The main differences between the permanent magnet motor and the excitation generator :
Different excitation methods. The permanent magnet generator uses the permanent magnet to generate a magnetic field without an external power supply for inspiration; the excitation generator requires an external power supply or the current output of its own generator to motivate the magnetic field.
The principle is different. The permanent magnet generator generates a magnetic field through the permanent magnet, and the rotation of the rotor causes the magnetic field to interact with the coils on the stator; the excitation generator controls the changes in the rotor magnetic flux by controlling the incentive current, which will generate the electromotive force.
Different structures. The structure of the permanent magnet generator is relatively simple, without complex excitation mechanisms, such as excitation winding and voltage regulatory controllers, etc.; Excitation generators usually require these complex excitation systems.
Efficiency is different. The efficiency of permanent magnet generator is usually higher than the excitation generator because they do not need additional excitation mechanisms.
The scope of application is different. The permanent magnet generator is suitable for small power and high -frequency fields, such as small wind turbines and solar generation systems; excitation generators are suitable for high -power and low -frequency fields, such as large thermal power plants and hydropower stations.
In general, due to its simple design, high efficiency, and reliability, permanent magnet generator is usually used for occasions that require high accuracy and reliability, while the excitation generator can adapt to different loads because it can adjust the excitation current to adapt to different loads. Changes are usually used for occasions that need to be controlled by complex power systems.
Features of low -speed permanent magnet generator:
Low -speed permanent magnet generator, high efficiency, high power factor, suitable for wind power, hydropower, new energy power generation, etc. It can achieve low speed, high -power, and frequency output. It can save the reducer, rectifier inverter, etc., to improve system efficiency and improve system stability.
1. There are a large number of permanent magnetic generators, which improves the frequency of electricity in the aircraft at low speed, solve the problem of unstable power generation voltage, improves the rectification inverter efficiency, and saves the cost of subsequent processing equipment.
2. The generator is optimized and analyzed by the finite element, the structure is reasonable, and the torque is small. It solves the problem that it is difficult to start at low speeds of windmills and improves wind energy utilization.
3. Low -speed permanent magnetic generator has delete the speed increaser, improves the reliability of power generation equipment, improves power generation efficiency, and small maintenance volume.
4. Carbon -free brush, no magnetic winding, non -inspirational control box, simple structure, no spark. High reliability, protection level: IP54, long service life.
5. Small size, light weight, high energy density, suitable for specific occasions.
6. The generators are operating efficiently throughout the speed range, and the power generation efficiency is high.
7. The generator adopts imported oil high -speed bearing, which is exempt from maintenance, high reliability, and long generator life.
8. Parameters such as generator voltage, speed, power, etc. can be changed as needed. It can change the installation method of generator appearance, can use flower keys axis, dual axis extension, upper and lower faste orchids.
Wind power generation low -speed permanent magnet generator:
Small wind turbine mainly uses a low -speed permanent magnet generator. This is mainly because the wind wheel of a small wind power generator is directly coupled on the axis of the generator, eliminating the heavier mechanism. So this required low speed generator such as several hundred rpm.
Small wind turbines can be DC generators or AC generators. At present, most of the generators used by small wind turbines are three -phase AC generators. Due to the different forms of magnetic fields, the three -phase AC generator has permanent magnetism and excitation types. The three -phase AC electricity generated by them all output DC power after rectifying the rectification of the diodes. In order to facilitate installation and maintenance, many small wind turbines now install the rectifier in the controller when using an AC generator.
Compared with DC generators, AC generators have the advantages of small size, light weight, simple structure, and good low -speed power generation performance. Especially the interference with surrounding radio equipment is much smaller than DC generators, so it is suitable for small wind turbines.
Hydropower permanent magnet generator:
The role of permanent magnet machines in the water wheel generator is very critical. It generates a magnetic field by permanent magnet, so that rotor rotates and outputs electrical energy. Compared with traditional generators, the incentive method of permanent magnet generator is simpler and reliable, and more energy -saving and environmentally friendly. In addition, in the field of hydropower, permanent magnet also has the following advantages:
1. Improve the efficiency of the generator:
The permanent magnet generator uses permanent magnetic rotor to save the excitation coil in the traditional generator, so it has higher efficiency.
2. Reduce maintenance costs:
The structure of the permanent magnet generator is simple, the maintenance cost is low, and it also has a long service life, which can effectively reduce the maintenance cost of the power plant.
3. Reduce the impact of the grid on the generator:
The permanent magnet generator can output high voltage and large current in a short time, which can effectively resist the impact of the power grid on the generator, and improve the stability and safety of the generator.
At present, permanent magnet generators have been widely used in the field of hydropower. The permanent magnet generator has high applicability in small hydropower stations, and it can generate electricity through small flow and low water resources. At the same time, the permanent magnet machine also has the following applications in the field of hydropower:
1. Ocean wave :
Using permanent magnet generators and hydraulic collectors can effectively use wave to generate power generation.
2. Micro -hydropower development:
The permanent magnet machine can be applied to the micro hydropower station, which is transformed into electrical energy through water energy to meet the electricity needs of some remote areas and rural areas.
As an important part of the hydraulic power generation system, the permanent magnet generator of the water wheel generator can achieve the rotation of the water wheel generator rotor and the production of electrical energy by permanent magnetic excitation. In the field of hydropower, permanent magnet generators have higher efficiency, lower maintenance costs and better stability. The application scope of permanent magnet generator is also gradually expanding, and in the future, permanent magnet generators will be widely used in the field of hydropower.