Code to crack t&d losses
- 1. 1 Consulting Electrical Engineers Associationof Maharashtra INTRODUCTION Power transmission and distribution (T&D) losses are common across the world. However the problem is most woeful in India as T&D losses accounts for 28 percent of its total output power, counterpart to losses in various other developed countries like it is in the range of 6 to 8 percent in countries like Australia, Europe and United States of America, nearly 4 percent in countries like Japan and Germany. Russia, on the other hand, has reported losses of around 12 percent. Even China has been able to check its T&D losses with just 7 percent loss reported. AT&C losses in India are among the highest in the world. From 19.8 percent in 1992-93, the losses rose to 33.98 percent in 2002. In 2009, average AT&C losses in the country were estimated to be 27.15 percent. In CODE TO CRACK T&D LOSSES IN INDIA southern region, the average AT&C losses were 19.49 percent whereas northern region reported losses at an average of 36.44 percent. AT&C losses fro North- Eastern region are the highest. In 2009-10, losses reports by North Eastern region were 36.44 percent against the national average of 27.15 percent. According to Planning Commission report, the reported Aggregate Transmission and Commercial (AT&C) losses are Rs. 28,853 crore for 20 major states in the X Plan is an underestimate. Actual AT&C losses are estimated to exceed Rs. 40,000 crore. AT&C LOSSES Aggregate Transmission and Commercial (AT&C) losses is compilation of technical and commercial losses. The category of technical losses comprises of energy dissipated in the conductors and equipments used for transmission, transformation, sub- transmission and distribution of power. Among all, the vital and most prominent equipment at each level are transformers, so it can be said that losses taking place in transformers are major contributor towards technical losses. In addition to it other resources of technical losses are improper load management, inadequate reactive compensation. Whereas on the commercial aspects, the major reason of T&D losses are insufficient investment made in the transmission and distribution sector. The investments have been particularly low in sub-transmission and distribution. While the investment is generation has increased steadily, transmission has kept up with it. This led to mismatch in the generation and supporting transmission system. Power theft is one of the major causes of high T&D losses in India. Inefficiency in the power distribution system has led to failure in checking of power theft and leakage continues to plague the sector. According AUTHORS Mr. Kapil Gautam Mr. Deepka Loya Executive Marketing Manager Marketing Skipper Electrical India Limited C-322, 215-Atrium, Chakala, Andheri (E), Mumbai 400 059 Tel.: 022-66972780 Email: kapil.gautam@skipperseil.com deepak.loya@skipperseil.com
- 2. 2 Consulting Electrical Engineers Associationof Maharashtra to the Economic Survey of 2006-07, loss due to theft and pilferage is estimated to be about Rs.20,000 crore annually. Unmetered supply to agricultural pumps and single point connections to small domestic consumers of weaker sections of the society is one of the major reasons for commercial losses. ‘TRANSFORMERS’ IS THE KEY! Whether it’s transmission, sub-transmission or distribution, nothing is feasible without transformation. The key of transformation are transformers. Either its power transformers or distribution transformers, their reliable and continued performance is most desirable. However today transformer fraternity is facing major challenge to maintain the quality. Mostly distribution transformers are being manufactured in unrecognized sector. There could be more than 800 to 900 manufacturers in India but hardly 10 percent could produce transformer of good quality in organized sector. As per the BEEs Gazette Notification 5th January 2010 and CEA’s Notification dated 20th August 2010, it has been mandated that only at least 3 star rated Energy Efficient Distribution Transformers can be manufactures and purchased in India. The effectiveness of energy efficient transformers can analyzed through the “Typical Loss comparison of 63 kVA Distribution Transformer” 63kVA Distribution Transformer Ordinary Conventional Transformer Energy Efficient Transformers 3 Star 5 Star Max. Total Losses at 50 % Loading (watts) 490 380 280 Max. Total Losses at 100 % Loading (watts) 1415 1250 1100 Difference in Power Saving at 100% loading (watts) 1415 – 1250 = 165 (3 Star) 1415 – 1110 = 315 (5 Start) Further the scope for improving the efficiency of distribution transformers can arise in a number of ways. Higher performance raw materials, particularly special steels for building transformer cores are continually being developed. Advancement in the core material, amorphous iron, produced by cooling molten metal alloy very rapidly, has become available and is getting wide acceptance in many utilities in Indian and across the globe. Losses in the core are less than 30% as compared to those of conventional steel cores. The size of transformers being installed in the network, and the way in which they are loaded, can also increase savings. Transformers are at maximum efficiency when approximately 50% loaded. Even though the more-efficient transformer costs more initially, its lower operating cost saves money over its life. Considering the vast potential of energy savings and benefits of energy efficiency, Bureau of Energy Efficiency has come up with reasonable solutions for strengthening and up gradation of the transformers used in the distribution system. Some of the short term and long term measures taken by BEE Bureau of Energy Efficiency operationalized™™ complete pilot phase of programme for energy efficiency in government building and prepare action plan for wider dissemination and implementation. Standards and Labelling (S&L) Programme has™™ been identified as one of the key activities for energy efficiency improvements. The S&L program ensures that only energy efficient equipment would be available for purchasers. Some of the electrical products to be covered under S&L program are: Agricultural pump sets, Distribution Transformers, Motors, Lighting products, refrigerators, etc. Energy – efficiency labels are informative labels fixed to manufactured products, which describe the product’s energy performance (usually in the form of energy use, efficiency, or energy cost) and rate the product on a comparative scale so that consumers can make appropriate decisions while purchasing electrical equipments. Energy-efficiency Standards are procedures and regulations that prescribe minimum efficiency performance standards of the manufactured products.
- 3. 3 Consulting Electrical Engineers Associationof Maharashtra Selection of better material for energy efficient transformer: In selecting the material for core, we say that amorphous metal core outflanks in reducing the no- load losses. This can summate immense economic savings to the electric utilities since they are one of the highest energy efficient transformers rated so far. A typical comparison is shown below which depicts the decrease by installation of energy efficient low loss amorphous metal core transformers. Rating (Three Phase) CRGO (in watts) AMDT (in watts) Reduction in Losses 25 kVA 100 32 68% 50 kVA 160 58 64% 100 kVA 260 85 67% 200 kVA 470 115 75% The above losses are indicative based on some design (Vijai Electricals Ltd). Loss reduction due to non-linear loading (i.e. harmonic distortion): Use of best quality core material like Amorphous Magnetic alloy offers great advantage not only at fundamental frequency but, the advantage increase manifold as the distortion in both load current and supply voltage increases. There is increase in total loss and decrease in efficiency with higher distortions, but this phenomenon is affecting this core material much less as compared to Transformer with poor quality core. A 3 phase, 250 kVA Transformer was tested under non- harmonic and harmonic conditions and the values noted down are as follows: Without Harmonic Distortion Losses AMDT CRGO Hysteresis (A) 99 155 Eddy Current (B) 33 311 Total Core Loss (C) = (A+B) 132 466 Coil Loss (D) 966 1084 Loading 55% 58% Total Loss (C + D) 1098 1550 With Total Harmonic Distortion of 26% Losses AMDT CRGO Hysteresis (A) 99 155 Eddy Current (B) 74 698 Total Core Loss (C) = (A+B) 173 853 Coil Loss (D) 1553 1671 Loading 55% 58% Total Loss (C + D) 1726 2524 Thus, it is very evident from above tables that AMDTs (Amorphous Metal Distribution Transformers) are no doubt superior and offer a better technology at our disposal. Hence,improvingefficiencyofdistributiontransformers is very much in need for our country to balance the demand and supply of electricity in coming years, resulting in huge savings to the utility, by chopping the running cost of the transformer.