1 Abstract—Synchronized phasor measurement based Wide Area Monitoring and Control (WAMC) system is becoming a reality within international research and development both in academia and industry. Timely and accurate data with high resolutions holds great promise for more responsible and advanced grid control and operation. Currently, most of the research focuses on the different control schemes and applications. A relatively less addressed aspect is the dependency of the WAMC system on the performance of the Information and Communication Technology (ICT) infrastructure, without whose support the projected functionalities of the WAMC systems will be not achieved. Possible delays brought by the complex data transfer and processing processes in WAMC systems are addressed in the first part of this paper. Thereafter, simulations where delayed Phasor measurements are fed to the Static Var Compensator (SVC) are conducted iteratively to detect its maximum tolerated delay. Furthermore, performance requirements for the centralized computation and control actuation are researched and analyzed based on simulation results. It also includes a study on feasibility of compensations using local signal based Power System Stablizers (PSS) in situations with much phasor data delay. The paper is concluded by suggesting ICT architecture for WAMC systems aiming to improve its robustness. Index Terms—WAMC systems, ICT infrastructures, PMU, phasor measurement latency, remote signal based SVC, PSS I. INTRODUCTION There is an international interest and implementation drive, in both academia and industry, on the prospects of Phasor Measurement Unit (PMU) based monitoring and control technology [1] [2]. These systems promise to offer more accurate and timely data on the state of the power system increasing the possibilities to manage the system at a more efficient and responsive level and apply wide area control and protection schemes [3]. A. Purpose The purpose of this paper is to demonstrate the consequence of delayed input data in WAMC systems and the performance requirements this poses on time available for decision making and control actuation. Furthermore, feasibility of compensating the delay by introducing local signal based controllers is studied. Finally, an ICT system K. Zhu, M. Chenine and L. Nordström are all with the department of Industrial Information & Control Systems, School of Electrical Engineering, KTH – The Royal Institute of Technology, SE-10044 Stockholm, Sweden. (E-mail: zhu.kun@ics.kth.se, moustafac@ics.kth.se, and larsn@ics.kth.se). architecture is suggested for this specify control scheme to enhance the robustness of WAMC system. B. Outline The rest of the paper is structured as follows: Section II presents an overview of WAMC system architectures outlining the main components of such systems. Section III addresses the communication system architecture and the possible delays in WAMC communication. Section IV describes the implemented simulation models and Section V explains the parameters in simulation scenario. The analysis of simulation results and a discussion can be found in Section VI and the paper is concluded in Section VII. II. WIDE AREA MONITORING AND CONTROL SYSTEMS A. WAMC system components A WAMC system includes 4 basic components: PMUs, PDC, PMU application systems and finally communication network according to NASPI [4]. Figure 1 illustrates the logical architecture of WAMC systems. PMU PMU PMU ... Phasor Data Concentrator Application Software Application Software ... Application Software Layer 1: Data Aquistion Layer Layer 2: Data Management Layer 3: Applications Figure 1: Layers and components of WAMC system. Layer 1 where the WAMC system interfaces with the power system on substation bars and power lines is named the Data Acquisition layer and this is where the PMUs are located. Layer 2 is known as the Data Management layer and this is where the PMU measurements are collected and sorted by the PDC, and afterwards a single time synchronized dataset is generated. Finally Layer 3 is the Application Layer that represents the real time PMU based application functions that process the time synchronized PMU measurements provided by the previous layer. The information transactions between these three layers are realized by a communication network. B. Communication network in WAMC systems The communication infrastructure is a critical component in the architecture of WAMC systems. This is because PMU Analysis of Phasor Data Latency in Wide Area Monitoring and Control Systems Kun Zhu, Student Member, IEEE, Ji Song, None Member, Moustafa Chenine, Student Member, and Lars Nordström, Member, IEEE