考虑谐波谐振和电压稳定的海上风电场无功优化配置方法

Reactive Power Configuration Method of Offshore Wind Farm Considering over Voltage and Harmonic Resonance

海上风电经长距离高压交流海底电缆接入电网,海底电缆容升效应显著,容易引起工频过电压,同时电力电子器件和线路电容引起的谐波谐振问题也严重影响着电网电能质量,因此进行海上风电场无功配置时应充分考虑过电压和谐波谐振问题。针对上述问题,建立了海上风电场谐波模型,对海上风电场的谐波模态阻抗进行扫描,继而分析海上风电场的谐振特性;然后研究了海上风电场无功特性,计算各种发电出力水平和并网点电压下的风电场无功缺额;接着以降低综合成本为目标,以静态电压稳定裕度、最小补偿容量、谐波谐振及过电压为约束,进行海上风电场无功优化配置;最后通过Matlab/Simulink仿真验证所提方法的有效性。

Offshore wind farm power is accessed to the power grid through the long-distance AC submarine cable,easily causing the power frequency over voltage due to the serious capacitance rise phenomenon.Simultaneously,the power electronic devices and the line capacitance also severely affect the power quality of the grid.Therefore,the over voltage and the harmonic resonance should be fully considered in reactive power compensation.In view of this problem,this paper analyzes the resonance characteristics of the offshore wind farm by establishing the harmonic model and sweeping the harmonic modal impedance.Furthermore,it studies the reactive power features and calculates the reactive power deficit of the wind farm under various power generation output levels and grid entry point voltages.Afterwards,aims to reduce the overall cost,the paper optimizes the reactive power compensation of the offshore wind farm under constraints of voltage stability margin,minimum compensation capacity,harmonic resonance and over voltage.Finally,the Matlab/Simulink simulation results show that this proposed method is effective.