There are broadly three types of insulators on the basis of material – Ceramic/Porcelain insulators, Composite/ Polymer insulators and Glass insulators. On the other hand as the voltage level increases the size of the insulator required is large and vice-a-versa is also true. The insulators are generally designed on the basis of pollution level by calculating the creepage taking dielectric material, shed profile, and shed angle into consideration. The shape of insulators is influenced by considering electrical, mechanical and thermal aspects considerations.
The insulators are used in transmission and distribution network, electrical traction system (railway, trolley bus, tramway etc.) telegraph and telephone lines or in equipment like Surge arresters, circuit breakers and instrument transformers.
Indian Insulator Industry is continuously keeping pace with technological advancement that is occurring globally. The domestic industry manufactures various types of insulators in all ranges for LT, HT and EHT. The industry is also manufacturing for the range up to 1200 kV.
Central power sector, state electricity boards, distribution companies, private sector power transmission companies, railways and telecom sector are all major customers for this industry. The insulator manufacturers have already supplied significant volumes of 765 kV insulators i.e. more than 4 million insulators in Indian market. In order to meet the country’s growing demand of up to 1200kV, all major domestic insulator manufacturers have also strived to build sufficient swappable capacity of insulators since. Indian manufacturers are not only catering to Indian market but it has also reached to more than 75 countries including Europe, USA and Latin America. This has proved the technological capabilities of our countries to supply high quality products.
State of Industry
The Government of India is into the process of initiating various Power Sector programme up to 2017 and to meet such huge requirement, the well-established manufacturers have doubled their production capacities over the last few years. However, the overall actual demand of the insulator is far behind the projected demand which resulted in overcapacity situation for this industry.
As compared to last year, the overall sale by volume has fallen down by 7-%. The major loss of sales has been observed for Hollow Insulators of LA, CTs & CAPs with over 50% decline. Pin & Post Insulators was marginally declined whereas Disc Insulators registered a moderate growth of 4%. Solid core Insulators declined by 12% however Long Rod Insulators grown by 11%. Insulators used in Transformers declined by 4%. Although, an import of Insulators through direct imports was declined by 40%; the Imports through Project Imports route continued to the tune of INR 350 crore including Insulators & other components, parts & fittings etc.
Cheaper imports from China have eroded the top line in both Porcelain and Composite insulator manufacturers including glass insulators, despite a growth in overall transmission line network. Unfortunately, the Indian procurement agencies float tenders with competing technology in the same tender harming the domestic industry and benefiting the Chinese.
The continuous rise in costs of fuel, power, raw materials and other inputs have been major cause of concern for the industry. Also, considerable delay in realization of payments faced by certain SEBs is aggravating the adverse situation. There has been a gradual shift of majority of the projects to EPC domain which requires altogether a different business model.