ECONOMIC IMPACT OF POOR POWER QUALITY IN VARIOUS INDUSTRIAL SECTORS IN INDIA

Transcription

1 ECONOMIC IMPACT OF POOR POWER QUALITY IN VARIOUS INDUSTRIAL SECTORS IN INDIA A report prepared by Prof.G.Bhuvaneswari and Prof.Bhim Singh INDIAN INSTITUTE OF TECHNOLOGY DELHI Under ASIA POWER QUALITY INITIATIVE (APQI) FUNDED BY INTERNATIONAL COPPER PROMOTION COUNCIL OF INDIA October 2011 Asia Power Quality Initiative India Survey Page 1

2 ABSTRACT This report brings out the findings of power quality survey conducted in various industrial sectors in India. To capture the impact of power quality problems on Indian industries, a survey questionnaire was prepared and sent to different industrial sectors which are electricity intensive such as Textile, Chemical and Fertilizers, IT sector, Iron and steel, Paper and pulp, Metallurgy, Manufacturing sector for electronic goods, universities/ institutions, Commercial sectors such as banks, hospitals and shopping malls. The data from the filled questionnaire has been compiled to obtain a snap-shot of what the industries face in terms of power quality problems. The exact quantification of economic problem is yet to be done. It is found form the responses obtained from the industries that many of them are still not aware of most of the power quality problems and do not have a way to quantify them. It is very clear that an awareness has to be created among the industries about the importance of power quality. For this, academicians, industrialists, consumers, utilities and regulatory bodies should come together and have several thorough brainstorming sessions. Finally, power quality standards have to be formulated by BIS and SERC for the manufacturers and utilities respectively. This will create a healthy and reliable power grid and utility in our country enhancing productivity and GDP growth. Asia Power Quality Initiative India Survey Page 2

3 I. INTRODUCTION Power Quality is a measure of how ideal a power supply system is. It looks into the voltage magnitude, frequency and wave shape. It takes into account all possible situations in which the waveforms of the supply voltage or load current deviate from the sinusoidal waveform at rated frequency with amplitude corresponding to the rated rms value for all three phases in a three-phase system. Power quality disturbance covers sudden short duration deviation, impulsive and oscillatory transients, voltage dips (or sags), short interruptions, as well as steady state deviations such as harmonics and flicker etc. In addition, the energy supplied to the customer must be uninterrupted from the reliability point of view. It is an important issue for electricity consumers at all levels of usage, particularly industries including service sector (especially IT/ITES and Health sector). It is a matter of concern especially when the interruption of grid supply occurs in a plant resulting in downtime. With the extensive application of sensitive power electronic s and non-linear loads in our industrial and commercial/domestic sectors, various problems like power surges/sags, poor voltage and frequency regulation, harmonics, switching transients, electrical noise and EMI effects are frequently encountered which leads to poor power quality. This results in damage of capitalintensive appliances, safety concerns, loss of reliability and above all a huge economic loss. Consequent to the enactment of Indian Electricity Act (EA) 2003, the Power Quality issue is becoming a priority among power supply utilities, and the regulatory bodies are expected to enforce Quality of Service regulations. Increase in industrial automation and importance of productivity in a competitive global market have driven PQ awareness so much that it has become a global issue now. Industry needs to gear up for a better understanding of this issue and adopt a long term approach on mitigating the same. In more than one sense, power quality problem is a financial problem, and not only a technical problem. Recent survey ( ) in Europe, by Leonardo Power Quality Initiative (LPQI) indicated an annual loss of more than 150 billion.the cost of wastage caused by poor power quality for EU-25 according to this analysis exceeds 150bn. Loss in industries accounts for over 90% of this wastage. Losses accounted for by the service sector are relatively smaller. European survey also brings out that in 30% cases PQ problems have external causes but in 70% cases the problem lies within the facility. If an establishment is well prepared for handling power quality problems right from its conception stage, it will cut down on huge losses related to power quality problems. Some of these upgrades related to PQ could cost about 1% of the building value in most of the establishments. Cost of the cure is <10% of the cost of the problem (2007 PQ survey). Earlier in the USA, the Electric Power Research Institute s (EPRI s) Consortium for Electric Infrastructure to Support a Digital Society (CEIDS) commissioned a study in the year Three sectors of the US economy like (a) Digital Economy, (b) Continuous Process Manufacturing and (c) Fabrication and essential services are found to Asia Power Quality Initiative India Survey Page 3

4 be particularly sensitive to power disturbances. At that time these three sectors accounted for approximately 40% of GDP. The study revealed that across all business sectors the US economy is losing between $104 billion and $164 billion a year due to outages and another $15 to 24 billion due to PQ phenomena. Unfortunately there is no such benchmark survey in the Indian electricity sector that can drive some policy initiatives as has been done in Europe or in the US. In the absence of any mandatory EMC directive, like in EU (EMC Directive 2004/108/EC), in our country today there is no thrust by designers on considering system performance requirements from power quality perspective. Similarly, recently (2008) British Standard BS 7671 (requirements for electrical installations) is revamped to align with the latest PQ requirements. In the project undertaken currently, which is called ASIA POWER QUALITY INITIATIVE, some efforts have been put in this direction in India. First, the existing power quality standards in Europe and the US have been surveyed; simultaneously any power quality related regulations available in India have been studied. From these, it is examined whether these standards can be adopted or new standards can be formulated for our power sector. Similar efforts are going on in other countries in Asia like Singapore, Malaysia, China, Thailand and Hongkong. Secondly, a questionnaire regarding major PQ related problems is prepared and sent to various industrial sectors like paper and pulp, textiles, IT sector, aviation, medical and health care sector and other process industries to assess the adverse impact power quality deviations on their performance and production. The responses from these industries are compiled to estimate the impact of major power quality problems so that these problems are brought to light and can be solved. II. NEED OF SURVEY Industry requires Standards and/or Guidelines to observe and follow norms in handling effectively such issues of concern. In India, essentially IEEE standards are referred as guidelines in electricity sector. In manufacturing sector normally IEC standards are being referred to. Bureau of Indian Standards (BIS) is facilitating to bring in such standards to compliment global effort in Harmonization of Standards. In the Transmission Grid level CEA/CBIP and CIGRE have been playing a vital role in setting up standards. As for distribution sector utility and its consumers, observations of State Electricity Regulatory Commission (SERC) Norms are mandated under the provisions of the EA But many a times in absence of updated and relevant inputs while formulating Supply Code or Standards of performance regulations, SERCs follow the provisions of IE Rules, many of which have possibly lost their relevance in increasingly digitized economy. Asia Power Quality Initiative India Survey Page 4

5 The manufacturing sectors and utilities in India follow different norms for power quality (if they follow any). It is necessary to formulate uniform regulations and norms related to power quality in general. Other countries within Asia like Singapore, Malaysia, Thailand and China face similar problems and challenges. A survey regarding standards and PQ related problems in various countries could help us in benchmarking and facilitating national effort in formulating standards and regulations. It is also needed to understand the present situation of power quality in the main industrial sectors and also to get some knowledge about the loss caused by PQ related problems. III. MAIN POWER QUALITY PROBLEMS The power quality standards vary between countries. In India, most of the industries are facing power quality problems which lead to reduction in productivity causing economical and technical losses. The main power quality problems are voltage interruption (complete loss of electric voltage), Voltage sag (reduction in the rms voltage in the range of 0.1 to 0.9 p.u. for duration greater than half a mains cycle and less than 1 minute), voltage swell ( increase in the RMS voltage in the range of 1.1 to 1.8 p.u. for duration greater than half a main cycle and less than 1 minute), voltage flicker (waveform amplitude is modulated at frequencies less than 25 Hz), harmonics ( periodic sinusoidal distortions of the supply voltage or load current), notch ( periodic transient that rides on the supply voltage), Outage (interruption that has duration lasting in excess of one minute), frequency deviation (variation in frequency from the nominal supply frequency above/below a predetermined level, normally +0.1%) etc. The notches can damage capacitive components connected in shunt due to high rate of voltage rise during the notches. Voltage dips results in machine/process downtime whereas transients result in tripping, component failure, hardware reboot required and poor product quality. Unwanted harmonic currents flowing through the distribution network can causes needless losses which can cause an additional 300Hz to 2500Hz signal added to distribution lines. This will also produce acoustic noise in power. Voltage flickers can be caused by arc discharge lamps, arc furnaces, starting of large motors, arc welding machines etc. The voltage flicker can have adverse effects on human health as the high frequency flickering of light bulbs, fluorescent tubes or television screen can cause strain on the eyes resulting in headaches or migraines and also reduce the life span of electronic, lamps etc. In commercial facilities, computers, lighting, and electronic office generate harmonic distortion, malfunction of ripple control or traffic control systems, losses and heating in transformers, electromagnetic interference (EMI) and interference with the communication systems. In industrial facilities, adjustable-speed drives and other power electronic loads can generate significant amounts of harmonics. We can therefore conclude that the lack of standard quality power can cause loss of production, damage of or appliances or can even be detrimental to human health. It is therefore imperative that a high standard of power Asia Power Quality Initiative India Survey Page 5

6 quality is maintained. This can be summarized as maintaining sinusoidal 50 Hz current and voltage of specified root mean square (rms) value. IV. METHODOLOGY Power quality survey has been done to collect information from various industrial sectors to get an estimate of the damage caused by PQ related problems. Desktop based literature survey and web based research with industry (particularly identified industries which are severely affected by poor PQ), discussions with consultants and research organizations, interview/ interaction based inputs on current practices followed in industries have been the various ways of collecting information about PQ problems. Queries related to these problems are combined in the form of questionnaire. This questionnaire is sent to various industries like paper and pulp, textiles, IT sector, aviation, medical and health care sector and other process industries to estimate the adverse impact of power quality deviations on the performance and production. The survey results are mainly categorized into various parts like name of the industry, sector, total energy consumption, incoming voltage level, used in the industries, power quality related problems such as voltage dips, short interruptions, long term power interruption and voltage waveform quality, harmonics, flicker, unbalance and neutral voltage and current. The resulting problems like failure of and loss of data have also been recorded in the survey. The responses from the industries are collected and compiled to excavate the major power quality problems so that an awareness can be created among the consumers, utilities and the regulatory bodies about the PQ related problems and the remedial measures. This will also enable us to make an effort to formulate the standards that are properly adapted for our country. V. STATISTICS OF VARIOUS INDUSTRIES Responses from the different industries related to power quality problems are obtained. From these responses, it is clear that the smaller industries mostly suffer from long term interruptions (1-20 hrs in a week) and also from short term interruptions. Other manufacturing sectors that are big such as iron and steel, cement and heavy electricals, have back-up power generation that they do not suffer from long and short term interruptions. The neutral current is observed is less than 1 A. The voltage harmonics is around 3%. Many of them suffer from capacitor bank failure and loss of data. Paper and pulp industry suffers from long and short term power interruptions that result in product defect. The neutral current observed in these industries is between 2-25A. They mainly suffer from capacitor bank failure, screen freeze, motors and drives malfunctioning, shocks due to neutral voltage. IT sector suffers from short term power interruption (5-10 minutes) and long term power interruption (3-4 hours) and neutral current observed is around 10A. The IT sector mainly suffers from capacitor bank failure, computer screen Asia Power Quality Initiative India Survey Page 6

7 freeze, damage of electronic and flickering of lights. Chemical industries also suffer from the short and long term power interruptions. The neutral current is around A which is very large. The current harmonic is 2-12% and voltage is 4-10%. They mainly suffer from loss of data, damage of electrical, flickering of lights (during voltage dips) and noise in telecom lines. Textiles industries suffer from large neutral currents (1-100A) and the current harmonics is around % and voltage harmonics are 2-15%. They mainly suffer from loss of data and computer screen freeze, flickering of lights, noise in telecom lines (in rainy season). Power generation industries suffer from very large neutral current (10-400A). They mainly suffers from capacitor bank failure, circuit breaker, computer screen freeze, loss of data, damage of electronic, flickering of lights, noise in telecom lines, overheating of motors, noise in electrical machines, loss of synchronism of and negative sequence current that causes rotor overheating. Hospitals suffer from mainly capacitor bank failure. They have not observed the current and voltage harmonics. Oil and petroleum industries are having noise in telecom lines, relay nuisance tripping and flickering of lights. They observed current and voltage harmonics both less than 5%. Manufacturing sectors of heavy electrical have seen capacitor bank failure, computer screen freeze, overheating of motors and overheating of cables and transformers (750KVA cable overheated). Food processing mainly suffers from capacitor bank failure and circuit breaker. Metallurgy industries suffer from short term power and long term power interruptions and flickers. A large neutral current of is observed. They suffer from Motor-drives malfunctioning, dimming of lights, CB/relay nuisance tripping, computer screen freeze, overheating of cables and motors, capacitor bank failure etc. Some electronic gets damaged. So from the discussion, it is very clear that almost all the industrial sectors are adversely affected by PQ related problems in one way or the other. VI. CONCLUSIONS The power quality survey has brought out one conclusion very clearly and loudly. Almost all the industries suffer due to various power quality problems. In fact, many of the industries are not even aware of various PQ problems like harmonics, flickers etc. They do not possess also to measure these aberrations in power quality. It is a must to educate and create awareness among industries regarding power quality. This calls for BIS taking a firm and bold step to introduce power quality standards for the manufacturers to adhere to and SERC to evolve power quality criteria to be followed by the utilities which will be formulated according to our country s requirements. For this, academicians, industrialists, consumers, utilities and regulatory bodies should come together and have several thorough brainstorming sessions. This will create a healthy and reliable power grid and utility in our country enhancing productivity and GDP growth. Asia Power Quality Initiative India Survey Page 7

8 TABLE: PQ Responses S.N o Industry 1. Iron & Steel 110 kv/33k 2. Paper And Pulp 3. Manufacturin g Sector of Electronics Goods Incomin Equipments used g Voltage V/11KV /6.6KV/ 415V (3- phase)/2 40V (single phase) 11 kv/33k V/110K V/132K V 11 kv/415 V (3 phase) Power Flicke Neutr Harmonics PQ Problems Interruptio r al I(%) V n(weekly) (week Curre (%) Long Short ly) nt UPS, capacitor banks, <1A - 3 capacitor bank failure telecom, and loss of data. security and access control systems, CFL, electronic Ballasts, reactors in filters, variable speed drives and other static converters, arc furnace and welding variable speed drives, UPS, capacitor banks, telecom, relay and CBs, UPS, welding, electronic appliances and security and access control system A- 25A UPS, capacitor banks, Rando20Am 1.5- networking and m p- -10 telecom, 400A security and access mp control systems, CFL and electronic Ballasts capacitor bank failure, screen freeze, motors and drives malfunctioning, shocks due to neutral voltage 2-3 Flickering of light electronic appliances like computers and CCTVs 4. Manufacturin 6.6KV/4 UPS, capacitor banks, capacitor bank failure g Sector of 15V (3-telecom, (rectified), circuit Heavy phase)/2 security and access breaker, computer Electricals 40V control systems, CFL, screen freeze, (single electronic Ballasts, overheating of motors, phase) variable speed drives overheating of cables and other static and transformers converters and welding (750KVA cable overheated) Asia Power Quality Initiative India Survey Page 8

9 5. IT Sector 11KV/415 UPS, capacitor banks, One is -<10A 5 3 capacitor bank V (threenetworking and telecom facing failure, computer phase) and, CFL, contin screen freeze, 240V electronic Ballasts, relay uousl damage of electronic (single and CBs, variable speed y and phase) drives and other static converters, CCTV during night flickering of lights 6. Chemicals 132 kv/66variable speed drives Loss of data, / KV/220 and other static A damaging of Fertilizers KV/11KV/ converters, UPS, electrical, 22 KV (3-capacitor banks, telecom flickering of lights phase)/240, CCTV, (during voltage V (singlereactors in filters, dips), noise in phase) welding units, security telecom lines and access control system and relays & CBs 7. Food 11/33KV UPS, capacitor banks, Capacitor bank Processing CFL, electronic Ballasts, 5-3 relay and CBs, welding, variable speed drives and other static converters, CCTV 10% failure, circuit breaker., reactors in filters, security and access control systems; some use CFL and electronic Ballasts 8. Textiles 33KV/11 variable speed drives, KV/ 66 kvups, capacitor banks, A (3- telecom, phase)/240 reactors in filters, V (singlesecurity and access phase) control systems, welding unit; some use CFL and electronic Ballasts 9. Metallurgy 132 kv (3-variable speed drives, phase)/220 UPS, capacitor banks, 60A kv/11kv/6 networking and telecom.6kv loss of data and computer screen freeze, flickering of lights, noise in telecom lines (in rainy season) Motor-drives malfunctioning, dimming of lights, CB/relay nuisance tripping, computer screen freeze, overheating of cables and motors, capacitor bank failure etc. Some electronic gets damaged Asia Power Quality Initiative India Survey Page 9

10 10. Power 220KV, Generation 110KV, 6.6KV UPS, capacitor banks, 1- telecom, 20 security and access control systems, CFL, electronic Ballasts, relay and CBs, variable speed drives and other static converters, CCTV and welding A 5 3 capacitor bank failure, circuit breaker, computer screen freeze, loss of data, damage of electronic, flickering of lights, noise in telecom lines, overheating of motors, noise in electrical machines, loss of synchronism of and negative sequence current and rotor overheating. One of the industries is facing the UPS card failure problem 5 5 capacitor bank failure and flickering of lights 11. University 33KV (3-UPS, capacitor banks, obser phase)/240 telecom, ved V (singlesecurity and access phase). control systems, CFL, electronic Ballasts, variable speed drives and other static converters and welding 12. Plastic & 110/33KV. They use UPS, capacitor A capacitor bank Rubber banks, telecom failure, computer, CFL, screen freeze, electronic Ballasts, relay damage of electronic and CBs, variable speed, noise in drives and other static telecom lines converters, CCTV 13. Oil & 110/220/11 UPS, capacitor banks, <5 <5 Noise in telecom Petroleum KV networking & telecom lines and relay, CFL, nuisance tripping, electronic Ballasts, relay flickering of lights. and CBs, and other static converters, CCTV and security & access control system Asia Power Quality Initiative India Survey Page 10

11 14. Pharmaceu 33KV ticals 15. Cement 6.6KV, 3.3KV, 33KV, 415V 16. Automobil e UPS, capacitor banks, 2-2 <100 Not Not capacitor bank telecom, A meas meas failure, circuit security and access ured ured breaker, computer control systems, CFL, screen freeze, loss of electronic Ballasts, relay data, damage of and CBs, variable speed drives and other static converters, CCTV and electronic, flickering of lights welding noise in telecom lines overheating of motors and negative sequence current and rotor overheating UPS, capacitor banks, Ver Very Very - <2 2 capacitor bank reactors in filters, y seldo seldo failure, circuit networking and telecom seldm m breaker, computer, security and om screen freeze, access control systems, overheating of CFL, electronic Ballasts, motors (under fault) relay and CBs, variable speed drives and other static converters, CCTV and welding 110/132/33 UPS, capacitor banks, 5(in - 10(in 20A 10 2 capacitor bank KV (threenetworking and telecom yea year) failure, overheating phase) and, CFL, r) of motors and cables 240V (single phase) electronic Ballasts, relay and CBs, welding, security and access control system, variable speed drives and other static converters, CCTV 17. Insurance 415V UPS, capacitor banks, 1ev 1 1-3% 5% computer screen Broker, telecom, ery freeze services CFL, electronic Ballasts, for CCTV, networking nig ht 18. Aviation 66KV UPS, capacitor banks, - Chan 2 Often 24 3 capacitor bank telecom, geov obser failure, circuit security and access er 2 ved breaker, computer control systems, CFL, electronic Ballasts, relay and CBs, variable speed drives and other static times screen freeze, loss of data, and damage of electronic specially CCTV and converters, CCTV and PLC, electrical welding shocks due to neutral Asia Power Quality Initiative India Survey Page 11

12 19. Hospital 415V (three UPS, capacitor banks, 7- phase). CFL, electronic Ballasts, 10 networking and telecom and electronic appliances like CCTV 20. Other 132KV Capacitor bank, On manufactu (three Reactors in filters ce ring Sector phase). (TCR),Variable speed in drives and other static yea converters, Relays and r CBs, Compact fluorescent lamps / electronic ballasts, UPS, Welding, Electronic appliance like computers, CCTV s,networking and telecom, Security and access control system voltage, flickering of voltage capacitor bank failure Once 4 in in year year Boilers For NA CFL, UPS, electronic Dai Very Power Sector Ballasts, security and access control system, ly in rare networking and telecom pea and electronic appliances like CCTV k tim es 22. Hotels 11KV Capacitor bank, Not Not Not Not Welding, Sig Signi Signif Signif Variable speed drives nifi fican icant icant and other static can t converters, Relays and t CBs, Compact fluorescent lamps, UPS, Welding, Electronic appliance like computers, CCTVs, Networking and telecom Security and access control system Asia Power Quality Initiative India Survey Page 12