多馈入直流输电系统交流侧滤波方案的设计

随着高压直流输电(HVDC)系统的发展及多馈入直流输电系统的逐步形成,多馈入直流系统的谐波问题日显突出.由于多馈入直流系统交流侧的母线电压严重畸变,现有的针对单谐波源的滤波方案已不再适用.文章提出了一种新的适用于多馈入直流输电系统的交流侧滤波方案,即在系统与负载之间并联由无源滤波器串联有源滤波器构成的混合滤波器,再在该混合滤波器之前与负荷串联一个有源滤波器.仿真比较了采用混合有源滤波方案与只投入无源滤波器时的滤波仿真效果,结果表明混合有源滤波方案可以显著降低母线上的谐波含量,从而抑制了负载谐波对系统的影响.

DESIGN OF FILTERING SCHEME AT AC SIDE OF MULTI-INFEED DC POWER TRANSMISSION SYSTEM

Along with the development of HVDC system and the gradual formation of multi-infeed DC (MIDC) power transmission, the harmonic pollution in MIDC system is becoming more and more serious. Because the busbar voltages at the AC side of MIDC system are seriously distorted, the existing filtering schemes for single harmonic source are no more applicable. Here, a new hybrid filtering scheme applicable to the AC side of MIDC system is proposed, that is, at the AC side a hybrid filter, which is composed by a passive filter in series with an active filter, is connected in parallel with the busbar and load, then another active filter is connected in series with the transmission line between the busbar and the load. The simulation of the scheme using hybrid active filter and that using passive filter only are carried out, and the comparison of the filtering results show that the harmonics on the busbar can be remarkably reduced by hybrid active filter scheme, and the impact of the harmonics from the loads on the system are eliminated.