11

2023

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07

Characteristics and advantages of permanent magnet generator

Author:

作者


Permanent magnet variable frequency brushless generator

definition:

A generator with permanent magnet excitation instead of electric excitation. There are no field windings, brushes and slip rings. Permanent magnets are generally set on the rotor, and permanent magnet generators are usually used as auxiliary exciters for turbogenerators.

structure:

The biggest difference between a permanent magnet generator and an excitation generator is that its excitation magnetic field is generated by permanent magnets. Permanent magnets are both a magnetic source and an integral part of a magnetic circuit in a motor. The magnetic properties of permanent magnets are not only related to the manufacturing process of the manufacturer, but also related to the shape and size of the permanent magnets, the capacity of the magnetizer and the magnetization method. The specific performance data are highly discrete. Moreover, the magnetic flux and magnetomotive force that the permanent magnet can provide in the motor also vary with the material properties, size and operating status of the rest of the magnetic circuit. In addition, the magnetic circuit structure of the permanent magnet generator is various, the leakage magnetic circuit is very complex and the proportion of the leakage flux is relatively large, the ferromagnetic material part is relatively easy to saturate, and the magnetic permeability is nonlinear. All of these increase the complexity of the electromagnetic calculation of the permanent magnet generator, making the accuracy of the calculation result lower than that of the electric excitation generator.

Features:

1 The permanent magnet generator eliminates the excitation winding, carbon brush and slip ring structure of the excitation generator, and the whole machine structure is simple, avoiding the easy burning and disconnection of the excitation winding, carbon brush and slip ring structure, and the whole machine structure is simple , to avoid the excitation generator excitation generator excitation winding easy to burn, disconnection, carbon brushes, slip rings easy to wear and other failures, the reliability is greatly improved.

2 Small size, light weight, high specific power

The adoption of the permanent magnet rotor structure makes the internal structure design of the generator very compact, and the volume and weight are greatly reduced. The simplification of the structure of the permanent magnet rotor also reduces the moment of inertia of the rotor, increases the practical speed, and achieves a very high specific power (that is, the ratio of power to volume).

3 Good power generation performance at medium and low speeds

In the case of the same power level, at idle speed, the output power of the permanent magnet generator is twice that of the excitation generator, that is to say, the excitation generator of the actual power level of the permanent magnet generator.

4 can significantly prolong the storage life shortened. The opening rectifier output pair of the permanent magnet generator is charged with a small current pulse, and the charging effect is better with the same charging current, thereby prolonging the service life of the battery.

5 high efficiency

The permanent magnet generator is an energy-saving product. The permanent magnet rotor structure eliminates the excitation power required to generate the rotor magnetic field and the mechanical loss of friction between carbon brushes and slip rings, which greatly improves the efficiency of the permanent magnet generator. The average efficiency of ordinary excitation generators is only 45% to 55% in the speed range between 1500 rpm and 6000 rpm, while that of permanent magnet generators can be as high as 75% to 80%.

6 with self-starting voltage regulator

No need for external excitation power supply. The generator generates electricity as long as it spins. When the battery is damaged, the car charging system can still work normally as long as the engine is running. If the car does not have a storage battery, the ignition operation can also be realized as long as the handle is turned or the car is slipped.

7 Especially suitable for working in wet or dusty harsh environments

8 No radio interference

The permanent magnet generator has no carbon brush and no slip ring structure, which eliminates the radio interference caused by the friction between the carbon brush and the slip ring; Requirements for ambient temperature.