Intelligent Power Grid Load Transferring Based on Safe Action-Correction Reinforcement Learning

When a line failure occurs in a power grid, a load transfer is implemented to reconfigure the network by changingthe states of tie-switches and load demands. Computation speed is one of the major performance indicators inpower grid load transfer, as a fast load transfer model can greatly reduce the economic loss of post-fault powergrids. In this study, a reinforcement learning method is developed based on a deep deterministic policy gradient.The tedious training process of the reinforcement learning model can be conducted offline, so the model showssatisfactory performance in real-time operation, indicating that it is suitable for fast load transfer. Consideringthat the reinforcement learning model performs poorly in satisfying safety constraints, a safe action-correctionframework is proposed to modify the learning model. In the framework, the action of load shedding is correctedaccording to sensitivity analysis results under a small discrete increment so as to match the constraints of line flowlimits. The results of case studies indicate that the proposed method is practical for fast and safe power grid loadtransfer.

The evolution of interstate power grid formation

This study analyzes the process of electric power system integration in various regions worldwide.This process is implemented by creating both interstate electric ties and power grids.The analysis is comprehensive and examines the system,spatial,technical,organizational,and market aspects of the integration.Various countries,including developed countries such as Europe and North America,as well as economically developing countries such as Central America and Africa,are involved in this process.However,the rates and scales of electric power integration differ across various regions worldwide.The analysis shows that the process of electric power integration,which has decades of history,is still ongoing,despite the growth of other trends,such as the development of distributed generation.Further electricity integration is expected to lead to the formation of a global power interconnection in the long term.

Protection Strategies against Cascading Failure for Power Systems of Ring Network

Power grid vulnerability is a key issue with large blackouts, causing power disruption for millions of people. The complexity of power grid, together with excessive number of components, makes it difficult to be modeled. Currently, researchers use complex networks to model and study the performance of power grids. In fact, power grids can be modeled into a complex network by making use of ring network topology, with substations and transmission lines denoted as nodes and edges, respectively. In this paper, three protection schemes are proposed and their effectiveness in protecting the power network under high and low-load attacks is studied. The proposed schemes, namely, Cascaded Load Cut-off (CLC), Cascaded Load Overflow (CLO) and Adaptive-Cascaded Load Overflow (A-CLO), improve the robustness of the power grids, i.e., decrease the value of critical tolerance. Simulation results show that CLC and CLO protection schemes are more effective in improving the robustness of networks than the A-CLO protection scheme. However, the CLC protection scheme is effective only at the expense that certain percentage of the network will have no power supply. Thus, results show that the CLO protection scheme dominates the other protection schemes, CLC and A-CLO, in terms of the robustness of the network, improved with the precise amount of load cut-off determined.

Caspian Energy Ring: Prospective vision

This paper presents the results of a technical and economic optimization study of the prospects of the Caspian Energy Ring(CER),connecting power systems of Russia,countries of the Caucasus,Central Asia,and South Asia.The CER,belonging partly to the emerging Asian Supergrid and partly to the existing European Supergrid,will become a bridge connecting these supergrids,laying the foundation for forming a global energy interconnection in the long term.The expansion of carbon-free renewable and nuclear facilities,low-carbon gas-fired power plants,and traditional thermal and hydro energy sources within the CER were considered in this study.The positive economic benefits of the creation of the CER are presented.Preliminary characteristics of the potential CER were also estimated.