Development Of Rectifier Equipment And The General Digital Control Device

With the development of power electronic technology and control technology，rectification device is applied most widely and plays a key role in the electrolysis,electroplating， metallurgy and other industrial field of variable flow control. More tothe point, the design of pulse triggering, adjust and control is of most importance inthe thyristor rectifier device. Because of the complexity and time invariance of theobject of rectification device, maintenance of output stability of the rectificationdevice and reasonable cohesion of each control link to achieve the optimal control isof paramount importance. Thus, the research and design of pulse control system withhigh-precision control, high-speed dynamic response and strong anti-interferencecapability has important theoretical significance and practical value.Based on single chip microcomputer MPC89E52, this thesis aims to combine thedigital trigger and digital controller to constitute a thyristor rectifier pulse controldevice, a coalition of Pulse trigger and control, from which the generated trigger pulseowns an excellent real-time ability, high-precision and stable control and wide rangeof application. Experiment shows that the pulse trigger control device can run in therectifier circuit with long-term stability and high-stability output voltage (current).This thesis makes a systematic conclusion of the research and development ofrectifier equipment and impulse control device, based on which the control scheme ofsuch system is improved. The main contents are introduced as follows:First, the basic principle of rectification device as well as pulse trigger controldevice is expounded and the hardware structure of the device is designed in this thesis.Hardware includes the rectifier device and the main circuit, control circuit andoperation circuit of the control system. The main circuit includes power supply,three-phase bridge rectifier circuit. Control circuit includes synchronous signaltransformation and detection circuit, phase sequence adaptive circuit, signal samplingand processing circuit, pulse trigger and direction-moving control circuit, and thepulse output amplifier circuit, etc. Operation circuit including phase-loss protection,over-current protection, pulse blockade and relay operation, etc.Second, the software process of rectifier equipment and control device isdesigned on the KEIL-C compiler platform. Software programs include the maincontrol program, the phase sequence judgment, phase-loss judgment, signal samplingand processing, PID control, pulse trigger, phase shift, fault monitoring, judgment and handling, over-current sectional pressure protection program, etc.At last, the rectifier equipment and its control device are debugged, the problemsappeared in the debugging process of the software and hardware are summarized, andthe overall test of the device is accomplished. Test results show that triggeringreliability and stability of the trigger control device is high enough to meet therequirement of the trigger pulse by the rectification device.On this basis, the thesis attempts to puts forward improvement scheme for DSPcontrol and make an in-depth introduction to the design scheme of the software andhardware of DSP.