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Low-voltage inverter: new opportunities for traditional upgrading

Aug 27, 2020

Low-voltage inverter: new opportunities for traditional upgrading

1. Industry Overview

1. The concept, classification and application of frequency converter


Frequency converter, namely AC motor variable frequency speed control controller, is a kind of power conversion equipment, which converts AC power with fixed voltage and frequency into AC power with adjustable voltage and frequency. The frequency converter is mainly composed of a power conversion unit, a braking unit, a drive unit, a detection unit, and a microprocessor unit. During operation, the microprocessor unit outputs drive pulses according to the system settings and the signals measured by the detection unit. After the drive unit is amplified, it directly controls the on and off of the IGBT in the power conversion unit to adjust the voltage and frequency of the output power supply, thereby adjusting the motor speed The purpose (according to the characteristics of AC induction/asynchronous motor speed is proportional to frequency).


According to different standards, inverters have a variety of classification methods. For example, according to the scope of application , inverters can be divided into general-purpose inverters and special-purpose inverters; according to conversion methods, they can be divided into AC-AC inverters and AC-DC inverters. -AC inverter; in AC-DC-AC inverter, according to the energy storage mode of the DC link, it can be divided into current type and voltage type inverter; according to the voltage level, it can be divided into low voltage inverter and medium voltage Frequency converter and high voltage frequency converter, etc.


The main function of the frequency converter is to continuously and steplessly adjust the speed of the motor. Therefore, it has the following effects: (1) Realize the energy-saving operation of the motor. Since the output power of the motor is proportional to the speed, when the load remains unchanged, after the motor runs at a reduced speed, its output power is correspondingly reduced, and the overall energy consumption is also reduced, thereby achieving the purpose of energy saving and emission reduction. (2) Realize the soft start and soft stop of the motor to reduce the starting current of the motor, reduce the motor's demand for grid capacity and impact on the grid, and avoid mechanical impact when the motor starts and stops, thereby reducing the capital of the early equipment Invest in, extend the life of the motor and load equipment, reduce equipment maintenance costs. (3) Replace the DC motor to meet the technological requirements of various occasions and equipment, increase production efficiency or improve product quality. Due to the introduction of vector control technology, the frequency converter achieves fast response and high-precision control comparable to DC motors. It can replace DC motors to achieve various process speed adjustments, save space, and is more convenient for installation and maintenance. In addition, the inverter has many application functions and protection functions, such as: PID adjustment, brake function, simple PLC, etc., so that the inverter can be used in hoisting, lifting, textile and other industries, expanding the application scope of the inverter ; Protection functions such as over current, over voltage, short circuit, overload protection, etc., make the inverter and motor run more reliable and safe.


At present, frequency converters have been widely used in various industries in our country, such as metallurgy, chemical, paper, machinery and other industries. More specific applications, small applications such as blowers, conveyors, feeders, mixers, grinders, shredders, paper cutters, calenders, extruders, valves, compressors, cooling towers, plastic machinery in various industries , Elevators, various textile machinery, large-scale applications such as paper machines in paper mills, injection molding machines in mold factories, steel rolling mills in metallurgical plants, and large fans, pumps, cranes, oil pipelines, etc. in chemical industries.


2. Overview of the development of the inverter industry


Compared with industrialized countries, my country's inverter industry started relatively late. From the late 1970s to the 1980s, my country's inverter development phase began. This stage is mainly the Tianjin Electric Transmission Institute (voltage type) of the Ministry of Machinery and Xi'an of the Ministry of Machinery Research and development of Power Electronics Technology Institute (current type). From the end of the 1980s to the end of the 1990s, it was the stage of foreign import of general-purpose inverters. The first was the Japanese Sanken SVF and the Japanese Fuji G5/p5, and then Mitsubishi, Yaskawa, Toshiba, Panasonic, ABB, AB, Siemens, etc. entered China one after another Under the background of technology introduction, domestic manufacturers have also successively developed domestic frequency converters. In the 21st century, with the development of the domestic power electronics and microelectronics technology, the drive industry scale fast speed expansion of domestic brands gradually rise, the market share of domestic brands have begun to gradually improve. Since 2006, due to the emergence and development of intelligent power modules, inverter companies can produce mature products as long as they control part of the circuit and the main power circuit and shell. Domestic inverters have appeared in a situation of contention. With rapid development, a large number of excellent domestic inverter brands have emerged, and domestic brands have further expanded their market share with the help of localized production, service network and price advantages.


There are more than 300 inverter manufacturers in my country, but their strength and scale are uneven. Individual companies still adopt a workshop-style production model, and the main brands are maintained at 20-30. In recent years, my country's frequency converter market has maintained a growth rate of 12% to 15%. As of 2013, the national frequency converter market is about 28.5 billion yuan. It is expected that the market demand for frequency converters will continue to grow by more than 10%. According to statistics on the prospects of the inverter industry, the total potential market space for inverters in my country is approximately 120 billion to 180 billion yuan.


3. Overview of the development of the low-voltage inverter industry


Low-voltage inverters are AC motor drive devices with adjustable output frequency with voltage levels lower than 690V. They first started in the United States in the late 1950s. Since the 21st century, my country's low-voltage inverters have gradually risen. According to data from the China Media Research Department : In 2006, the market size of China's low-voltage inverter industry was 9.260 billion yuan. In 2013, the scale of China's low-voltage inverter industry reached 21.405 billion yuan, with a compound annual growth rate of 12.72%. According to the "2013 China Low-Voltage Inverter Market Research Report" by the China Media Research Department, the growth rate of my country's low-voltage inverter market will continue to maintain above 10%, and the total market in 2016 will exceed 26 billion yuan.

Low-voltage inverters are divided into four parts according to different user groups : <=7.5KW, 11-30KW, 37-90KW, and >=110KW. Among them, the application of low-voltage inverters below 30KW is the most common. Mainly used in high-power project market, or large-scale machinery equipment manufacturers to European and American systems -based, such as Siemens, ABB, An Fusen ( Afsen ); up to medium power applications, including traditional fan and pump applications, or complex mechanical applications For project applications, all major suppliers have products in this power range ; low power is represented by mechanical applications, mainly Japanese manufacturers and some European, American and Taiwanese manufacturers, such as Delta, Fuji, and Mitsubishi. According to the report of the Research Department of Zhongzi Media, the distribution of power segments in the low-voltage frequency conversion market in 2012 is shown in the following figure :



Low-voltage inverters are classified into lifting loads, mechanical loads and fan and water pumps according to different application loads. Which mainly refers to lift the load lifting and elevators, are also included to enhance the class of applications in other industries involved to ABB, Siemens, Yaskawa and An Fusen ( Afsen ) mainly; the mechanical load accounted for more than half of the market, including textile machinery, packaging Mainstream machinery and equipment such as machinery also include machinery applications in non-OEM fields. According to the report of the Research Department of Zhongzi Media, the low-voltage frequency conversion market in 2012 is classified by application load as shown in the figure below:


The development of low-voltage inverter products is closely related to industrial production, and its downstream application market distribution is basically the same as the industrial distribution. According to the " 2014 China Low-voltage Inverter Market Research Report", the five major industries of elevators, wind power, lifting machinery and textiles, and municipal administration are The main application industries in the low-voltage inverter market.

2) The scale of the low-voltage inverter market will continue to grow steadily



A. The upgrading of equipment manufacturing industry and the rapid growth of the new energy industry promote the continuous expansion of the entire market



Low-voltage frequency conversion technology emphasizes adjustment accuracy and range, and is closely linked with front-end PLC control and back-end servo motors in the field of industrial automation to form an industrial automation control system. The "Twelfth Five-Year Plan" proposes to "renovate and upgrade the manufacturing industry," which includes the "development of advanced equipment manufacturing industry", and upgrading the level of automation will become the focus. The demand for low-voltage frequency conversion is directly related to the overall industrial development level. With the upgrade of downstream equipment in the entire manufacturing industry, the low-voltage frequency conversion industry will continue to maintain a growth rate of about 15%.



On the other hand, after the Copenhagen Conference, new energy investment has become the focus of the world's attention. New energy and low-carbon economy have become the focus of development in various countries. Wind energy with the most mature technology will be the first choice for renewable energy. Low-voltage inverters are widely used in the drive system of the wind power industry. The main function is to merge the wind power with variable frequency into the power grid with constant frequency, which has the same direction, same frequency and same voltage. Since the drive technology and wind power automation control system technology is the key technology of wind turbines, wind power industry has become a low-voltage inverter industry in downstream applications accounted for a relatively large, rapid growth of industry applications. By 2020, China's installed wind power capacity will reach 100 million kilowatts. Such a huge market space will surely drive the continued rapid growth of the entire low-voltage inverter industry.



B. Import substitution has become a long-term driving force for domestic low-voltage inverter manufacturers to seize market share



The entire low-voltage inverter industry is mainly occupied by European American and Japanese manufacturers . With the continuous improvement and maturity of domestic inverter technology, product prices have become the primary consideration for downstream customers. Given the current price gap between domestic and foreign firms are still large areas of strength and major domestic manufacturers of low-voltage inverter is relatively fragmented, such as the British Witten mainly concentrated in the lifting, drawing and coal, while the Department of Sichuan technology is reflected in the elevator and injection molding machine market Due to the differentiation of competition, domestic inverter manufacturers will not experience fierce competition in the short term, so import substitution will be the main factor for domestic low-voltage inverter manufacturers to maintain high growth rates for a period of time.

2. Industry management system


1. Industry regulatory system



The competent authorities of the low-voltage inverter industry are the National Development and Reform Commission and the Ministry of Industry and Information Technology. National Development and Reform Commission and its subsidiary bodies mainly responsible for the system set industrial policy to guide the industry structure adjustment, industrial restructuring, technological progress and technological innovation work. The business management and production operations of all enterprises in the industry are completely market-oriented. The industry self-regulatory organization is the Inverter Branch of the China Electrical Equipment Industry Association. Its main responsibilities include: collecting basic information and research related conditions of the inverter industry at home and abroad, and making suggestions on the development of the industry to the government; assisting the government in preparing industry development plans, Promote the coordinated development of relevant aspects in the industry; assist the standardization authority to formulate and revise the national and industry standards of the industry, organize the establishment of the industry's technical and economic information network, and carry out experience exchanges and cooperation between international and domestic enterprises.



2. Main industry policies and regulations











Industry-related main content



"Guide to Priority Development of High-Tech Industrialization Key Fields ( 2007)"




National Development and Reform Commission , Ministry of Science and Technology, Ministry of Commerce, State Intellectual Property Office


Include "power electronic devices and converter devices" as a national priority development project.

"Energy Conservation Law of the People's Republic of China"




Adopted at the 30th meeting of the Standing Committee of the Tenth National People's Congress


The state implements industrial policies that are conducive to energy conservation and environmental protection, restricts the development of high energy-consuming and high-polluting industries, and develops energy-saving and environmentally friendly industries; encourages and supports the research, development, demonstration and promotion of energy-saving science and technology, and promotes energy-saving technology innovation and progress; People’s governments at all levels are required to strengthen energy conservation, rationally adjust industrial structure, enterprise structure, product structure, and energy consumption structure, promote enterprises to reduce energy consumption per unit output value and unit product energy consumption, eliminate outdated production capacity, and improve energy development and processing , Conversion, transportation, storage and supply to improve energy efficiency.



"Industrial Structure Adjustment Guidance Catalog (2005 Edition)"




National Development and Reform Commission


Include "Development and Application of Energy-saving Technology for AC Frequency Conversion Speed Regulation" in the encouraged category.



"Outline of the 11th Five-Year Plan for National Economic and Social Development"




The Fourth Session of the Tenth National People's Congress



List "resource conservation and environmental protection" as a basic national policy, requiring the construction of a low-input, high-output, low-consumption, low-emission, recyclable, sustainable national economic system and a resource-saving and environment-friendly society. At the same time, 10 key energy-saving projects are put forward , of which "motor system energy-saving project" is located in the fifth item, encouraging the promotion of frequency conversion and speed regulation energy-saving technology, formulating relevant economic incentive policies and technical policies, and improving the motor energy efficiency standard system and other supporting measures.



"China Energy Conservation Technology Policy Outline ( 2006)"




National Development and Reform Commission , Ministry of Science and Technology


Clearly point out "development and promotion of frequency conversion speed regulation technology and devices", including "development of energy-saving speed regulation devices for motor drive, AC speed regulation devices for process speed regulation, and AC speed regulation devices for special speed regulation."



Ten measures to boost domestic demand and Si Wanyi RMB to invest in programs




State Council


In the next two years, the central government will allocate 350 billion yuan to "accelerate energy conservation, emission reduction and ecological construction projects" and 160 billion yuan to "accelerate independent innovation and industrial restructuring."



"Urgent implementation of the work plan for an additional 100 billion yuan of central investment"




National Development and Reform Commission , Ministry of Finance


It is stipulated that a total of 2.5 billion yuan will be invested in the central budget in the “ten key energy-saving projects, circular economy and industrial pollution control projects in key river basins” of the country’s additional 100 billion yuan of central investment in 2008.



"Implementation Rules for the Adjustment and Revitalization Plan of the Equipment Manufacturing Industry"




Office of the State Council


In the "Guiding Ideology, Basic Principles and Objectives", it is proposed that "adhere to the combination of the development of the complete machine and the improvement of the basic supporting level. Strive to realize the independence of major technical equipment and drive the development of basic supporting products. Improve the technical level of basic parts, develop special raw materials, and reverse Basic supporting products are mainly dependent on imports. Improve the quality of domestic equipment and expand the domestic market. The domestic market satisfaction rate for domestic equipment has stabilized at around 70%. The "Implementation Rules" put forward in the "Main Tasks of Industrial Adjustment and Revitalization" that "increase investment in technological transformation, promote advanced manufacturing technologies and cleaner production methods, improve material utilization and production efficiency, reduce energy consumption, and reduce pollutant emissions" . The "Implementation Rules" put forward in the "Policy Measures" that "encourage the use of the first (set) of domestically-made equipment. Establish a risk compensation mechanism for the use of the first (set) of domestically-made equipment.", "Increase investment in technological progress and technological transformation. Formulated. The "Equipment Manufacturing Technology Progress and Technological Transformation Projects and Product Catalog" supports the use of the first domestically-made major technical equipment, the autonomy of the equipment in the catalog, the transformation of energy saving, material reduction and emission reduction, the integration of internal resources after enterprise mergers and reorganizations, The construction of four regional basic technology centers, the development of modern manufacturing services, etc.", "Implement energy-saving product subsidies and agricultural machinery purchase subsidy policies. Make good use of energy-saving product subsidy funds, and provide subsidies to end users who purchase high-efficiency energy-saving equipment products, 2009 In 2011, we will first launch subsidies for the promotion and application of high efficiency motors.



"Motor Energy Efficiency Improvement Plan ( 2013-2015)"




Organization of Ministry of Industry and Information Technology, General Administration of Quality Supervision, Inspection and Quarantine


The plan clearly pointed out the goal of implementing energy-saving technology transformation of the motor system: from 2013 to 2015, a total of 100 million kilowatts of motor systems will be retrofitted, of which 30 million kilowatts will be retrofitted in 2013, 30 million kilowatts will be retrofitted in 2014, and 40 million kilowatts will be retrofitted in 2015. The plan recommends that companies apply technologies such as frequency conversion and speed regulation to transform fans, compressors, pumps and other equipment in the electric power, metallurgy, petrochemical, chemical, machinery, building materials, food, textile, and paper industries.

3. The main factors affecting the development of the industry


1. Favorable factors



1) Strong support from national policies



The Twelfth Five-Year Plan proposes to transform and upgrade the manufacturing industry, improve the level of basic technology, basic materials, basic component R&D and system integration , and promote the manufacturing industry to become stronger and become the direction for future development. Frequency conversion technology will be further promoted in the fields of industrial speed regulation and precision control due to its excellent performance. Especially the low-voltage frequency conversion technology widely used in the manufacturing industry, the upgrading of industrial automation level and the upgrading and transformation of manufacturing equipment will greatly drive the demand for low-voltage frequency converters and become an effective driving force for continuous growth.



2) Strong sustainability of market development



From the perspective of demand, low-voltage inverters are also gradually becoming diversified. The emergence of general-purpose and special-purpose products are all to meet the diverse needs of users. With more and more attention to energy conservation and new energy, low-voltage frequency conversion technology is also in the process of transition from speed regulation to energy conservation. On the other hand, the domestic low-voltage inverter industry is transforming from simply providing products to providing users with systematic solutions, from importing high-end products to the rapid rise of domestic brands and gradually opening up the international market. The division and positioning will surely drive the rise of the domestic low-voltage inverter industry.



3) Continuous expansion of downstream applications



With the expansion of the market and the diversification of user- side needs , low-voltage inverter product functions continue to improve, the degree of integration and systematization is getting higher and higher, and the operation is more convenient. Due to professional demand, there are also special low-voltage for certain industries Inverter products. In addition, with the continuous progress of industrial development level and technical level, the application fields of low-voltage inverters are also expanding. In recent years, municipal engineering and wind power industries have gradually surpassed the original traditional manufacturing downstream industries. These new application fields will surely be further expanded. The entire low-voltage inverter market space provides good development opportunities for low-voltage inverter manufacturers.



2. Unfavorable factors



1) Increased market competition



In the context of the strong support of national industrial policies and the continuous expansion of downstream applications, the low-voltage inverter market attracts more companies to enter the market. Some companies with low technical level and poor product quality will further escalate price competition in the industry. The market development and maintenance of large traditional fields and advantageous regions are difficult, and corporate profits will be compressed. Therefore, only by continuously improving the technical level, focusing on differentiated markets, and shifting from a single product provider to a customer system provider, can we continuously improve our competitive strength and ride on the rapid development of the industry.



2) The dependence of core components on imports restricts industry development



IGBT devices are important raw material components of low-voltage inverters. As the current domestic technology is not yet mature, and IGBT standardization requirements are high, it is directly related to the product quality of low-voltage inverters. Therefore, domestic manufacturers mainly rely on imports, which are extremely important to foreign suppliers. Dependence, so IGBT has become an important bottleneck restricting the development of domestic low-voltage inverters. The Ministry of Information Industry has included the development of fully controlled power electronic devices in its work plan. With the massive investment in research and development, there are already many domestic enterprises that can produce them, but the scale and technical level still need to be improved.



Fourth, the relationship between the industry and upstream and downstream



1. The upstream industry of the inverter manufacturer



Inverter manufacturer upstream industry is mainly a variety of electronic components, sheet metal radiators and other raw material suppliers.



2. The downstream industry of the inverter manufacturer



The downstream industries of inverter manufacturers are petrochemicals, power plants, water plants, metal smelters, and various machinery industries. These industries are all important industries related to the national economy and people's livelihood, and most of them are industries with huge energy consumption.

Low-voltage inverter products can be used to improve the process of many enterprises, and can play a role in energy saving and emission reduction. China is a big energy consuming country, the state has in environmental protection, saving energy and reducing discharge aspects of the introduction of many policies, which will provide industry, large-scale development of the inverter manufacturer has also brought good market base.



Five, the main barriers to entering the industry


1. Technical barriers



Low-voltage inverters are high-tech products, involving power electronics technology, microelectronics technology, automation control technology, mechatronics technology, motor control technology and other multi-disciplinary and multi-field technologies. Low-voltage inverters must meet the requirements of various production industries and various technical indicators. In addition, the manufacturing technology level, life, harmonics, efficiency, power factor, long-term reliable operation, communication standards, input and output interfaces of low-voltage inverters, etc. There are high requirements for technical level and experience accumulation, and product quality and application scope are also closely related to this. Therefore, technical level constitutes a barrier to new entry into this industry.



2. Brand barriers



After years of development, international brand manufacturers have established their own dominant positions in many downstream application industries and projects in low-voltage inverters by virtue of advanced technology advantages, reliable and stable performance advantages, and formed a good brand effect. The high-end market in low-voltage inverters has long been monopolized by top international brands, so it is very difficult for new entrants to enter the superior areas of these international manufacturers. Qidian Electric relies on the precise segmentation of the market, relying on the accurate positioning of the market, mainly concentrates on the relatively blank areas of international manufacturers and the huge price advantage of project bidding for differentiated competition. At present, it has a certain brand foundation in the industry.



3. Barriers to marketing channels



Low-voltage inverter technology is mature and application is simple. Many user-side engineers are familiar with its application. Therefore, most suppliers in the industry mainly rely on distributors to sell in the form of products. Under this background, some excellent distributor resources have been ranked by the industry. Monopolized by former brand manufacturers, channel marketing costs for new entrants are higher and the cycle is longer. With the intensified competition in the low-voltage inverter market, the quality and function gaps of products of different brands are getting smaller and smaller. The final price, service and technical support will become the main influencing factors, so good after-sales service and technical support are becoming more and more popular. The attention of dealers constitutes the constraints of new entrants in terms of cost, technology and manpower.



6. The basic risk characteristics of the industry


1. Risks of increased market competition



At present, there are many domestic companies engaged in the manufacture of low-voltage inverters. In addition, international brands like ABB and Siemens have a fierce competition. Some companies use their own brand and technology, cost control and other advantages to fight price wars. Manufacturers cause considerable pressure to survive.



2. Risks of changes in the macroeconomic environment



Since the downstream application industries of low-voltage inverters are mainly electric power, metallurgy, petroleum and petrochemical, mining, chemical industry, construction, etc., the development scale and growth rate of the entire industry have a strong correlation with the overall development of my country's national economy, so the economic environment directly affects low-voltage Inverter industry.



3. Raw material supply risks



Manufacturer of raw materials in the inverter main products account for a significant proportion of sheet metal, the heat sink, variable pressure, electrolytic capacitors and other components of the material are copper, iron, aluminum and other metals, by the international futures prices, these metals The price fluctuations of this part will inevitably affect the price trend of this part of the raw materials, so the cost will have a certain impact. The important raw material component IGBT devices of this low-voltage inverter industry currently most dependent on imports, IGBT supply and procurement prices basically stable during the reporting period, a once foreign suppliers raise prices or IGBT control supply, or adverse changes in the international trade situation, the Will face the risk of IGBT supply shortage or purchase price fluctuation.