13 December 2016

New Delhi Railway Station Get A Digital Substation

Ministry of Railways in partnership with United Nations Development Programme (UNDP) is promoting energy efficiency in the Indian railways. The partnership has taken numerous steps to reduce greenhouse gas emissions. Towards this end UNDP has funded a pilot project for implementing Supervisory Control and Data Acquisition (SCADA) System at New Delhi Railway station (NDLS).
Delhi Division of Northern Railway is one of the premier divisions of Indian railways. It maintains power supply at 218 electrified stations, staff quarters, hospitals, LT supply over 600 places and 11 KV HT supply at 89 places. Continuous and manual monitoring of these power supply installations is a challenge in view of the scarcity of the staff. All 11KV substations are manually monitored and many are even unmanned. Any failure of Power used to take a lot of time to report, followed by long time to identify the problem and longer time to rectify the same.
To address such situations SCADA was installed on Pilot basis at NDLS for monitoring of breaker Status of each 11KV panel, energy parameters for both 11KV and 415V LT feeder Panels / Distribution Boxes and centralized monitoring and control of the Power Supply Network.
Major challenge was ensuring compatibility of SCADA with existing architecture and adaptability of proposed SCADA architecture for future expansion.
After considering every aspect in detail a tender was floated and the work was awarded to M/s SYNERGY Systems & Solution at a cost of Rs.91.04 Lac in which 9 locations of New Delhi railway station were covered for proposed implementation.
SCADA system consists of dual redundant hot-standby SCADA server-cum-operator workstations. The connectivity with the substations is achieved through GPRS-based communication and various computers and the communication gateway were connected with each other over LAN as shown below

At each substation, a Remote Terminal Unit (RTU) was installed to interface with the local switchgear which consists of a Power Supply Unit, a CPU, I/O Cards and GPRS modem module to be interfaced with the local switchgear as well as Intelligent Electronic Devices (IEDs) present in the substation. A battery-backed power pack was also provided inside the RTU so that it can remain alive during total-blackout scenario. Under this project, old Voltage circuit breakers (VCB) were replaced with latest VCB panels in accordance to Research Designs and Standards Organization (RDSO) specifications. These VCB panels provided metering as well protection functions. Monitoring was done in such a way that the complete Power Network was connected to the SCADA server and all relevant values were displayed on user-friendly graphics for supervisor’s convenience. The Servers also helped the supervisors with intelligent output by flashing alarm messages from unwanted happenings such as tripping, low voltage, phase imbalance etc. It also monitors the health of all the SCADA equipment such as computers, RTU electronics, communication channels etc. Therefore any failure in SCADA elements is also notified to the supervisor.

After successful installation of the system, power restoration of the whole system improved to a great extent and hence it was possible to operate the circuit breakers remotely in case of failure. In addition oil temperature as well winding temperature of transformers was also monitored by installing relays and connecting it to local RTU for transfer to SCADA and above all metering of incoming supply from BSES and 11kV incoming/outgoing feeder was provided using Class 0.5 Multi-function Meters (MFM) hence energy consumption and load profiles of various consumers on the platforms, like refreshment stalls, lighting and ventilation, etc. was very easily monitored.
SCADA system at NDLS provided following benefits:
Increased Efficiency of operations:
      o Increased efficiency of Power Operations
      o Lesser deployment of power due to centralized monitoring & Control
       o Better response time to any outage.
Better energy Management:
       o Identification of major sources of power consumption and targeting these for load reduction
       o Identify losses and take action
       o Reports for Analysis
        o Maximum Demand Monitoring & Regulation

After doing cost benefit analysis of the project it was found that payback could be achieved after 1.8 years which takes into consideration saving on manpower, reduced damage to the equipment, reduced outage and saving of man days for preparing reports. Further analysis and working on SCADA established that if reporting feature can be fine-tuned to suit requirements of various agencies and provision of important alarms messages system to be sent on mobiles of personnel responsible is introduced along with extension of reach to cover LT feeders, substations  and also facilities which are currently not included into the system, such as pumps/AC plants/street lights etc. ,this system can bring fruitful results both on financial front in terms of savings of Rs.69,40,000 annually and environmental front in terms of CO2 reduction.
It can be said that SCADA system provides a strong base for enhancing the monitoring and controlling capabilities while protecting Railways investment in the currently bought equipments. So Replications of this effort is possible in future as well in the form of integration of further substations and Covering other cities as well. While some suitable locations that are identified in Delhi division are Hazrat Nizamudin, Delhi, Ghaziabad, Tughlakabad railway stations where multiple HT supply/Sub-station are being maintained.