永磁直驱风力发电系统故障穿越过程瞬态行为分析

Transient Analysis for Fault Ride-Through in Permanent Magnet Synchronous Generator System

采用非线性模态级数法对故障穿越情况下并网永磁直驱风力发电系统的瞬态行为进行分析,使传统的定性分析转入到定量分析。通过建立系统的数学模型,推导出相应的二阶模态级数模型,并进行了数值模拟和理论分析,得出的系统二阶准谐振边界将参数空间分为正常运行区域和二阶谐振区域。研究结果表明:系统在故障穿越情况下的瞬态过程中存在着丰富的交互模式,特别是存在着很强的二阶交互模式;通过选择合适的参数削弱二阶模态交互作用,可以有效地减小在故障穿越过程中系统振荡的幅值和持续时间。对于系统的二阶准谐振边界,当选择控制参数落入正常状态区域时,能够避免发生二阶谐振,使系统在故障穿越情况下快速实现稳定运行。

The transient behavior of fault ride-through process in grid-connected permanent magnet synchronous generator（PMSG） system is evaluated with nonlinear modal series method,so as to transfer the traditionally qualitative project to quantitative one.Theoretical analysis and numerical simulation are conducted by developing the mathematical model and deriving corresponding second order modal series of the PMSG system.Then the second order quasi-resonance boundaries are obtained to divide the parameter space into the normal operation region and second order resonance region.The results show that there are abundant modal interactions,particularly the stronger second order modal interaction,in the system transient fault ride-through process.Selecting the appropriate parameters to weaken second order modal interaction,the amplitude and duration of the system oscillation are reduced effectively during fault ride-through process.For the second order quasi-resonance boundaries,second order resonance can be avoided when the selected control parameters are located in the normal state region,so that the system quickly gets stable.