The application range of permanent magnet synchronous motors, the advantages and disadvantages of pe

In recent years, the permanent magnet drive system, as an important supporting component of the mine, has become the mainstream of the mining motor market with the advantages of energy saving, environmental protection, small body, light weight and more stable product operation.

The product does not need to be connected to other mechanical transmission equipment when it is used, and the permanent magnet motor is directly connected to the load, which simplifies the transmission system structure and reduces maintenance requirements. The product has the advantages of high torque, high efficiency, fast response, simple structure and reliable operation, and has been listed as the first choice for the drive system by the mine, and has also set off a revolution in the motor drive system of coal mining enterprises for a time.

Application range of permanent magnet synchronous motorsIt can be applied in coal, electric power, building materials, metallurgy, fermentation, chemical industry and other fields.

The range of applications includes belt conveyors, ball mills, elevators, vertical mills, separators, mixers, cooling towers and other products.

The advantages and disadvantages of permanent magnet synchronous motors are as follows:

1. Advantages of permanent magnet synchronous motor.

Compared with DC motors, permanent magnet synchronous motors do not have the disadvantages of DC motors such as commutators and brushes. Compared with the asynchronous motor, it does not require reactive excitation current, so it has high efficiency, high power factor, large moment of inertia ratio, reduced stator current and stator resistance loss, and rotor parameters can be measured and the control performance is good.

Compared with ordinary synchronous motors, permanent magnet synchronous motors eliminate the need for excitation devices, simplify the structure, and improve efficiency. The vector control system of permanent magnet synchronous motor can achieve high precision, high dynamic performance, and a wide range of speed regulation or positioning control.

2. Disadvantages of permanent magnet synchronous motors.

Compared with asynchronous motors, permanent magnet synchronous motors have disadvantages such as relatively high cost and difficult starting.

The controller of the permanent magnet synchronous motorformula

The constant voltage frequency ratio control method of permanent magnet synchronous motor is similar to that of AC induction motor, and the amplitude and frequency of the input voltage of the motor are controlled to change at the same time, so that the magnetic flux of the motor is constant, and the constant voltage frequency ratio control method can be adapted to the requirements of a large-scale speed regulation system.

Under the premise of not feeding back physical signals such as current, voltage or position, the permanent magnet synchronous motor can still achieve a certain control accuracy, which is the biggest advantage of the constant voltage frequency ratio control method. The constant voltage frequency ratio control method has a simple control algorithm and low hardware cost, and has been widely used in the field of general-purpose inverters.

Permanent magnet synchronous motor.

It is a synchronous motor that uses a permanent magnet to establish an excitation magnetic field, mainly by a stator.

The rotor and end cover are composed of components, which have the advantages of simple structure and energy saving, and are widely used in industry, agriculture and other industrial fields. Next, a brief introduction to the classification and advantages of permanent magnet synchronous motors.

Classification of permanent magnet synchronous motors1.Press the excitation current.

The supply mode can be classified as separately excited motor and self-excited motor.

2.According to the lead light power supply frequency, it can be classified as a permanent magnet brushless motor.

Permanent magnet brushless motors include permanent magnet brushless DC motors.

and permanent magnet brushless AC motors.

3.According to the distribution of the magnetic field of the air gap, it can be classified as a sine wave.

Permanent magnet synchronous motor, trapezoidal wave permanent magnet synchronous motor.

Advantages of permanent magnet synchronous motors1.The permanent magnet synchronous motor has a simple structure, small volume and noise.

2.The permanent magnet synchronous motor has good dynamic performance, compact structure and reliable operation.

3. The allowable overload current of the permanent magnet synchronous motor is large, and the reliability is significantly improved.

1.According to the type of working power supply: it can be divided into DC motor and AC motor.

1) DC Motor:

According to the structure and working principle, it can be divided into: brushless DC motor and brushed DC motor.

It can be divided into permanent magnet DC motor and electromagnetic DC motor.

The permanent stool is similar to the magnetic DC motor and is divided into rare earth, iron large limb oxygen, and alnico permanent magnet DC motor according to the material.

According to the excitation mode, electromagnetic DC motors are divided into series excitation, parallel excitation, separate excitation and compound excitation DC motors.

2) AC motors can be divided into: single-phase motors and three-phase motors.

1.According to the type of working power supply: it can be divided into DC motor and AC motor.

Features of permanent magnet synchronous motors:

1. Small size and light weight: In recent years, with the continuous application of permanent magnet materials, the power density of permanent magnet synchronous motors has been greatly improved. Compared with the asynchronous motor in the same volume, its volume, weight and materials used have been reduced to about 30%.

2. Low temperature rise: Because the permanent magnet in the rotor of the motor will not have resistance loss, and there will be no reactive current in the stator winding, the temperature rise of the motor is relatively low.

3. Strong bearing capacity: due to the mechanical characteristics of this type of motor are relatively hard, it has a strong bearing capacity for the disturbance of motor torque caused by the change of load, and the instantaneous torque can reach more than three times of the rated torque, which is suitable for use in the working state with large changes in load torque.

4. High work efficiency: when the rotor is installed with permanent magnets, the magnetic field of the rotor and stator is synchronized during normal operation, and the rotor winding has no induced current, so there will be no rotor resistance and hysteresis loss, which improves the work efficiency of the motor.

5. High power factor: The high power factor of this type of motor has nothing to do with the number of stages of the motor. When the motor is fully loaded, its power factor will be close to one.

Compared with the asynchronous motor, its current is smaller, the stator copper loss is relatively smaller, and the efficiency is higher. In addition, due to its relatively high power factor, the power supply capacity of the motor can be reduced.

Interesting motor - permanent magnet synchronous motor, take it apart and take a look, the difference is so big!

The permanent magnet synchronous motor is a synchronous motor that generates a synchronous rotating magnetic field by the excitation of a permanent magnet, the permanent magnet is used as a rotor to generate a rotating magnetic field, and the three-phase stator winding reacts through the armature under the action of the rotating magnetic field to induce a three-phase symmetrical current.

Compared with synchronous motors and asynchronous motors, permanent magnet synchronous motors do not have electric excitation and corresponding losses, the permanent magnet rotor does not generate heat, and the electrical load can be selected very high, so the volume is small and the power density is high. With the rapid development of new motor control theory and rare earth permanent magnet materials, the performance of permanent magnet synchronous motors has been further improved. So, what are the characteristics of permanent magnet synchronous motors?

1. High efficiency and energy saving. Because the excitation magnetic field is provided by the permanent magnet, the permanent magnet rotor does not need to be excited, and the efficiency can be as high as 90%. Compared with asynchronous motors, the high-efficiency operation speed range is wide, and the energy saving is significant.

This is especially true when operating at low speeds. Second, the temperature rise is low. No electric excitation means no loss of heat, so the temperature rise of permanent magnet motors is generally very low.

3. Good starting performance. Self-starting permanent magnet synchronous motors generally also use asynchronous starting. The rotor winding of the permanent magnet synchronous motor does not work during normal operation, and the rotor winding of the permanent magnet motor can be designed to fully meet the requirements of high starting torque, such as increasing the starting torque multiple from multiple to double or larger.

Fourth, the impact on the operation of the power grid. The asynchronous motor should absorb a large amount of reactive current from the power grid, resulting in a large amount of reactive current in the power grid transmission and transformation system, which will reduce the quality factor of the power grid and increase the load of power transmission and transformation equipment and power generation equipment. At the same time, the reactive current consumes part of the electric energy in the power grid transmission and transformation system, resulting in the low efficiency of the power grid operation, and then superimposed with the low efficiency of the asynchronous motor and the absorption of more electric energy from the power grid, the power loss is aggravated, and the power grid load is more and more aggravated.

The unique advantages of non-electric excitation and high power factor of the rotor of permanent magnet motor help to improve the quality factor of the power grid or make it no longer necessary to install compensators in the power grid.

5. Permanent magnet motors have the characteristics of wide range of efficient operation, and are widely used in the field of new energy vehicles.

6. Small size and light weight. The application of high-performance super permanent magnet materials greatly reduces the volume and weight of permanent magnet motors, and the power density is at least twice that of ordinary three-phase asynchronous motors.

Permanent magnet synchronous motor has small size, power saving, energy saving and emission reduction, high work efficiency, synchronization can be used as a generator, the disadvantage is that the structure is complex, the brush is easy to break, I hope to help you.