异步联网工程柔性直流测量异常导致功率反转机理分析和优化策略研究

云南电网与南网主网直流背靠背异步联网工程中采用了柔性直流输电技术,针对异步联网工程柔性直流因直流电压测量异常导致功率反转的问题进行了分析。在现有异步联网工程柔性直流输电系统控制器结构的基础上,通过理论分析得到了发生功率反转时测量偏差系数的临界值和功率反转期间直流电压的真实值计算方法;提出了逆变侧只采用定有功功率控制且选取整流侧和逆变侧计算的有功功率较大者作为控制器功率测量值输入的优化策略。通过异步联网工程柔性直流的EMTDC仿真模型,验证了所提优化策略的有效性和可行性。

Mechanism analysis and optimization strategy of active power reversal caused by abnormal measurement of flexible HVDC in asynchronous interconnection project

The flexible HVDC transmission technology is adopted in the back-to-back DC asynchronous interconnection project between Yunnan Power Grid and the main grid of China Southern Power Grid, and the active power reversal problem caused by the abnormal measurement of DC voltage is analyzed. Based on the existing controller structure of flexible HVDC system in the asynchronous interconnection project, the critical value of the measured deviation coefficient while occuring active power reversal and the calculation method of real DC voltage value in the active power reversal process are obtained by theoretical analysis. The optimization strategy is proposed that only the constant active power control is adopted in the inverter side and the lager active power calculated of the rectifier side and the inverter side is chosen as the power measurement input of controller. The validity and feasibility of the proposed optimization strategy are verified by the EMTDC model of the flexible HVDC in the asynchronous interconnection project.