Ordinary motor: The motor is a device that converts electrical energy into mechanical energy. 70%-95% of the electrical energy absorbed by the motor is converted into mechanical energy. This is often referred to as the efficiency value of the motor, which is an important technical indicator of the motor. The remaining 30%-5% is consumed by the motor itself due to heat, mechanical loss, etc., so this part of the electrical energy is wasted.

High-efficiency motor: The motor with a high energy utilization rate is called a high-efficiency motor, or "high-efficiency motor" for short.

For ordinary motors, it is not easy to increase the efficiency by 1 percentage point. The material will increase a lot, and when the motor efficiency reaches a certain value, no matter how much material is added, it cannot be improved. Most of the high-efficiency motors on the market are upgraded products of three-phase asynchronous motors, that is, the basic working principle has not changed.

High-efficiency motors mainly improve the efficiency of motors through the following ways:

1. Increase materials: increase the outer diameter of the core, increase the length of the core, increase the size of the stator slot, and increase the weight of the copper wire to achieve the purpose of improving efficiency. For example, the outer diameter of the Y2-8024 motor is increased from the current Φ120 to Φ130, and some foreign countries increase it to Φ145, and at the same time increase the length from 70 to 90. The amount of iron used in each motor increases by 3Kg. The copper wire increases by 0.9Kg.

2. Use silicon steel sheets with good magnetic conductivity. In the past, hot-rolled sheets with large iron loss were used, and now high-quality cold-rolled sheets with low loss are used, such as DW470. Even lower DW270.

3. Improve processing accuracy and reduce mechanical loss. Replace small fans to reduce fan loss and use high-efficiency bearings.

4. Optimize the design of the electrical performance parameters of the motor, and optimize the parameters by changing the slot shape.

5. Use cast copper rotors (complex process and high cost).

Therefore, to make a truly efficient motor, the design, raw materials, and processing costs are much higher, so that electricity can be converted into mechanical energy to the greatest extent.

Energy-saving measures for efficient motors

Energy saving of motors is a systematic project, involving the entire life cycle of motors, from motor design and manufacturing to motor selection, operation, adjustment, maintenance, and scrapping. The effect of energy-saving measures should be considered from the entire life cycle of the motor. In this regard, domestic and foreign countries mainly consider improving efficiency from the following aspects.

The design of energy-saving motors refers to the use of modern design methods such as optimization design technology, new material technology, control technology, integration technology, and test and detection technology to reduce the power loss of motors, improve the efficiency of motors, and design efficient motors.

While converting electrical energy into mechanical energy, the motor itself also loses some energy. Typical AC motor losses can generally be divided into three parts: fixed loss, variable loss, and stray loss. Variable loss changes 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 the voltage, among which hysteresis loss is inversely proportional to the frequency; other stray losses are mechanical losses and other losses, including friction loss of bearings and wind resistance loss caused by rotation of fans and rotors.

Features of high-efficiency motors

1. Save energy and reduce long-term operating costs. It is very suitable for textiles, fans, pumps, and compressors. The purchase cost of the motor can be recovered by saving electricity in one year;

2. Direct start or speed regulation with frequency converter can fully replace asynchronous motors;

3. Rare earth permanent magnet high-efficiency energy-saving motors can save more than 15℅ of electricity compared to ordinary motors;

4. The power factor of the motor is close to 1, which improves the quality factor of the power grid without adding a power factor compensator;

5. The motor current is small, which saves power transmission and distribution capacity and extends the overall operating life of the system;

6. Power saving budget: Taking a 55Kw motor as an example, a high-efficiency motor saves 15% more electricity than a general motor. The electricity fee is calculated at 0.5 yuan per kilowatt-hour. The cost of replacing the motor can be recovered by saving electricity within one year by using an energy-saving motor.

Advantages of high-efficiency motors

Direct start, can fully replace asynchronous motors.

Rare earth permanent magnet high-efficiency energy-saving motors can save more than 3% of electricity compared to ordinary motors.

The motor power factor is generally higher than 0.90, which improves the quality factor of the power grid and does not require a power factor compensator.

The motor current is small, saving power transmission and distribution capacity and extending the overall operating life of the system.

Adding a driver can achieve soft start, soft stop, and stepless speed regulation, further improving the power saving effect.