共查询到20条相似文献,搜索用时 31 毫秒
1.
Xiong xingyu 《保鲜与加工》1988,(1)
This paper presents a new practical method for PI or PID industrial regu-lator optimal adjustments.This method is well feasible for off-line theoreticaladjustment of a control system and provided for closed loop identification withon-line regulator tuning.The proposed algorithm is based on approximationinversion of s-domain disturbance property of a control system by shiftedChebyshev's series.The PI or PID regulator parameter optimization usings-domain approximation representation of time-domain performance index of acontrol system is exclusively discussed with an example of using the algorit-hm.The introduced method is proved convenient to industrial process withhigh-order mathematical model.And it has both theoretical and engineeringsignificance. 相似文献
2.
This paper presents the character of cascade control system and the design of the main loop and subloop. A cascade PID control system based on MATLAB is designed, which is controlled by MATLAB control program based on incremental PID control algorithm and PID parameter tuning method based on computer control. The results show that the control system has good performance. 相似文献
3.
Xang Xuejun Yang Yongzhen 《保鲜与加工》1988,(5)
In this paper,the open loop response curve is computed by a computer after the process paramter estimatio The parameters of PI or PID controller are computed by the method of respose curve. Then in order to obtain better control performance, the parameters of PI or PID controller are gradually optimized.This algorithm is with wider application range compared with the other self-tuning PID control algorithms. The computer simulation and real-time control trials shows a good result. 相似文献
4.
WU Kui~ LI Run-fang~ JIANG Wei~ity Chingqing Chin . Chongqing Institute of Petroleum Chingqing Chin 《保鲜与加工》2004,(5):17
The computer monitor and control system for hydropower station is always a structure system of laminate distribution and open style. The system can adjudge active power and inactive power of water turbine according to the requirement. The operators in active-control level give the value of active power and inactive power for water turbine by computer workstation. PLC of LCU run the power control procedure by net communication in order to realize power adjust. The power adjust of water turbine mainly by speed control system and magnetization system. The 2-D Fuzzy PID Control Model is proposed in order to carry out power adjust of water turbine . In this new method the parameter of PID can self-neaten on line according to power deviation and power deviation rate. By means of this procedure the machine unit can obtain given power value rapidly, exactly and stably. It can make the power adjust of monitor and control system obtain good control characteristic and robust, and it is benefit to extend the work life of machine unit. 相似文献
5.
Chou Yongjin Tang Luping 《保鲜与加工》1988,(4)
This paper introduces a controlled temperature system in which the silicon controlled rectifier is controlled by a TP-801 microcomputer. A common-used PID expression is usually applied to control temperature, but it is necessary to adjust three parameters, making the operation quite inconvenient. This system adopts the measurement of a simplified expanded-critical proportion, only one parameter is necessarily adjusted. In addition, the method of digital triggering is applied so that the D/A transfer and silicon adjuster are omitted, thus decreasing the cost and increasing the reliability of operation. This system has higher precision of control and better degree of linearity of temperature increment or decrement. 相似文献
6.
在10 L自动发酵罐上,研究了控制不同Kla值和DO值对谷氨酸棒杆菌发酵生产色氨酸的影响。采用正交试验设计,得到最佳的分段控氧模式:0~24 h时,DO值为30%,24~48 h时,DO值为20%,48~72 h时,DO值为30%。在此控氧模式下,色氨酸5批罐发酵平均产量达9.73 g/L,比分段控氧前提高了13.4%。 相似文献
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8.
Aiming at systems which are of characteristics of multi-input and multi-output, nonlinearity and time-variation in the industrial control fields, this paper presents a intelligent PID control method based on ameliorative RBF neural networks, which constructs RBF neural networks identifier on-line and identifies a controlled object on-line by means of adopting the nearest neighbor-clustering algorithm, and adjusts parameters of PID controller on-line and realizes decoupiing control of multivariable, nonlinear and time-variation system. The simulation result indicates that the controller can get parameters which are optimal under some control law, it makes the decoupled system, compared to the PID control method based on the conventional RBF neural networks, has perfect dynamic and static performances, possesses the advantages of high precision, quick response speed and is of great adaptability and robustness. 相似文献
9.
The construction and function of high temperature melt viscosity test instrument are introduced in this paper. And the character of temperature control system is given. In order to improve dynamic and static performance of the temperature control system, a new method is proposed which combines threshold control with adaptive fuzzy PID control. While the current temperature of the heating furnace is much lower than the given temperature, threshold control works in order to protect system and improve dynamic performance. When the current temperature is close to the given value, adaptive fuzzy PID control works to improve static performance. At last, simulation and experiment results validate the proposed control method. 相似文献
10.
Carburization is a complex manufacturing process with serious disturbance and time delay,which is multi-variable and uncertain.It is difficult to set up an exact mathematic model.Moreover,by means of conventional control methods and experience,satisfying control result can't be obtained.In this paper,according to the characteristic of controlled-object,Fuzzy control method has been chosen to design a Fuzzy-PI controller and a mixed-PID Fuzzy controller.The result of simulation shows that the robust performance and control result of the new Fuzzy controllers is better than the conventional PID controller.The overshoot is smaller.It is helpful to improve the quality of carburizing workpieces. 相似文献
11.
This paper proposes a control scheme for a doubly-fed induction generator (DFIG) wind farm with VSC-HVDC grid integration to ensure secure and reliable operation of power system with fluctuated wind power penetration. The whole system dynamic models are respectively described. Based on vector control system with a virtual voltage orientation, a steady-state voltage control block and a dynamic voltage control block with a cross-product term of d-q currents are separately designed for WFVSC to control the corresponding parts of the wind farm voltage. Meanwhile, with the consideration of AC and DC side parameter variation and external disturbance, an improved backstepping control scheme with Lyapunov stability provement is also proposed for the GSVSC. The combination of the two schemes makes up the new control design of this study. Besides, to verify the performance of the proposed new control design, three different cases are suggested which contain the AC and DC side parameter variation and external disturbance such as local load cut off-in, grid voltage harmonics. Finally, numerical simulations using MATLAB/Simulink are presented for a 200MW DFIG wind farm with VSC-HVDC grid integration to validate the proposed control scheme and demonstrate the improved system operation performance. Moreover, the corresponding discussions are also presented for further illustrations. 相似文献
12.
Fuzzy PID controller was applied in variable air volume system. The task was to control the temperature of supply air and the temperature of air conditioned room (the return air temperature) close to their respective targets. The fuzzy PID control system of supply air temperature and return air temperature was designed respectively. The supply air temperature was controlled through adjusting the valve opening of chilled water. And the indoor temperature was controlled through adjusting the rotational speed of variable frequency ventilator. The supply air temperature and the indoor temperature (return air temperature) were controlled online by fuzzy PID controller. Thus, it was shown that the design of fuzzy PID controller was reasonable and the effect of fuzzy PID control was well. 相似文献
13.
This paper introduces the development of the electronic throttle control system (ETCS) , the structure and the principle of the system are also involved. After analyzing the nonlinearity problem existing in the mechanical structure of the system, a mathematical model of the ETCS is built up. Then three controllers (PID controller, Fuzzy controller, sliding mode controller) were designed and simulated in the matlab simulink. The result indicates that the PID controller has an overshoot,but the Fuzzy controller and the sliding mode controller can settle the nonlinearity problem better. 相似文献
14.
15.
Chen Ganping Qin Yihong Xu Guoyu 《保鲜与加工》1989,(4):55-62
This paper obtains the mathematical model of a single machine infinite bus power system using the idea of parameter identifications. Because the noise is considered in parameter identification process, the model reflects the real system more exactly. On the base of the identified model this paper also presents a discrete automatic voltage regulator by minimum variance control principles. In order to avoid the static error, we combine discrete minimum variance control with continuous integral control and get very satisfactory effects. This proposed control strategy is very easy to realize. The simulation results show that in every case the dynamic qualities of the proposed control strategy are incomparably superior to that of the conventional PI regulator, which means the proposed control strategy has great practical values. 相似文献
16.
Nitrogen transformation characteristic experiments of organic fraction of municipal solid waste (OFMSW) in a batch hydrolysis-UASB two-phase anaerobic digestion are carried out to solve the problems of total ammonia-nitrogen (TAN) accumulation and obtain appropriate key process control parameters. Based on the experiment results, TAN accumulation prediction model in the two-phase anaerobic digestion of OFMSW with digestive effluent reuse is established. And then with the prediction model analyzed, reflux ratio is obtained as a key process control parameter to prevent TAN accumulation. In the end, verification tests are designed to validate the feasibility and practicability of resolving TAN accumulation by controlling reflux ratio. In verifying experiment, when reflux ratio is set at 0.85, TAN concentration of UASB effluent is increased to a constant value, which is 1 900 mg/L. Furthermore, the accumulated TAN has no negative influence on the population and activity of methanogens, on the contrary, it develops the buffer capacity to acid and alkaline and keeps the anaerobic system more steadily. To sum up, a method of resolving the problem of TAN accumulation by controlling reflux ratio of digestive effluent has been ascertained radically, and the method can be used in the preventing of ammonia inhibition in two-phase anaerobic digestion process. 相似文献
17.
In order to investigate the influence factor of short cut nitrification and denitrification, the rapid startup and steady operation of the short cut nitrification and denitrification with real time control were studied. The results show that the short cut nitrification and denitrification can be rapidly setup by the control of DO and pH cooperated with low DO. The excessive aeration has negative effect on the accumulation of NO -2-N for primary short cut nitrification and denitrification sludge. With real time control and reasonable aeration time, the ammonia can be oxygenated completely and the nitrite can not be oxygenated when aeration stops and ammonia oxygenation just completes. Thus the real time control strategy not only realizes the short cut nitrification and denitrification, but also maintains such steady operation. 相似文献
18.
Control model for secondary cooling of continuous casting based on compensation temperature of the difference between liquidus and solidus
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LIU Qing LIU Xiaoshan ZHANG Xiaofeng JU Qiping XIE Feiming WANG Bin LI Hongwei LU Xinchun 《保鲜与加工》2013,(7):85-92
During continuous casting process, the composition of molten steel often varies with different heats, which leads to the big fluctuation of billet surface temperature when the traditional parameter water control model is applied to control the process. Additionally, it is difficult to keep the temperature at the straightening point of the billet within a reasonable range. Given above consideration, a new control model for secondary cooling of continuous casting based on compensation temperature of the difference between liquidus and solidus has been presented. Meanwhile, the temperature field of the billet is simulated with both the parameter water control model and the new secondary cooling control model, and the results indicate that the new control model for secondary cooling of continuous casting could perform better when it is used to control the surface temperature at straightening points of billet, thereby ensuring the quality of the billet. 相似文献
19.
An control algorithm with goed robustness has been developed,based on the combination of poletassignment self- tuning control algorithm with robust estimation and control al-gorithms,while the input signal and process parameters are varied on a large scale. The design of controller based on presented algorithm is simple,with good robustness for parameter changes and a strong ability for overcoming determined disturbance.The simulating research results proved the ef-fectiveness of the pole- assienment self-tuning robust control algorithm. 相似文献
20.
通过城市污水处理厂的活性污泥培养出好氧颗粒污泥并处理高浓度猪场废水,对pH值、溶解氧浓度、进水浓度等主要操作条件进行了单因素试验。实验结果表明,颗粒污泥具有良好的生物活性。在进水氨氮浓度较高(>800mg/L)、pH为8左右、溶解氧浓度在2.0mg/L的条件下,稳定运行数天后,氨氮和COD的去除率均可达到80%以上。 相似文献