The Application Of DSP_based Frequency Inversion Technique In Electric Actuators

With the development of control technology and the increasing of domestic industry's automation, people have make new requirement to the implementation which is the end of the industrial process control.Traditional implementation because of low reliability, low precision, slow and lift small, could not satistify the requirement, so the new implementation is need to instead of the old,the new electric actuators replace the currently used in order to improve the automation of the product and the efficiency of the production all of these in the process of the automation industry production can save energy, reduce the operator's intensity, so paly an important role in the safe operation about production and extend equipment life.At present,the most of electric actuator apply the AC motor and worm gear combination group, we use the SCR and two group relays can reach the aim which is reversible control about the motor, if we depend on the worm gear to change the speed,we must change the worm gear group,but which are can't change when they are producted. So the currently control method we used can make a big starting current can make an impact on the motor when starter the motor, this appearance can reduce the life of the motor; meanwhile, this phenomenon also emerge in the the motor when it stop,because of when it stop the speed can't reduce preparatory.Because of the worm gear is fixed,between the regulation the speed and sensitivity about the motor have an contradiction. So we should use the new technology to solve this problem about the implementation.With the appear of the IGBT which is power gate turn-off semiconductor device,companion the microprocessor technology and variable frequency control method in-depth study, the frequency contol technology become more and more mature, this skill have already apply in some filed such as fans,pumps,compressors, machining center, lifting appliances, multi-motor belt and rolling production line,this skill have a lot of advantages,energy-saving effect is remarkable,or improve production efficiency,or improve product quality,had a huge economic and social benefits. This is because the frequency control use of maintenance-free squirrel cage motors, the adjustment range can reach 99%, at any time the motor's running direction can change,constant torque speed soft start, fast electric brakes,emergency gear such as hard acceleration than other motor Control methods can not match advantage.Frequency conversion of these advantages for the development of electric actuators to overcome the shortcomings of conventional actuators,to achieve high positioning accuracy and high speed, high-performance regulation offers the possibility of electric actuator.But if we want make high performance electric actuator,can not simply be applied to the frequency composition of traditional actuators,must match the corresponding frequency control strategy,base on the above discussion,we use the frequency control which is based on DSP technology in the application of electric actuators for high performance variable frequency electric actuator is worth attempt.tThis design is divided into two parts, hardware and software, the hardware section includes the IPM-based rectifier and inverter circuit design, DSP control circuit design,testing part of the design,interface design; software is part of the independent development of Dalian Jiaotong University, the field of industrial automation-oriented multi-module control MMB (micro message bus) control system software for the platform, frequency control and direct torque control implementation of appropriate strategies.