| 引用本文: | 陈凌彬,夏向阳,李 红,等.不对称故障下考虑光储出力的最优电压支撑策略研究[J].电力系统保护与控制,2023,51(9):76-87.[点击复制] |
| CHEN Lingbin,XIA Xiangyang,LI Hong,et al.An optimal voltage support strategy considering the photovoltaic and storageoutput under asymmetric faults[J].Power System Protection and Control,2023,51(9):76-87[点击复制] |
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| 摘要: |
| 电网发生不对称故障会导致公共连接点(point of common coupling, PCC)电压下降，严重情况下还存在切机风险。而传统电压支撑策略易受到机组出力影响，不能灵活支撑PCC电压。针对上述问题，提出了一种不对称故障下考虑光储出力的最优电压支撑策略。首先分析了不对称故障下的电压支撑原理，推导了电压支撑方程。然后基于上述方程，以并网标准对PCC电压的运行要求为目标，考虑电流峰值和有功功率波动幅值为约束条件，得出了理想的电压支撑方案。进一步根据光储实际出力和理想的有功功率参考值，对光储出力场景进行分类。当理想的电流参考值无法满足最优解时，联立电压支撑方程和相应约束方程，建立关于电流各分量的非线性方程组，可解得最优电流参考值。最后通过仿真验证了所提策略的有效性和灵活性。 |
| 关键词: 不对称故障 光伏 储能 电压支撑 低压穿越 |
| DOI：10.19783/j.cnki.pspc.221346 |
| 投稿时间：2022-08-22修订日期：2022-09-20 |
| 基金项目:国家自然科学基金项目资助(51977014) |
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| An optimal voltage support strategy considering the photovoltaic and storageoutput under asymmetric faults |
| CHEN Lingbin,XIA Xiangyang,LI Hong,LIAO Yiding,GUO Yuan,GUAN Weide |
| (School of Electrical and Information Engineering, Changsha University of Science and Technology, Changsha 410114, China) |
| Abstract: |
| Asymmetric faults in the power grid will lead to voltage drop at the point of common coupling (PCC), even resulting in severe risk e.g. cutting machine. However, the traditional voltage support strategy is easily affected by the output of the unit, and cannot flexibly support the PCC voltage. For the above problems, an optimal voltage support strategy considering the photovoltaic and storage output under asymmetric faults is proposed. First, the principle of voltage support under asymmetric fault is analyzed, and the voltage support equation is deduced. Then, based on the above equation, taking the grid-connected standard's operating requirements for PCC voltage as the target, and considering the current peak value and active power fluctuation amplitude as constraints, the ideal voltage support scheme is obtained. Further, according to the actual output of photovoltaic and energy storage and the ideal reference value of active power, the output scenarios of photovoltaic and energy storage are classified. When the ideal current reference value cannot satisfy the optimal solution, the voltage support equation and the corresponding constraint equation are combined to establish a nonlinear equation system about each component of the current, and the optimal current reference value can be solved. Finally, the effectiveness and flexibility of the proposed strategy are verified by simulation. |
| Key words: asymmetric fault photovoltaic energy storage voltage support low voltage ride through |
