G series YVP/YVF variable-frequency variable-speed three-phase asynchronous motor is a special asynchronous motor applicable to the operation of variable-frequency variable-speed system powered by frequency converter. It can realize stepless speed regulation of cage-type three-phase asynchronous motor. It has the mechanical characteristics of low-speed constant torque output and high-speed constant power output. It has the advantages of compact structure, good speed regulation performance and obvious energy-saving effect, and can be widely used in machinery, building materials Beverage and other industries generally need power machinery matching occasions with speed regulation. It can be used for open-loop or closed-loop control, and can also be interfaced with computer control to realize automatic control. It is an ideal product for stepless speed regulation of AC motors.
The electromagnetic design of the characteristics of the permanent variable frequency motor:
For ordinary asynchronous motors, the main performance parameters to be considered during redesign are overload capacity, starting performance, efficiency and power factor. As the critical slip is inversely proportional to the power frequency, the variable-frequency motor can be started directly when the critical slip is close to 1. Therefore, the overload capacity and starting performance need not be considered too much. The key problem to be solved is how to improve the adaptability of the motor to non-sinusoidal power supply.
The methods are generally as follows:
1) Reduce stator and rotor resistance as much as possible.
Reducing the stator resistance can reduce the fundamental copper loss to compensate for the increase of copper loss caused by higher harmonics
2) In order to suppress the high order harmonics in the current, it is necessary to properly increase the inductance of the motor. However, the rotor slot leakage reactance is large and its skin effect is also large, and the copper loss of higher harmonic is also increased. Therefore, the size of motor leakage reactance should take into account the rationality of impedance matching in the entire speed range.
3) The main magnetic circuit of the variable-frequency motor is generally designed to be in an unsaturated state. One is to consider that higher harmonics will deepen the magnetic circuit saturation, and the other is to consider that at low frequency, the output voltage of the converter is appropriately increased in order to improve the output torque.
2. Structural design
In the structural design, the influence of non-sinusoidal power supply characteristics on the insulation structure, vibration, noise cooling mode and other aspects of the variable frequency motor is also mainly considered, and the following issues are generally noted:
1) The insulation grade is generally F or higher, and the strength of ground insulation and wire turn insulation should be strengthened, especially the ability of insulation to withstand impulse voltage.
2) For the vibration and noise of the motor, the rigidity of the motor components and the whole shall be fully considered, and its natural frequency shall be increased as much as possible to avoid resonance with each force wave.
3) Cooling mode: forced ventilation cooling is generally adopted, that is, the cooling fan of the main motor is driven by an independent motor.
4) Measures to prevent shaft current: bearing insulation measures shall be taken for motors with capacity more than 160KW. The main reason is that it is easy to produce magnetic circuit asymmetry and shaft current. When the current generated by other high-frequency components acts together, the shaft current will increase greatly, resulting in bearing damage. Therefore, insulation measures should be taken generally.
5) For constant power variable frequency motors, when the speed exceeds 3000/min, special grease with high temperature resistance shall be used to compensate for the temperature rise of bearings.
Common synchronous motor:
1、 Features:
1. The power factor is advanced, and the general rated power factor is 0.9, which is conducive to improving the power factor of the grid and increasing the capacity of the grid.
2. The operation stability is high. When the grid voltage suddenly drops to 80% of the rated value, its excitation system can automatically adjust and implement forced excitation to ensure the stable operation of the motor.
3. The overload capacity is larger than the corresponding asynchronous motor.
4. High operating efficiency, especially low speed asynchronous motor.
2、 Start mode
1. In asynchronous starting method, most synchronous motors are equipped with a starting winding similar to the cage winding of asynchronous motors on the rotor. The re-excitation circuit is connected in series with an additional resistance of about 10 times the resistance value of the excitation winding to form a closed circuit. The stator of the synchronous motor is directly connected to the power grid so that it can be started as an asynchronous motor. When the speed reaches sub-synchronous speed
(95%), then cut off the additional resistance.
2. Variable frequency starting, starting with frequency converter, will not be repeated.
Overview of permanent variable frequency motor
G series YVP/YVF variable-frequency variable-speed three-phase asynchronous motor is a special asynchronous motor applicable to the operation of variable-frequency variable-speed system powered by frequency converter. It can realize stepless speed regulation of cage-type three-phase asynchronous motor. It has the mechanical characteristics of low-speed constant torque output and high-speed constant power output. It has the advantages of compact structure, good speed regulation performance and obvious energy-saving effect, and can be widely used in machinery, building materials Beverage and other industries generally need power machinery matching occasions with speed regulation. It can be used for open-loop or closed-loop control, and can also be interfaced with computer control to realize automatic control. It is an ideal product for stepless speed regulation of AC motors.
The company has the ability to develop special-shaped products. It can be customized according to customer requirements and drawings.
[Hengshui Yongdong Motor Manufacturing Co., Ltd.] Service commitment and product delivery guarantee:
The motor materials of our company are brand new and all copper. Within one year from the date of purchase, there will be free replacement in case of quality problems.
The default voltage of Y, Y2, YX, YE, YVF, YCT, YEJ, YD, and other motors is 380v, the reference frequency is 50Hz, the installation mode is B3, B35 rises by 3%, and the price of different voltage, different frequency, double output shaft, V1, IP55 rises by 8%.