光伏直流升压汇集系统关键控保技术研究

Harmonic resonances and reactive power transmission issues of the traditional AC boosting and collection system are gradually prominent with the increasing scale of PV power plants. Consequently, safety and stability of the PV power plants and the power system are interfered. Transmission capability of the PV power plants is also constrained. Adopting DC instead of AC is an optimal scheme to solve above technical and economic issues. Therefore, the PV power plant utilizing DC boosting and collection becomes a new trend. Control and protection techniques are of vital importance to the safety and stability of DC boosting and collection systems. Currently, there are no field projects of DC boosting and collection system of PV power plants. Related control and protection research mainly focuses on individual equipment level. Considering the lack of coordination among individual equipment/subsystems inside of the PV power plants with the new scheme of DC boosting and collection, this research project studies three contents from the whole system perspective: 1) the fault process analysis which containing equipment level, collection spacing level and station level; 2) the multi-level coordinating control and protection; 3) the asymptotic fault diagnosis, in order to comprehensively provide effective protection for the DC boosting and collection system. The results will be validated by digital simulations and power-hardware-in-loop experiments. The above research is beneficial to improve the system safety level and prompt the engineering and industrialization of the PV power plants with DC boosting and collection.

随着光伏电站规模的不断扩大，传统交流升压汇集系统谐波谐振、无功传输问题日益突出，一方面严重影响光伏电站与电力系统的安全稳定, 另一方面严重影响光伏电站的送出能力。采用直流替代交流是解决上述技术及经济问题的优化方案，因而光伏电站采用直流升压汇集成为新的发展方向。控保技术对保障光伏直流升压汇集系统安全稳定至关重要，由于当前还未有光伏直流升压汇集工程，已有控保理论研究主要集中在孤立的设备级控保层面。针对直流升压汇集这种新方案下光伏电站内部各设备/子系统协同控保研究的空白，本项目从系统整体角度出发，研究涵盖光伏电站设备层、汇集间隔层和场站层的故障全过程分析技术、多层协同控保技术和渐近性故障诊断技术，全方位立体化为光伏直流升压汇集系统提供有效保护。通过仿真与半实物试验验证有关成果的有效性。上述研究有助于提高光伏电站的安全水平，对光伏直流升压汇集系统工程化及产业化有积极的促进作用。

随着光伏电站规模的不断扩大，传统交流升压汇集系统谐波谐振、无功传输问题日益突出，一方面严重影响光伏电站与电力系统的安全稳定, 另一方面严重影响光伏电站的送出能力。采用直流替代交流是解决上述技术及经济问题的优化方案，因而光伏电站采用直流升压汇集成为新的发展方向。控保技术对保障光伏直流升压汇集系统安全稳定至关重要，针对直流升压汇集这种新方案下光伏电站内部各设备/子系统协同控保研究的空白，本项目从系统整体角度出发，研究涵盖光伏电站设备层、汇集间隔层和场站层的故障分析、多层协同控保技术和渐近性故障诊断技术，全方位立体化为光伏直流升压汇集系统提供有效保护。通过仿真与半实物试验验证有关成果的有效性。上述研究有助于提高光伏电站的安全水平，对光伏直流升压汇集系统工程化及产业化有积极的促进作用。