摘要
研究了直驱永磁同步机组(permanent magnet synchronous generator,PMSG)卸荷电阻最优取值和投切策略问题。根据直流电容过电压能力和网侧变流器过电流能力,确定卸荷电阻理论上限。考虑到电网故障期间网侧变流器功率输出的实际情况,再根据理论上限值得到的直流电压与直流电容最大允许电压的差值,确定卸荷电阻实际上限。根据卸荷电阻允许温升,得到卸荷电阻下限,确定卸荷电阻取值范围。根据会引起直流电压剧烈波动的电网电压跌落区间,最后确定卸荷电阻最优值。采用双电阻选择投切,以抑制直流电压剧烈波动。在传统直流电压作为卸荷电路投切判据基础上,增加直流电容两侧功率差判据,以避免直流电压剧烈波动、增加机组输出功率、减少卸荷电路投切次数。仿真结果验证了该算法的可行性。
The optimal value and switching strategy of dump resistance（DR） for permanent magnet synchronous generator（PMSG） are researched.Based on the ability of DC capacitor to endure overvoltage and the ability of grid-side converter（GSC） to endure overcurrent,theoretical upper limit of DR is determined.Considering actual condition of GSC during grid fault and according to the difference between DC voltage obtained by theoretical upper limit and the maximum allowable voltage of DC capacitor,actual upper limit of DR is determined.According to the allowable temperature rise of DR,the lower limit of DR is attained,thus the value range of DR is determined.According to the grid voltage dip region that may cause serious fluctuation of DC voltage,optimal value of DR is finally decided.Selective switching of dual DR scheme is adopted to suppress serious fluctuation of DC voltage.The criterion based on power difference between both sides of DC capacitor is added to traditional DC voltage-based switching criterion for chopper circuit to avoid serious fluctuation of DC voltage,increase power output of PMSG and decrease switching times of chopper circuit.The feasibility of the proposed algorithm is verified by simulation results.
出处
《电网技术》
EI
CSCD
北大核心
2013年第7期1868-1873,共6页
Power System Technology
基金
国家自然科学基金项目(51277049)~~
关键词
直驱永磁同步机组
低电压穿越
卸荷电阻
最优阻值
分组投切
双判据
direct-drive permanent synchronous generator
low-voltage ride through
dump resistance
optimal resistance
group switch
dual criterion
