Security Enhancement of Power Systems with Smart Grid Implementation
Smart Grid has become an attractive option for a power system operational strategy due to various technical and economic factors. This paper is basically present about the security enhancement for power system with smart grid concept implementation. The smart grid is a network of computers and power infrastructures that monitor and manage energy usage. Each energy producer maintains operational centers that receive usage information from collector devices placed throughout the served area. One of the smart grid’s most attractive features is its ability to support widespread customer energy generation. Smart Grid design and deployment must take into account the current cyber vulnerabilities in the legacy power grid. In this project, power system with Smart Grid concept implementation is to be simulated by using PowerWorld simulation software. From the developed model for the system, security assessment analysis is performed on the selected test system. The effects when the disturbances occurred have been observed.
2012 1st International Conference on Future Trends in Computing and Communication Technologies Security Enhancement of Power Systems with Smart Grid Implementation Noorpi N. Sabrina Hana A. Halim Universiti Malaysia Perlis (UniMAP), Universiti Malaysia Perlis (UniMAP), Perlis, Malaysia Perlis, Malaysia email@example.com firstname.lastname@example.org Nurhakimah M. Mukhtar Melaty Amirruddin Universiti Malaysia Perlis (UniMAP), Universiti Malaysia Perlis (UniMAP), Perlis, Malaysia Perlis, Malaysia email@example.com firstname.lastname@example.org Abstract— Smart Grid has become an attractive option constraints, line flows and voltage magnitudes are for a power system operational strategy due to various within limits. Even though a system is normal, a technical and economic factors. This paper is basically contingency may push it to a state where present about the security enhancement for power system load/engineering constraints may not be satisfied. Then with smart grid concept implementation. The smart grid is a network of computers and power infrastructures that we call the state insecure. There are critical monitor and manage energy usage. Each energy producer contingencies which an operator may know based on maintains operational centers that receive usage past experience or can be calculated On-Line. If the information from collector devices placed throughout the system is normal for the critical contingencies then the served area. One of the smart grid’s most attractive system is secure. features is its ability to support widespread customer The issue of power systems security has increased energy generation. Smart Grid design and deployment awareness of many parties in multidiscipline such as, must take into account the current cyber vulnerabilities in industry, scientist and academician. E. M. the legacy power grid. In this project, power system with Voumvoulakis et. al.  have proposed a method to Smart Grid concept implementation is to be simulated by using PowerWorld simulation software. From the assess the dynamic performance of the Greek mainland developed model for the system, security assessment Power System and to propose a load shedding scheme analysis is performed on the selected test system. The in order to maintain voltage stability under various effects when the disturbances occurred have been loading conditions and operating states in the presence observed. of critical contingencies including outages of one or more generating units in the south part of the system. A Keywords - Smart Grid, security enhancement, power Decision Tree is used to assess the dynamic system, PowerWorld, power grid. Performance of the system. The candidate attributes of the Decision Tree are chosen through a data mining process. I. INTRODUCTION Extensive research is being carried out to conduct a Power system security means the ability of a system comprehensive study on security considerations that to withstand unexpected failure and continue operating need to be addressed while opting for the Smart Grid without interruption of supply to the consumer. It also and microgrids (future concepts of Smart Grid) can be defined as the degree of risk in the ability to implementation. For example, H. Cheung et. al.  survive imminent disturbances (contingencies) without have recommended a new network access control interruption of customer service . The power system strategy and role-based model to increase the power- must also be secure against contingencies that would grid network security. Recent development of not be classified as stability problems such as damage microgrids in power systems, the introduction of open to equipment or failure of a cable. Essentially, the new access competition by governments in electricity electricity supply industry presents increasing industries, and increased use of network-controlled challenges for stable and secure operation of power devices in power systems have resulted utilities in a systems. greater reliance on computer networks for proper The smart grid is a network of computers and power power-grid operations. infrastructures that monitor and manage energy usage. The new model extends the network access control The smart grid is required to be self-healing and from a single security domain to multiple domains for resilient to system anomalies . It predicts looming interconnecting microgrids. This paper also proposes a failures and take corrective action to avoid or mitigate security policy managing method using XML to system problems. simplify power-grid network security administrations. A system is normal when it satisfies all load With the proposed method, the authorization is 84 2012 1st International Conference on Future Trends in Computing and Communication Technologies independently defined and separated from policy demand only . In addition to that, due to the representations and implementation mechanisms, and a hierarchical topology of its assets, the existing digital credential is introduced to establish trust and role electricity grid suffers from domino effect failures. assignments for users in different microgrid domains. The next-generation electricity grid, known as the “smart grid” or “intelligent grid,” is expected to address II. SECURITY ASSESSMENT ANALYSIS the major shortcomings of the existing grid. It can be The flow of electricity in a power system depends defined as a network of technologies that makes on several factors such as power generated by information available about energy flows in the grid and generators, power consumed by loads, and transmission the state of the grid-assets . It makes energy flows network topology. Any change in any of these factors controllable for efficient use and to support energy affects the flow of electricity in the system. For transition. In essence, the smart grid needs to provide example, if one transmission line disconnected, the the utility companies with full visibility and pervasive power flow through the disconnected line would be control over their assets and services. displaced to other lines. Another example is if the The smart grid creates more benefits. It helps more power consumed by load increases, the generator has to business cases close, when all of the benefits of an increase its output to balance the system. activity are linked to all of the utility’s departments and Power system security can be defined as the ability goals. Often this results in significant system of a system to withstand unexpected failure and integration. In fact one experimental factor in smart grid continue operating without interruption of supply to the projects is the need for modern enterprise architecture, consumer. A system is normal when it satisfies all load consisting of a service oriented approach, consistent use constraints, the line flows and voltage magnitudes are of data models, and effective governance . Such a within the limits . condition produces more scientific once the additional Security assessment means the evaluation of data, data from new smart grid devices becomes available to provided by security monitoring, to estimate the relative all applications. robustness (security level) of the system in its present state. For instance, the determination of whether the system is in the Normal or Alert operating state. Security enhancement signifies specific operations taken on-line to improve system robustness such as to raise the performance level of system security. Includes or is also referred to variously in the literature as security dispatch, security control, corrective rescheduling, preventive action. . A. Dynamic/Transient Security Assessment Dynamic security assessment is the evaluation of the ability of the system to supply the load against system dynamic problems of transient instability, and oscillatory instability. It deals with the angle stability. Dynamic security assessment system based on grid technology includes system voltage early warning, system power angle and flow early warning, system frequency early warning and system equipments early warning. Figure 1. Basic Smart Grid Ingredients. B. Static/Steady State Security Assessment This type of security assessment is the ability of the To allow pervasive control and monitoring, the system to supply load without violating operating smart grid is emerging as a convergence of information conditions and load curtailment. It is related with technology and communication technology with power violation of voltage constraint and thermal line limit. system engineering. Figure 1 depicts the salient features of the smart grid in comparison with the existing grid. Given the fact that the roots of power system issues are III. SMART GRID typically found in the electrical distribution system, the The existing electricity grid is unidirectional in point of departure for grid overhaul is fi rmly placed at nature. It converts only one-third of fuel energy into the bottom of the chain. electricity, without recovering the waste heat. Almost Utilities believe that investing in distribution 8% of its output is lost along its transmission lines, automation will provide them with increasing while 20% of its generation capacity exists to meet peak capabilities over time. Within the context of these new 85 2012 1st International Conference on Future Trends in Computing and Communication Technologies capabilities, communication and data management play an important role. These basic ingredients enable the Zone 1 utilities to place a layer of intelligence over their current and future infrastructure, thereby allowing the introduction of new applications and processes in their businesses. The convergence of communication technology and information technology with power system engineering, assisted by an array of new approaches, technologies and applications, allows the existing grid to traverse the complex yet staged trajectory of architecture, protocols, and standards towards the smart grid. Zone 2 IV. RESULTS AND DISCUSSIONS Figure 3. Simulated 30 bus system with specified zones. The single line diagram for IEEE 30 bus system for given data has been constructed in PowerWorld The selection of outage line can be selected in simulator. PowerWorld Simulator is an interactive Contingency Definition Dialog. The circuit outage is power systems simulation package designed to simulate simulated in one branch which causes a power flow high voltage power systems operation. The snapshot of violation in the other branch. the single line diagram is shown in Figure 2. Figure 5 shows how many lines which have the violation, such as overloaded line after the disconnection of lines stated. Disconnection of one line will affect the nearest lines or adjacent lines. Figure 4. Example of diconnection of line for Line 1-2. 2 line violation Number of Figure 2. Simulated 30 bus system. 1 For small cases, the system will usually not need to be separated to different zones or area. But it can be very useful for the large cases. The 30 bus system is 0 divided into 3 different zones in order to make it easier 1_2 1_3 2_5 3_4 6_7 12_13 to be analyzed. Most of the generator buses are located Disconnected Line in Zone 1 while most of the load buses are located in Zone 2 and Zone 3. Figure 3 shows the example of 30 Figure 5. Number of line violation over disconnected line for 30 bus bus system with specified zones. system. 86 2012 1st International Conference on Future Trends in Computing and Communication Technologies Figure 6 illustrates Bus Low Volts violation report REFERENCES for interconnected lines of 30 bus system. After the disconnection of one line, some buses in this system  P. Kundur, “Power System Security in the New Industry went low volts. The graph below shows how many Environment: Challenges and Solutions”, IEEE Toronto busses went low volts when the stated lines opened. Centennial Forum on Reliable Power Grids in Canada, October 3, 2003.  H. Farhangi, “The Path of the Smart Grid”, IEEE Power & 10 Energy Magazine, January/February 2010, vol. 8, No. 1, pp. 18- Number of bus violation 28. 8  E. M. Voumvoulakis, A. E. Gavoyiannis, and N. D. Hatziargyriou, “Decision Trees for Dynamic Security 6 Assessment and Load Shedding Scheme”, IEEE, 2006.  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