动力换挡变速器换挡平稳性

通过对典型动力换挡变速器液压控制系统和动力换挡变速器的换挡过程进行分析得出了改善换挡平稳性的途径。     

石杉碱甲透皮控释制剂督脉经穴给药改善东莨菪碱小鼠记忆障碍作用及机理初探1

目的 观察石杉碱甲透皮控释贴片(Hup-ATDDS)督脉穴位给药对东莨菪碱(Scop)致小鼠学习记忆障碍的影响,比较穴位给药与一般部位给药的作用差异,探讨督脉穴位给药机理,为穴位透皮控释给药新途径提供初步实验依据。方法 采用跳台、“Y”迷宫等行为药理学实验方法,观察Hup-A TDDS穴位给药与一般部位给药对Scop 小鼠记忆障碍的改善作用,并以小鼠脑胆碱酯酶活性等指标初步探讨穴位给药的作用机理。结果 跳台试验和电迷宫试验表明,Hup-A TDDS 督脉百会穴用药后3 ~ 6 h间有明显的改善学习记忆作用:13.4 μg/0.25cm² 组用药后4h 为佳,5~6 h 时作用减弱;26.7μg/0.25cm² 组自药后3 h 起作用明显,药后4 h 作用最为显著,维持至6h 仍有良好作用;Hup-A TDDS 26.7 μg/0.25cm² 经百会、哑门、大椎、至阳和命门五个穴位给药均有明显的改善学习记忆作用,其中以百会穴组的作用最为显著;Hup-A TDDS 经百会穴或一般部位(选臀位)给药均有改善学习记忆作用,但以百会穴给药较臀位用药作用更为显著,且Hup-A TDDS26.7 μg/0.25cm² 组对小鼠脑胆碱酯酶活性有明显抑制作用。结论 Hup-A TDDS 督脉穴位给药的改善记忆作用优于一般部位给药;其改善学习记忆作用可能是由于抑制脑CHE 活性,改善胆碱能系统功能所致。     

水电站微机调速器典型故障处理方法

对水电站带空放阀的微机调速器的几个典型故障做了较详细的阐述,分析故障的原因,简要介绍相应的处理方法。     

水轮机调节系统控制策略发展与应用

概述了水轮机调节系统的特点及其调速器的发展,着重介绍了PID控制、自适应控制和智能控制的特点及其在水轮机调节系统中的应用.提出将多种控制策略相结合形成复合控制,将是水轮机调节系统控制策略的发展方向.     

机械液压调速器增减负荷缓慢原因及处理

从理论上分析增、减负荷缓慢的原因，提出简易的处理办法，指出操作上应注意的问题。     

交流变频调速器在油田油气密闭集输控制系统中的应用

分析了油气密闭集输控制系统的特点。在油气密闭集输调节系统中用变频器代替调节阀，提高了油气密闭集输的可靠性，减少了调节间节流压降能量损失，达到了节能的目的。并对变频调节的节能效果进行了分析。     

右江水电厂调速器建模试验

水电厂调速器建模试验是系统稳定分析计算的重要依据,同时可以考察机组调速器的性能,优化机组动态协调特性,介绍了对右江水电厂机组进行的静态和动态带荷的相关试验,并对试验结果进行了数据分析,为机组和电网安全稳定运行提供了依据.     

Non-linear sliding mode load frequency control in multi-area power system

This paper addresses non-linear sliding mode controller (SMC) with matched and unmatched uncertainties for load frequency control (LFC) application in three-area interconnected power system. In conventional LFC scheme, as the nominal operating point varies due to system uncertainties, frequency deviations cannot be minimized. These lead to degradation in the dynamic performance or even system instability. In this paper, an effective control law is proposed against matched and unmatched uncertainties.. The proposed controller has ability to vary closed-loop system damping characteristics according to uncertainties and load disturbances present in the system. The frequency deviation converges to zero with minimum undershoot/overshoot, fast settling time, significantly reduced chattering and ensures asymptotic stability. In addition, the controller is robust in the presence of parameter uncertainties and different disturbance patterns. It also guarantees high dynamic performance in the presence of governor dead band (GDB) and generation rate constraint (GRC). Simulations are performed to compare the proposed controller with linear SMC. Using proposed control strategy, undershoot/overshoot and settling time gets reduced by approximately 30% with respect to linear SMC. The computed performance indices and qualitative results establish the superiority as well as applicability of the proposed design for the LFC problem. Further, the proposed controller scheme is validated on IEEE 39 bus large power system.     

Load frequency control of power system under deregulated environment using optimal firefly algorithm

In this paper, a novel Firefly Algorithm (FA) optimized hybrid fuzzy PID controller with derivative Filter (PIDF) is proposed for Load Frequency Control (LFC) of multi area multi source system under deregulated environment by considering the physical constraints such as Generation Rate Constraint (GRC) and Governor Dead Band (GDB) nonlinearity. As the effectiveness of FA depends on algorithm control parameters such as randomization, attractiveness, absorption coefficient and number of fireflies are systematically investigated, the control parameters of FA are tuned by carrying out multiple runs of algorithm for each control parameter variation then the best FA control parameters are suggested. Additionally, the superiority of the FA is demonstrated by comparing the results with tuned Genetic Algorithm (GA). To investigate the effectiveness of the proposed approach, time domain simulations are carried out considering different contracted scenarios and the comparative results are presented. Further, sensitivity analysis is performed by varying the system parameters and operating load conditions. It is observed from the simulation results that the designed controllers are robust and the optimum gains of proposed controller need not be reset even if the system is subjected to wide variation in loading condition and system parameters. Finally, the effectiveness of the proposed control scheme is evaluated under random step load disturbance.     

A novel hybrid PSO-PS optimized fuzzy PI controller for AGC in multi area interconnected power systems

In this paper, a novel hybrid Particle Swarm Optimization (PSO) and Pattern Search (PS) optimized fuzzy PI controller is proposed for Automatic Generation Control (AGC) of multi area power systems. Initially a two area non-reheat thermal system is used and the gains of the fuzzy PI controller are optimized employing a hybrid PSO and PS (hPSO-PS) optimization technique. The superiority of the proposed fuzzy PI controller has been shown by comparing the results with Bacteria Foraging Optimization Algorithm (BFOA), Genetic Algorithm (GA), conventional Ziegler Nichols (ZN), Differential Evolution (DE) and hybrid BFOA and PSO based PI controllers for the same interconnected power system. Additionally, the proposed approach is further extended to multi source multi area hydro thermal power system with/without HVDC link. The superiority of the proposed approach is shown by comparing the results with some recently published approaches such as ZN tuned PI, Variable Structure System (VSS) based ZN tuned PI, GA tuned PI, VSS based GA tuned PI, Fuzzy Gain Scheduling (FGS) and VSS based FGS for the identical power systems. Further, sensitivity analysis is carried out which demonstrates the ability of the proposed approach to wide changes in system parameters, size and position of step load perturbation The proposed approach is also extended to a non-linear power system model by considering the effect of governor dead band non-linearity and the superiority of the proposed approach is shown by comparing the results of hybrid BFO-PSO and craziness based PSO approach for the identical interconnected power system. Finally, the study is extended to a three area system considering both thermal and hydro units with different controllers in each area and the results are compared with hybrid BFO-PSO and ANFIS approaches.