Wide-area Coordination Research Articles

Optimal siting, sizing, and parameter tuning of STATCOM and SSSC usingMPSO and remote coordination of the FACTS for oscillation damping of powersystems

In electromechanical oscillation damping within power system, power system stabilizers (PSSs) are often deployed. However, a PSS is less effective in damping interarea oscillation and is limited by changes in network configuration due to weak tie-lines and load variations. Consequently, this paper presents a wide-area coordination approach that damps interarea oscillations using FACTS devices and phasor measurement units. We selected a static synchronous compensator (STATCOM) and static series synchronous compensator (SSSC) for realistic power system interarea oscillation damping. The performance of the coordinated FACTS installed in a power system depends on their suitable locations, sizes, tuned parameters, and remote input signal selection. Hence, we formulated a multiobjective problem to provide the STATCOM and SSSC's optimal solutions using multiobjective particle swarm optimization. In addition, we employed a participation factor to select suitable generator speed deviations as the wide area stabilizing signal. The proposed approach was tested on different configurations of the Kundur $2$-area $4$-machine test system within MATLAB and Psat environments. The outcome of the nonlinear simulation proved that the multimachine power system stability was enhanced.

A Summary of Research on Wide-area Distributed Electric Vehicle and Grid Interaction Technology

Electric vehicle charging behavior and grid interaction technology, including the impact assessment of electric vehicles for distribution networks and the planning and operation optimization of electric vehicles connected to the grid.Specifically, the main contents include: researching the agglomeration characteristics of large-scale electric vehicle charging behavior based on statistical data and charging history data, and evaluating the regulatory potential of large-scale electric vehicles; wide-area coordination strategy and station-level and regional-level orderly charging.The interaction mode and architecture, the hierarchical control strategy of large-scale electric vehicle charging behavior and grid interaction.

Countermeasures on preventing backup protection mal-operation during load flow transferring

Abstract Removal of transmission lines in power systems may result in load flow transferring and unreasonable operations of backup protections, which may develop into cascading tripping accidents and even blackouts. Traditional backup protection based on local measurement information has disadvantages in preventing from cascading trip because it cannot distinguish the over load reason between due to faults and due to load flow transferring. On the premise that the load flow transferring can be identified based on wide-area coordination system, concise adaptive adjustment methods for the operation characteristics of zone III distance protection and overcurrent protections are proposed to avoid the mal-operation caused by load flow transferring. Meanwhile, their backup protection functionality can be reserve to a great extent. The simulation test results illustrate the validity of the proposed method.

Beehive: low-cost content subscription service using cloudlets

In recent years, Content Subscription Service (CSS) is showing a notable success in helping users fetch unpopular data in P2P networks. It works by maintaining a storage pool to pull the subscribed file and then redistribute them to the requestor. However, existing commercial CSS incurs huge bandwidth/equipment cost due to introducing a third-party cloud storage. We present Beehive, a low-cost yet efficient CSS, which leverages the idle node bandwidth/storage (i.e., cloudlets) in the original P2P system to form an inherent cloudlet storage. Since P2P nodes are geographically distributed, highly dynamic and heterogeneous, Beehive adopts three key techniques to achieve high performance. First, by applying random linear network coding, multiple seeders can upload the same file simultaneously without complicated wide-area coordination. Second, a model is developed to set the coding parameters so that the cloudlet storage achieves guaranteed performance in file availability and data distribution efficiency. Finally, by performing task outsourcing, overloaded seeders quickly offload their tasks to idle peers, which effectively balances the load and utilizes the system resources. We implement Beehive with 29,000 lines of C++ codes and deploy it in a real P2P file-sharing system. Results show that Beehive improves the success ratio of pulling peer-side files from 38.7% (traditional online download) to 84.3% (users offline waiting for less than three days), and provides users with over 200 kB/s download speed.

The Basic Philosophy and Improvement on Reliability of Electric Power Systems in Japan

An outline of the electric power system and the present status of power system failures in Japan where "wide area coordination" is adopted, are described. To increase the reliability of the electric power system, it should be simple, streng, and flexible in its arrangement and also easy in its operation. Thus it is essential that it be composed as a well-balanced, powerful, and living system. According to this concept, an intensive study has been made on the system reliability, especially from the viewpoint of equipment and also of operation. Ten typical approaches to improve the system reliability in Japan are shown. The economic aspect, which is most important in improving the system reliability, is now under study. A comparison of the amount of investment with the expected profit is being undertaken.