面向暂态功角稳定提升的水光互补发电系统紧急切机控制

Emergency Generator Tripping Control of Integrated Systems With Photovoltaic and Hydropower Generation for Improving Transient Power Angle Stability

我国西南地区水电和光伏资源丰富,利用水光资源的互补特性,促进清洁能源的高效消纳,是实现“双碳”目标的有效途径之一。水电资源一般集中于偏远地区,长距离输电导致其与主网连接较弱,暂态功角稳定问题较为突出,水光互补系统中高比例光伏发电的接入进一步增加了系统暂态稳定问题的复杂性。然而当前光伏发电对互补系统暂态稳定影响机理尚不明晰,且缺乏基于定量计算的紧急切机控制方法。为此,首先建立了水光互补系统的等效功角曲线,详细分析了光伏接入前后系统的加减速面积变化情况。在此基础上,基于等面积法则提出水光协调的3种紧急切机控制方法,并根据综合评价指标选取优化切机方案。最后,基于单水单光-无穷大系统及四川省某县水光互补系统验证了所提方法的有效性。研究结果有助于推动解决新能源电力系统中新能源机组和同步机的切机量定量计算缺乏数学理论指导这一难题,能够提升水电和光伏的消纳与送出能力。

In southwest China, there are superior conditions of power generation. Making good use of the complementary characteristics of hydropower and photovoltaic power there is one of effective ways to achieve the "dual carbon" goal and promote the consumption of renewable energy. However, as the hydropower resources are generally distributed in the remote areas, long-distance power transmissions may increase a rather weak connection with the main network with a hidden dangerous of transient power angle stability. Besides, the high proportion of photovoltaic power generation also increases the complexity of the transient stability of the system. At present,there is not a clear mechanism to explain photovoltaic power generation’s influence on the transient stability of complementary systems, and not an effective system emergency control methods based on quantitative calculations.To this end, this paper proposes an emergency generator tripping control method for improving transient power angle stability. Firstly, the equivalent power angle curve of the integrated system is established, analyzing the changes of the acceleration/deceleration areas in the integrated system before and after the photovoltaic connection. Subsequently, based on the equal area criterion, three emergency generator tripping control schemes for hydropower and photovoltaic coordination are proposed, and the optimal scheme is selected according to the comprehensive evaluation indexes. Finally, the effectiveness of the proposed method is verified based on the single hydropower generation and single photovoltaic generation-infinity system and the integrated system of Sichuan province.