DYNAMIC MODELING AND TRANSIENT SIMULATION FOR VOLTAGE SOURCE CONVERTER BASED HVDC
DYNAMIC MODELING AND TRANSIENT SIMULATION FOR VOLTAGE SOURCE CONVERTER BASED HVDC
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作者：
Ruo-mei Li
基于节点注入电流法，建立了电压源换流器型高压直流输电（VSC-HVDC）的详细动态模型，电压源换流器、直流系统内部动态模型和控制系统。利用电力系统分析软件包（PSASP）提供的用户自定义功能，通过对VSC-HVDC/AC并联输电系统的暂态仿真，验证了所建VSC-HVDC动态模型的正确性。仿真结果还表明：（A）VSC-HVDC直流侧电容值和换流器Transformer泄漏阻抗值对阻尼负荷角振荡的作用不明显;（B）当VSC-HVDC两端的VSC采用恒交流电压控制模式时，获得了更好的电压稳定性，但当系统受到扰动时，该控制方式下VSC-HVDC两端VSC的过载程度要比恒定无功功率控制方式下VSC-HVDC两端VSC的过载程度严重。
Based on the method of injecting current at nodes, a detailed dynamic model for voltage source converter based HVDC (VSC-HVDC) is built up, which includes three parts, i.e., the voltage source converter, the internal dynamic model of DC system and control system. By use of the user-defined function provided by Power System Analysis Software Package (PSASP), the correctness of the built dynamic model for VSC-HVDC is verified by transient simulation of parallel VSC-HVDC/AC transmission system. Simulation results also show that: (A) the value of capacitors at DC side of VSC-HVDC and that of the leakage impedance of converter transformer do not take evident effect in damping load angle oscillation; and (B) when constant AC voltage control mode is applied to VSCs at both ends of VSC-HVDC, a better voltage stability is obtained, but when the system is disturbed the overload extent of VSCs at both ends of VSC-HVDC is more severe under this control mode than overload extent of VSCs at both ends of VSC-HVDC under constant reactive power control mode.