The advantages of permanent magnet generator

May 04, 2022

Permanent magnets are not only a magnetic source in a motor, but also an integral part of the magnetic circuit. Permanent magnet generators have the following advantages


1. Simple structure and high reliability

The permanent magnet generator eliminates the structure of the excitation winding, brushes and collector rings so that the structure is simple, which avoids the faults such as burning and disconnection of the excitation winding, and the wear and tear of the brushes and collector rings. Reliable performance.


2. Small size, high power

The permanent magnet generator adopts a simplified rotor structure, and there are two types of parallel magnetic field structure and series magnetic field structure: the rotor of the parallel magnetic field structure is made by casting and pressing, the permanent magnet is embedded in the inner surface, and the rotation speed is high. The rotor of the series magnetic field structure adopts a steel structure, and the permanent magnet is embedded on the surface. The magnetic induction intensity on the surface of the rotor is strong, and the overall structure is firm and reliable. Due to the simplification of the rotor structure, the internal structure of the generator is compact, the moment of inertia of the rotor is small, and the practical rotational speed is increased, therefore, the power ratio (ratio of power to volume) is improved.


3. Good low-speed power generation performance

The permanent magnet generator has good low-speed power generation performance and high output power. When running at idle speed, the output power of the permanent magnet generator is twice as high as that of the excitation generator.


4. High efficiency and energy saving

The average efficiency of general excitation generators is only about 50% in the speed range between 1500-6000r/min; while the average efficiency of permanent magnet generators can reach 75% to 80%. Therefore, permanent magnet generators are more energy efficient.


5. High voltage regulation accuracy, can prolong the service life of the battery

The permanent magnet generator adopts switching rectification and voltage regulation mode, and adopts small current pulse charging, which avoids the possibility of damage to the battery caused by over-current charging, and can prolong the service life of the battery.


6. No wireless interference

The permanent magnet generator has no brushes, no collector rings, and no electric sparks generated during operation. Therefore, there is no wireless interference, which greatly improves the performance.


However, due to the high cost of dilute permanent magnet materials, the manufacturing cost of permanent magnet generators is generally higher than that of excitation generators.