Mid-term Voltage Stability Assessment and Measures for Mitigating Voltage Collapse in Interconnected Power Grids

电力系统的电压稳定性评估和增强在很大程度上取决于能否成功地解决一些基本问题。这些是使用长期动态模拟来确保适当的余量，可靠模型的存在，以及制定智能无功功率管理和控制策略，这些策略稳健，准确，快速。仅仅向操作员提供有关安全边际的信息并不总是足够的。这些信息必须在即将到来的电压不安全之前提供，以便采取适当的预防控制措施。许多专家担心，在目前放松管制的环境下，无功管理将成为一个至关重要的可靠性问题——这是一种源于服务分拆的情况。面对竞争，许多系统运营商选择不保持可接受的电压分布，系统现在面临着电压崩溃的新威胁。有几份报告称，由于无功储备不足，出现了大范围的级联停电。本文旨在完成以下三个任务：(1)建立准确的中期电压稳定性评估模型；(2)开发了一种基于静态插值误差估计的动态模拟聚合方法；(3)引入了快速有效的缓解电网中期电压不稳定的补救措施。增强稳定性的措施将需要许多自动方案，包括过励磁限制器、发电机自动电压调节器（avr）、并联电容器组、区域无功协调、欠压负载减少等。使用模糊集和/或神经模糊控制算法将研究更严格的控制。该项目将由在电力系统建模、仿真和智能控制算法方面具有30年经验的研究人员领导。与行业专家的互动将为开发实用设计提供指导。为了实现项目的教学目标，将在电力系统稳定性和智能控制方面设置新的课程模块。

Voltage stability assessment and enhancement in power systems will depend, to a large extent, on successfully addressing a number of fundamental issues. These are the use of long-term dynamic simulations to ensure proper margins, the existence of reliable models, and the formulation of intelligent reactive power management and control strategies that are robust, accurate, and fast. Just providing the operator with information on the security margins is not always adequate. This information has to be provided well in advance of impending voltage insecurity, such that appropriate preventive control actions can be taken. Many experts fear that reactive power management will become a crucial reliability issue in the present deregulated environment - a scenario stemming from the unbundling of services. With many system operators opting against maintaining acceptable voltage profiles in the face of competition, systems are now facing renewed threats of voltage collapse. There have been several reports of widespread cascading outages due to inadequate reactive reserves.This proposal is aimed at accomplishing three tasks, those of (i) developing accurate models for mid-term voltage stability assessment; (ii) developing a new aggregation method for dynamic simulations based on the estimated interpolation errors of static states, and (iii) introducing fast and effective remedial measures for mitigating mid-term voltage instability in power grids. Stability enhancement measures will entail a number of automatic schemes encompassing over-excitation limiters, generator automatic voltage regulators (AVRs), shunt capacitor banks, area reactive power coordination, under-voltage load shedding, etc. The use of fuzzy sets and/or neuro-fuzzy control algorithms will be investigated for tighter control. The project will be led by investigators with a combined thirty years of experience in power systems modeling, simulations, and in intelligent control algorithms. Interactions with industry experts will provide guidance in developing practical designs. New course modules in power system stability and in intelligent controls will be put in place in order to fulfill the educational objectives of the project.