永磁直驱式风电变流器整流侧过电压抑制方法

Method of Suppressing Overvoltage on Rectification Side of Permanent Magnet Direct Drive Wind Power Converter

永磁直驱式风电变流器在风电系统中扮演着重要角色,但整流侧过电压问题一直是影响其安全稳定运行的关键因素,因此提出了一种针对永磁直驱式风电变流器整流侧过电压的抑制方法。首先,分析了整流侧过电压的产生机理,包括电网电压波动、风力变化等因素对整流侧电压的影响。然后,设计了一种基于负荷能量泄放回路和储能单元的过电压抑制策略,当检测到直流母线电压过高时自动投入负荷泄放回路,消耗掉富余能量,抑制直流侧过电压,同时通过在直流母线上设计专用储能单元,将富余能量转移到储能系统中存储,故障恢复后或按需要将所存储的能量馈入电网。此外,还探讨了如何通过电力电子双向变换设备将储能单元接口到变流器的直流母线,以实现能量的高效利用和电压的稳定控制。

Permanent magnet direct drive wind power converters play an important role in wind generation systems,but the issue of overvoltage on the rectification side has always been a key factor affecting their safe and stable operation.This work studied a method to suppress overvoltage on the rectification side of permanent magnet direct drive wind power converters.First the mechanism of overvoltage on the rectification side was analyzed,including the impact of factors such as grid voltage fluctuations and wind power changes on the rectification side voltage.Then an overvoltage suppression strategy based on load energy release circuit and energy storage unit was designed,which automatically activated load relief circuit when an excessive DC bus voltage was detected to consume excess energy and suppress the DC side overvoltage.In addition,by designing dedicated energy storage units on the DC bus,surplus energy was transferred to the energy storage system for storage.After fault recovery or as needed,the stored energy was fed into the power grid.Moreover,this paper also explores how to interface the energy storage unit to the DC bus of the inverter through power electronic bidirectional conversion equipment,in order to achieve efficient energy utilization and stable voltage control.