Design And Implementation Of The SCR Digital Trigger Controller

SCR(Silicon Controlled Rectifier) is a kind of semiconductor devices with the function of switching which has widely used in the large capacity of controllable rectification system. The center of the silicon controlled rectifier system is the controller of SCR generates control thyristor conduction of trigger pulse whose control performance is directly related to the performance of the controllable rectification system. Weak in anti- interference ability, low in accuracy, poor in pulse symmetry and single in control function make the most frequently used simulate trigger controller cannot be satisfied to change of rectifier system and the increasingly perfecting of application requirements. The development of digital integrated circuit for digital control technology which is widely used in the SCR trigger controller overcomes the disadvantages of analog trigger to a certain extent. With the increasing requirement of the controllable rectification system for thyristor trigger controller, high-performance trigger controller is imperative in the future. The so-called high performance mainly embodied in three aspects: first is the supporting to remote monitoring with more equipment networking; second is the fast speed of controller response; finally is the intelligent which can automatically adapt to various working environment. What we research in this paper is a high-performance digital SC R controller design of the control system of the prototype with the foundation of three-phase ful y-controlled bridge rectifier circuit based on SCR.In this paper, the principle and characteristics of thyristor, conducting condition and related theoretical knowledge in full controlled rectifier circuit is introduced at first. The detailed analysis of the working characteristics of the circuit, trigger modeand so on for SCR in three-phase fully- controlled bridge rectifier circuit come following. The digital phase shift trigger controller design scheme based on FPGA, the main modules of hardware circuit design, human-computer interaction interface circuit and phase discriminator circuit was made with the detailed system application requirements. Easy in hardware circuit, independent in running and handiness in operating are realized in it. On the other hand, the communication module design with the ARM chip in order to improve the scalability of the controller is given which can master control system realizes the network control and monitoring.Secondly, the FPGA design and implementation method of the internal control logic is introduced on the basis of completed the controller hardware circuit. The module includes: main control module, UART communication module, processing module, pulse phase pulse generating module, man- machine interface control module, control module, the feedback data reading module EPROM, speaking, reading and writing. The introduction in detail of the function for each module is described.Finally, the research and implementation of PID control algorithm comes. A single neuron adaptive PID control algorithm which combined with neuron learning after the introduction of a simple analog PID controller and the basic principle of digital PID controller is introduced. The PID control algorithms can real- time self- tuning PID control parameters with the characteristics of less control overshoot, high precision and fast adjustment speed. The internal control logic is introduced the algorithm in detail with the FPGA realization method at last.