Arshad Saleem

A multi-agent system for distribution grid congestion management with electric vehicles

Abstract Electric vehicles (EVs) are widely regarded as valuable assets in the smart grid as distributed energy resources in addition to their primary transportation function. However, connecting EVs to the distribution network and recharging the EV batteries without any control may overload the transformers and cables during peak hours when the penetration of EVs is relatively high. In this study, a two level hierarchical control method for integrating EVs into the distribution network is proposed to coordinate the self-interests and operational constraints of two actors, the EV owner and Distribution system operator (DSO), facilitated by the introduction of the fleet operator (FO) and the grid capacity market operator (CMO). Unlike the typical hierarchical control system where the upper level controller commands the low level unit to execute the actions, in this study, market based control are applied both in the upper and low level of the hierarchical system. Specifically, in the upper level of the hierarchy, distribution system operator uses market based control to coordinate the fleet operator׳s power schedule. In the low level of the hierarchy, the fleet operator use market based control to allocate the charging power to the individual EVs, by using market based control, the proposed method considers the flexibility of EVs through the presence of the response-weighting factor to the shadow price sent out by the FO. Furthermore, to fully demonstrate the coordination behavior of the proposed control strategy, we built a multi-agent system (MAS) that is based on the co-simulation environment of JACK, Matlab and Simulink. A use case of the MAS and the results of running the system are presented to intuitively illustrate the effectiveness of the proposed solutions.

Agent services for situation aware control of power systems with distributed generation

Electric Power system of Denmark exhibits some unique characteristics. An increasing part of the electricity is produced by distributed generators (DGs). Most of these DGs are connected to the network at the distribution level. At the same time the concept of vehicle to grid (V2G) is already in the process of realization. This situation has created an incentive in electric power industry to utilize modern information and communication technologies (ICT) for improving the distribution system automation. This paper describes our work on how significantly increased amount of distributed generation could be exploited for the robust control of electric power systems. In particular, we present our work on the implementation of a dynamic service oriented system, in which autonomous agents represent different components of low voltage grid. These agents could offer and utilize electric power control services. We present results from several experiments where agents offer and utilize services in order to achieve distributed and autonomous control for subgrid operation of a distribution system. Finally it is discussed how the service oriented architecture can be combined with knowledge based reasoning to implement situation awareness required in complex control situations.

Smart Grid Architecture Model use case management in a large European Smart Grid project

On European level the EU Mandate M/490 including the final reports of the respective working groups are gaining momentum in the community. Two of the mandates core results deal with architecture description and use case management. As a response to the mandate, among other deliverables, the Smart Grid Architecture Model (SGAM) has been developed to provide a framework for Smart Grid architectures. Additionally, use case templates as well as a comprehensive methodology for use case management have been specified. The focus of this contribution is to demonstrate how use case management and the SGAM, and thus recommended by the EU, can be applied together in practice to specific use cases provided by the DISCERN project. The very purpose of the SGAM application is to share information among projects that implement similar use cases based on different technical solutions. Finally, open issues and research gaps to be addressed in order to utilize the SGAM will be presented.

Multiagent-Based Distribution Automation Solution for Self-Healing Grids

A multiagent-based distribution automation solution is proposed to be used in the distribution of self-healing grids to solve the service restoration part of the Fault Location, Isolation and Service Restoration (FLISR) task. The solution reduces the grid topology to an undirected weighted graph and executes a distributed implementation of Prims minimum spanning tree algorithm to solve the problem. The solution is compliant with state-of-the-art standards within smart grids, including but not limited to IEC61850. To test the performance of the algorithm, a testbed is assembled consisting of a physical dc grid model and several Arduino microcontrollers and Raspberry Pi computers. The test results show that the proposed algorithm can handle complex FLISR scenarios.

Control architecture of power systems: Modeling of purpose and function

Many new technologies with novel control capabilities have been developed in the context of “smart grid” research. However, often it is not clear how these capabilities should best be integrated in the overall system operation. New operation paradigms change the traditional control architecture of power systems and it is necessary to identify requirements and functions. How does new control architecture fit with the old architecture? How can power system functions be specified independent of technology? What is the purpose of control in power systems? In this paper, a method suitable for semantically consistent modeling of control architecture is presented. The method, called Multilevel Flow Modeling (MFM), is applied to the case of system balancing. It was found that MFM is capable of capturing implicit control knowledge, which is otherwise difficult to formalize. The method has possible future applications in agent-based intelligent grids.

Coordinated control scheme of battery energy storage system (BESS) and distributed generations (DGs) for electric distribution grid operation

This paper describes a coordinated control scheme of battery energy storage system (BESS) and distributed generations (DGs) for electric distribution grid operation. The BESS is designed to stabilize frequency and voltages as a primary control after the electric distribution system enters into the islanding operation mode, while the centralized joint load frequency control (CJLFC) utilizing DGs handles the secondary frequency regulation. The BESS with the associated controllers has been modelled in Real-time digital simulator (RTDS) in order to identify the improvement of the frequency and voltage response. The modified IEEE 9-bus system, which is comprised of several DG units, wind power plant and the BESS, has been employed to illustrate the performance of the proposed coordinated flexible control scheme using RTDS in order to verify its practical efficacy.

A case study of multi-agent interoperability in IEC 61850 environments

The IEC 61850 is the most promising standard for design of substation communication and automation systems. On the other hand multi-agents systems are attracting growing interest for different applications of substation automation systems. In multiagent systems agents represent different stake holders in the power system and based on implemented decision making logic they determine optimal operational conditions for the power systems given boundary conditions. Interoperability is of course a necessary pre-requisite for such architectures. Here we identify two aspects of interoperability; horizontal and vertical. Horizontal interoperability is relies on common semantic models of the power system that the agents can use to make decisions. One such semantic model is presented in the IEC 61970 Common Information Model (CIM). At this level, the IEC 61850 standard provides a model for access to information and control functions that has the necessary flexibility needed. In this paper we discuss the mapping between a multi-agent based architecture for power system control and the IEC 61850 standard for utility automation. The mapping is based on a use-case drive approach, in which the information exchange need is defined by the multi-agent system.

SGAM-based methodology to analyse Smart Grid solutions in DISCERN European research project

The design of future energy automation and management systems requires Distribution System Operators (DSOs) to analyse and compare different technical solutions for determining which of these could be best implemented in their networks. This paper presents a methodology that helps DSOs carry out such a complex task. The methodology is based on the Smart Grid Architecture Model (SGAM) framework. It was implemented using a web-based application that facilitates editing and automatic analysis of SGAM architectures. The methodology was successfully evaluated in the context of DISCERN European research project.

Service level agreement: Coordination and monitoring of actors in Smart Grid

Smooth and reliable operation of the future Smart Grid requires addressing coordination and interoperability issues. In Smart Grid, the coordination of new actors and monitoring of new business processes, such as Active Demand and Electric Vehicles is non-trivial. These new actors and related business processes change the landscape of power grid from traditional passive Demand Side Management of loads to active customers connected in Active Distribution Grid. Smart Grid operations require monitoring and coordination between high-level business requirements and low-level infrastructure affordances. To support such perspectives of the power grid an additional ICT infrastructure supplementing traditional SCADA systems is required. We argue that to enable and validate end-to-end interoperable solutions a new tool is required. In this paper we introduce Service Level Agreement as one such a tool, supporting design and implementation of well-coordinated interoperable information flows and ensuring shared agreed-upon situation awareness among stakeholders. Finally we illustrate our approach in Smart Grid Electric Vehicle systems.

Decentralized topology inference of electrical distribution networks

Power system operation and control relies heavily on models for decision making. Topology is a critical part of producing these models and maintaining up-to-date topologies of electrical distribution networks is a resource consuming and challenging task. This paper proposes a methodology and system architecture for inference of electrical topology using process and model data from IEC 61850 compliant substation automation devices. A system of autonomous intelligent agents communicating via an overlay network is proposed where agents are capable of communicating on the IEC 61850 station bus. An algorithm for topology inference using structured exchange and comparison of process and model information is developed. The capabilities of structured information exchange and interfacing of substation automation devices enables plug-and-play operation of the topology inference requiring minimal prior knowledge of electrical network structure. Decentralized topology inference forms the basis for future work in operation and management of active distribution networks.