The composite insulator is a kind of device which apply to withstand voltage and mechanical stress in the connection tower of high voltage wire and substation. It has stable mechanical properties, pollution flash resistance, ice flash resistance, small volume, light weight, good environmental protection, clean maintenance, comprehensive high cost performance advantages, by the power industry warmly welcome.

With the continuous development of China's economy and society and the significant improvement of people's living standards, both power generation and electricity consumption have achieved rapid growth. According to statistics, China's total electricity consumption reached 6,307.7 billion kilowatt-hours in 2017, ranking first in the world. At the same time, the huge market consumption has put forward higher requirements for power generation, transmission and distribution equipment in the electric power industry. Composite insulator is such a device applied to withstand voltage and mechanical stress on the connecting tower of high voltage wire and substation.It has stable mechanical properties, pollution flash resistance, ice flash resistance, small volume, light weight, good environmental protection, clean maintenance, comprehensive high cost performance advantages, by the power industry warmly welcome. This paper will analyze the development status of the composite insulator market.

The insulator market is divided into three parts, the failure rate of composite insulators is the lowest, but the number of network has doubled year after year

The development of  insulator enterprises in China began in the 1980s, and the early products were AC composite post insulators with voltage grades of 252 kV and below. After more than 30 years of development, there are more than 60 insulator manufacturers with a certain scale, whose products basically cover all downstream applications. High-voltage grade and high-tonnage products with technical difficulties have been realized domestically.The main reason for the leap-forward development is the construction and transformation of the national city network, the transmission of power from west to east and the ultra-high voltage network project.

In recent years, the domestic insulator market tends to be saturated, but the output is still rising, and the export scale of products is constantly expanding. In the past 10 ten years, the production of glass insulators grew the fastest.

Before the 1990s, the insulator products in China were mainly porcelain, and the production of glass insulator was very small, while the composite insulator was still in the laboratory stage. Since 1995, it has entered the practical stage. Then the number of composite insulators in the net doubled year after year. Since 2001, key manufacturing technologies and processes have advanced rapidly, with integral injection molding, crimping joints and various forms of sealing processes maturing. This makes the composite insulator become one of the most effective ways to solve the problem of flashover in the polluted areas of transmission lines. After 2004, domestic products gradually occupy the dominant position, and the scale of foreign insulator manufacturers is shrinking. 300-550 kN products have been successfully developed, leading the development of composite insulator manufacturing technology .In 2008, the failure rate of composite insulators in China was 1 in 10,000. At present, there are more than 100 composite insulator manufacturing enterprises in China, and more than 10 enterprises are leading in technology.

The domestic composite insulator market is diversified, and the number of high-quality enterprises is numerous

At present, the development of composite insulator market shows a trend of diversification, with a large number of high-quality enterprises, the main production enterprises include: PINGGAO GROUP CO.,LTD., Jiangsu Shemar, Xiangfan Insulator, Zibo Taiguang, Dalian Electric Ceramics, Hebei Silicon Valley Chemical Co., Ltd, Guangzhou Maclin, CYG Insulator Co.,Ltd, etc.

CYG Insulator Co.,Ltd is one of the largest composite insulator manufacturers in China. It is a holding company subordinate to CYC GROUP a listed company.With an annual production capacity of 1.6 million 110KV insulators, more than 9.3 million insulators have been operating stably, safely and reliably in China's major power grids and more than 20 countries around the world. As a kind of high-energy electrical smart grid equipment, the operating income of the smart grid equipment segment of composite insulator in 2016 increased by 11.90% over the previous year, and the gross profit rate was 42.41%, which decreased by 2.81 percentage points compared with last year.

Jiangsu Shermar has the National Key Laboratory of Energy and Power Insulation Composite Materials, and has more than 50,000 hollow composite products of 110kV to 1000kV voltage grade widely used all over the world. According to the data of ABB of Sweden in 2011, the world market share of the composite insulator of the power station of Shermar has far exceeded the European competitors such as Tyco, McLean and MR, and has become the largest composite insulator manufacturer in the world. The technology of power transmission and transformation of hollow composite insulators has filled the gap in China and broken the long-term international monopoly on hollow insulators on UHV level in China. Moreover, the company has become the main setting unit of national standards for this product.

Xiangfan State Grid Co., Ltd., whose predecessor was branch of Xiangfan Power Equipment Plant Composite Insulator, established in 1987, which is the earliest enterprise in China and the seventh enterprise in the world that develops and produces composite insulators.The company is the largest composite insulator production base in the Asia-Pacific region, with an annual production capacity of 1 million standard composite insulators, covering 31 provincial administrative regions of the State Grid and China Southern Grid and 28 countries such as Italy, the United Kingdom, Iran, Vietnam, South Korea and so on.

Conclusion

With the continuous improvement and development of power infrastructure, China's composite insulator technology has been relatively mature, and even led the development of composite insulator manufacturing technology. At present, the annual output of composite insulators in China exceeds 13.05 million, and there are more than 100 manufacturing enterprises, many of which are of high quality. Compared with similar products, composite insulators have the lowest failure rate and less demand for replacement. The domestic market tends to be saturated until there are new power grid construction projects and large power industry investment.For the foreign market, China's composite insulator technology and price advantages are obvious, which provides sufficient impetus for the development of the industry.