Davood Babazadeh

SITL and HLA co-simulation platforms: Tools for analysis of the integrated ICT and electric power system

Due to the necessity of developing analysis tools in the integrated ICT and power system domain, this paper describes and compares the architecture and configuration of two different ITC-power system co-simulation approaches called SITL (System in the Loop) and HLA (High Level Architecture) Co-simulation platforms. Both platforms make use of the communication network simulator OPNET (Optimum Network Performance). As indicated by the names, the former operates in real time, in order to perform SITL simulations, whilst the latter is based on the HLA interface between OPNET and the power network simulation environment EMTP-rv (Electromagnetic Transient Program). We provide several details on their implementation and present their features by means of the results obtained for two test cases. The paper aims at clarifying the type of analysis that can be effectively carried out by using the two different platforms.

A platform for wide area monitoring and control system ICT analysis and development

PMU-based Wide Area Monitoring and Control (WAMC) system is introduced to improve the monitoring of power grid across large geographic areas and control the grid using more efficient and smart applications. The performance of WAMC applications in real power system scenarios and impact of their supporting Information and Communication Technology (ICT) on the data quality can be quantified and analyzed by pseudo-real co-simulation test beds. The purpose of this study is to propose and develop a WAMC testing platform to facilitate the real-time simulation of dynamic power grid, the ICT infrastructure that overlays the grid and WAMS applications. The platform consists of OPNET, a powerful communication network emulator, connected to a real-time power system simulator through virtualized PMU device. The end point stations such as Phasor Data Concentrator or PMU-based applications are also linked to the platform through OPNETs real-simulation gateway called SITL (System-In-The-Loop). To assess the performance of the platform architecture, a case study has been performed with five PMUs which collect the data from a power model and deliver to PMU-based mode-estimation application over a typical communication network. In this study, the results explicitly intend to quantify the effect of network protocols on data delay.

Survey on the Factors Required in Design of Communication Architecture for Future DC grids

This paper aims first to survey various aspects of DC grids from grid topologies to TSOs structure which has been carried out in several studies, and second try to highlight the factors to be considered in the design of the universal communication architecture for DC grid control and protection purposes. The result of the survey will be used as the first step to introduce the possible communication solutions such as network and data transfer protocols in order to ensure the reliable data delivery in operation of multi-national DC grids.

Cyber Physical Approach to HVDC Grid Control

This chapter presents a cyber-physical approach to design of HVDC control system architectures and evolving HVDC grid operation and control modes. In addition, the chapter describes the communication system architectures needed for centralized and distributed operation and control of HVDC grids. Modeling and analysis methods suitable to analyze such systems using graph theoretic concepts, and also the design of distributed control systems utilizing a Multi-Agent approach and its dependence on the information graph theory. The chapter is concluded with a description of an application for distributed control of DC grids utilizing the concepts introduced. The application is presented both with regards to comparison with other design choices and analysis of performance and robustness of the algorithm versus communication metrics.

Test platform for synchrophasor based wide-area monitoring and control applications

Synchrophasor technology is considered as a main enabler for the envisioned Smart Grid at the transmission level. Despite some preliminary field test results reported from China Southern Grid, the majority of the synchrophasor applications are still in the engineering or advanced laboratory tests phases. One possible impedance of any real-life adoption of such applicationsis a lack of test platforms that are able to verify the proposed application paradigms in cost efficient manners, and also to demonstrate the interactions between the power system and the supporting ICT systems with sufficient details. In this paper, we report on the continuing research efforts targeting at developing a test platform for the development of the synchrophasor based applications. The platform incorporates a virtual Phasor Measurement Unit (PMU), a real-time simulator for power systems, a real-time simulator for communication networks, and an implementation of an open-source Phasor Data Concentrator. Specifically, this article focuses on the implementation and verification of the virtual PMU, and on the extension of its functionality to incorporate communication over UDP.

Implementation of agent-based power flow coordination in AC/DC grids using co-simulation platform

This paper presents work on the coordination of power sharing contribution of converters in an overlaid HVDC grid using a Multi-Agent System (MAS) approach. This approach is further implemented in a real-time co-simulation platform in order to study the proposed control scheme including the supporting information and communication Technology (ICT) systems. The platform consists of OPNET, a communication network simulator, connected to a real-time power system simulator through virtualized and real devices. Furthermore, the impact of different supporting system parameters such as bit-error rate has been studied using this real-time co-simulation platform.

Consensus control for induction motors speed regulation

Cyber Physical Energy Systems (CPES) development requires the combination of distributed intelligence to fulfill the future complex tasks and reach the increase the energy demands. Electrical Industrial Systems (EIS) are in continuous evolving integrating new technologies allowing to a better performance and increase the efficiency. This paper applies the consensus protocol for Multi-Agent Systems (MAS) to control the speed of multiple induction motors. In this paper, the behaviour of the system under different disturbances and scenarios has been simulated, thus, confirming the suitability and simplicity of this method for coordinating the control actions.

Distributed ancillary service support for independent AC-areas through HVDC grid

This work aims to study different ancillary services such as frequency support, rotor angle stability and voltage stability that can be provided to independent AC areas through Multi-Terminal HVDC grid. An agent-based control scheme has been suggested to support the frequency of the imbalanced AC area using other intact areas during a disturbance. The frequency support is carried out through some agents/controller, where the objective of the agents is to reach a common value for a given state, i.e. frequency, using the local and neighbouring information. In this scheme, the concept of Adaptive Graph (AG) has been introduced to the consensus problem to deal with the limitation of original scheme in considering the rated capacity of HVDC converters. In this case, the frequency consensus can be reached to a new stable value by removing one or several converters from the communication graph when reaching rated active power capacity. In order to test the proposed scheme, a model of 7-terminal dc-grid and corresponding AC areas is developed in real time simulator OPAL-RT. The results show that the adaptive graph scheme improves the reliability of the system during distributed frequency support.

Stateful Data Delivery Service for Wide Area Monitoring and Control Applications

Recent Information and Communication Technology (ICT) advances have enabled power system applications using measurement signals across the Wide Area Network (WAN). The application control performance relies on the quality of data delivery service. However, the characteristics of Quality of Service (QoS), such as latency, packet loss, and packet jitter, are unavoidable. It is a trend to take QoS metric requirement into the consideration of controller design. But, how to ensure the application receiving the data within the designed tolerant range is another challenge. This paper presents ongoing work on a novel Stateful Data Delivery Service (SDDS) for power system application to address the challenge from the side of the communication infrastructure. The SDDS monitors the QoS performance on-line and identifies the signals which satisfy the requirement for the application to use. As a proof of concept, a Power Oscillation Damping (POD) controller is connected to the SDDS. The result shows the improvement in robustness of the POD controller by application of the SDDS. The paper also shows the feasibility of applying SDDS to WAC applications.

Agent-based control of VSC-HVDC transmission grid - A Cyber Physical System perspective

This paper proposes a control scheme to coordinate the DC voltage of converters in a HVDC grid using a Multi-agent System concept. Such interactions between agents, converters, and communication units are approached from a Cyber-Physical System (CPS) perspective. The Multi-agent based control scheme tries to update the DC voltage set-points of the converters based on local and neighboring information. The information exchange between the agents and communication delay tolerance of the control scheme is studied by means of graph theory. The multi-agent control scheme has been implemented for a seven-terminal HVDC grid in a real time simulator and the impact of communication delay on this distributed control approach has been studied and is presented in the result.