Integration Smart grids (SGs) are massively dispensed systems having severa heterogeneous components. Information is available all alongside the allotted grid from generation, transmission, distribution and utilization. SGs are motivated to apply this information from diverse part integration of the electricity grid for improving the over-all efficiency, and to enhance – reliability, performance, robustness, and safety. Advanced manipulate techniques that use grid facts are required for realizing SG. Moreover, control implementation needs to be dispensed in various components inside the grid. Currently, the control is centralized and not suitable for SG thinking about distributed entities like DERs, plug-in electric powered vehicles (PEVs) etc. The control desires to be decentralized to bear in mind the numerous distributed entities connected to the grid. Automation supposed for SG ought to additionally assist such decentralized control. This calls for interoperability among numerous devices, controllers and various other components in SG. Standardization is needed for interoperability. The goal of this investigation is to demonstrate the want for integrating requirements IEC 61850 and OPC UA for enforcing MAS primarily based dispensed control in SG.
Integration of IEC 61850 and OPC UA for clever grid automation is a recent research topic and no longer many results are available. It became showed by way of S. Lehnhoff et al., that OPC UA gives an alternative way of verbal exchange following the IEC 61850 version. Further, it has been argued that mapping the AddressSpace of OPC UA with the IEC 61850 data version effects in verbal exchange architecture with many benefits in phrases of safety, interoperability, and internet conversation. The motivation of this research is to show communication mappings between IEC 61850 and OPC UA. However, this research does no longer look at SG control the use of this mapping. N. Higgins et al. , studied the automation of disbursed power systems the usage of IEC 61850 and IEC 61499. V. Vyatkin et al. also proposed to use the IEC 61850 based totally decentralized control for multiagent systems (MAS). But, the usage of information model for deriving open and interoperable MAS has now not been considered. Apostolov  demonstrated the connection among the principles in IEC 61850 and their applications to multi-agent structures for protection, manipulate, tracking, and recording in substations. Further, the use of Substation Configuration Language become analysed as a device that identifies the relationship among distinct additives in a multiagent primarily based substation automation system. However, the usage of IEC 61850 and OPC UA has no longer been presented in the context of MAS. Motivated by way of these studies gaps, this research illustrates the use of OPC UA and IEC 61850 integration for MAS based totally SG manipulate and automation. In particular, we show application to MAS primarily based hierarchical manipulate and fault-monitoring and preventive maintenance. The paper is prepared into five sections along with the introduction. In segment 2, we briefly give the overview of OPC UA and IEC 61850 standards. Section 3 illustrates integration of OPC UA and IEC 61850 inside the context of SG control.
The Open Process Control (OPC) is broadly used in the industries for decades. The OPC foundation has launched contemporary model of OPC called OPC Unified Architecture which mitigates most the problems of the older version of OPC. Some of the troubles are platform dependence, enhanced security version, support for embedded devices etc. OPC-UA presents an answer for exchanging data among gadgets on the plant ground to company application. OPC UA framework is based totally on client-server architecture. The OPC-UA server affords actual-time system facts, surroundings metadata and even non-method information to customers, in a completely unique and platformindependent manner. The OPC UA records version presents a standard manner for the server to show Objects to Clients. Objects in OPC UA phrases are composed of different Objects, Variables and Methods. The set of Objects and related statistics OPC UA server referred as AddressSpace and, it includes Nodes and References. The predominant position of the Nodes is to expose the underlying technique nation as a selected, well-described piece of information. Nodes are divided into classes. The price of Value Attribute ought to be bound with a actual statistics source, e.G an analog sign to represent real time method kingdom. On the opposite side, the Method magnificence represents features which could be known as via the clients related to the server. The actual-time technique bindings are responsible for conveying the Parameters cutting-edge values, invoking the represented feature and returning the execution result. These instructions are the primary constructing blocks of the server that need to be coupled with the contemporary kingdom and behavior of underlying technique. Thus, to preserve this coupling, there need to be mounted a connection to bodily plant ground devices that needs to transfer real time technique information.
The another important capabilities of OPC UA server is it’s Security Model. The OPC UA safety is designed for authentication of Clients and Servers and the authentication of the users, transaction integrity and confidentiality. The OPC-UA safety model is quite bendy to configure security desires for a given installation. The OPC-UA framework additionally has minimum set of safety profiles that every one UA servers ought to help. The software level security is based on a secure communique channel which is active for duration of utility consultation and insures the integrity of message exchange.
IEC 61850 AND OPC UA INTEGRATION FOR MAS IMPLEMENTATION
First, we take into account the implementation of open MAS having an agent verbal exchange language following IEC 61850 and OPC UA for interoperability among devices of various vendors. We then use the MAS framework to look at the trouble of hierarchical manage. Finally, we present the use of standardization and integration inside the context of faultdiagnosis and preventive maintenance. This research proposes a layered architecture for substation automation as proven in Figure 1. A similar layered architecture has been proposed in  for understanding manipulate and optimization functionalities in SGs. The substation unit IEC 61850 defines the communique and information model on this layer. The physical layer has controllers and different devices like the IEDs (Intelligent Electronic Devices) and it employs area level conversation standards. The interface among the bay manage, subject devices and field gadgets makes use of IEC 61850 standard, whereas the agent framework interacts with the manipulate the use of OPC UA.
Enabling Implementation of Multi-agent structures based totally Control Design Using IEC 61850 and OPC UA integration
Sophisticated controllers using grid records in control are required for SGs, thereby making manipulate layout more complex. Further, manipulate desires to be autonomous, flexible, and scalable for handling numerous SG additives. Further, these components are conceptually specific and heterogeneous as well. Control design calls for a version of SG components along their interactions. Further, they also ought to version dynamic sellers like distributed electricity resources (DERs), and plug-in electric vehicles (PEVs) need to model getting into and leaving the grid based totally on positive gird conditions. Seeing the capability of MAS in modeling and control of SG, the IEEE energy engineering society (PES) created a workgroup (WG) on multi-agent systems (MAS) , and 3 remits were identified to recognise MAS based SG, they are: (i) identify the drivers and advantages of SG, (ii) identify the challenges in implementing MAS for SG, and (iii) offer leadership and guidance by way of supplying standards, and layout methodologies
In order to enforce the hierarchical control, we bear in mind the trouble of heating, ventilation and air-conditioning (HVAC) structures in client premises. Each patron inside the premises may be modeled to be an agent with – related behavior, methods, variables, and conversation protocol for records change amongst sellers. Consumer agent can be similarly categorized as – residential, commercial, small industry, medium industry, heavy industry, critical and noncritical etc. One may additionally visualize that each one these dealers are inherited from the patron agent class.
Considering the manipulate structure proven in following figure, one may verify that the centralized controller is the bay controller and the nearby controller is inside the physical layer. Information change between physical layer and the bay manage layer is the use of OPC UA, and that within the substation layer, and bay manipulate layer is the use of IEC 61850 data models. In order to put into effect the hierarchical manipulate hassle the use of MAS framework, we endorse the architecture in following figure.
The agent coordination layer carries the templates of marketers in SG. The 2nd layer is the software layer which incorporates the software sellers with ACL that helps interoperable facts-models. These dealers have interfaces to consumer premises the use of OPC UA. It also instantiates the ontology agent for mapping OPC UA to IEC 61850, and sends the field level statistics to the substation level the use of the ontology agent. Now, the climate and cargo flow statistics at the substation layer is transmitted from substation and bay manage layer using IEC 61850 records models. On the alternative hand agent framework interacts the usage of OPC UA with the distributed manipulate. The ontology agent placed inside the software program layer is then used to map between OPC UA and IEC 61850 information model. The proposed hierarchical manipulate structure is enabled via the integration of OPC UA and IEC.
FAULT DIAGNOSIS AND PREVENTIVE MAINTENANCE
Over the closing years, the importance of substation automation is realized and well time-honored worldwide. Most of the analogue gadgets including relays are being replaced by using digital gadgets. It increases control, protection, monitoring and communication skills of entire substation gadget. Monitoring and preventive maintenance are the key for preventing breakdown and preventing faults. In standard there may be two possibilities in which fault can occur. The first might be real prevalence of event, and second might be fake events sign generated through IEDs. In both these instances minor to major impact can occur on substation system. To decrease such situation, the ”Monitoring and Predictive Maintenance” application can provide effective solution. For an example, inside the case of CB, the internal condition of device can be recognized and predicted by measuring time to make and spoil contact, basic energy meter measurements, metering statistics, harmonics/inter-harmonics measurements etc. For the predictive maintenance application, the principle requirement is access of present and history facts of tool. In Figure 4, the substation physical device can be mapped to virtual physical tool as in keeping with IEC 61850-five and IEC 61850- 7-four standard.