Simulation And Application Of Intelligent PID Control

There are two parts of work in this thesis. One is to simulate intelligent PID control method based on the poloidal field power supply system of TOKMAK, the other is to design and commission the power supply control system of the equipment for producing acetylene from coal pyrogenation by hydrogen plasma. The poloidal field power supply system is one of the most important subsystems of TOKMAK, which supplies the energy for producing and heating plasma, and provides the necessary magnetic field configuration for confining and maintaining plasma, and gives the necessary means for controlling the current, position, shape, distribution and disruption of plasma. The parameters of poloidal field power supply system are variable, nonlinear and uncertain for its work condition, and conventional PID controller is not good at high precision control. This paper describes an intelligent PID control method and a simple mathematical model of the poloidal field power supply system, and simulates the fuzzy PID control arithmetic based on the model by numerical value method. Simulation results show that the arithmetic is high sensitive, and has very stable and robust performance. The control efficiency will be better when it is used in poloidal field power supply control system. The load of the equipment for producing acetylene from coal pyrogenation by hydrogen plasma is a V type ion torch, which produces arc by high voltage of DC3000-5000V in nitrogen condition, then keeps the arc running in steady state according to the given current value, and then adds the coal powder after the nitrogen arc converses to hydrogen arc, it will react and produce hydrocarbon compound of acetylene etc. The load character varies greatly after the arc appears, which leads to output voltage of the rectifier changes rapidly. So it is very difficult to control the current steady, and conventional PID controller can't achieve the control object. A power supply control system of the equipment for producing acetylene from coal pyrogenation by hydrogen plasma is presented in this paper, which makes use of the advantage that expert PID control method can convert control parameter for different load character, to control the circuit current by real-time feedback. The system is running after commission. The expert PID control method is respectively simulated by MATLAB numerical value method and SIMULINK toolbox. The control performance of expert PID control method is good and achieves control object prearranged. For several months running, the power supply and its control system can produce arc and maintain the arc running steadily, the practical current accords with the prearranged, and the control capability is good.