status quo
(1) At present, the provinces and cities with high output of small and medium-sized motors are Shandong, Jiangsu, Hebei, Shanghai, Zhejiang, Guangdong and Liaoning in order, which shows that most of the enterprises are concentrated in coastal areas.
(2) Due to the development of emerging private enterprises, joint ventures, and foreign-invested enterprises, the proportion of state-owned enterprises in the small and medium-sized motor industry has declined, and the output of small and medium-sized motors has gradually been concentrated to "large producers".
(3) The three-phase asynchronous motors Y, Y2, Y3 series have been completely established for small and medium motors.
In 1985, the Y series and its derivatives were quickly promoted. Its power range was 0.55 to 250 KW, and the center height of the base was 80 to 315. Through the introduction and digestion of technologies from Westinghouse and BBC, the Y series 6KV, 220～2800KW medium-sized high-voltage three-phase asynchronous motor developed by ourselves, with a novel box structure, is currently the leading product of domestic medium-sized high-voltage motors. As China's power grid voltage increased from 6KV to 10KV, 10KV series of small and medium-sized high-voltage asynchronous motors were developed.
In 1996, the Institute of Electrical Engineering led the relevant manufacturers to complete the development of the Y2 series, with a power range of 0.12 to 315KW and a base height of 63 to 355. This series of products significantly reduces no-load noise and effectively suppresses load noise.
In 2003, relevant institutes organized by the Institute of Electrical Engineering established a complete series of Y3 series using cold-rolled silicon steel sheets. Its energy consumption reached the national standard GB18163-2002 energy consumption limit value, and also reached the European eff2 efficiency standard, and the main The performance index has reached the advanced level of similar international products.
development trend
a Further promote high-efficiency asynchronous motors
In 1992, the US Department of Energy issued new energy regulations, which proposed the efficiency standard (ie EPACT index) of high-efficiency three-phase asynchronous motors, and stipulated that from October 24, 1997, the efficiency of all general-purpose motors manufactured and imported must meet This standard. In the future, ultra high efficiency motors (NEMAPremium) will be further proposed. In 1999, the European Association of Motor and Power Electronics Manufacturers (CEMEP) established three levels of efficiency standards, eff1, eff2, and eff3, and decided to reduce motor production by 50% below the eff3 standard level by 2003, and no longer produce after 2006.
In August 2002, my country officially implemented the national standard (GB18163-2002) of "Limited Values of Energy Efficiency and Evaluation of Energy Conservation for Small and Medium-sized Three-phase Asynchronous Motors". Therefore, through energy-saving planning and the decree that "replace heat with cold", the new Y3 series should be vigorously promoted to become the leading product of China's low-voltage three-phase asynchronous motors, and the new round of derivative products should also be in the new Y3 series Expand on.
Induction motor
b Further promote the development and application of three-phase asynchronous motor series powered by inverter
In recent years, the demand for fans and pumps in various sectors of the national economy has been increasing. According to statistics from relevant departments, the total installed capacity of fans and pump motors in the country is about 35,000MW, and the power consumption accounts for about 40% of the national electricity consumption. Taking thermal power plants as an example, according to statistics, the total capacity of supporting high-voltage motors for blowers, induced draft fans, primary fans, powder discharge fans, boiler feed pumps, circulating water pumps, condensate pumps, and mortar pumps of thermal power plants in the country is about 15000MW. The equipment is in continuous operation for a long time but is often in a low-load or variable-load operating state, so its energy saving potential is great. It is estimated that the energy saving potential of improving the operating efficiency of fans and pump systems through frequency converter speed regulation can reach 30-50 billion degrees per year, which is equivalent to the annual total power generation of 6-10 large thermal power plants with a installed capacity of 1000MW. Therefore, it is very meaningful to vigorously promote the application of inverters, especially high-voltage inverters. At present, the international research on high-frequency motor frequency conversion speed regulation technology is very active, and there are many types of frequency converters. Most high-voltage motors in my country are rated at 6KV and 10KV. Due to the voltage limit of power electronic devices, it is still difficult to achieve the direct high-voltage output of inverters of this level. The output voltage of the unit series multilevel inverter can reach 10KV or higher, and the input and output waveforms are good, and the harmonic pollution to the power grid is small, so it is widely used in my country. The technology is relatively mature in the world, the output voltage can reach 14.4KV, the inverter uses water cooling technology, and the maximum capacity of a single machine can reach 15000KW. my country uses air cooling technology, the power of the motor driven by the inverter is below 3500KW.
Foreign frequency converters have basically achieved trinity control of open loop, closed loop and speed sensorless control, while most of our products are still ordinary V/F control methods. Many researches have been carried out in the industry on frequency converter speed control systems. The most urgent task is how to convert theoretical knowledge into industrial products to improve the performance and quality of my country's frequency converters.
The development of the frequency converter puts forward new requirements for the electric motors matched with it. In the past, the research on supporting motors mainly focused on the reduction of motor loss, temperature rise, vibration, noise and harmonic torque caused by the harmonic components of the inverter power supply. In recent years, with the application of IGBT in the inverter, the carrier frequency has even reached 20K, which brings a series of negative effects, such as high-frequency PWM pulse waves seriously affect the insulation and life of the motor, the common mode voltage output by the inverter , Shaft current is formed, causing bearing pitting corrosion, thereby shortening the life of the motor. In this regard, the Institute of Electrical Engineering and related manufacturers have completed the development of YVF2 series inverter-specific motors, and completed the project of "New Type High Frequency Pulse-Resistant Electromagnetic Paint Wire Using Nanotechnology". The ability of this kind of enameled wire to withstand high-frequency pulses is ordinary 51 times the line.
In addition, the power supply of the frequency conversion motor is modulated by high frequency, and its performance test method is different from the power frequency motor. It is urgent to develop a method and a testing instrument suitable for the performance test of the frequency conversion motor.
(1) At present, the provinces and cities with high output of small and medium-sized motors are Shandong, Jiangsu, Hebei, Shanghai, Zhejiang, Guangdong and Liaoning in order, which shows that most of the enterprises are concentrated in coastal areas.
(2) Due to the development of emerging private enterprises, joint ventures, and foreign-invested enterprises, the proportion of state-owned enterprises in the small and medium-sized motor industry has declined, and the output of small and medium-sized motors has gradually been concentrated to "large producers".
(3) The three-phase asynchronous motors Y, Y2, Y3 series have been completely established for small and medium motors.
In 1985, the Y series and its derivatives were quickly promoted. Its power range was 0.55 to 250 KW, and the center height of the base was 80 to 315. Through the introduction and digestion of technologies from Westinghouse and BBC, the Y series 6KV, 220～2800KW medium-sized high-voltage three-phase asynchronous motor developed by ourselves, with a novel box structure, is currently the leading product of domestic medium-sized high-voltage motors. As China's power grid voltage increased from 6KV to 10KV, 10KV series of small and medium-sized high-voltage asynchronous motors were developed.
In 1996, the Institute of Electrical Engineering led the relevant manufacturers to complete the development of the Y2 series, with a power range of 0.12 to 315KW and a base height of 63 to 355. This series of products significantly reduces no-load noise and effectively suppresses load noise.
In 2003, relevant institutes organized by the Institute of Electrical Engineering established a complete series of Y3 series using cold-rolled silicon steel sheets. Its energy consumption reached the national standard GB18163-2002 energy consumption limit value, and also reached the European eff2 efficiency standard, and the main The performance index has reached the advanced level of similar international products.
development trend
a Further promote high-efficiency asynchronous motors
In 1992, the US Department of Energy issued new energy regulations, which proposed the efficiency standard (ie EPACT index) of high-efficiency three-phase asynchronous motors, and stipulated that from October 24, 1997, the efficiency of all general-purpose motors manufactured and imported must meet This standard. In the future, ultra high efficiency motors (NEMAPremium) will be further proposed. In 1999, the European Association of Motor and Power Electronics Manufacturers (CEMEP) established three levels of efficiency standards, eff1, eff2, and eff3, and decided to reduce motor production by 50% below the eff3 standard level by 2003, and no longer produce after 2006.
In August 2002, my country officially implemented the national standard (GB18163-2002) of "Limited Values of Energy Efficiency and Evaluation of Energy Conservation for Small and Medium-sized Three-phase Asynchronous Motors". Therefore, through energy-saving planning and the decree that "replace heat with cold", the new Y3 series should be vigorously promoted to become the leading product of China's low-voltage three-phase asynchronous motors, and the new round of derivative products should also be in the new Y3 series Expand on.
Induction motor
b Further promote the development and application of three-phase asynchronous motor series powered by inverter
In recent years, the demand for fans and pumps in various sectors of the national economy has been increasing. According to statistics from relevant departments, the total installed capacity of fans and pump motors in the country is about 35,000MW, and the power consumption accounts for about 40% of the national electricity consumption. Taking thermal power plants as an example, according to statistics, the total capacity of supporting high-voltage motors for blowers, induced draft fans, primary fans, powder discharge fans, boiler feed pumps, circulating water pumps, condensate pumps, and mortar pumps of thermal power plants in the country is about 15000MW. The equipment is in continuous operation for a long time but is often in a low-load or variable-load operating state, so its energy saving potential is great. It is estimated that the energy saving potential of improving the operating efficiency of fans and pump systems through frequency converter speed regulation can reach 30-50 billion degrees per year, which is equivalent to the annual total power generation of 6-10 large thermal power plants with a installed capacity of 1000MW. Therefore, it is very meaningful to vigorously promote the application of inverters, especially high-voltage inverters. At present, the international research on high-frequency motor frequency conversion speed regulation technology is very active, and there are many types of frequency converters. Most high-voltage motors in my country are rated at 6KV and 10KV. Due to the voltage limit of power electronic devices, it is still difficult to achieve the direct high-voltage output of inverters of this level. The output voltage of the unit series multilevel inverter can reach 10KV or higher, and the input and output waveforms are good, and the harmonic pollution to the power grid is small, so it is widely used in my country. The technology is relatively mature in the world, the output voltage can reach 14.4KV, the inverter uses water cooling technology, and the maximum capacity of a single machine can reach 15000KW. my country uses air cooling technology, the power of the motor driven by the inverter is below 3500KW.
Foreign frequency converters have basically achieved trinity control of open loop, closed loop and speed sensorless control, while most of our products are still ordinary V/F control methods. Many researches have been carried out in the industry on frequency converter speed control systems. The most urgent task is how to convert theoretical knowledge into industrial products to improve the performance and quality of my country's frequency converters.
The development of the frequency converter puts forward new requirements for the electric motors matched with it. In the past, the research on supporting motors mainly focused on the reduction of motor loss, temperature rise, vibration, noise and harmonic torque caused by the harmonic components of the inverter power supply. In recent years, with the application of IGBT in the inverter, the carrier frequency has even reached 20K, which brings a series of negative effects, such as high-frequency PWM pulse waves seriously affect the insulation and life of the motor, the common mode voltage output by the inverter , Shaft current is formed, causing bearing pitting corrosion, thereby shortening the life of the motor. In this regard, the Institute of Electrical Engineering and related manufacturers have completed the development of YVF2 series inverter-specific motors, and completed the project of "New Type High Frequency Pulse-Resistant Electromagnetic Paint Wire Using Nanotechnology". The ability of this kind of enameled wire to withstand high-frequency pulses is ordinary 51 times the line.
In addition, the power supply of the frequency conversion motor is modulated by high frequency, and its performance test method is different from the power frequency motor. It is urgent to develop a method and a testing instrument suitable for the performance test of the frequency conversion motor.
