直流配电系统有源阻尼控制的阻抗释义与谐振点灵敏度参数调节方法

Impedance Explanation and Resonance Point Sensitivity-based Parameter Design Method of Active Damping Applied to DC Distribution System

直流配电系统有源阻尼控制一般通过在换流站配置补偿环节调节输入或输出阻抗来实现。为进一步阐述有源阻尼补偿环节对系统阻抗的影响机理,并指导其参数调节和设计,首先在建立定电压控制换流站阻抗降阶模型的基础上,分别以串、并联虚拟阻尼支路对直流电压反馈、直流电流前馈两类补偿环节进行溯源。其次,分析补偿环节对定电压站输出特性的影响,并在阻抗-频率曲线维度重构Nyquist稳定性判据,确定对有源阻尼补偿环节的基本约束。结合阻抗灵敏度,推导建立阻抗-频率曲线的谐振点灵敏度,提出采用阻抗/谐振点灵敏度的有源阻尼补偿环节参数调节方法。最后,以双端与四端直流配电系统为例,通过对比扫频结果展示了定电压站降阶阻抗模型的准确性,并分别在定电压站与定功率站配置补偿环节,以Nyquist曲线、MATLAB/Simulink时域仿真为参照,验证重构稳定性判据和所提阻抗/谐振点灵敏度参数调节方法的有效性。

The active damping control of DC distribution system is usually realized by adjusting input or output impedance in the converter station. To further elaborate the influence principle of active compensators on systematic impedance and guide the parameter adjustment and even design, based on the reduced-order impedance model of converter station with DC voltage control, firstly, the origin of two active compensators using DC voltage feedback and current feedforward was traced in this paper. Secondly, the influence of compensators on the output characteristics of converter station with DC voltage control was also analyzed, and the Nyquist stability criterion was reconstructed in the field of impedance-frequency curve to determine the basic stability constraint on active compensators. Then, the resonance point sensitivity of impedance-frequency curve was derived from the impedance sensitivity, and a sensitivities-based adjustment method of parameters in active compensators was proposed. Compared with the impedance result of converter station obtained by frequency sweep in the two-and four-terminal DC distribution system, the accuracy of the derived reduced-order impedance model was verified. Configurating compensation was deployed in the converter station with DC voltage control and the converter station with power controlrespectively Nyquist curve and Matlab/Simulink time-domain simulation were used as reference for test results to demonstrate the validity of the reconstructed Nyquist stability criterion and sensitivities-based parameters adjustment methods.