Distributed Generation-Based Smart Mini Grid System Using NI CompactRIO and NI LabVIEW

Author(s):

Alekhya Datta - The Energy and Resources Institute (TERI)
Mukesh Gujar - The Energy and Resources Institute (TERI)
Parimita Mohanty - The Energy and Resources Institute (TERI)

To cope with utility changes and challenges, many utility companies in India are planning to implement smart grid technology. An SMG system is a subset of a smart electric grid and is generally defined as an intelligent electricity distribution network operating at or below 11 kV and providing electricity to a community. It is supplied by a diverse range of distributed energy resources (DERs), including small, conventional generators such as diesel generators combined with a range of renewable generators such as microhydro, wind turbine, biomass, and solar photovoltaic. SMGs can either be connected to the conventional utility grid or be isolated and provide electricity to a localized load only. An SMG is an application of digital information and communication technology (ICT) and uses advanced sensing, communication, and control technologies to optimize electrical power generation, delivery, and ultimately its end use within the domain of the microgrids. An SMG provides dynamic communication and balancing of the electrical network, thus minimizing losses and increasing the stability of the grid.

Benefits of an SMG

The benefits of an SMG include the following:

• Fostering demand-side management and demand-side response
• Reducing power outages and increasing the reliability, efficiency, and safety of the grid
• Reducing the carbon footprint and minimizing fossil fuel consumption
• Providing better autonomy to customers to manage their electricity needs

Initiative Taken by TERI on SMG Systems

Under the auspices of the Asia Pacific Partnership program, TERI submitted a proposal to the Ministry of New and Renewable Energy, and the Commonwealth Scientific and Industrial Research Organization submitted a proposal to the Commonwealth of Australia Department of Environment, Water, Heritage and The Arts to obtain funding to develop and demonstrate distributed generation-based SMG systems and control techniques that could be applicable to Indian sites and facilitate the deployment of SMGs in India. To optimize the multiple generating resources and the varying loads to be served, TERI designed and developed the SMG system in one of its research facilities at TERI Retreat in Haryana, India.

Unique Features of the TERI SMG Model

The unique features of the TERI SMG model include the following:

• Integrated multiple DERs to ensure maximum utilization of renewable energy sources
• Performing resource and load profiling, controlling, and forecasting
• Centralized control (intelligent dispatch controller) for resource optimization and demand management
• Initiated load prioritization—total loads were classified into critical, essential, and nonessential loads
• Integrated, high-speed, FPGA-based digital communication using LabVIEW system design software for acquiring data and sending and receiving controls
• Completing real-time data acquisition and monitoring of several electrical, weather, and physical parameters through installed sensors
• Minimizing outages and fast responses to network disturbances through automatic connect/disconnect of system components

The TERI SMG system also integrated the following DERs:

• 10.5 kWP solar photovoltaic (crystalline silicon-based solar module) systems installed on the roof of the north block of the TERI Retreat
• 2 kWP solar photovoltaic (crystalline silicon-based solar module) systems installed on the roof of the Biomass Gasifier building
• 1 kWP thin-film-based solar photovoltaic system on the roof of the south block of the TERI Retreat
• 3.3 kW wind turbine generator (WTG)
• 100 kW biomass gasifier (woody) system in the Biomass Gasifier building
• Battery bank of 48 V, 600 Ah for energy storage
• Diesel generators and a utility grid

The TERI Retreat is a residential, multifacility complex equipped with modern facilities including conference halls, official and residential premises, laboratories, and sports grounds. The electricity demand of the complex varies widely depending on the season, occupancy level of the residential premises, the number of conferences being held, and several other factors.

Developing an Intelligent Smart Dispatch Controller Using CompactRIO and LabVIEW

The heart and main brain behind an SMG system is the smart controller, which was developed using the CompactRIO platform. The NI cRIO-9022 is used along with the NI 9227 current input, NI 9225 analog input, NI 9481 relay, NI 9211 thermocouple input, NI 9205 analog input, and NI 9403 bidirectional digital I/O C Series modules to gather electrical and weather data from various sources and control.

Data Logging Using NI C Series Modules

Table 1. Measurement of Electrical Parameters

Table 2. Measurement of Weather/Physical Parameters

Development of an SMG SCADA System Using the LabVIEW Platform

The Supervisory Control and Data Acquisition (SCADA) system for the SMG was developed using the NI Developer Suite, including the following LabVIEW modules: 

• LabVIEW Datalogging and Supervisory Control (DSC) Module
• LabVIEW Real-Time Module
• LabVIEW FPGA Module
• LabVIEW Electrical Power Suite (EPS)

Communication Between the SCADA System and Smart Controller
A third-party GSM/GPRS SA 1802 C Series module was used as a communication medium between CompactRIO and the SCADA system. The data collected from the various data nodes was transmitted via Ethernet using Modbus protocol and a GSM modem using TCP/IP.

Real-Time Data Acquisition Dashboard for the SMG System

The NI Developer Suite, including the LabVIEW DSC, LabVIEW Real-Time, and LabVIEW FPGA modules, was used to develop the dashboard for the SMG system in which all real-time information such as electrical and weather parameters and daily energy consumption is provided. The dashboard of the SMG system is used to communicate with the SMG SCADA system using Ethernet (Modbus protocol).

Applications of the SMG System

The SMG system can be used in the following areas:

• Industrial and commercial complexes such shopping malls, hotels, and hospitals
• Residential complexes such as apartments and townships
• Educational institutions
• Off-grid rural and periurban locations
• Telecom base stations

Benefits of a System Based on the NI Platform

The SMG system developed using the NI platform is a reliable and consistent solution and is uniquely placed to strengthen the country’s electricity sector by creating a platform to optimally use distributed power while enhancing the performance of rural electricity supply systems. It can be incorporated as part of the government of India’s flagship programmes such as the Jawaharlal Nehru National Solar Mission and Rajiv Gandhi Grameen Vidyutikaran Yojana. The facility was successfully commissioned by Dr. Farooq Abdullah, union minister for new and renewable energy, along with Shri Sushil Kumar Shinde, honorable union minister for power, and Dr. R.K. Pachauri, director general for TERI.

Author Information:

Alekhya Datta
The Energy and Resources Institute (TERI)
Centre for Distributed Generation (CDG),Energy Environment Technology Development (EETD) Division,TERI – The Energy and Resources Institute,Darbari Seth Block, India Habitat Centre (IHC) Complex,Lodhi Road
New Delhi 110 003
India
Tel: +91 11 4150 4900 (Extn: 2146)
alekhya.datta@teri.res.in