风光火打捆系统暂态稳定性及其虚拟同步机策略研究

Research on Transient Stability of Bundled Wind-photovoltaic-thermal System and Its Virtual Synchronous Generator Strategy

风力、光伏发电是我国大力发展的清洁能源,将风电、光伏与火电三者打捆通过长距离通道外送能够有效解决我国能源逆地势分布的问题,而将虚拟同步机策略(virtual synchronous generator,VSG)与打捆系统中的风电、光伏机组有效结合,是针对新能源高比例并网造成的送端惯量缺失问题的一种有效解决方式。基于PSCAD仿真软件,首先搭建了风光火打捆外送系统的基础仿真模型,并通过仿真分析了不同的交流故障类型、送端风光火三者占比以及直流整流侧控制方式对打捆外送系统暂态稳定的影响,仿真结论与理论基本一致。之后在双馈风电机组和光伏的外送换流器环节中引入虚拟同步机控制策略,并通过仿真验证了虚拟同步机策略对于提升风光火打捆系统送端惯量的有效性。

Wind and photovoltaic power generation are the clean energy developed vigorously in China.Bundling wind,PV and thermal power through long-distance channels can effectively solve the problem of energy distribution against topography in China.The effective combination of the virtual synchronous generator(VSG)strategy with photovoltaic units and wind power in the bundling system is an effective way to solve the problem of the lack of inertia at the sending end caused by the high proportion of new energy sources connected to the grid.Based on the PSCAD simulation software,the basic simulation model of bundled wind-PV-thermal delivery system was firstly established.Then through the simulation,we analyzed the effect of the different types of AC faults,the proportion of wind-PV-thermal at the sending end and the control mode of the DC rectifier side on the transient stability of the bundled delivery system.And the simulation result was basically consistent with the theory.Afterwards,the VSG control strategy was introduced to the DFIG and photovoltaic grid-connected converter.And the effectiveness of the VSG strategy in improving the inertia of the sending end of the wind-thermal bundled system was verified through simulation.