The Rs 1,500 crore Indian insulator industry is growing due to capacity addition and upgradation, says Daya Kingston.
Economic growth and infrastructure development have lent impetus to the growth of the electrical insulator industry. Insulators are integral to power transmission through overhead lines since they provide mechanical support and electrical protection.
Globally, the size of the insulator industry is valued at Rs 15,000 crore and the Indian market clocks Rs 1,500 crore. The industry is posting a health growth and demand is growing. Apart from capacity addition and new projects, replacement and upgradation are other growth drivers.
Ceramic vs composite insulators
The demand for composite insulators is growing steadily. Since these typically use engineered polymers, they offer higher mechanical strength, greater design flexibility, reduced weight and lower breakage rates compared to ceramic components.
The resistance to flashovers in a polluted space and resistance to punctures is high in composite insulators and low in ceramic insulators. Also in polluted surroundings, the performance of ceramics gets affected while composites deliver unfettered performance. Ceramics are non-hydrophobic while composites are hydrophobic, implying low current leakage losses.
Malik, Marketing Manager, Rashtriya Electrical and Engineering Corporation, said, "Polymer insulators are the latest technology, their quality is better and they also handle the power system and line faults better."
Bipul Bhattacharya, Senior Manager, Sales and Marketing, General Power, said, "We manufacture porcelain and composite polymeric insulators. The high glaze and superior quality are our strengths. The market has a lot of potential and is on the upswing. Our challenge is the tough competition from Chinese manufacturers."
Another company in the segment, Goldstone Infratech claims to have pioneered the revolution in insulator technology in India through extensive in-house research in the development of composite (polymer) insulators as a substitute for the existing ceramic insulators.
DPK Udas, Vice President (Marketing) Goldstone Infratech, said, "Our plant at Hyderabad is equipped with a strong R&D department. We use advanced polymer technology and unlike ceramics or glass, composite polymers do not break, are easy to transport, lighter in weight, deliver good performance even under polluted conditions and are also cheaper. As a safety measure we incorporated bird guards on insulators to protect them from getting electrocuted and leading to outages."
He said, "With the growth in transmission networks, the industry is growing at a rapid pace. One of the major problems the industry faces is the dumping of cheaper products by China. The next big advance in this industry is likely to be insulators made from liquid silicon. This is still at the development stage though."
Based in Kolkata (West Bengal), Reliance Potteries manufactures and exports high tension electro-porcelain insulators and has a plant that manufactures a wide range of ceramic and ESP insulators to handle different voltage capacities.
Mainak Das, CEO, Reliance Potteries, said, "The Indian market looks very promising and is likely to grow at 25-30 per cent for the next five years. We are one of the few plants in the country to have facilities for manufacture and testing."
Commenting on advantages of ceramic insulators, Das said, "They are ideal for our weather conditions as they can withstand the high temperatures in various parts of the country and also endure pollution. Though the initial cost is higher compared to polymers, the rejection rate is lower." When queried about issues confronting this industry segment, he said, "The lack of raw material is becoming a problem. Another challenge is the high prices of oil and diesel. It would be good if the government promotes natural gas which would also be more environment-friendly."
Factors affecting insulators
Since they have to face the vagaries of the weather, they have to be robust. Their service life can be affected by electrical, mechanical and environmental stresses. For instance, ceramic glaze can be eroded by windblown sand and dirt, whereas resilient polymer surfaces are less susceptible to erosion from such abrasive particles.
Surface contamination is another issue. This refers to airborne contamination that settles on the insulator surface due to salt spray, ocean fog, or from industrial sources due to agricultural spraying, automotive exhaust, etc. When contamination build-up is exposed to moisture, it could result in development of an electrolytic film causing excessive leakage current, dry band arcing and eventually a flashover.
Propelled by the growth of the economy, this industry is set to grow in a big way and there's room for innovation. Innovation and usage of newer materials will be the key to growth.
Insulators plays a vital role in the three phases of power sector of generation, transmission and distribution but their value is very small compared to the overall project cost.
Insulators used for high-voltage power transmission lines are made from glass, porcelain or composite polymer materials.
Besides glass, porcelain, mica and ceramic can withstand the highest volts of electrical current and have always been a popular choice. In fact, ceramic and glass are ideal for high-voltage insulators and lightning arresters since they offer good resistance to electrical stress and outdoor exposure without significant deterioration.
Porcelain insulators are made from clay, quartz or alumina and feldspar and are covered with a smooth glaze to shed water. Insulators made from porcelain and rich in alumina are used where high mechanical strength is a criterion.
Though insulators made from glass have higher dielectric strength, they attract condensation and the thick irregular shapes needed for insulators are difficult to cast without internal strains.
Of late, polymer or composite insulators have been gaining popularity. Composite insulators consist of two components of different materials. Insulator housings are made from materials like ethylene propylene rubber (EPR), polytetrofluoro ethylene (PTFE), silicone rubber or other similar materials. For HV applications, lighter weight polymeric materials have been developed.
Recently, some utilities have begun converting to polymer composite materials. These are typically composed of a central rod made of fibre reinforced plastic and an outer weather shed made of silicone rubber or ethylene propylene diene Monomer (EPDM). Composite insulators are cheaper, lighter in weight and have excellent hydrophobic capability. This combination makes them ideal for service in polluted areas. However, these materials do not have the long-term proven service life of glass and porcelain.
Although pottery and ceramic is a prehistoric origin of India, the HT insulator industry has a recent origin. The first unit was set up in the 1950s at Bangalore but the main expansion of the industry took place in the 1970s. HT insulators are used in electrical transmission lines, substations and electrical equipment. There has been an upgradation of transmission voltages and already 765 kV AC transmission lines have been constructed and commissioned. But the industry needs to develop and produce HT insulators of higher ratings for transmission lines, substations and equipment.
There are around 15 units manufacturing electro porcelain HT insulators with an installed capacity of approximately 2 lakh mt pa.
Latest equipment such as microprocessor-controlled firing kilns, photo-scanning lathes, automatic grinding and airing machines and others available internationally for the manufacture of HT insulators have been installed selectively by the industry to meet the product quality requirement. Computer-controlled tunnel and shuttle kilns are being used by a number of units.
Major capital equipment like photo-scanning microprocessor controlled lathes/forming machines, automatic insulator grinding and cutting machines, kiln designs, microprocessor controls and critical kiln equipment, etc, are not available from indigenous sources. So the requirement for such equipment is being met through imports. There is scope for acquisition of the latest technology for manufacture of major capital equipment indigenously to meet the long range demand of the industry.
Central Power Research Institute (Bangalore), ERDA (Baroda) and National Test House (Kolkata) are some reputed institutions where testing facilities for HT insulators are available.
Alpha alumina required for high strength porcelain insulator and rapid hardening high strength cement required for assembly of metal components is being imported because the quality of indigenously produced alumina and cement is not of the required standard.
Some Indian manufacturers use indigenous cement with special hardeners and curing techniques, which give excellent mechanical strength. The quality of raw material inputs available in the country has a direct bearing on the quality of the product and is therefore crucial for achieving the export thrust.
Major manufacturing and testing equipment required for the industry is not available indigenously and most of the requirements are met through imports. Steps to indigenise the major items of plant and machinery used for manufacture of insulators need to be taken up to achieve self-sufficiency in the field.
The industry and national research institutions have the capability to upgrade the technology with their own R&D. Easy availability of foreign collaborations for technology upgradation has become an impediment in the way of technological self-reliance. On the other hand, the industry which has acquired a sufficiently good base should be encouraged to initiate its own R&D projects to achieve technological self-sufficiency.
A specialised centre should be created in a suitable national institute to undertake research on various aspects of insulator designs and raw materials used. This institute must take up such R&D projects sponsored by the industry on a time-targeted basis. The proposed R&D facility and industry need to work in liaison with each other and progress on the research projects must be reviewed at least twice a year by an expert panel to ensure making available to the industry its achievements on reasonable terms for commercial exploitation.
To improve the quality and appearance of fired insulators, the international trend is to use gas as the firing medium. Since the availability of the gas has improved, the HT insulator industry should be given preference to improve the quality and finish in keeping with global trends.
A number of measures need to be taken up on a priority basis. Export of HT insulators is the only solution to effectively use the excess installed capacity in the industry and to enable the industry to have the requisite competitive edge over international competitors. Due to the limited domestic market, Indian companies should pursue the possibility of technology exports also to developing countries, which form a growing market. The Indian electro-porcelain insulator industry is fairly mature and has acquired the capability and know-how to manufacture HT insulators at par with those manufactured internationally.
China and Korea are exporting insulators at lower rates as compared to Indian manufacturers to establish themselves in the international export market. It has been observed that these countries use such strategies to enter export markets and then raise their prices to make exports commercially viable. A special subsidy, at least for five years, should be given to the industry to study and evaluate bidding patterns of China and Korea in international tenders to counter and make our rates more competitive.
Types of insulators
Insulators can be specific to low or high voltage applications. The types of insulators are:
Pin insulators: These are used in medium voltage overhead distribution lines (15, 25, and 36 kV) and to fix conductors to tower bodies. These in turn distribute power from substations to towns and inside the town networks. These come in the form of single or multi-piece constructions. The advantage of a multi-piece construction is that they are sturdier and can withstand line voltages for a considerable time without difficulty.
Cap and pin insulators: These are used in overhead transmission and distribution networks to push bulk power over long distances. They may be in suspension or tension mode in string form to insulate the conductor from the tower. Depending on pollution levels, the standard or anti-fog option can be used.
Post insulators: These are used in medium and high voltage applications in substations to insulate high voltage switcgears and transformers. Some of them can be stacked to support additional voltage.
Solid core line post insulators: These can be used on medium voltage overhead distribution lines (36 kV) for fixing conductors to tower bodies and in town distribution systems. They are ideal for polluted zones and areas prone to vandalism. Even if the insulator shed gets damaged, there will be little decrease in flashover voltage and power supply will not be disturbed.
Disc insulators: These are the most widely used models for T&D lines. In strings, they can be used for any voltage. Some have features such as anti-fog.
Shackle insulators: These insulators are applied on low voltage overhead distribution lines for fixing of conductors to poles. These can handle normal domestic voltage and usually come with a semi-vitreous body.
Guy insulators: These are designed specifically for use in radio frequency (RF) applications. They are rugged, resistant to mechanical breakage and have zero moisture absorption.
Long rod insulators
These insulators are used on medium and high voltage overhead distribution and transmission lines for suspension or tension of the conductor to tower bodies. These are absolutely puncture-proof and deliver excellent anti-pollution performance.
These are used for both outdoor and indoor applications and improve the field distribution inside a transformer.
I wish to start pvc / pp electric wire unit in Delhi. What kind of information I can get if I subscribe for your magazine
Pls invite me all auction in gujarat
we are doing business developing for solar power ,thermal power , customer supporting and we have 45 mw splar power on hand needs investors.....
pls call +910842559230