Managing green Energy feed-in uncertainty for cost-efficient and reliable power system operation via AC CHance-constrained security constrained Optimal power flow (ECHO)

ECHO项目主要研究安全约束(或事故约束)的最优潮流(SCOPF)，旨在改善电力系统运行的提前计划的决策，即确保第二天每小时的电力系统调度具有成本效益和可靠性。此外，由于波动较大的可再生能源发电量越来越多，电力系统面临着越来越不确定的运行条件。SCOPF的确定性版本只适用于最有可能预测的情景，但不再适用，因为它可能导致次优或不可靠/危险的运行条件。为了克服这一限制，ECHO项目将开发一种新的SCOPF方法，该方法通过机会约束优化来管理不确定性，该优化强制执行约束集以满足用户定义的概率水平。为此，我们求助于机会约束优化领域的一种新方法--内-外逼近法。现有的关于这一主题的工作很少是基于有问题的交流电网模型近似为线性直流(DC)模型(由于忽略无功和母线电压的变化，其最优控制行为对于网络的实际运行可能是不可行的)，并应用于小系统。与以前的工作不同的是，ECHO项目首次被用于建立适用于中型电力系统(例如，国家一级)的准确的完全非线性交流电网模型。该项目将全面探讨采用机会约束进行安全管理的方面和影响。ECHO项目将证明，在不确定情况下对电力系统运行进行安全管理的综合SCOPF方法确实是可能的，这将导致在可再生能源普及率较高的情况下，在最优和可靠性之间取得更好的平衡。我们预计，这种方法将引起学术界、公用事业公司和软件开发商的兴趣，并可以支持网络运营商在能源过渡阶段的政策制定。

The ECHO project focuses on the security-constrained (or contingency-constrained) optimal power flow (SCOPF), aiming at improving the decision-making for day-ahead planning of power system operation, i.e., to ensure a cost-efficient and reliable power system scheduling for every hour of the next day. In addition, power systems are facing increasingly uncertain operation conditions, due to growing amounts of fluctuating renewable generation. The deterministic version of SCOPF, which fits only the most likely forecasted scenario, is not anymore suitable since it may lead to either sub-optimal or unreliable/risky operating conditions. To overcome this limitation, the ECHO project will develop a new SCOPF approach which manages the uncertainty via chance constrained optimization that enforces the set of constraints to satisfy a user-defined probability level. To this end, we resort to the inner-outer approximation method, which is a new method recently developed by the applicants in the area of chance constrained optimization. The very few existing works on this topic were based on the questionable AC grid model approximation as a linear direct current (DC) model (whose optimal control actions could be infeasible for real operation of the network as reactive power and bus voltages variations are ignored) and were applied to small systems. Unlike these previous works, the ECHO project is leveraged for the first time to the accurate fully nonlinear AC grid model for a medium size power systems (e.g. at country level). The project will comprehensively explore the aspects and implications of adopting chance constraints for security management. The ECHO project will demonstrate that a comprehensive SCOPF approach to security management of power system operation under uncertainty is indeed possible and this will lead to a better trade-off between optimality and reliability in the presence of a large penetration of renewable generation. We expect that this approach would be of interest to academia, utilities, and software developers, and it could support policy making of the network operators during the energy transition phase.