The accidental outages of generating units are increasing in power systems, which can bring huge power shortage suddenly and lead to severe system oscillations. The secure operation of power systems sometimes cannot be guaranteed only by regulating traditional generating units, due to the rapid regulation requirement of making up for power shortage. To address this issue, this paper proposes using emergency demand response (DR) to provide contingency reserve capacities by adjusting the power consumption of flexible loads (FLs). Firstly, in order to analyze the dynamic regulation process of power systems in accidental outages, the power system model in faulty condition is reconstructed to obtain the regulation power from well-running generators. On this basis, FLs are modelled and integrated into the novel reconstructed power system model to be as an alternative method of making up for the fast regulation capacities. Considering that the inevitable communication time-delay probably leads to the slowdown of response speed and endangers the system security, an adaptive time-delay control (ATDC) scheme is proposed and integrated into the control process of aggregated FLs. In this manner, the regulation speed of FLs can be accelerated, the control precision of response capacities can be improved, and the power system frequency deviations caused by time-delay can be decreased. Finally, the proposed models and methods are verified by numerical studies. The results in the test system show that the frequency deviations can be decreased effectively from −0.3276 Hz to −0.1337 Hz in accidental outages by using the ATDC scheme of FLs.

电力系统中发电机组的意外停电正在增加，这可能突然带来巨大的电力短缺，并导致严重的系统振荡。由于弥补电力短缺的快速调节要求，有时不能仅通过调节传统发电机来保证电力系统的安全运行。为了解决这个问题，本文建议使用紧急需求响应（DR）通过调整弹性负载（FL）的功耗来提供应急储备能力。首先，为了分析电力系统在意外停电时的动态调节过程，建立了故障状态下的电力系统模型，以从运行良好的发电机中获得调节功率。在此基础上，将FL建模并集成到新颖的重构电力系统模型中，作为弥补快速调节能力的替代方法。考虑到不可避免的通信时延可能会导致响应速度的降低并危及系统安全，提出了一种自适应时滞控制（ATDC）方案并将其集成到聚合FL的控制过程中。以这种方式，可以加快FL的调节速度，可以提高响应能力的控制精度，并且可以减少由时间延迟引起的电力系统频率偏差。最后，通过数值研究验证了所提出的模型和方法。测试系统中的结果表明，频率偏差可以有效地从-0.3276 Hz减小到-0。