Energy-saving variable frequency motor control technology

As in recent years to create a resource-saving and environment-friendly society, energy conservation has increasingly become the focus of concern of the industry. In practical terms, the motor inverter control technology is the rapid development of energy-saving, energy-saving technology frequency control because the motor can effectively reduce the energy consumption of the motor, the motor cost savings, enable enterprises to gain greater economic benefits, and thus subject to all professionals in attention and concern. Variable frequency motor control technology is mainly by changing the input frequency of the three-phase alternating current to change the motor speed, the use of power semiconductor devices will be the role of the on-off frequency to another frequency power conversion power control device. Currently on the market using the motor drive mainly AC - DC - AC manner that VF or vector control frequency inverter technology.

Frequency electric circuit having easy control characteristics, the cost is relatively low, and the mechanical characteristics of a good hardness, able to meet the requirements of low-speed transmission smooth, easy to be widely used in various industries. However, it also has some drawbacks, e.g., at low frequencies using this control mode, because the output voltage is relatively low, the voltage drop across the stator resistance torque that is significantly affected, resulting in the maximum output torque decreases. Inverter motor also has the system performance is not high torque utilization is not high, because of the presence of stability stator resistance and inverter dead effects worse characteristics.

Reduce the frequency of major and several of the following factors:

(1) motor load factor. At low load factor of the motor, it can save electricity rate is relatively high;

(2) a reasonable degree the original operating condition parameter values. When the motor traffic, speed and other factors can be adjusted larger the value, the savings in electricity rates will be more, if the amount of adjustable smaller, less savings in electricity rates;

(3) the original adjustment mode and speed mode;

(4) work using the motor itself.

Frequency control of motor energy-saving technology compared with weak, mainly in two aspects. First, the efficiency of the motor and passive facilities is low. Although China's production of electrical motors and foreign production levels considerably, but compared with foreign motor, higher prices, lower market share, manufacturing technology and process level there is a certain gap. Second, the low efficiency of the motor system. China's motor system often match unreasonable situation, leading to long-term equipment running low load. The system adjusts the motor way backward, causing energy waste. Motor frequency control energy-saving technology can reduce energy use, reduce greenhouse gas emissions, and reduce the cost, to achieve emission reduction targets.