Deliverables UNIMI results One of the goals of the EXaMINE project was the study of the dependability of control systems for power distribution networks under different conditions, namely preventive mode (PM), emergency mode for voltage stability problem (EM-VS), and emergency mode for transient stability problem (EM-TS). A dependability analysis of the proposed solution is the main contribution of University of Milano. The target of the analysis was the system as a whole and its communication architecture, whose design was also part of the project. At system level, the Dependable Systems of Systems (DSoS) project approach was adopted, as it allows to explicitly consider the time dependency of the various components comprising the entire system, which was identified as a crucial aspect in the project definition. The three modes were classified by specifying their attributes according to the DSoS taxonomy, starting from their operational goals. For the Emergency Modes the high level operational specifications of the interfaces of the components of the systems have been defined and analysed. The result of this study has confirmed the consistency of the choices made in the design of the system. From the communication architecture point of view, the advances in network technologies during the lifespan of the project have made possible the definition of an effective solution based on off-the-shelf components. Such a solution satisfies the timing and a security requirement expressed by the project and has the advantage of making the implementation of the EXaMINE components in existing facilities simpler since it relies on well-known technologies and protocols. Attention was also placed in the analysis of fault tolerance and communication security issues. AiA results The survivability of an electric network to contingencies with a certain probability to be present in the network is one of the main characteristics of the network operation. The list of contingencies considered in security analysis are used to measure the risk of insecurity in the context of the network operation. In general the acceptable level of risk is fixed by Regulators and administrative Authorities and the system operator is responsible to guarantee to final consumers and to all agents acting in the electricity market that this level is not exceeded (in other words, that the corresponding security level is guarantied). This is a responsibility that needs to be managed in two different time frames: - Under Operation Planning conditions. The results of the electricity market will determine which power plants will be operating in the next period (from a few hours to the next day, depending on each country regulation) and which will be the level of generation. The System Operator is responsible to accept the market results or modify them, according to certain pre-established rules, if the security level is not fulfilled. - In Real Time Operation. Many different network conditions may change from the forecasted conditions, such as changes in generation or load profiles, changes in network availability or in its topology. The SO must still guarantee that the network maintains the risk level established by the regulator. To fulfil these responsibilities, the SO must perform a security assessment process where the effects of contingencies are evaluated against the scheduled or actual networkconditions. The security assessment process has as final objective to measure the risk level and to define the corrective actions needed to guarantee the quality of service to all consumersand agents. The solution proposed and implemented in EXaMINE is based on the so-called ''Distributed-Parallel-Load-Flow'' algorithm developed by AIA. Roughly speaking, this algorithm allows carrying out load-flow type of calculations over a power system model partitioned into sub-regions by exchanging only boundary variables and sensitivities. This approach can be used both for state estimation and for static security assessment. In the context of EXaMINE this algorithm is used in order to carry out calculations over a power system model covering several TSOs : at each TSO a computer is installed to run the part of the algorithm corresponding to the internal network of that TSO. At each iteration these computers can exchange information about boundary nodes so as to let the various computers converge to a consistent solution. The database of each computer is synchronised with the real-time database of the corresponding EMS. This allows sharing implicitly the databases of the different TSOs without explicitly providing and exchanging sensitive information. The work carried out in this context in the project aimed at developing a fully operational prototype, installing this prototype in the field and carrying out tests in order to demonstrate the effectiveness of the approach. The field tests carried out considered the Iberian peninsula power system, which was split artificially into three regions: Portugal, Spain dry and Spain wet. Three computers where installed in the national control centre of REE and interfaced with their real-time SCADA database (which actually covers the whole peninsula). These tests fully demonstrate the feasibility of the approach. The main limitation of the proposed system is that it can be used only for static security assessment in preventive mode. Sema results The main result for Sema is the design, implementation, delivery and support to the experimentation of a Prototype for improving the Power network security by static analysis (preventive mode). The Preventive Mode (SC-PM) prototype developed in the EXaMINE project is built around the AIA algorithms Distributed State Estimator (DSE) and Distributed and Parallel Load Flow (DPLF). These algorithms were developed before and during the EXaMINE project and the EXaMINE SC-PM Prototype allowed to tune and test these algorithms in near real situation. The concept is to place one prototype per country to monitor. One prototype, placed inside one control centre, is connected to the SCADA/EMS and to the planning system in order to receive the real-time and operation planning data. On the SC-PM prototype, the system operator is able to run the distributed algorithms (DSE or DPLF) on a chosen data set (case). The algorithms can also be computed cyclically to provide reusable data sets. The system installed inside a control centre has a database related only to its electrical supply network, and a real description of the tie lines with the adjacent countries. The use of an external equivalent model is not needed for the countries fitted with a SC-PM prototype. The System Operator can ask the SC-PM prototype to provide him the description of the current situation of his electrical supply network or that of the 24 hours of the next day. The Prototypes installed in each control centre carry out calculations relating to their network. This computing process is iterative. At each iteration, there are exchanges of information between one prototype and its neighbours, until convergence of this computing process. Finally each System Operator can visualise on the Prototype display the electric situation relating to his own network, in coherence with the impact of the adjoining networks. The system makes it possible to make a calculation for: - The situation in real time. In this case the state of each network is given on the basis of the last digital data (P,V) acquired by each one of the networks. Calculations are mainly based on the DSE algorithm. - The future situation (the 24 hours of the next day). In this case the state of each network is given on the basis of estimated data of each part concerned. Calculation is mainly based on the DPLF algorithm. Prototype Overview: After the functional specification phase, which allowed to draw the outlines for an integrated Security Control System and to define precisely the functions to implement for each prototypes, Preventive and Emergency modes, the development work for the Preventive Mode Prototype was shared between AIA and Sema. The SC-PM Prototype contains and manages the specific algorithms to improve network preventive security. These algorithms, developed by AIA, are: - Distributed Parallel Load Flow algorithm (DPLF) - Distributed State Estimator algorithm (DSE). The SC-PM Prototype handles with the following functions: - configuration of its database (network model) taking from the Control Centre configuration files, - communication with the systems providing the information: SCADA/EMS and Planning system, - Man Machine Interface (MMI) allowing the system operator to run the specific algorithms and to display the results, - communication with the other EXaMINE SC-PM Prototypes which collaborate to the algorithms, - management of algorithms (cyclic or on demand computation, choice of data set), - storage and management of data sets corresponding to specific situations (cases) Experimentation of a distributed power flow The use of the new Distributed Power Flow and State Estimator, algorithms and Prototype developed with the EXaMINE, implies the definition of interfaces with proprietary EMS/SCADA Systems, to interchange not only the dynamic data but also the structural data Electric Power System Model, due to the proprietary nature of the EMS/SCADA and the lack of standardized interfaces, one of the problems to solve is the definition, and test of an interface loosely coupled to allow the secure interchange of the information with the EMS/SCADA including the automatic update of the power system model. The criteria followed to define and test this interface is a result that could be used by other systems faced with similar problems. By other hand the experience gained in the test phases of the prototype is also a tangible result that could be used both in the dissemination of the EXaMINE and in the future potential implementations of industrial versions of the developed products. UNI GENOA results The result obtained basically concern three different topics: a. Development and testing of algorithms for optimal placement of advanced monitoring devices (PMU = Phasor Measurement Units) within electrical transmission grids. These algorithms address the problem of PMU locating according to multiple possible approaches: a1. Dynamic state estimation, considering complete ability for observation, also accounting for N-1 security, in terms of loss of connections and measuring devices. a2. Observation of critical dynamic phenomena, in particular transient stability and voltage stability at both generation and load nodes. a3. Multi purpose monitoring for several critical dynamic phenomena, in case of cost constrained availability of reduced number of measurement devices. b. Contingency location and nature identification via voltage phasor measuring at electric power system transmission nodes. This result allows producing correct diagnoses in most cases before collecting information showed by conventional SCADAs at insufficient scanning rate, particularly in case of fast dynamic phenomena. c. Definition and testing on simulation environment, including complete model of a national electric transmission network, of novel, on-line conceived, criteria for voltage instability occurrence. Dissemination and use of the outlined result, in its final stage, is mainly devoted to European Transmission System Operators. It should be preceded by additional validation efforts to be performed in close collaboration with Electric Power Research Centres. Of course, dissemination within the scientific community is also highly commendable, in order to collect eventual improving suggestions and/or corrective remarks. The key innovative features of the result regard the chance of exploiting in an efficient way the potentialities of Phasor Measurement Units using such devices for multiple tasks. Among these we can annotate: - Support to conventional state estimation and development of a dynamic version; - Collection of measures liable to produce simple, therefore easily implemental and on-line usable, stability indicators to address appropriate solving procedures and trigger suitable remedial actions. The current status of development of the result is an exhaustive testing, based on a simulation campaign on a national electric transmission grid. Validation of the result is expected via foreseen installation of PMUs within transmission grids of UCTE countries. In that case there could be the chance of field-testing the effective reliability of the proposed algorithms. The expected benefits are the improvement of the present stage of development of European emergency controls and defence plans, producing a comprehensive approach to the different types of critical phenomena, also overtaking present limits due to the commitment of traditional control centre SCADAs, insufficient to cope in terms of speed with faster dynamics. Emergency control algorithms: SIME and RL The solution proposed and investigated in the EXaMINE project for emergency control is based on the use of phasor measurement units, fast telecommunications and measurement based (as opposed to event driven) detection and control algorithms. In its principle, this approach can be applied to any kind of fast or slow dynamic phenomena. In the project transient instabilities and voltage collapse phenomena were studied more in depth, the former because it is the most constraining one in terms of response times, the latter because it is a rather frequent problem encountered in modern power systems. In TS-EC (Transient stability emergency control), the E-SIME algorithm developed at the University of Liège was implemented and tested. This method detects impending loss of synchronism, identifies critical power plants and determines how many generators should be tripped to avoid loss of synchronism. A module to estimate dynamic values of rotor angles and speeds from phasor measurements was developed and tested in the simulation environment. A scheme to detect fault clearing was also designed. In this context, similar algorithms were also developed based on the use of reinforcement learning agents. Both algorithms were tested in the context of off-line simulations. TS-EC algorithm was integrated in a laboratory test bench simulating also telecommunications and measurement systems together with the dynamics of the Italian HV system. CESI results CESI is a company operating for more than 40 years in the electro-energetic and environmental sectors in more than 35 Countries all over the world. It is market leader in testing and certification of electromechanical equipment and power system studies and consultancy, CESI competencies cover all stages of power system life cycle and are made available to power producers, electrical Utilities, electromechanical industry, electronics manufacturers, large-scale users of electricity as well as to Financial Institutions and Public Administrations as supporting services designed for the solution of their problems. The proposed SC-EM (Security Control - Emergency Mode) solution was investigated in the EXaMINE project and it is based on the use of PMUs (Phasor Measurement Units), fast telecommunications and detection and control algorithms. VIDA (Voltage Instability Detection Assessment) and TS-EC (power system Transient Stability - Emergency Control) algorithms were integrated in a laboratory test bench simulating the characteristic dynamics and behaviour of the Italian power system, with telecommunications and measurement systems. GRTN results The role of GRTN in the project, as end-user, has been mainly focused on the definition of the Emergency Control requirements (''Needs expression phase'') and on the start-up of the ''sample field experimentation''. As far as this last issue, it has been scheduled with the primary objective to validate the selected SC-EM architecture, and to gather more information on the on-site behaviour of PMUs. GRTN, as Italian Transmission Operator, has the responsibility to implement this task on the Italian grid. This activity has been mainly concentrated on the development of a communication scheme, based on two complementary directions: a) from the field to the central system, taking care of data acquisition and elaboration of appropriate control strategies; b) from the centre to the field, aiming at issuing appropriate commands to some fast tripping equipment. a) In order to pursue the EXaMINE objectives, it has been planned to install a number of Phase Measurement Units (PMUs) in the Italian electric system, with the purpose of recording inter-area oscillations and supporting the identification of transient and voltage stability phenomena. As a first step, it has been decided to install 5 PMUs at some important electric nodes of the Italian network, mainly with the scope of validating calculation algorithms, data transfer procedures and following elaborations. The implementation of these monitoring systems is in progress. As already mentioned, the agreed chronological program foresees the completion of installations by the end of 2003. b) The need of very fast tripping signals is a critical point for SC-EM. In order to overcome this problem, it was decided to develop some equipment capable to manage both generators tripping and load shedding actions in very fast time (< 200 ms). This equipment is going to be widely installed on the Italian grid both for EXaMINE purposes and for other real-time applications, like the fast management of Interruptible Contracts. The main objective of the future GRTNs Exploitation plan is the integration of the EXaMINE concept into a comprehensive Emergency Control strategy in Italy (SICE - Sistema Integrato per il Controllo in Emergenza del sistema elettrico). The main activities to be performed are as follows. 1) Complete implementation of the on-going first-step open-loop Mini SCADA experimentation. The full implementation will be based on the validation of the first-stage Fast tripping and Monitoring System experimentations and then on the following integration of these two parts into a single overall communication scheme for SC-EM. 2) Full integrated testing environment. GRTN will give its support to the Research partners of the project for the finalization of the full integrated testing environment, in order to start-up an extended simulation campaign for validating the E-SIME and VIDA algorithms. 3) Installation and possible improvements analysis of the currently available equipment. The analysis of data from the field experimentation should give evidence of the adequacy of the currently available equipment. Further investigations should be continued on commercially available new apparatus, following the international trend of enriching traditional transient recorders with additional functions, including phasor measurement. A wide installation of PMUs in the Italian Grid is expected in the near future. Moreover, the possibility of integrating in a single apparatus both fast-tripping functions and phasor measurement capabilities will be investigated. 4) SICE development. If the previous testing activities will be successful, the Integration into a single environment (SICE) of the EXaMINE machine with another on-going GRTN project, related to the network Dynamic Security Assessment, will be undertaken. 5) Integration of SC-PM and SC-EM. In parallel with the SICE integration, an in-depth analysis for the possibility of implementing the EXaMINE Static Security Analysis in the Italian context will be undertaken, with a view for introducing Distributed Parallel Load Flow and State Estimator as an alternative to the currently available algorithms at GRTN. Searching for OpenAIRE data... There was an error trying to search data from OpenAIRE No results available
