Indian DS
recently i have spent some time studying about Indian distribution systems (A paper by m v krishna rao and radha krishna) I came to cognizant of how poor is India in power sector especially the quality of power supply to rural India. India is facing power losses as high as 25% the major contribution to these losses are from distribution system. most of the Indian DS is on low voltage ie 220 AC ph to gn (3 ph 4 wire system)
Reasons for such a heavy losses in DS
they mainly due to heavy loading for feeders and improper reactive power compensation. As India power demand is increasing at a very high rate as 10% every year so it is unable to meet its power requirement as a remedy the rural India is given power based on no of hours for eg: in Andhra Pradesh rural people will get 8 hr of power supply per day because of this there will be heavy loading on the feeders during this time because all the pump sets will be working at this particular 8 hr of time in that region this leads to heavy I 2 R losses. most of the pump sets used for the agriculture purpose r 3ph ac motors generally with low quality this is the main cause for the low power factor on the DS 3ph ac motor is having pf of around 0.5 so this will make a lot of reactive power to swing in the DS which creates lot of power losses and most of the times this is main cause of failures of distribution transformers in rural areas of India. typical DS in rural India is mainly radial type and as the losses r more some time the end user on the particular feeder gets around 7% of the rated supply aftermath there will a loss of his utilities like burning of motors fridges etc. and not the forget the little culprit that is unsymmetrical currents which leads to the flow of current in the neutral wire so extra (I1-I2-I3)*0.5R losses.
Suggestions
As suggested in the paper some of the measures like proper reactive compensation using capacitor banks, placing voltage booster, and network reconfiguration are normally done but the tough job is to effetely placing of these things on a DS that can be decided based on the some calculation considering load flows, demand forecasting and economic factors which essentially requires a very good software (GECE is currently working on this). conversion of existing LVDT to HVDT is inevitable for loss reduction
I feel the work needs to be done more on alternate sources for energy like solar energy for distributed power generation as India has many sunny days expessely peak power demands in summer can be met using this technology. and development of single phase ac motor with good PF should be used for agriculture loads below 5hp loads government should give subsidy on such motors. drip irrigation should be encouraged . and most important is loads management using some distribution management systems software. for avoiding heavy loading and balancing unsymmetrical loads
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finally this year our president commence on to reduce afflicts of Indian power systems read full article here : HINDU NEWS PAPER
NEW DELHI, AUG. 24. Expressing concern over mounting transmission and distribution (T&D) losses in the power sector, the President, A. P. J. Abdul Kalam, today asked the Union Power Ministry to bring down these losses from 31,000 MW to 12,000 MW within the next three years. The President pointed out that in developed countries, the T&D losses were only 12,000 MW, which meant India was losing an additional 19,000 MW, compared to the developed world.
Posted by sandeepeecs 