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| V8-H permanent magnet synchronous motor driver - permanent magnet synchronous motor operating mode |
| 1, the generator to obtain the excitation current in several ways
1) excitation mode of DC generator
Excitation system of the generator has a dedicated DC generator, the special DC generator said DC exciter, exciter generally coaxial with a generator, generator excitation windings by mounted on the shaft, slip ring and a fixed brush DC current from the exciter. This kind of exciting mode has the advantages of independent excitation current, reliable operation and less consumption of electricity consumption. It is the main excitation mode of the generator in the past several decades, and has more mature operation experience. The disadvantage is that the excitation regulator is slow, and the maintenance workload is large, so it is seldom used in the units of 10MW or more.
2) excitation mode of AC exciter
Some of the modern large capacity generators use AC exciter to provide exciting current. AC exciter is also installed on the generator shaft, it is the output of the AC current
Stream is supplied to the rotor of the generator excitation, at this time, generator excitation mode is he excitation mode, and as a result of the use of static rectifier device, so it is also called as he excited static excitation, AC auxiliary exciter provides excitation current. AC exciter can be a permanent magnet machine measuring device or AC generator with self excitation and constant voltage device. In order to improve the speed of excitation regulation, AC exciter usually uses 100 - 200Hz if the generator, and the AC exciter is used in the 400 - 500Hz if the generator. The generator of DC excitation winding and a three-phase AC winding around in the stator slots and rotor only the teeth and the slots without winding, like a gear. Hence, it has no brush and slip ring rolling contact component, with the advantages of reliable work, simple structure, manufacturing process is convenient and the utility model. The disadvantage is that the noise is larger, and the harmonic component of the AC potential is larger.
3) excitation mode without exciter
In excitation mode is not set up special exciter, and from the generator itself made excitation power, the rectifier to supply generator excitation, the self-excited static excitation. Self-excited static excitation can be divided into self excitation and self excitation in two ways. Self excitation mode of it through the next exciting current in the generator outlet of the rectifier transformer, the rectifier to supply the generator excitation, the excitation mode has the advantages of simple structure, less equipment, save investment and little maintenance work. In addition to the rectifier transformer, a high power current transformer which is connected in series with the stator circuit of the generator is also provided. The function of this kind of mutual inductor is in short circuit, to the generator to provide a larger excitation current, in order to make up the deficiency of the output of the rectifier transformer. This exciting mode has two kinds of excitation power supply, through the rectifier transformer to obtain the voltage power supply and through the series transformer to obtain the current source. | | | author: Published at: 2016/7/15 16:26:13 |  |
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