Multi-model Predictive Control of Ultra-supercritical Coal-fired Power Unit

The control of ultra-supercritical(USC) power unit is a difficult issue for its characteristic of the nonlinearity, large dead time and coupling of the unit. In this paper, model predictive control(MPC) based on multi-model and double layered optimization is introduced for coordinated control of USC unit. The linear programming(LP) combined with quadratic programming(QP) is used in steady optimization for computation of the ideal value of dynamic optimization. Three inputs(i.e. valve opening, coal flow and feedwater flow) are employed to control three outputs(i.e. load, main steam temperature and main steam pressure). The step response models for the dynamic matrix control(DMC) are constructed using the three inputs and the three outputs. Piecewise models are built at selected operation points. Double-layered multi-model predictive controller is implemented in simulation with satisfactory performance.

Nonlinear inversion-based output tracking control of a boiler-turbine unit

The capability to perform fast load-following has been an important issue in the power industry. An output tracking control system of a boiler-turbine unit is developed. The system is composed of stable inversion and feedback controller. The stable inversion is implemented as a feedforward controller to improve the load-following capability, and the feedback controller is utilized to guarantee the stability and robustness of the whole system. Loop-shaping H∞ method is used to design the feedback controller and the final controller is reduced to a multivariable PI form. The output tracking control system takes account of the multivariable, nonlinear and coupling behavior of boiler-turbine system, and the simulation tests show that the control system works well and can be widely applied.

ESO-based decoupling control with multi-objective optimization for boiler-turbine unit

A model-assistant extended state observer(MESO)-based decoupling control strategy is proposed for boiler-turbine units in the presence of unknown external disturbance and model-plant mismatch. For ease of implementation, the decoupling compensator is reduced to the proportion integration(PI) decoupler with the frequency domain analysis, where the decoupling error in collusion of uncertainties and disturbances can be estimated by the proposed MESO and then compensated. To decrease the sensitivity of the dynamic error for the decoupling control and fulfill various requirements of constraints, such as safety operation, energy conservation, emission reduction, etc., the plant is transmitted through a scheduled steady state region which is achieved from the optimized reference governor in advance. Simulation results show that the proposed control strategy can well suppress various disturbances including a decoupling error, and multi-objective optimization can meet multiple requirements with the premise of safety production.

Hardware-in-the-Loop Research on the Electronic Control Unit for Diesel Engines

A hardware-in-the-loop simulating platform is developed to avoid designing defects caused by the complicated logical structure and multiple-functional buildup of the dectronic control unit（ECU）in modem diesel engines, and to diminish potential damages on components or human exposure to dangers in R＆D en- deavor. This plat-form consists of a computer installed with software Matlab/Simulink/RTW and dSPACE/ ControlDesk; a diesel engine ECU, and a dSPACE autobox which runs a real-time diesel engine model. A typical model of diesel engine with turbocharger and intercooler is presented. Based on this model our research is carried out with a real ECU to test its software control strategies. Results show that by using the diesel engine model downloaded inside, the hardware-in-the-loop platform can simulate diesel engine＇s working conditions and generate all kinds of sensor signals which ECU needs on a real-time basis. So the ECU control strategies can be validated and relevant parameters roughly calibrated.

Design of 32 kbit one-time programmable memory for microcontroller units

A 32 kbit OTP(one-time programmable)memory for MCUs(micro-controller units)used in remote controllers was designed.This OTP memory is used for program and data storage.It is required to apply 5.5V to BL(bit-line)and 11V to WL(word-line)for a OTP cell of 0.35μm ETOX(EEPROM tunnel oxide)type by MagnaChip.We use 5V transistors on column data paths to reduce the area of column data paths since they require small areas.In addition,we secure device reliability by using HV(high-voltage)transistors in the WL driver.Furthermore,we change from a static logic to a dynamic logic used for the WL driver in the core circuit.Also,we optimize the WD(write data)switch circuit.Thus,we can implement them with a small-area design.In addition,we implement the address predecoder with a small-area logic circuit.The area of the designed 32 kbit OTP with 5V and HV devices is 674.725μm×258.75μm(=0.1745mm2)and is 56.3% smaller than that using 3.3V devices.

MicroGrid Designer:user-friendly design,operation and control assist tools for resilient microgrid and autonomous community

During this decade,many countries have experienced natural and accidental disasters,such as typhoons,floods,earthquakes,and nuclear plant accidents,causing catastrophic damage to infrastructures.Since the end of 2019,all countries of the world are struggling with the COVID-19 and pursuing countermeasures,including inoculation of vaccine,and changes in our lifestyle and social structures.All these experiences have made the residents in the affected regions keenly aware of the need for new infrastructures that are resilient and autonomous,so that vital lifelines are secured during calamities.A paradigm shift has been taking place toward reorganizing the energy social service management in many countries,including Japan,by effective use of sustainable energy and new supply schemes.However,such new power sources and supply schemes would affect the power grid through intermittency of power output and the deterioration of power quality and service.Therefore,new social infrastructures and novel management systems to supply energy and social service will be required.In this paper,user-friendly design,operation and control assist tools for resilient microgrids and autonomous communities are proposed and applied to the standard microgrid to verify its effectiveness and performance.

Research on the Application of Evidence-Based Quality Control Circle to Improve the Implementation Rate of Airway Management Measures in Adult Critically Ill Patients

Objective: To explore the effect of evidence-based quality control circle (QCC) in improving the implementation rate of airway management measures in adult critically ill patients. Methods: Based on the Joanna Briggs Institute (JBI) evidence-based health care model, the best evidence of airway management in adult critically ill patients was obtained and applied to the clinic. Results: The total implementation rate of airway management measures in adult critically ill patients increased from 23.62% before the implementation of quality control circle to 88.82%, and the pulmonary infection rate in critically ill patients decreased from 42.31% to 21.74%, with statistical significance between the two groups (P 0.05). Conclusion: Evidence-based quality control circle activities can standardize the practice standards of airway management in critically ill patients, reduce the occurrence of patients’ airway related complications, and improve clinical outcomes.

Type selection and maintenance of the control system of large-scale air separation units

Based on the practice of Baosteel＇ s 60000 m3/h air separation unit （ASU） ,which is the first domestically- integrated unit of such a scale, this paper studies the principles of type selection of the distribution control system （DCS）. It discusses the design of the unit＇s control system,which involves a compressor system,a purification system （molecular sieving）, a turbo expansion system and an air separation system. The final part of the paper discusses the maintenance and future development of the ASU control system at Baosteel.

Research on OPC-based Fracturing Unit Control System

With the large-scale integration of fracturing unit’s on-site construction,traditional industrial buses are increasingly unable to meet the requirements for the quantity transmission between various equipment in large-scale fracturing units,and different models of different equipment manufacturers cannot cooperate with each other as there are“Islands of information”in the control system.This article uses industrial Ethernet as the physical medium for data transmission.In addition,different equipment manufacturers use OPC as the core technology of the fracturing unit control system network,and set up an intelligent fracturing unit control system,so that the control network can quickly,accurately,and safely control the fracturing truck control system.The sand truck control system monitors and analyzes,saves,and prints the construction data in the vehicle instrument.At the same time,the network control system uses the vehicle instrument as the core of the network.It can control fracturing vehicles from different manufacturers.The sand mixer truck performs network control,which effectively avoids incompatibilities between various equipment manufacturers at the construction site.

Application of Homemade DCS in Integrated BOP Control of 600-MW Supercritical Unit

The PLC and upper computer are used in BOP control system of traditional thermal power plant to monitor the in-situ equipment. It is complicated and wastes labor and resources. It is difficult to maintain and manage them. Beijing GuoDian ZhiShen Control Technology applied the homemade DCS (EDPF-NT System) to the integrated BOP control system of 600-MW supercritical power unit, which offers advantages in efficiency promotion, cost reduction and resource sharing. That also reflects the dominance of EDPF-NT System in performance, price, real-time DUP, network compatibility and communication. This article introduces the main characteristics, structure and configuration of EDPF-NT System, as well as the hierarchical operation, the multi-domain network structure and the private network router developed for Zhuanghe Power Plant.

Wind Turbine Speed Compound Control of a New-Type Wind-Electric Hybrid Power Pumping Unit

Because the load of the oil beam pumping unit driven by pure electric motor changes sharply during operation,the power of the driving motor does not match and the energy efficiency is low.In this paper,a new type of wind-driven hydro-motor hybrid power system is proposed.The motor and the hydraulic motor are jointly driven,and the energy is recovered by a hydraulic pump with controllable displacement,so that the speed of the driving motor is relatively stable.In order to control the fan speed and keep up with the drastic changes of the outside wind speed,a control strategy of hybrid power system based on wind speed feed-forward compensation is proposed.Through simulation and experimental results,the following conclusions can be drawn:to begin with,the mathematic model is proved to be effective;next,simulation studies show that the proposed feed-forward control method can improve the response rate as well as reduce the response lag.This research can be a reference for the application of the feed-forward control method on the hybrid power system of beam pumping unit.system.

Toddlers’ choice:Yo-Yoing diabetes control or deci-unit insulin dosing?

While the incidence of toddlers’ diabetes is soaring,their mainstay insulins were withdrawn,namely the weak 10% or 20% insulin mixtures (WIM),which were injected only once or twice daily.Consequently,toddlers are coerced to use an insulin pump,multi-dose insulin regime (MuDIR),mix or dilute insulins.This paper highlights the difficulties and proposes a simple solution.While an insulin pump is the best available option,it is not readily available for everyone.Mixing insulins is not sufficiently precise in small doses.Although diluting insulin would allow precise dosing and reduce the dose variability secondary to dribbling after injections,it,like insulin mixing,deprives children from using the pen and related child-friendly accessories.In MuDIR,we inject 4-5 small doses of insulin instead of 1-2 daily larger doses of WIM.Thus,on using a half unit (unit) insulin pen,a dose of 0.5,1,1.5 and 2 units are adjusted in steps of 100%,50%,33% or 25%;unlike the advisable 5%-20%.This does not easily match the tiny erratic meals of grazing toddlers.Maternal anxiety peaks on watching yo-yoing glycemia.Carers have to accept either persistently high sugar or wild fluctuation.The risks of such poor glycemic pattern are increasingly recognized.Using insulin U20 in a unit disposable pen allows deci-unit dosing,with 5%-20% dose-tuning,greater accuracy on delivering small doses and reduction of dose variability from dribbling.Deci-unit dosing may help avoid wide glycemic swings and provide the affordable alternative to insulin pumps for toddlers.Deci-unit pen materializes the Human Rights of Children,a safer and effective treatment.

初二英语Units 24-26典型错误例析

1.楼下那个人睡不着觉。[误]The downstairs man couldn’t go to sleep.[正]The man downstairs couldn’t go to sleep.[析]以today,here,there,downstairs,upstairs, below,above等作定语修饰名词时常放在名词之后。2我正想出去,铃响了。[误]I just went out when the bell rang.[正]I was just going out when the bell rang.[析]由when连接的两个分句,其中—个谓语动词是延续性,另一个谓语是终止性动词时,此处的when是并列连词,意为“这时 (突然)”,所以要将went out改为was going out.

初二英语Units 21-23综合检测题(英文)

I.单项选择:从A、B、C、D四个选项中,选出可以填入空白处的正确答案。1.Are you__ the 100-metre race today? A.on B.to C.for D.in2.I’m afraid you didn’t do your homework__ A.careful enough B.carefully enough C.enough careful D.enough carefully3.They__a class meeting last Friday. A.hold B.held C.take D.took4.__Jack came a moment__ . -Why did he come__? A.late;later B.late;late C.later;late D.later;

初三英语Units4-6 常见错误例析

1.你必须尽快把书还到图书馆。[误]You must return the book to the library as quickly as possible.[正]You must return the book to the library as soon as possible.[析]as quickly as possible与as soon as possible都可表“尽快”地,但前者是指做事的速度快,可以用as fast as possible来替换;而后者则指做事的时间尽可能早。

初三英语单元综合训练题(Units1-3)(英文)

I.单项选择:从A、B、C、D四个选项中,选出可以填入空白处的正确答案。