量相关的惯性支撑系数,定量评估了不同运行工况下风电机组的惯性支撑能力,以此选择合适的虚拟惯性系数。然后,建立了小信号模型,对所提控制策略进行理论分析,针对初始阶段产生的电压突变,采用前馈补偿进行了修正。研究结果表明,类虚拟同步发电机控制能利用风机的转子动能为系统提供惯性支撑,使直流电压具有更好的动态特性。最后,通过RT-LAB实时仿真平台仿真验证了所提控制策略的有效性。
The DC microgrid with distributed energy has low inertia,and the bus voltage is easily affected by load power fluctuations;meanwhile,the rotor of the wind turbine contains a lot of kinetic energy.Therefore,the control strategy of the wind turbine side converter can be changed,so that the rotor of the generator can release or store kinetic energy,which provides inertial support for the DC voltage.First,an analogous virtual synchronous generator inertial control strategy for wind turbines in DC microgrids is proposed by analogy to the virtual synchronous generator control in the AC grid.Secondly,the inertial support coefficient related to the rotational kinetic energy of the rotor and the adjustable capacity of the converter is introduced to quantitatively evaluate the inertial support capacity of the wind turbine under different operating conditions,so as to select the appropriate virtual inertial coefficient.Then,a small-signal model is established,the proposed control strategy is theoretically analyzed,and the abrupt change of voltage in the initial stage is corrected by feedforward compensation.The research results show that the virtual synchronous generator control can use the rotor kinetic energy of the fan to provide inertial support for the system,so that the DC voltage has better dynamic characteristics.Finally,the effectiveness of the proposed control strategy is verified by RT-LAB real-time simulation platform simulation.
作者
沈可心
薛博文
朱晓荣
SHEN Kexin;XUE Bowen;ZHU Xiaorong(Department of Electric Power Engineering,North China Electric Power University,Baoding 071003,China)
出处
《高电压技术》
EI
CAS
CSCD
北大核心
2023年第6期2526-2535,共10页
High Voltage Engineering
关键词
直流微网
直驱风机
类虚拟同步发电机
惯性支撑
小信号模型
DC microgrid
direct-driven wind generation system
analogous virtual synchronous generator
inertial support
small signal model
