With the establishment of a resource-saving and environment-friendly society in recent years, energy conservation and emission reduction have increasingly become the focus of the industry. In terms of practicality, the motor frequency conversion control energy-saving technology is developing rapidly, because the motor's variable frequency control energy-saving technology can effectively reduce the energy consumption of the motor, save the cost of the motor, and enable the enterprise to obtain greater economic benefits, thus being recognized by professionals from all walks of life. Value and attention. The variable frequency motor control technology mainly changes the speed of the motor by changing the frequency of the input three-phase alternating current, and uses the on-off function of the power semiconductor device to convert the power frequency power source into another power control device. At present, the motor frequency converters used in the market mainly adopt the AC-DC-AC mode, that is, the VF frequency conversion or vector control frequency conversion technology.
The variable frequency electric motor has the characteristics of easy control circuit, the cost is relatively low, and the mechanical characteristic hardness is good, which can meet the requirements of smooth and low speed of transmission, and is widely applicable in various industries. However, it also has some disadvantages. For example, when the control mode is used at a low frequency, since the output voltage is relatively low, the torque is significantly affected by the stator resistance voltage drop, resulting in a decrease in the output maximum torque. The variable frequency motor also has low system performance, low torque utilization, and stability due to the deterioration of stator resistance and inverter dead-end effect.
