Fault Compensation Control Of Fused Magnesium Furnace System

Fused magnesia is widely used in metallurgy industry, glass industry, cement industry, household electrical appliances such as heaters and temperature of the chemical industry in many fields of refractories. Fused magnesium furnace is one of the most wide devices used in the fused magnesia production industry. Its safety must be ensured in order to make the normal operation of fused magnesium furnace. When a fault occurs during normal operation, if the fault can not be timely adjustment or compensation, the performance of control system has been severely damaged, or even closed-loop system stability is total destroied, causing serious harm. For system security and reliability, such the fault must be properly compensated. No matter from the point of view of the theory and practice, for the control system, fault compensation is an important and challenging problem. The following is the main contents of this paper:(1) Analyzing the structure of electric furnace, the model of the fused magnesia furnace is established on the basic of it, previous models established mostly study the relationship of the arc length, the arc length in actual electrode operation process is difficult to accurately detecte, however, electrode voltages can easily detect, so the problem of the arc can be transformed into the arc voltage. The relationship between arc voltage and current is established, the current is introduced in a closed-loop control system, it is can make current in optimal value of the stable. So the model has great practical value.(2) Fault diagnosis and detection of the system are designed, the state variables are estimated using the fault detection observer. The basic idea is to use the system model and information measured to design an observer in order to measure system variables, and use the difference between the observer status and real system state as the residual, through the analysis and processing of residuals to diagnosis system’s fault.(3) The state feedback and output feedback controllers of the system are designed basing on linear matrix inequality method. The controller designed in this paper can rapidly compared to improve the performance of the system compared to the previous controller. If there is no fault, only a normal controller is designed, if the system contains the fault, the fault compensation controller needs to be designed, fault compensation controller can ensure the system’s performance indicators in a stable condition. The simulation results show that the method is correct.