Development And Application Of Vector - Based Frequency Converter Based On

Three-Phase asynchronous motor has advantages of sample structure, durability, easy maintenance, low price.With continuous appearance of AC frequency variable technology and new control strategies, Asynchronous Motor Regulating Speed System was applied more and more extensively. The strategies of AC Frequency Conversion Control include variable voltage variable frequency (V/F), vector control (VC) and direct torque control (DTC). The rapid development of industry put forward higher request for the inverter used in AC Speed Regulation. Among them, vector control, which is superior in speed adjustment, gradually becomes a research focus. Therefore, this paper used the strategy of vector control, designed the VC Inverter, and used it in multi-motor synchronous system.The paper contents as follows:(1) Described the theory of asynchronous motor vector control, and analysised Principle of coordinates transformation and SVPWM.(2) With TI’s TMS320F2812DSP as the main controller, designed the hardware circuit of variable frequency control system, which including auxiliary power supply, power circuit and control circuit. The flyback switching power supply was the core of Auxiliary power supply, Generated15V,5V,3.3V and other to supply power circuit and control circuit; The power circuit comprises a rectifier circuit, inverter circuit and isolation drive circuit; The control circuit comprises a sampling of current, speed, DC bus voltage, and generates PWM signal through the control of TMS320F2812DSP.(3) Used a off-line parameter identification with more easy realization and low computational complexity. Through the DC chopping test, the single-phase alternating current test and no-load test, obtained required parameters by algorithm of SVPWM, and use Polar Coordinates method to simplify the calculation of power factor.(4) Implemented the software design of the asynchronous motor vector control algorithm, and verified the performance and reliability of the vector control system in the experiment. Realized settings and display of the parameters of converter based on Requirement of functions of General Inverter.(5) The designed inverter applied to multi-motor synchronous system of elliptical shale shaker to further verify the speed performance of inverter.Through test, the designed inverter has good static and dynamic performs.The test showed that hardware circuit of the designed inverter was reliable, and the identification of motor parameters was accurate.then it obtains good effect in applications.