- Smart Grid - Home
- Smart Grid Introduction
- What is an Electric Grid?
- Electric Grid Evolution
- What is a Smart Grid?
- Smart Grid - Functions
- Smart Grid - Characteristics
- Smart Grid - Advantages
- Smart Grid - Components
- Smart Grid - Challenges
- Smart Grid Technologies
- Smart Energy Resources
- Power System Automation
- Smart Substations
- Substation Automation
- Smart Grid - Feeder Automation
- Energy Management System
- Smart Grid - FACTS
- HVDC Transmission
- Wide Area Monitoring
- SCADA in Smart Grid
- Smart Grid - DMS
- Smart Grid - OMS
- Volt/VAR Control
- Smart Grid - FMSR
- Smart Grid - HEDT
- Phase Shifting Transformers
- Smart Grid - PHEV
- Advanced Metering Infrastructure
- Smart Meters - Introduction
- Smart Meters - AMI
- Smart Meters - AMIS
- Communication Architecture
- Drivers & Benefits
- Phasor Measurement Unit
- Intelligent Electronic Devices
- Power Quality Management
- Power Quality in Smart Grid
- Power Quality Issues
- Power Quality Monitoring Techniques
- Power Quality Conditioners
- Electromagnetic Compatibility (EMC)
- Power Quality Audit
- Smart Grid Communication
- Smart Grid Communication
- Communication Network
- Communication Technologies
- Broadband Over Power Line
- Internet Protocols
- Web Services in Smart Grid
- Cloud Computing
- Multi Agent System Technology
- IP Based Protocols
- Cyber Security
Web Services in Smart Grid
A web service is nothing but a communication method that used in smart grids to connect two or more smart devices over a network. In web service, the devices communicate through a software using a particular network address over the web.
This communication method helps in creating a more efficient and reliable smart grid system. In smart grids, the web services enable seamless communication and information exchange across the smart grid and it allows different components of the smart grid to communicate and operate in a coordinated manner. It also provides a standardized way of integrating web-based applications into the smart grid communication.
What is a Web Service?
A web service is a communication method used for connecting two or more electronic devices over a network. According to World Wide Web Consortium (W3C), a web service is defined as a software system designed to support interoperable machine to machine interaction over the internet.
In this architecture, the software system that requests for data and information is known as service client or service requester, while the system that processes the request and provide the data and information is known as server or service provider.
In smart grid technology, web services are used to provide communication link between various devices, systems, and applications, so that they can exchange data with each other. This whole communication takes place over the internet or any other network provided in the smart grid communication infrastructure.
The primary aim of using web services in smart grid is to connect different components like smart meters, sensors, automation and control systems, etc. to interact seamlessly.
Components of Web Service
In smart grids, a web service consists of several important components to provide communication facility and exchange of information over a network. The following are the key components of a web service −
- Service Provider − It is a software system in the web service architecture that processes requests and provides requested data and information. In a smart grid system, it can be a smart meter, sensor, or any other device that can provide information.
- Service Requester − It is the software system in the web service architecture that requests data and information from the service provider. In smart grids, it can be a grid monitoring system, energy management system, or any other system that requests data from other devices.
- Service Registry − It is like a directory where the service providers list their services and the service requesters use it to discover these services. It simplifies the searching and communication processes for smart grid components. In smart grids, UDDI (Universal Description, Discovery, and Integration) standard is commonly used for maintaining the service registry.
- Service Description − This component of web service provides details about the operations, data formats, and communication protocols provided and used in the web service. The service description is written in a machine-readable format by using a web service description language (WSDL).
- Communication Protocols − These are the sets of rules and regulations for data exchange between service provider and the service requester. The common protocols used in web services employed in smart grids are SOAP (Simple Object Access Protocol) and REST (Representational State Transfer). These protocols provide guidelines about how messages are formatted and transmitted over the communication networks.
Working Steps of a Web Service
We can understand the operation of a web service in smart grids by breaking it down into the following steps −
Step 1: Searching for a Service
The operation of a web service starts with the service requester searching for a desired service. In this process, the service requester queries the service registry to find a most suitable service provider that can provide the desired service.
Step 2: Service Request
Once the desired service is discovered, the service requester sends a request to its service provider. The request is appropriately formatted as per the SOAP or REST protocols.
Step 3: Service Response
After processing the service request, the service provider returns a suitable response that could be a piece of data or information like data on energy usages or execution of an action like regulating the output of a generating plant.
Step 4: Exchange of Data
During this whole process, exchange of data takes place between service provider and the service requester. This transaction occurs in a standard format like XML or JSON.
Step 5: Service Termination or Repetition
Once the response is received and processed by the service requester, the web service is terminated or repeated depending on the requirements.
This is how a web service works in a smart grid communication system.
Web Service Protocol Library
Protocols are the backbone of any web service communication as they define how data has to be exchanged over a network successfully and securely.
The web service protocol library used in smart grids includes the following important protocols −
Simple Object Access Protocol (SOAP)
SOAP is used in smart grid web services for exchanging structured information. It uses XML (Extensible Markup Language) for message formatting and uses HTTP (Hypertext Transfer Protocol) or SMTP (Simple Main Transfer Protocol) for operation. SOAP is best suited for complex communication processes in smart grid systems because it supports various robust security standards.
Representational State Transfer (REST)
This web service protocol uses HTTP requests to perform Create, Read, Update, and Delete (CRUD) operations in a web service. In smart grids, this protocol is used to perform less complex and lightweight communication tasks like requesting for sensor data, control setting updating, etc.
Web Services Description Language (WSDL)
It is an XML-based language used for writing service descriptions like operations offered, protocols used, data type formats, etc. for web services. It is an essential protocol in smart grid web services for seamless exchange of information. It allows smart grid components to understand how to interact with other components during a web service.
Universal Description, Discovery, and Integration (UDDI)
It is a framework in a web service that provides services like describing, discovering, and integrating web services. It acts like a directory for web services where service providers can list their services while the service requesters can discover these services. In smart grid web services, UDDI helps in effectively managing different services provided by various components and systems.
Extensible Markup Language (XML)
XML is a markup language similar to HTML (Hypertext Markup Language). It is used in web services for encoding information in a machine-readable format. Its primary purpose is to ensure data exchange over the world wide web.
Web Service Architecture
In a smart grid system, the web service architecture is built-up of the following four main layers −
- Service Transport Layer − This layer is responsible for transportation of message between applications. This layer mainly uses HTTP, SMTP, and FTP protocols.
- XML Messaging Layer − This layer is responsible for encoding message in XML format so that the service requester can understand it. This layer uses XML, RPC, and SOAP protocols.
- Service Description Layer − This web service layer is responsible for describing public interface to a specific web service. It uses WSDL for this purpose.
- Service Discovery Layer − This layer takes care of centralization of different web services into a common registry and providing service discovery through UDDI.
Conclusion
Web services are communication methods used in smart grids for exchanging data between two or more electronic components or systems Web services play a vital role in developing a reliable, efficient, and sustainable electricity delivery system.
Web services use standard communication protocols and data formats to provide seamless communication and information exchange among various devices and systems in a smart grid.