向无源网络供电的VSC-HVDC离散模型及其控制策略

Study of VSC-HVDC connected to passive network discrete model and its control strategies

推导了在dq同步旋转坐标系下电压源高压直流输电(VSC-HVDC)系统的离散化数学模型,针对向无源网络供电的VSC-HVDC系统设计了相关的离散化控制器。基于换流器离散化数学模型,整流侧控制器采用定直流电压和定无功功率控制器;逆变侧控制器则采用定交流电压控制器,对无源网络的交流母线电压实现控制。应用电磁暂态仿真软件PSCAD/EMTDC建立VSC-HVDC向无源网络供电的数字仿真模型及其离散化控制器。在各种工况下的仿真结果验证了所设计的离散模型的正确性以及控制策略的有效性。

The discrete mathematical model VSC-HVDC system in dq reference frame is derived and discrete controllers are designed for transmitting power to passive network via VSC-HVDC system. According to the discretely steady mathematical model of the converter, a constant DC voltage and constant reactive power controller is used in the rectifier-side; a constant AC voltage controller is used in the inverter-side to control the AC bus voltage. The VSC-HVDC connected to passive network digital simulation model is set up by the electromagnetic transient simulation software PACAD/EMTDC. Simulation results, in the case of various engineering, verify that the designed discrete model is correct and the control strategy is effective.