Sensorless Velocity-adjustable System For PMSM

In the electrical system, motor as the main power equipment is widely used in various aspects, and the speed-adjusted performance, as the main feature of motor, plays a decisive role in improving products'quality, improving labors'productivity and saving energy.Permanent magnet synchronous motor (PMSM) is the very kind of motor which owns superior performances and widely applied-prospects. The speed-adjusted system for Permanent magnet synchronous motor is used VVVF technology. In a high-performance AC motor system, the speed signal of rotor's position is essential, Which is traditionally measured by the mechanical and electrical sensors. However, in the actual system, the speed sensor which could introduce deviation to the system does not only increase the complexity, but also decrease the robustness and reliability. In addition, in some cases speed sensor is difficult to install. Due to these reasons, sensorless control system has been a hotspot in recent years. And with and the rapid development of the automatic control theory, digital signal processing and digital technology, many universities and institutes home and abroad are having dedicated a great deal of effort to the AC motor speed-adjusted sensorless studies.This paper, is a study of speed-adjusted sensorless system for PMSM. Construction adopted of the system is the three-loop theory which is builded by the q-axis double-loop and the d-axis single-loop. The main method is by measuring the motor's current and voltage and other easily measured signals but not speed, which is more difficult to obtain. Then, estimating the rotor position through the specific observable strategy which is used to complete the closed-loop control system. In this paper, work can be divided into three parts. First, model analysis for PMSM and speed estimation. Second, constitute the sensorless PMSM control system and then check its performance with simulation. Third, design hardware and software for the sensorless PMSM control system. What have been done are as follows:1. Study and analyze the permanent magnet synchronous motor model, speed estimated model and the control strategy more systematicly.2. Build the construction of speed-adjusted control system with sensor, gradually, on its foundation, construct the sensorless PMSM control system.3. simulate the completed system by PSIM, validate the performance.4. design hardware to the sensorless PMSM control system with chip TMS320F2812.5. raise some ideas to software designing.Sensorless speed-adjusted motor control scheme reduces the system's cost, increases the system's reliability and durability in the engineering fields. In the future, with the development of control technology, sensorless control system will be used more and more, espectly in some special occasions.