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为了给高压直流输电系统选择合适的锁相环(PLL)参数,在PSCAD/EMTDC环境下,对CIGRE HVDCBenchmark模型的启动过程进行了仿真,得到了采用不同阻尼比和不同自然角频率PLL条件下的整流侧电流波形、逆变侧定电流和定熄弧角控制切换波形、PLL误差波形.仿真结果表明:在高压直流输电系统的启动过程中,随着PLL阻尼系数ζ或自然角频率ω_0取值的增大,电流波动增大,直流电流到达额定值的时间、逆变侧控制切换点的时间也变长.建议PLL阻尼系数ζ宜在0.707～1.414之间取值;自然角频率ω_0应适当取小.“,”In order to choose appropriate parameter of PLL in an HVDC system, we simulated the starting process of the CIGRE HVDC Benchmark model based on PSCAD/EMTDC, and obtained waveforms of current in rectifier, switching waveform between the constant current control and the constant turn-off angle control in inverter, and er-ror of PLL with different damping ratio and frequency of oscillation.The results show that, as the damping ratio or frequency of oscillation increases, the undulation of the direct currents becomes more acute, and the time of the di-rect current reaching the rating or the time of the switching of inverter control is elongated.At last, it is proposed that the damping ratio of PLL should be between 0.707 and 1.414, and the frequency of oscillation of PLL should properly be smaller.