构网型全功率风电变流器的平滑模式切换策略  

Smooth Mode Switching Strategy for Grid-forming Full-power Wind Turbine Converters

作　　者：代鹏程 张兴[1] 谢震[1] DAI Pengcheng;ZHANG Xing;XIE Zhen(National and Local Joint Engineering Laboratory for Renewable Energy Access to Grid Technology,Hefei University of Technology,Hefei 230009,China)

机构地区：[1]合肥工业大学可再生能源接入电网技术国家地方联合工程实验室,合肥230009

出　　处：《高电压技术》2025年第4期1589-1598,I0006-I0008,共13页High Voltage Engineering

基　　金：国家重点研发计划(2022YFB4202302)。

摘　　要：全功率风电变流器的跟网/构网模式切换是提高其电网强度适应性的一种有效方式。直流电压同步的构网方案由于需要控制直流电压,在切换时易产生严重的直流电压暂态冲击,进而引发直流撬棒误动作,降低硬件使用寿命。为此,首先通过矢量分析法确定了平滑模式切换原则,结合切换扰动对直流电压的传递函数和切换扰动本身,分析了直流电压暂态冲击的成因。然后,基于该分析,提出了直接切换方案以解决稳态工作点的阶跃扰动问题,但仍存在电流指令随机扰动的问题。进一步,提出了延时切换方案,通过延迟切换信号使得电流指令扰动最小化。RT-LAB硬件在环实验结果表明,直接切换方案能够大幅改善直流电压的暂态冲击,延时切换方案能进一步保证切换过程平滑无波动。An effective way for full-power wind turbine converters to improve the adaptability of power grid strength is to switch smoothly between the grid-following mode and grid-forming mode.The scheme of DC voltage synchronization takes DC voltage as the control target,which is easy to produce serious transient shock of DC voltage during switching,leading to misoperation of DC chopper and reduction in the service life of hardware.Therefore,firstly,the smooth mode switching principle is determined by vector analysis method,and the causes of transient shock of DC voltage are analyzed by combining the transfer function of switching disturbance to DC voltage and switching disturbance itself.Then,based on the analysis,a direct switching scheme is proposed to solve the step disturbance problem of steady-state operating point,but there is still a random disturbance of current given.A delay switching scheme is proposed to minimize the given current disturbance by delaying switching signals.RT-LAB hardware-in-the-loop experiments show that the direct switching scheme can greatly improve the transient shock of DC voltage,while the delay switching scheme can further ensure the smooth switching process without fluctuation.

关 键 词：全功率风电变流器 直流电压同步 跟网 构网 模式切换 稳态工作点 

分 类 号：TM614[电气工程—电力系统及自动化]