Resilient Wide-Area Damping Control Using GrHDP to Tolerate Communication Failures

This paper proposes a goal representation heuristic dynamic programming (GrHDP)-based resilient wide-area damping controller (WADC) for voltage source converter high voltage direct current (VSC-HVDC) employing redundant wide-area signals as input signals to tolerate communication failure. A supervisory fuzzy logic module is proposed and added in the resilient WADC to adjust the learning rate of GrHDP online when encountering communication failure. Moreover, the resilient WADC does not need the accurate model of the power system and has the adaptability to the variation of operation conditions and communication failures. Case studies are conducted in a 10-machine 39-bus system with one VSC-HVDC transmission line. Simulation results show that the resilient WADC can counteract the negative impact of communication failures on control performance under a wide range of system operating conditions

Design and real-time implementation of data-driven adaptive wide-area damping controller for back-to-back VSC-HVDC

This paper proposes a data-driven adaptive wide-area damping controller (D-WADC) for back-to-back VSC-HVDC to suppress the low frequency oscillation in a large-scale interconnected power system. The proposed D-WADC adopts a dual-loop control structure to make full use of the active and reactive power control of VSC-HVDC to improve the damping of the power system. A data-driven algorithm named the goal representation heuristic dynamic programming is employed to design the proposed D-WADC, which means the design procedure only requires the input and output data rather than the mathematic model of the concerned power system. Thus, the D-WADC can adapt to the change of operating condition through online weight modification. Besides, the adaptive delay compensator (ADC) is added to effectively compensate the stochastic delay involved in the wide-area feedback signal. Case studies are conducted based on the simplified model of a practical power system and the 16-machine system with a back-to-back VSC-HVDC. Both the simulation and hardware-in-loop experiment results verify that the proposed D-WADC can effectively suppress the low-frequency oscillation under a wide range of operating conditions, disturbances, and stochastic communication delays

Design of a Limited State Feedback Wide-Area Power System Damping Controller Without Communication Channels

The wide-area controller (WAC) is used to damp out inter-area oscillations in the power system. Conventionally, to implement WAC in the power system, efficient wide-area communication channels are essential. The performance of the WAC can get degraded with under-performing communication channels. Although, the communication are begin made efficient and redundant, data integrity may pose another threat to the performance of the WAC. In order to subside the dependency on wide-area communication channel, this paper proposes a communication free wide-area controller (CF-WAC) to damp out inter-area oscillations even in the worst scenarios (in terms of communication channels). The CF-WAC is designed based on the state feedback principle and with limited states. The chosen design path can be achieved by using structurally constrained $H_{2}$ -norm optimization. The proposed CF-WAC is designed in a centralized manner and implemented in a decentralized way and yet retain the near conventional WAC performance. The performance of the proposed CF-WAC is compared with full-scale WAC (FS-WAC i.e., conventional WAC), sparsity-promoting WAC (SP-WAC), and reduced-scale WAC (RS-WAC). Simulation studies are carried out on the IEEE 68-bus test system to evaluate the potential of the CF-WAC in damping inter-area low-frequency oscillations by considering different disturbances and communication channel losses. © 2013 IEEE

A Procedure to design fault-tolerant wide-area damping controllers

The idea of a smart grid is based on the increased integration of information technologies throughout the power grid. Technologies, such as phasor measurement units, are being deployed to increase the number of wide-area measurements across the bulk power system providing increased awareness of the system operational state. However, from a critical infrastructure perspective, the advanced metering infrastructure introduces a concern: the loss of communication among devices and the power grid. This communication loss may interfere with the wide-area control system performance and adversely affect the power system dynamics. This paper proposes a method based on genetic algorithms for wide-area robust damping controller design considering multiple operation points and loss of communication links related to the input and to the output of the central controller. The method is applied to enhance the damping of the electromechanical oscillations in an IEEE benchmark system: the simplified 14-generator model of the Southeastern Australian power system. The performance of the designed controller is evaluated using modal analysis and non-linear simulations in the time domain. The obtained results demonstrate the effectiveness of the method to design a single centralized controller that provides satisfactory damping to the electromechanical oscillations over several operating points, even when there is a loss of a communication link, thus being robust with respect to is an important aspect of a critical power grid infrastructure62338323405FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP2015/02569-6; 2015/24245-8; 2015/18806-7; 2016/08645-

Smart DIPSS for Dynamic Stability Enchancement on Multi-Machine Power System

Disruption of the electric power system always results in instability. These disturbances can be in the form of network breaks (transients) or load changes (dynamic). Changes in load that occur suddenly and periodically cannot be responded well by the generator so that it can affect the dynamic stability of the system. This causes the occurrence of frequency oscillations in the generator. A poor response can cause frequency oscillations for a long period. This will result in a reduction in the available power transfer power. In a multi-machine power system, all the machines work in synchrony, so the generator must operate at the same frequency. Therefore, disturbances that arise will have a direct impact on changes in electrical power. In addition, changes in electrical power will have an impact on mechanical power. The difference in response speed between a fast electrical power response and a slower mechanical power response will result in instability. As a result of these differences, the system oscillates. The addition of the excitation circuit gain is less able to stabilize the system. To solve the problem, additional signal changes are required. The additional signal is generated by the Dual Input Power System Stabilizer (DIPSS) setting using the Ant Colony Optimization (ACO) method.Disruption of the electric power system always results in instability. These disturbances can be in the form of network breaks (transients) or load changes (dynamic). Changes in load that occur suddenly and periodically cannot be responded well by the generator so that it can affect the dynamic stability of the system. This causes the occurrence of frequency oscillations in the generator. A poor response can cause frequency oscillations for a long period. This will result in a reduction in the available power transfer power. In a multi-machine power system, all the machines work in synchrony, so the generator must operate at the same frequency. Therefore, disturbances that arise will have a direct impact on changes in electrical power. In addition, changes in electrical power will have an impact on mechanical power. The difference in response speed between a fast electrical power response and a slower mechanical power response will result in instability. As a result of these differences, the system oscillates. The addition of the excitation circuit gain is less able to stabilize the system. To solve the problem, additional signal changes are required. The additional signal is generated by the Dual Input Power System Stabilizer (DIPSS) setting using the Ant Colony Optimization (ACO) method

Influence of Adding BESS as Ancillary Controller of Wind Power Plant on Low Frequency Oscillation

Abstract: This paper introduces the influence on integrating battery energy storage system (BESS) as ancillary controller of wind power plant in small signal stability. Modified two area power system is used as the test system. The modification has been made by replacing one synchronous generator with wind and PV generation. Modal analysis and phase portrait analysis are used to investigate the influence of adding BESS on wind power plant. From the simulation results it is found that the small signal stability performance can be enhance by adding BESS as ancillary controller of wind power plant. This result indicated by increasing damping performance on the critical mode. Furthermore, the oscillatory condition is more damped compared to the base case scenarios. These results indicated by the smallest circular on the phase portrait analysis. Moreover, by adding BESS as ancillary controller the structured singular value (SSV) of the investigated system is 0.8321. It can be stated that the proposed method is robust against uncertainty (SSV must below 1). Keywords: BESS, Clean energy technology, Oscillatory stability

Novel PID Controller on Battery Energy Storage Systems for Frequency Dynamics Enhancement

Frequency dynamics is one of the important aspects of power system stability. From the frequency dynamics, the operator could plan how is the reliability of the electricity. The frequency can be maintained by controlling the balance between load demand and generation. To maintain the balance of the generation, the governor is playing an important role to increase the speed of the turbine and enhance the generating capacity of the generator (ramp-up). However, as the speed of the governor is slower than the increasing load demand, in the sub-transient area, the frequency may experience higher overshoot. Hence, it is important to add additional devices such as battery energy storage systems to enhance the frequency dynamics response in the sub-transient area. One of the important parts of storage is the controller. The controller must make sure the storage charges and discharge energy are in the sub-transient area. Hence PID controller can be the solution to make the storage operate optimally This paper proposed a novel PID controller on battery energy storage systems (BESS) to enhance the dynamics performance of frequencies. The five-area power system is used as the test system to investigate the efficacy of the proposed novel idea. Time domain simulation is investigated to see the improvement of the frequency dynamics response. From the simulation results, it is found that adding a PID controller on BESS could enhance the BESS response and result in frequency dynamics response improvement

A critical survey of technologies of large offshore wind farm integration : summary, advances, and perspectives

Offshore wind farms (OWFs) have received widespread attention for their abundant unexploited wind energy potential and convenient locations conditions. They are rapidly developing towards having large capacity and being located further away from shore. It is thus necessary to explore effective power transmission technologies to connect large OWFs to onshore grids. At present, three types of power transmission technologies have been proposed for large OWF integration. They are: high voltage alternating current (HVAC) transmission, high voltage direct current (HVDC) transmission, and low-frequency alternating current (LFAC) or fractional frequency alternating current transmission. This work undertakes a comprehensive review of grid connection technologies for large OWF integration. Compared with previous reviews, a more exhaustive summary is provided to elaborate HVAC, LFAC, and five HVDC topologies, consisting of line-commutated converter HVDC, voltage source converter HVDC, hybrid-HVDC, diode rectifier-based HVDC, and all DC transmission systems. The fault ride-through technologies of the grid connection schemes are also presented in detail to provide research references and guidelines for researchers. In addition, a comprehensive evaluation of the seven grid connection technologies for large OWFs is proposed based on eight specific indicators. Finally, eight conclusions and six perspectives are outlined for future research in integrating large OWFs

A scientometric analysis of the emerging topics in general computer science

Citations have been an acceptable journal performance metric used by many indexing databases for inclusion and discontinuation of journals in their list. Therefore, editorial teams must maintain their journal performance by increasing article citations for continuous content indexing in the databases. With this aim in hand, this study intended to assist the editorial team of the Journal of Information and Communication Technology (JICT) in increasing the performance and impact of the journal. Currently, the journal has suffered from low citation count, which may jeopardise its sustainability. Past studies in library science suggested a positive correlation between keywords and citations. Therefore, keyword and topic analyses could be a solution to address the issue of journal citation. This article described a scientometric analysis of emerging topics in general computer science, the Scopus subject area for which JICT is indexed. This study extracted bibliometric data of the top 10% journals in the subject area to create a dataset of 5,546 articles. The results of the study suggested ten emerging topics in computer science that can be considered by the journal editorial team in selecting articles and a list of highly used keywords in articles published in 2019 and 2020 (as of 15 April 2020). The outcome of this study might be considered by the JICT editorial team and other journals in general computer science that suffer from a similar issue