Low-voltage electrical appliance market has great potential

China has become a major producer of low-voltage electrical appliances and has become a major exporter. The research and development of high-end products will remain the main direction of the industry in the future. According to the corresponding distribution equipment required for newly-increased power generation equipment during the “Twelfth Five-Year Plan” period and the needs of existing power equipment replacement and maintenance, it is expected that universal circuit breakers, plastic shell circuit breakers, miniature circuit breakers, AC contactors, and heat The demand for relays, residual current circuit breakers and other products will reach more than 200 million units.

The market has great potential

After more than 50 years of development, the low-voltage electrical industry has formed a complete industrial system. Its products have a wide range of applications and huge market potential. According to statistics, domestically produced low-voltage electrical products have about 1000 series, and the output value has reached 20 billion yuan. There are more than 2,000 production enterprises above the scale, mainly concentrated in coastal provinces such as Guangdong, Zhejiang, and Shanghai. At present, low-voltage electrical products are in the first-to-third-generation level, and the fourth-generation products are still under development.

In addition, the domestic market share of most products is still very low, and the demand for high-end low-voltage electrical appliances in the domestic market still depends on imports.

Seven characteristics of development

The domestic low-voltage electrical appliance manufacturing enterprises are small in scale and excessive in quantity. More than 90% of the enterprises are in the middle and low-grade product repetitive production, and the three generations of products coexist. According to the trend of national policies, the structure of low-voltage electrical products needs further adjustment in the coming period. Products with backward processes, large volumes, high energy consumption and environmental pollution will be eliminated.

A group of famous low-voltage electrical manufacturers abroad have successively introduced a new generation of products, among which the frame circuit breakers include the Schneider MT Series, the Siemens 3WL Series, the ABB E Series, the GE M-PACT Series, and the Kama Magnum Series; Circuit breakers include Schneider NS series, Siemens 3VL series, ABB Tmax series, GE company Recordplus series, Moeller NZM series, Kama G series, and Mitsubishi WS series. In addition to the high-performance, electronic, intelligent, modular, modular, and miniaturized features, the new generation of products also features increased communication, high reliability, good maintenance performance, and compliance with environmental requirements. In particular, a new generation of products can be connected with fieldbus systems to realize system networking and make a qualitative leap in the function of low-voltage electrical products.

high performance. The rated short-circuit breaking capacity and rated short-time withstand current are further improved, and Icu=Ics, such as Schneider's MT series products, have short-circuit breaking and ultimate short-circuit breaking capacity of up to 150 kA.

High reliability. In addition to requiring higher performance, the product can be used without derating, and can be used long-term without overheating at full capacity to achieve safe operation.

Electronic. Modern companies have adopted PC control systems instead of systems consisting of electrical-mechanical components, which are already the mainstream of mechanical electrical control systems. The system requires electrical products with high reliability and high immunity to interference. It also requires the contacts to be able to reliably turn on low voltage and weak currents. The arc at the time of contact disconnection cannot interfere with the normal operation of the electronic circuit.

Intelligent. With the advent of application-specific integrated circuits and high-performance microprocessors, circuit breakers have realized the intelligentization of trip units, which greatly enhanced the protection functions of circuit breakers, enabling overload long delays, short circuit short delays, and short circuit transients. Grounding, undervoltage protection, and other functions, can also display on the circuit breaker voltage, current, frequency, active power, reactive power, power factor and other system operating parameters, and can avoid the occurrence of malfunction under the influence of higher harmonics.

Fieldbus technology. The new generation of low-voltage electrical appliances realizes communication and networking, and can connect with a variety of open field buses to conduct two-way communication and realize the functions of remote control, remote signaling, telemetry, and remote adjustment of electrical products. The application of fieldbus technology can not only monitor the distribution quality, but also reduce losses. Moreover, field bus technology can realize regional chaining of multiple circuit breakers in the same regional power grid, realize the automation of power distribution protection, and further improve the reliability of power distribution systems. The buses used in the industrial fieldbus field include Profibus, Modbus, DeviceNet, etc., among which Modbus and Profibus have a greater impact.

Modular and modular. Like the Tmax series introduced by ABB, thermomagnetic, electronic, and electronically commutable trip units are interchangeable. All accessories are modular and can be installed without opening the lid. Combining different functional modules into modular modular appliances according to different requirements is the development direction of today's low-voltage electrical appliances industry. The auxiliary contact assembly, time delay assembly, self-locking assembly, interface assembly, mechanical interlocking assembly and surge voltage assembly are installed on the body of the contactor, which can meet the requirements of different occasions, thereby expanding the scope of application of the product and simplifying the production process. , user-friendly installation, use and maintenance. At the same time, it will further improve product reliability and product quality.

Use green material. The selection, production process and use of product materials do not pollute the environment and comply with EU environmental directives.

Manufacturing technology keeps improving

The manufacture of low-voltage electrical products involves a variety of professional processes, such as cold stamping, plastic molding, coil winding, contact welding, mold processing, SMT chip technology, etc. Therefore, the improvement of low-voltage electrical product manufacturing technology and the improvement of these professional skills Inseparable.

According to Yin Tianwen, secretary-general of the General Electric Low-voltage Appliances Branch of the China Electrical Equipment Industry Association, “At present, there are less than 10 large-scale enterprises with annual sales revenue and total assets of over 500 million yuan in low-voltage electrical appliance manufacturing enterprises in China. The vast majority are small and medium-sized enterprises. , resulting in the lack of economies of scale and competitiveness of enterprises, as well as the dispersal of economic resources and the lack of efficiency."

With the improvement of the level of domestic power construction and the continuous development of low-voltage electrical production technology, a new generation of low-voltage electrical appliances featuring intelligent and communicable features will become high-end products. At present, domestic low-end low-voltage electrical appliances basically account for most of the domestic market, but the domestic high-end low-voltage electrical appliances can be divided equally with foreign similar products. Parts processing tends to be high speed, automation, and specialization. Stamping parts account for a large proportion of low-voltage electrical parts, about 70%, so the processing of stamping parts occupies an important position in the production of low-voltage electrical appliances. To improve the production efficiency and quality of stamping parts, it is imperative to adopt high-speed automatic punch presses and multi-position progressive punching dies. Plastic parts are important parts of low-voltage electrical appliances, using automatic or semi-automated thermoplastic or thermosetting injection molding machines and adopting centralized feeding methods. Widely used in automated welding machines, the welding current, pressure, pulse cycle can be adjusted to maintain the temperature controllable to ensure the welding strength.

Parts are automatically assembled. For key components with large production volume and strict technical requirements, such as thermal magnetic release and control electrical cores, automatic assembly technology is used.

Product requirements online testing. Online testing equipment for production process is the main gap between the manufacturing level of low-voltage electrical appliances in China and foreign countries. It is the main reason that affects the stability and consistency of electrical appliances quality, and is also the direction of future technological development.