An Optimal Control Method for Electrode Adjustment of Fused Magnesium Furnace with Input Time Delay

Abstract

The invention provides an optimization control method for electrical magnesite melting furnace electrode adjusting with an input delay. The method comprises the steps that an input delay electrode adjusting system linear model and an input delay-free electrode system linear model of a three-phase magnesite melting furnace are built; the input delay-free electrode system linear model of the three-phase magnesite melting furnace is solved to obtain a Riccati matrix of the input delay-free electrode adjusting system and the electrical magnesite melting furnace adjusting optimal control rate; an input delay electrical magnesite melting furnace electrode adjusting optimal controller of the three-phase electrical magnesite melting furnace is determined; in the working process of the melting stage of the three-phase electrical magnesite melting furnace, a deviation between a set melting current value and an actual melting current value of the three-phase electrical magnesite melting furnace serves as input of the input delay electrical magnesite melting furnace electrode adjusting optimal controller, the rotating speed of a three-phase motor is obtained, and a motor rotor of the electrical magnesite furnace is controlled to work. According to the method, the control effect on a current loop of the electrical magnesite furnace is effectively improved.

Description

technical field [0001] The invention belongs to the technical field of process control of an electric fused magnesium furnace, and in particular relates to an electrode adjustment and optimization control method of an electric fused magnesium furnace with input time lag. Background technique [0002] Fused magnesia, also known as fused MgO, is an important oxide of magnesium, usually using magnesite ore as the main raw material for production. A three-phase AC electric melting magnesium furnace is used for smelting, and the current of the three-phase electrodes is controlled by adjusting the position between the three-phase electrodes and the liquid surface of the molten pool, so that an arc is generated, and the raw materials in the furnace are heated and melted to form a melt through the heat release of the arc. The melt is then cooled and crystallized to form a finished product. [0003] The influence of time lag on the grade of fused magnesia deserves special attention....

AI Technical Summary

Problems solved by technology

In the three-phase electrode melting stage, the motor is used to adjust the electrode position to change the arc length, so that the actual melting current can quickly and effectively track the ideal melting current. However, due to the gap between the motor gear and the gear, the motor rotor itself is due to wind resistance and bearing friction. And other reasons, the motor will always be unable to quickly adjust the rise and fall of the electrode, that is, there is a certain time lag, which has a great impact on the taste of fused magnesia. In the actual industrial production process of fused magnesia furnaces, commonly used PID control algorithm, this is because the structure of PID control algorithm is simple, parameter adjustment is relatively easy, and it is easy to be accepted by factory workers, but PID control algorithm ignores the factor of time lag, which greatly reduces the impact of fused magnesia to a certain extent. grade

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