Weichuang Inverter plays a major role in saving energy
The so-called Weichuang Inverter It converts the three-phase power frequency (50Hz) AC power supply (or any power supply) into a three-phase voltage adjustable, frequency adjustable AC power supply, and sometimes the frequency converter It is called the variable voltage inverter VVVF. Mainly used for the adjustment of the speed of the AC motor (asynchronous machine or synchronous machine).
An AC motor variable frequency speed control system consists of three parts: the inverter motor driver AC motor and controller. The key core equipment is the inverter, which is used to achieve smooth changes in motor voltage and frequency. 1.3
Frequency control in the frequency range, static accuracy, dynamic quality, system efficiency, perfect protection function, easy to achieve automatic control and process control, etc. The voltage regulation, variable pole speed regulation, cascade speed regulation, slip speed regulation and hydraulic coupler speed regulation are incomparable. It is recognized as an ideal promising speed control solution for AC motors, representing the future development of electric drives.
In the past 30 years, frequency control has been in steel, metallurgy, petroleum, chemical, textile, chemical fiber, light industry, paper, rubber, plastic, electricity. Widely used in industries such as water and water. The application of low-voltage motor frequency conversion speed regulation has been very popular and mature. The high-frequency motor frequency control is also being paid attention to and gradually applied. In addition to excellent speed regulation performance, AC motor frequency control has significant functions such as saving energy and protecting the environment. It is an ideal speed control device for technological transformation and product upgrading. 2, frequency control and fan pump energy saving
2.1 power supply and demand contradiction (supply in short supply) there is a large power gap, need to save electricity. According to the statistics of relevant departments, in 2002 China's power generation installed capacity was 31.9 billion kW, and the annual power generation was 1,346.6 billion kWH. Although the power scale ranks second in the world, the per capita electricity consumption is the world's countdown position. Moreover, China's rapid economic development requires more electricity. If the national economy grows by 8% and the power is increased by 11%, by 2010 China's power generation capacity should be 5.7-600 million kW, and the annual power generation will reach 28,000-290 billion kWH. The continuous high temperature in the summer of 2003 caused some provinces and cities to have tight power supply and was forced to take measures to cut power. Due to the excessive burden of the power network, the local power system is unstable.
The above shows that China's power supply and demand is not balanced, and supply is less than demand. Therefore, it is necessary to save electricity. 2.2 Wind turbine water pump frequency conversion speed regulation energy saving efficiency
China's total installed motor capacity reached 450 million kW, about 65% of the national consumption Power generation. Therefore, how to achieve motor power saving is very important. Generally, there are two ways to save energy in the motor: one is to improve the efficiency of the motor itself to achieve long-term high-efficiency operation, mainly for constant speed machinery; the other is to improve the control precision of the motor speed, so that the motor runs at an energy-saving speed.
Fans, pumps and compressors are large-capacity motor-driven equipment produced by the national economy. The total motor capacity is 150 million, and the electricity consumption accounts for the whole country. About 35% of the power generation, of which about 20% to 30% of the fan pump needs speed regulation.
2.2.3 Frequency control is a good solution for energy saving of fan and water pump. According to the fluid theory, the shaft power of a centrifugal fan pump is a cubic function of the speed. When the speed is reduced, its power consumption will drop drastically. For example, at 50% speed, the shaft mechanical power is only 12.5%. Of course, the efficiency of the speed control scheme varies greatly. After the slip, the hydraulic speed control device is not efficient, η≈(1-S), at 50% speed, ηvs≈50%, and the efficiency of the inverter, The efficiency factor is high, ηvvvF≈95%~98%, and it is approximately unchanged. Therefore, in many speed control schemes, the frequency conversion speed regulation and energy saving benefits are good, and it should be a good solution.