Difference between AC & DC
Single Phase AC
Three Phase AC
Resistance, Reactance and Impedance
Facets of Energy
Sources of Generation
Generation of Electricity
Constructional Features of PT
Net & Gross Metering
Fuse Wire Table
Size of Earth lead
Size of Earth lead
Station Battery Maintainence
Calculation of VR
11KV UG cable VR
Calculation of Power loss and VR
Basic checks of Relays
BEE Star Labels
Financial health of SEBs – a matter of grave concern
Losses- Rs. 50,000 crores= 1.5% of GDP
55% of energy billed; 41% realized
ATC losses= 45-50%
Find out: where is the leakage, wastage or inefficient use
T & D Losses:
T&D losses in India-among the highest in the world:35-45%
Due inadequate investments over the years for system improvement works
Unplanned extension of distribution lines
Overloading of lines and transformers
Lack of adequate reactive power
As the T&D loss was not able to capture all the losses in the network, concept of Aggregate Technical and Commercial loss was introduced
It captures technical as well as commercial loss in a system
It is a true indicator of total losses in the system
Mainly due to Low metering Efficiency, Theft and Pilferage.
Improving meter efficiency
Proper energy accounting and auditing
Improving billing and collection efficiency
Fixing of accountability on the employees
Energy Audit: Definition
The verification, monitoring and analysis of use of energy including submission of technical report containing recommendation for improving energy efficiency with cost benefit analysis and an action plan to reduce energy consumption
Steps involved in Energy Audit
Network Documentation: an activity that covers network survey in the field and documentation of the surveyed network in software
Consumer Indexing: an activity to identify location of consumers in a distribution network and identifying their source of supply
Network Documentation: Survey
The survey starts from the MUSS where from 11 kV lines emanate. It covers:
Tracing the HT lines
Noting the conductor used
Noting the HT poles and type of poles
Noting the location and capacity of Transformers
Tracing the LT lines
Noting the conductor used and the wire configuration of the LT lines
Noting the LT Poles and type of poles
Noting the number of consumers (service cables) connected to each pole, with approximate service cable size and length
Codifying/numbering the poles
Once a survey is carried out, it is necessary to document the survey findings in a suitable software
Method or process for field survey :
Field surveys are generally carried out by low skill manpower and there is need to have a system in place survey efforts are not duplicated, all areas covered, quality checked.
It is advisable start with a map of the area where a network survey is needed.
Satellite based maps is very useful.
Steps in a survey :
Digitize the map. Assign different layers for roads and buildings. .
Indicate the scale in the map.
Mark useful and important landmarks.
Survey team then marks poles, transformers, lines, distance between poles, consumers.
Type of poles, configuration of wires, capacity of transformer are noted.
Many carry walk through surveys.
This is error prone because of jumble of wires and underground of cables.
In some cases, the power supply is switched off to find out which house has gone dark so that consumers can be identified
Keep consumer identification updated regularly
Energy Accounting & Audit:
Energy Accounting is a statement of energy input, output and loss for a system for a specified period of time.
Energy Audit is the segregation of the total loss as found from energy accounting into the technical and commercial loss components.
Difficulties in Energy Accounting:
Consumer end meter readings are taken on staggered dates.
Many houses are locked, meters are faulty leading to provisional billing.
Consumers are disconnected mid-way during a month.
New connections are given any time in a month.
There is change in electrical configuration and some consumers may be supplied power from different feeders during a month.
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