What is the difference between high efficiency motor and ordinary motor?

Editor:浙江汇迅骏机电技术有限公司 │ Release Time:2021-08-28 

Ordinary motor: the motor is a device that convert electrical energy to mechanical energy, motor absorption into mechanical power is 70% to 95%, that's the beauty of the efficiency value of the motor, it is an important technical indicators of the motor, the rest 30% to 5% by motor itself because of fever, such as mechanical consumption consume, so this part of the electrical energy wasted.  

High efficiency motor: the motor with high energy utilization rate is called high efficiency motor, referred to as "high efficiency motor". For ordinary motors, it is not easy to improve the efficiency of 1 percent, the material will increase a lot, and when the motor efficiency reaches a certain value, no matter how much material can not be improved. Most of the high-efficiency motors on the market are the replacement products of three-phase asynchronous motors, that is to say, the basic working principle has not changed. 


The efficiency of high-efficiency motor is mainly improved through the following ways: increase material: increase the outer diameter of the core, increase the length of the core, increase the size of stator groove and increase the weight of copper wire to improve the efficiency, such as: The outer diameter of y2-8024 motor will be increased from the current φ 120 to φ 130, some foreign increase φ 145, and the length will be increased from 70 to 90. The amount of iron used for each motor increases by 3Kg. The copper wire increases by 0.9kg. The silicon steel sheet with good magnetic conductivity is used. In the past, the hot rolled sheet with large iron loss is used. Now, the cold rolled sheet with low loss is used, such as DW470.  Even lower than DW270. Improve machining accuracy and reduce mechanical loss Replace small fan to reduce fan loss adopt high-efficiency bearings. The electrical performance parameters of the motor were optimized by changing the groove shape. Adopt cast copper rotor (complicated process, high cost).  Therefore, to make a truly efficient motor, much higher costs in design, raw materials and processing can make electricity into mechanical energy to a large extent. 


Effective energy saving measures of the motor: the motor energy saving is a systematic project, involving motor of whole life cycle, from the design, manufacture of the motor to motor selection, operation, adjustment, repair, scrap, to the entire life cycle from the motor considering the effect of energy saving measures, main consideration in this respect at home and abroad from the following several aspects to improve efficiency. The design of energy-saving motor refers to the use of optimization design technology, new material technology, control technology, integration technology, test and testing technology and other modern design means to reduce the power loss of the motor, improve the efficiency of the motor, the design of efficient motor. When the motor converts electric energy into mechanical energy, it also loses part of its energy. The typical AC motor loss can be divided into fixed loss, variable loss and stray loss. Variable loss varies with load, including stator resistance loss (copper loss), rotor resistance loss and brush resistance loss; Fixed loss is independent of load, including core loss and mechanical loss. Iron loss is composed of hysteresis loss and eddy current loss, which is proportional to the square of voltage, and hysteresis loss is inversely proportional to frequency. Other stray losses are mechanical losses and other losses, including friction losses of bearings and wind resistance losses caused by rotation of fans and rotors. 


Advantages of high efficiency motor: direct start, asynchronous motor can be replaced. Rare earth permanent magnet energy-saving motor itself can save more than 3% energy than ordinary motor.  Motor power factor is generally higher than 0.90, improve the grid quality factor, no need to add power factor compensator. Motor current is small, save the transmission and distribution capacity, prolong the overall operating life of the system. Add driver can realize soft start, soft stop, stepless speed regulation, power saving effect is further improved.