风电直流微网的电压分层协调控制

Hierarchical Coordinated Control of Wind Turbine-based DC Microgrid

对于以新能源发电为主的微网系统,直流微网以其显著优势成为微网技术新的研究方向。该文以风电直流微网为例,在分析直流微网的构成以及各种运行模式的基础上,提出电压分层协调控制策略。该控制策略通过检测直流电压的变化量来协调各电力电子变流器的工作方式,从而确保在不同工况下都能保持微网内的有功功率平衡。各变流器独立工作,无需相互通信,可简化控制系统结构,并使直流微网具备"即插即用"功能。通过对含永磁风电机组、储能蓄电池的直流微网的仿真分析,验证所提控制策略对直流微网的有效控制。在风速或负荷变化、电网故障、蓄电池达到容量限定值等各种工作状态下,各端变流器都能根据直流电压变化量做出快速响应,从而提高了系统的稳定性和供电质量。

For the microgrid system dominated by new energy power generation,the DC microgrid has become a new microgrid technology with its advantages.Taking a wind turbine-based DC microgrid configuration as an example,different operation modes are described and a three-layer voltage hierarchical coordinated control strategy is proposed.Each power electronic converter coordinates its control method by monitoring the DC voltage variation to keep the power balance of the DC microgrid under different operating conditions.Each unit is controlled independently without communicating with each other,which simplifies the control structure and increases the control flexibility.The proposed control strategy is validated by simulation on a DC microgrid with permanent magnet synchronous generator based wind turbines and energy storage battery.The simulation results show that the converters have the ability to respond quickly to the DC voltage variation caused by the various operating conditions,such as variations of wind speed and loads,AC grid fault,so that the stability and the power supply quality of the DC microgrid system are improved.