1.Key Advantages of Permanent Magnet Synchronous Motors
Permanent magnet synchronous motor has many significant advantages. It is highly energy-efficient, even at speeds above its rated level, it maintains high efficiency, significantly reducing energy consumption compared to traditional asynchronous motors. For example, when driving a fan or pump load in industrial production, the efficiency of permanent magnet synchronous motors in the light load area is far higher than that of asynchronous motors, which can effectively save energy costs.
In terms of power output, the permanent magnet synchronous motor has a large power density and can output greater torque under the same volume, which makes it perform well in application scenarios with limited space, such as the drive system of electric vehicles, which can provide strong power in a compact body space and improve the performance and endurance of the vehicle.
High control accuracy is another advantage of permanent magnet synchronous motor, which can achieve accurate speed adjustment and torque control. In the automated production line, its high-precision control characteristics can ensure the precision and stability of the production process, effectively improve product quality and production efficiency.
The response speed of the permanent magnet synchronous motor is fast, and it can quickly respond to load changes, which is suitable for frequent start and stop and speed regulation occasions, such as the drive system of the elevator, which can achieve smooth and fast lifting and improve the use experience of passengers.
In addition, permanent magnet synchronous motors operate with less noise and vibration, thanks to their simple rotor structure and small rotor inertia. In environments with strict noise requirements, such as ventilation equipment or air conditioning systems used in hospitals, libraries and other places, permanent magnet synchronous motors can effectively reduce noise interference.
Its structure is relatively simple, since the rotor contains no windings, the number of components is reduced, not only reduces the weight and volume of the motor, but also improves reliability and service life, and reduces maintenance costs.
2.Reasons for Phasing Out Asynchronous Motors
The low power factor of induction motors requires power factor correction devices, which increase system cost and complexity to improve power quality, increasing equipment cost and system complexity. In some places where power supply is tight or power quality requirements are strict, such as precision electronics manufacturing plants, low power factor induction motors may have an adverse effect on the entire power system.
During operation, the noise of the induction motor is relatively large, which is due to the existence of induction current in the rotor, resulting in large electromagnetic vibration and mechanical vibration inside the motor, and then generate noise. In environments with strict noise requirements, such as hospitals, libraries, recording studios and other nearby equipment, if the use of asynchronous induction motors, the noise generated may interfere with normal work, study and life.
The temperature rise of the motor is high, because the loss during operation is large, mainly including copper loss, iron loss and mechanical loss. Higher temperature rise will not only affect the service life of the motor, but also may cause the motor performance to decline, and even failure. In the high-temperature environment or long-term continuous operation of the occasion, such as steel mills or generator sets in large hydropower stations, the generator set of large hydropower station, etc., the temperature rise of the induction motor needs special attention, and usually needs to be equipped with special cooling devices, such as fans, radiators, etc., which increases the volume, cost and energy consumption of the equipment.
Although speed regulation can be achieved through frequency conversion technology, the speed regulation range of the induction motor is relatively limited, and it cannot meet the application needs of some wide speed regulation range requirements. In some equipment that requires a wide range of speed regulation, such as CNC machine tools, electric vehicles, etc., their limited speed regulation can restrict equipment performance.
The induction motor has high requirements on the stability and quality of the power supply, and the voltage fluctuation and frequency change of the power supply may affect its normal operation. In some areas with unstable power supply or in equipment with high power quality requirements, such as electronic instrumentation manufacturing equipment, precision machining equipment, etc., induction motors may run unstable, reduce efficiency or even damage due to power supply problems.
It requires a large starting current when starting, which may have an impact on the power grid, affecting the stability of the power grid and the normal operation of other equipment. In some occasions where the power grid capacity is small or sensitive to power grid shocks, such as small factories, residential power supply systems, etc., the large starting current of the asynchronous induction motor may cause voltage fluctuations, light flickering and other problems, and even lead to other equipment failures.
Due to the uneven distribution of the induced current in the rotor, the induction motor may have a large torque fluctuation during operation, which will affect the smooth operation of the motor and the normal operation of the load. In some equipment with high torque stability requirements, such as textile machinery, printing machinery, etc., the torque fluctuation of the asynchronous induction motor may lead to problems such as reduced product quality and increased equipment wear.