At present, AC asynchronous motor is widely used in related fields. According to the actual operation of the machine tool under the three-phase asynchronous motor, the actual operation efficiency of the motor is low and the energy consumption is high because of the use problem of "big horse pulling car". In practical work, it is an urgent problem to reduce voltage and save energy and increase efficiency of three-phase asynchronous motor. This paper briefly studies and discusses the method of reducing voltage and saving energy of three-phase asynchronous motor, in order to provide reference for future work.

    Based on the characteristics of low price, simple operation and maintenance management, AC asynchronous motor is widely used in the field of machine tool cutting. In the actual work process, because the motor is designed to achieve normal operation under overload, so in its operation process, the existence of load operation state makes the overall energy consumption of the motor is not proportional to the benefit output, and the power consumption is huge. In view of this, it is necessary to conduct in-depth research and Discussion on this issue.

    1. Starting point of energy saving design

    In the process of implementing this design concept, we can start from the following three aspects:

    ① Optimize and perfect the process, structure and parts of the motor, fully integrate the energy-saving concept in the work, and reduce the overall energy consumption of the motor by optimizing the parameters of the motor.

    ② The corresponding frequency conversion energy-saving technology is integrated into the motor speed control. The application of this energy-saving technology can make the motor keep different speed under different operating conditions, so as to achieve the purpose of energy saving. In the process of practice, it is necessary to make energy-saving design for the voltage and frequency of the driving power supply, ensure its speed, and make it be able to optimize the adjustment according to the corresponding output in a smooth way, so as to achieve the goal of energy saving.

    ③ It can reduce voltage and save energy. The loss of a motor is the difference between the output mechanical loss and the input active power. In the three-phase asynchronous motor, iron loss and copper loss are the main energy consumption points. Therefore, this paper mainly studies the corresponding copper loss and iron loss under the motor loss. According to its relationship with rotor current and working voltage, the voltage at the working end can be optimized continuously, and the goal of reducing voltage and saving energy can be realized by reducing voltage.

    2. Energy saving module

    2.1 design of energy saving module

    During the operation of three-phase asynchronous motor, its working load state can be divided into constant rotation load and variable torque load. The results of correlation analysis show that in order to realize the step-down energy-saving design of motor, the sum of iron loss and copper loss can be reduced, or the output power of motor can be reduced, which lays the foundation for realizing the goal of reducing voltage and energy saving.

    In the design of energy-saving module, the first step is to design voltage regulating power. At present, there are two kinds of AC voltage regulating circuits: chopper and phase control. Based on the phase control voltage regulation circuit, it can lay the foundation for changing the output voltage, and the overall structure is simple, and the actual operation response speed is fast. The circuit based on chopper type realizes the control of the power supply by means of the corresponding full control switch, which lays the foundation for regulating the output voltage of the motor, and at the same time, its response speed is relatively fast. In this voltage regulating circuit, with the help of double narrow pulse thyristor, the load can pass through the relevant circuit. In the process of practical application, the advantage of the circuit is convenient wiring. For the working mechanism of trigger angle voltage regulation, when the trigger angle is larger than the freewheeling angle, the motor is in voltage regulation state, which can ensure that the corresponding thyristor is always in the correct trigger state; when the trigger angle is between zero and freewheeling angle, the current is a complete sine wave, and the voltage regulator is out of control. In order to solve this problem, it is necessary to optimize the trigger pulse. In general, pulse width can be used to solve the problem. In the voltage regulation trigger module, it needs to combine the phase condition and pulse width condition to design. Under the condition of phase, the trigger signal should be synchronized with the voltage of motor power supply; under the condition of pulse width, single narrow pulse should not be used as far as possible, but double narrow pulse should be used to meet the demand of pulse width.

    In the application of voltage regulating module, due to the limitation of thyristor, it is necessary to configure the corresponding thyristor according to the motor model to meet the actual operation requirements of the motor. In view of the motor overload and other abnormal, it can be compensated by thyristor. For the main circuit, it is necessary to add phase loss protection relay to ensure the stable operation of voltage regulation.

    2.2 application effect of pressure reduction and energy saving model

    The practical application shows that the application of voltage regulating module can achieve good energy-saving effect whether the three-phase asynchronous motor is in the state of unsteady load or constant load. It can effectively improve the energy-saving rate on the basis of reducing the voltage, improve the operation efficiency and prolong the service life of the motor on the basis of realizing the energy-saving goal. Therefore, the application of this step-down energy-saving design in machine tool motor can further implement the concept of energy-saving and consumption reduction while improving the production efficiency, and fundamentally enhance the competitiveness of enterprises, and lay a foundation for its sustainable development.

    Conclusion

    To sum up, in the process of three-phase asynchronous motor operation, a lot of electric energy is often wasted due to the existence of load state, and it is widely used in various fields. Therefore, in order to achieve the goal of reducing voltage and saving energy, this paper determines the starting point of implementing the work of motor energy saving and reducing voltage, completes the design of this energy-saving module, and applies it to practice