基于电力电子技术电气制动在大电网中的应用

Application of Electric Braking Technology in Large Power Grid Based on Power Electronics Technology

直流换相失败等故障带来的巨大能量冲击可能会引起区域联络线振荡解列以及新能源大量脱网。目前主要通过功率预控的形式避免出现上述问题,但会带来弃风、弃水、弃光问题,引起资源浪费。在此首先分析了电网存在的安全风险,介绍了基于电力电子技术的大容量电气制动系统设计方案,为工程实施提供借鉴。其次,从理论分析角度阐述制动电阻用于提升系统功角稳定、频率稳定、解决暂态过电压问题的机理。最后,以西北电网为例,研究电气制动应用于提升系统稳定水平的效果。仿真结果表明,该技术可有效提升系统功角和频率稳定性、抑制暂态过电压,同时可减少系统稳定措施量。

The huge energy impact caused by DC commutation failure and other faults may cause oscillatory discon nection of regional tie lines and a large number of new energy disconnection. At present, the above problems are mainly avoided by power pre-control, but it will lead to wind abandonment, water abandonment, light abandonment and waste of resources. Firstly, the security risks of power grid isanalyzed and then the design scheme of large-capaci ty electric braking system is introduced based on power electronics technology, which provides a reference for the im plementation of the project.Secondly, the mechanism of brake resistance used to enhance power angle stability, fre quency stability and solve transient over-voltage problem is expounded by theoretical analysis.Finally, taking northwest China power grids as examples, the effect of electric braking applied to enhance the stability level of the system is investigated.The simulation results show that the technology can effectively improve the power angle and frequency stability, suppress transient over-voltage, and reduce the amount of system stability measures.