The Research Of Sensorless DTC Algorithm Based On PC

This dissertation detailly analyzed the modern ac motor drive theory, such as ac motor driver, vector control theory, field oriented control theory and direct torque control (DTC) theory. The dissertation also introduced the state-of-art technology and future trends of sensorless ac motor control. Combined the advantages of both DTC and vector control and based on the DTC theory, This dissertation presents a novel method to estimate the flux angle of stator, which isθ_s, and to calculate the rotate speed. Compared to other traditional sensorless control algorithms, this novel method has many advantages, such as only need to measure the stator current and voltage, the parameters show very robust under different operation environment, the structure design is very simple and clear also the calculation is very simple.Using the design criterions of C language, this dissertation finished the simulation and software programme of this novel algorithm. Also established a hardware experiment prototype based on PC control. Based on this, the dissertation verified and optimized the theory control algorithm and finished improvement of inverter circuit, drive circuit and signals sensor method. Also finished the control software realization and testing.To make the research result producible, this dissertation designed the SPWM algorithm based on FPGA, finished the programe by Verilog HDL and finished the prophase research of the sensorless algorithm of DTC using FPGA.Finally, the experiment results of a 4kw ac asynchronous machine show greatconsistency with the theory analysis results and simulation results. It verified thefeasibility and practicability of this novel algorithm. The results of this dissertationprovide a development base for the future theory research and future manufacture.