Silicon Molybdenum Rod Furnace Temperature - Current Double Closed Loop Of Intelligent Systems Research And Design

Molybdenum disilicide (MoSi2) is a resistance generate-heatingcomponent, it can be used in the highest temperature up to 1800℃duringoxidizing atmosphere. In the high temperature it can protect the elementnot to be oxidized, So it has been widely used in the process of industrialheating. The equivalent resistance of this element is very low when it is ina low temperature, while the equivalent resistance increases fast alongwith the temperature going up. This characteristic may lead to the currentovershoot in the process of heating, current overshoot may directly effectthe life-span of these elements. This thesis focused to the element'scharacteristic of current-resistance and put forward the control strategy oftemperature-current double loop. The temperature loop is introduced asthe out loop to control the temperature of MoSi2 furnace, while thecurrent loop was introduced as the inside loop to control the surface loadof MoSi2 furnace. Using the Fuzzy-PI control strategy as the regulatingmode of temperature loop, considering that the PI regulating mode'sadaptability is limited in the time-invariant system, two fuzzy controllerwere imported to on-line and real-time modify the parameters of P and I.Classic regulating mode was applied to the Current loop, by theintegral-saturation to limit the current of MoSi2. In addition to eliminatethe effect coursing by the delay of the object, a smith predictor wasintroduced in this controller. By the results of simulation, this controlstrategy can obtain a preferable control effect in the application.A research was applied to the MoSi2 furnace as the plant firstly,and then according to the result of research, the control strategy of doubleloop with temperature-current with Smith predictor was put forward; thedesign course of each part of this strategy and the design of software andhardware of this controller was presented secondly in this thesis. Finallyby analyze the results of strategy-simulation and controller-debug, theadvantage of the applying of this control strategy in the system of MoSi2 furnace was proved.