海上风电柔性直流输电变流器控制与试验系统设计

Design of HVDC-Light Converter Test System in Offshore Wind Farm

简要介绍了柔性直流输电系统的控制方法,基于三相静止对称坐标系和dq同步旋转坐标系建立了柔性直流输电系统换流站数学模型,采用双闭环直接电流控制方法,设计了以tms320f28335作为dsp控制芯片,由dsp输出的信号控制三相两电平变流器逆变与整流波形。在换流站级控制采用双闭环直接电流控制,基于换流站的dq模型分别控制d轴和q轴电流实现对有功和无功功率的分别控制,减小了控制环节的稳态误差,完善了控制环节的动态特性。解决了海上风电由于其间歇性和不确定性在并网过程中引发的谐波污染、电压间断和波形闪变等问题。试验系统主要测试整流端输出的母线电压电流特性和逆变端输出的并网电压电流特性,以及对功率的控制特性,达到了较好的整流和并网效果。

This paper briefly introduces controlling methods of the HVDC-light system and builds the models of HVDC-Light converter station both in the three-phase static coordinators and in the dq synchronous reference frame.The hard-ware system is based on the direct-current controlling method in double closed loop and the driving signals passed to the three-phase two-level converter are produced by the DSP TMS320F28335.The direct current controlling method is adopted so that the active and reactive power can be manipulated respectively as the power vector is projected to the d axis and q axis in the dq synchronous reference frame which declines the steady-state error in the controlling system and improves the dynamic characteristics.This solution solves the harmonic pollution,voltage interruption and waveform flicker problem caused by the intermittent and uncertainty of offshore wind power in the synchronization process.