Research Of Power Unit Cascade Type HVC And VCS

At present, the market of high voltage frequency converter mainly adopts multiple powerunit cascaded topology structure. Based on cascade type high voltage inverter as the foundation,put forward a kind of can realize energy feedback improvement scheme. That is the maturethree-phase PWM rectifier technology, with full control switch device IGBT replaceuncontrolled diode composition three-phase PWM rectifier, and H bridge inverter unit of powerunit with the rectifier and inverter link.In the high pressure frequency converter cascade topology and SPWM modulation methodon the basis of cascade type high voltage frequency converter speed sensorless vector controlsystem to carry on the thorough research. That is a speed sensorless vector control of speedidentification and flux observation. Magnetic flux observation, the first lists the voltage, current,magnetic flux observation model and co., LTD., after the compensation voltage model fluxobservation model, and in turn gives three kinds of model of advantages and disadvantages, andgive choose co., LTD., compensating voltage model basis. Speed identification, analysis of thedirect calculation method and model reference adaptive method of advantages and disadvantages,and the model reference adaptive method of pure integral improvement. This paper puts forwardwith a first-order low-pass links and first-order qualcomm link form a closed loop instead of pureintegral element, the simulation results proved the feasibility of this scheme.In this paper, the cascade type high voltage frequency converter speed sensorless vectorcontrol system of detailed analysis, and at the same time, using MATLAB established theinduction motor speed sensorless vector control simulation platform, and obtained the goodsimulation waveform.In the above theoretical analysis, simulation research basis, based on TMS320F2812digitalsignal processor and FPGA as the core, formed a full digital controller, and in a6.7kW inductionmotor is carried out on the experimental research, the experimental results demonstrate thevalidity of the theoretical analysis and feasibility.