腈纶压滤机新型液压控制系统的研制

针对腈纶压滤机设备存在的漏胶严重 ,系统无法正常保压和定位的情况 ,提出了以电气 (PLC)与液压技术相结合方式 ,成功地实现了压滤机的工业自动化和节能化。

辅机循环泵液控蝶阀控制系统改造

针对京隆发电有限责任公司2*600MW直接空冷燃煤发电机组工程的辅机循环冷却水系统现状,指出了当前系统存在的问题,通过对辅机循环冷却水泵液控蝶阀控制系统的改造,极大地方便了运行人员选择液控蝶阀的运行方式和对设备的有效监控,系统投入运行后,故障率大大降低,也大大减少了运行和检修人员的劳动强度,其经济效益和社会效益是显著的。

一种300t转炉裙罩升降液压控制系统

设计一种具有油缸位置自动补油调整功能的裙罩升降液压控制系统。通过利用油缸位置传感器经由电气连锁、优化程序控制实现裙罩液压升降系统的闭环控制。实现了马钢300t转炉裙罩油缸位置自动补油调整功能,其最终达到了液压开环系统的闭环控制。改良的裙罩升降液压控制系统能够有效消除液压马达精度劣化、油缸内泄等原因带来的位置误差,极大的提高了转炉裙罩升降系统的安全性、有效性,减少了裙罩维护次数,增加了冶金厂效益,在冶金行业有一定推广价值。

Applicahon of a Simplified Model Reference Adaptive Algorithm

The application of a simplifed model reference adaptive control(SMRAC) on a typical Pump controlled motor electrohydraulic servo system is studied here. The algorithm of first-order scalar SMRAC ac second-order vector SMRAC are derived. Computer simulations of the algorithms are presented. Experimental results prove that the method of control adopted here perform satisfactorily over a wide range of operating conditions.

Application of Fuzzy Modification Strategy in MRAC

Based on a simplified model reference adaptive control(SMRAC) algorithm a parameter modification algorithm according to fuzzy laws is proposed in this paper. The method makes the adaptive parameters in SMRAC only rely on the status of performance error. Thus it eliminates the influences of gain coefficients in SMRAC and the amplitude of input signal on the dynamic characteristics. Experiments on various step amplitudes and loads show that the performances of SMRAC are improved by incorporating fuzzy modification method.

Active disturbance rejection control for hydraulic width control system for rough mill

The highly nonlinear behavior of the system limits the performance of classical linear proportional and integral （PI） controllers used for hot rolling. An active disturbance rejection controller is proposed in this paper to deal with the nonlinear problem of hydraulic servo system in order to preserve last response and small overshoot of control system. The active disturbance rejection （ADR） controller is composed of nonlinear tracking differentiator （TD）, extended state observer （ESO） and nonlinear feedback （NF） law. An example of the hydraulic edger system case study is investigated to show the effectiveness and robustness of the proposed nonlinear controller, especially, in the circumstance of foreign disturbance and working condition variation, compared with classic PI controller.

Fuzzy NN based predictive control and its application to green liquor system

The fuzzy NN predictive control algorithm introduced in this paper uses fuzzy neural network to model the nonlinear MIMO process. Its training method that integrates LS and BP algorithm brings quick convergence. GPC algorithm is used as the predictive component. The fuzzy neural network has six layers, including input layer, output layer and four hidden layers. An application to a MIMO nonlinear process(green liquor system of the recovery system in a pulp factory shows that this algorithm has better performance than normal PID algrithm.

An Experimental Study on Microcomputer Control of Pump Controlled Motor Systems

Pump controlled motor electrohydraulic servo systems are much used in circumstances where high power drive is needed. This kind of system has the advantage of energy-saving. But, it also has some defects that have to be improved. Microcomputer control of a pump controlled motor electrohydraulic servo system is studied. A PID controller is first adopted on the closed loop control system, and experimental results are obtained. Then, a model reference adaptive controller is designed and realised on the same system applying a single board microcomputer. Experimental results show that the dynamic properties of the adaptive control system is much better than those of the PID system under different inertia load conditions.

Stability Monitoring and Control of Generation Based on the Synchronized Measurements in Nodes of Its Connection

Synchronized distributed measurements of mode parameters create a technical feasibility for development and implementing new technologies of control the mode stability and the admissibility of EPS （electric power system） mode. Discussion will focus on different models obtained from data synchronized measurements for operational and automatic emergency control without EPS being totally controlled. According to the proposed technology, the generator＇s output power restrictions are determined in real-time by the terms a static stability using the generators＇ mode model as a multipole with connection nodes of generators＇ electromotive forces （the matrix of SMA （self and mutual admittances） of electromotive forces of generators）. Potential applications of the technology are distribution network with the main substation and generators of commensurable capacity, and transmission network with large power plants （generators） distributed into the network. The one-level control system for all of generators with defining the generator＇s power limits relative to the main substation is implemented in the first case. In the second case, the two-level control system is brought in, based on the separation of large and small generation motion. The results of the method and technology efficiency verification are shown in the paper, by both computer simulations of the power system modes and its physical model.

Energy-Saving Design for Hydraulic Tube Bender

Generally speaking, hydraulic control systems can be divided into two different driving concepts. The first one is the well-known hydraulic valve-controlled system and the second one is the pump-controlled system. The former possesses the feature of fast dynamic response. However, the poor energy-saving performance is its major fault. On the contrary, the hydraulic pump-controlled system has the significant advantage of energy-saving which meets the current demand in modem machine design. In this paper, the simulation analysis using MatLab/SimuLink and DSHplus software for a newly developed energy-saving hydraulic tube bender is conducted. Instead of the conventional fixed displacement hydraulic pump, the new hydraulic tube bender utilizes an internal gear pump with AC servomotor as its driving power source. In the new energy-saving hydraulic circuit, the use of conventional pressure relief valve and unloading valve are no longer necessary since the demanded flow-rate and pressure output can be precisely obtained by continuously changing the speed of the AC servomotor. In addition, two closed-loop control schemes using fuzzy sliding-mode controller are adopted and compared. To compare the energy-saving control systems, such as load-sensing control system, constant supply pressure control scheme and conventional hydraulic control scheme. Furthermore, the simulation results also show that the newly developed hydraulic tube bender can save up to 43% of energy consumption in a working cycle as compared to the conventional hydraulic tube bender.

Energy-saving technologies for construction machinery:a review of electro-hydraulic pump-valve coordinated system

With the rapid development of the global economy,more and more attention has been paid to the energy conservation of construction machinery.The hydraulic system is the key component of construction machinery,and improving its energy utilization rate has become an important means to achieve energy conservation.In conventional valve-controlled or pump-controlled hydraulic systems of construction machinery,controllability and energy-saving performance typically cannot be considered at the same time.The pump-valve coordinated system combines the energy-saving characteristics of the pump-controlled system and the high-precision and high-frequency response of the valve-controlled system,which has the potential to become a primary research direction of electro-hydraulic systems.This review summarizes the recent research progress in energy-saving technologies based on pump-valve coordinated systems.Particularly,we discuss the structures of hydraulic systems in different categories of construction machinery,various control methods of the electro-hydraulic system,novel hydraulic hybrid energy regeneration systems,and key components.In addition,future directions and challenges of the pump-valve coordinated systems are described,such as independent metering system(IMS),common pressure rail(CPR),and hybrid power source(HPS).