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The effects of adding different ratios of DRI （direct reduced iron） to Consteel EAF on smelting technical and economic indicators， molten steel cleanliness， and the ingredients of acr furnace final slag were studied by conducting experiments on all scrap steel and adding 10%， 20%， and 30% ratios of DRI. And based on the experimental results， the key points of smelting control such as adding metal materials， blowing oxygen and carbon， adding slag making auxiliary materials， and slag discharge were analyzed.The results show that as the proportion of DRI added increases， the consumption of electricity， steel material， slag making auxiliary material， and slag amount gradually increase. When the proportion of DRI addition is 30%， due to the large amount of slag， slag overflows from the furnace door in the middle and late smelting process； At the same time， the cleanliness of the molten steel significantly increases after adding DRI to the EAF， and the mass fraction of nitrogen， phosphorus， sulfur and residual elements at the end of EAF smelting is reduced. And as the proportion of DRI added increases， the rate of decrease in nitrogen mass fraction at the endpoint of the electric furnace decreases. In addition， with the increase of DRI addition ratio， the FeO mass fraction of final slag showed a decreasing trend. When DRI is added at a proprotion of 20%， the effect is better， the smelting cycle is lower， the increase in electricity consumption is not high compared to the total scrap steel furnace， and the nitrogen and residual element content is lower， meeting the requirements of most steel grades.

This paper proposes a cascade approach based on a sliding mode observer (SMO) for estimating the state of charge (SoC) and state of health (SoH) of lithium-ion (Li-ion) batteries using a single particle model (SPM). After convergence, the observation error signal of the current node in the cascade observer is generated from the output injection signal of the previous node's observer. The current node's observer generates its output injection signal, leading to its convergence. This sequential process accurately determines the observed values of each node using only the battery's current and voltage. Subsequently, the SoC and SoH are estimated using observations of lithium-ion concentrations on the surface and inside the battery anode. The accuracy of this approach is validated using Dynamic Stress Test (DST) and Federal Urban Driving Scheme (FUDS) experimental data. A comparative analysis with conventional SMO and Extended Kalman Filter (EKF) algorithms demonstrates the approach's effectiveness and superior performance, confirming its practical applicability. [ABSTRACT FROM AUTHOR]

Summary: Control systems are frequently subject to the negative effects of time delays and disturbances, which diminish the systems' tracking performance. In response to these challenges, this paper presents a novel approach, that is, the improved sliding mode observer based repetitive control (ISMO‐RC), to enhance the system's periodic signal tracking in the presence of the input and state time delays and the input disturbances. The design takes the advantages of RC and ISMO, in which RC effectively compensates periodic signals, while ISMO compensates both aperiodic disturbances and the time‐varying input and state delays. The stability of the whole system is guaranteed via the linear matrix inequality (LMI) and the Lyapunov–Krasovskii functional analysis. The proposed controller is evaluated through extensive simulations and experiments, which demonstrate its superiority over comparative control methods. [ABSTRACT FROM AUTHOR]

A novel robust finite time disturbance observer (RFTDO) based on an independent output-finite time composite control (FTCC) scheme is proposed for an air conditioning-system temperature and humidity regulation. The variable air volume (VAV) of the system is represented by two first-order mathematical models for the temperature and humidity dynamics. In the temperature loop dynamics, a RFTDO temperature (RFTDO-T) and an FTCC temperature (FTCC-T) are designed to estimate and reject the lumped disturbances of the temperature subsystem. In the humidity loop, a robust output of the FTCC humidity (FTCC-H) and RFTDO humidity (RFTDO-H) are also designed to estimate and reject the lumped disturbances of the humidity subsystem. Based on Lyapunov theory, the stability proof of the two closed-loop controllers and observers is presented. Comparative simulations are carried out to confirm that the proposed controller outperforms conventional methods and offers greater accuracy of temperature, humidity, and carbon dioxide concentration, having superior regulation performance in terms of a rapid finite time convergence, an outstanding disturbance rejection property, and better energy consumption. In addition to presenting the comparative simulation results from the control applications on the VAV system, the quantitative values are provided to further confirm the superiority of the proposed controller. In particular, the proposed method exhibits the shortest settling time of, respectively, 15 and 40 min to reach the expected temperature and humidity, whereas other comparative controllers require a longer time to settle down. [ABSTRACT FROM AUTHOR]