| In high-voltage and the large capacity transmission domain, the Wound-Field synchronous machine has its own advantage: the power density is higher, the machinery size and the rotation inertia are smaller, the capacity of the inverter is smaller, the controlled precision is higher, and the rate of magnetism weakens is bigger comparatively. Since 20th century 90's, Almost countries in the world have already regarded the synchronous machine as the trend of large capacity AC machine velocity modulation Synchronous machine has been used widely in industry and agriculture production domains, and has achieved the goals of accuracy control and saving the energy.This article take the alternating current synchronous machine's velocity modulation method as a center, has discussed the traditional LCI control and the advanced vector control. The LCI control uses one 6-pulse wave current-fed inverter to impel synchronous machine. Use the rotor position sensor to examine the rotor position to control the inverter. Along with rotor revolving, We can circularly trigger the thyristors. And the shutdown of thyristor can be completes by the inverse-EMF of synchronous machine, does not need the special circuit to shutdown the thyristors, and make the converter very simple and economical. The shortcoming is the torque pulsation is big, that we can also see through the computer simulation, specially when the leading angle is big in order to improve the reliability. The torque pulsation is truly quite big. Through analyzes the principle of LCI method to have the torque, proposed the multiple inverter to increase the frequency of synchronous machine's magnetomotive force in stator side , achieved 12-pulse waves, the beat frequency ascension obviously reduced the torque pulsation, we have also proven this point through the simulation experiment. We have chosen the air gap flux linkage direction detection control in the the vector control algorithm, the primary cause is the rotor flux linkage direction detection which is used in permanent magnetism synchronous machine. As the load increase, the stator current increases, as a result of the armature reaction influence, the synchronous machine stator voltage will ascend sharply simultaneously causes the power factor of the synchronous machine to become low. To the high performance, the large capacity synchronous machine is uneconomical. The air gap flux linkage direction detection control has some shortcomings: the control isn't decoupling, cannot maintain the air gap flux linkage constant in the transient, has used the stator current excitation component compensation method to atonement the shortcomings.To reduce the shake of δ angle, we propose a method to control δ angle directly. Make the δ angle change by the rule which we already set before. This method can solve the question, and the computer simulation result has also proven this method's validity.This article also discussed the electric current modulation which is used in the vector control, the electric current and the voltage model which is used to observe the magnetic field, and the improvement of voltage model. We use a fuzzy controller to substitute the traditional PI adjustment the rpm control, the effect is quite obvious that we can see through the simulation result.Based on above algorithm, we constructed an experimental platform, used DSPTMS320LF2407 as the processor, gathered each variable, the operation, generated the trigger pulse. Simultaneously it has a interface which is used to communicate with the computer, change thereal-time system setting value, and revises the system program. |
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