The Research Of Special Inverter For Centrifuges And Control System

AC variable speed technology is an important engineering achievement in late 20th century. After the development of four generations, AC speed control modes have developed rapidly. Direct torque control (DTC) is an AC speed control technique that directly analyzes the AC motor mathematical model and controls motor flux and torque in the stator coordination, possessing high dynamic response, simple control structure, direct control mode.First, the paper presents the development and current situation of AC speed control and the significance of the subject; Next, we introduce the theory, system architecture, and principles of direct torque control; Then, we introduce the hardware circuit design of the dedicated converter for centrifuge control system, including the main circuit, the voltage detection circuit, the current detection circuit, the speed detection circuit, drive and isolation circuit, protection circuit and the power supply circuit. Especially, a hardware platform of the special centrifuge frequency converter control system is built; Second, we introduce the software implementation of direct torque control under the CCS3.3, a DSP integrated development environment, mainly including the specific implementation of modules such as speed detection, speed display, voltage and current detection and their 3/2 transformation, flux and torque calculation, torque given, flux and torque adjusting, flux sectors selection, switch signals selection and voltage states output; Finally, experiments are performed to verify the validity of the design and the performance of the DTC, and some analysis and explanations are given according to some experimental data obtained.