Research On And Apply Three-level Inverter's Speed-adjustable & Variable Frequency System Of Synchronous Motor

AC speed-adjustable system of high performance not only conserves energy, but also improves the running performace of high-power synchronous motor remarkably. At the same time, due to the multi-level inverter circuit's remarkable advantage (for example:less output harmonic & on-off frequency, etc.), it should be the preferred scheme which controls the main circuit of mine hoist speed-adjustable by using frequency conversion. Therefore, this paper which is based on mine hoist by using three-level & synchronous motor drive system, aimming at the studies of the diode-clamped three-level inverter system by using frequency conversion.Firstly, synchronous motor speed control technology, multi-level inverter of the status quo, control strategies, as well as the inverter circuit topology, and so on were reviewed in this article. On this basis, focusing on the three-level static inverter coordinate system and non-orthogonal coordinate system of SVPWM algorithm were analysised and simulationed. At the same time, it was discussed in detail the three-level inverter midpoint of the potential hazards and wave, as well as the mechanism solution, and gives a mathematical solution. Based on non-orthogonal coordinate system of three-level inverter SVPWM control strategy r for simulation, simulation results were given, as well as the mid-point potential waveform. Finally, on a trip of mine hoist control features and technological requirements, given the speed of analysis of the way, contrast and speed closed-loop speed control system on a complex control theory means in the practice.In this paper, under the per-unit value of the mathematical model has been established in the synchronous motor dq coordinate system. On the basis of the space vector of fixed synthesizing vectors which the pre-researcher has brought forward, this paper has explored the three-level & synchronous motor DTC control strategy elementary and builded the system design figure as a whole, combining with two-level DTC control method. And, the corresponding simulative model has been established, which was confirming the validity of academic production. Finally, it has also designed and studied the system's key taches such as inverter, excitation rectifying device and main control fibre-optical communication, combining with ACS6000 hoist drive. Through the debugging software DriveWindows, locate debugging has been carried through. Contrasted with locate debugging waveform shape, it also confirm the correctness of the given simulation scheme which this paper has done. It has also suggestted that the drive system worked reliably and satisfied with the manufacture craftwork's desire.