But tradition hydraulic control has many demerits . and the digital electronic controller characters with high running speed , high precision , flexibility , full authority digital electronic control system is the direction of aero - propulsion control system 由于机械液压不能实现多回路解耦控制、无法实现复杂的控制算法等诸多缺点，而数字式电子控制器不但能克服机械液压系统的缺点，还具有运算快、精度高等优点。
Secondly , considering the complexity of cement rotary kiln system , we build up the models of this system with the integration techniques of artificial neural network and expert system . the improved ebp neural network algorithm is used in this system 第二，根据水泥回转窑系统具有多变量、多回路、非线性、分布复杂和经典数学模型难以建立的特点，运用神经网络与专家系统集成技术对预分解窑系统进行了建模与研究。
The paper ' s contents involve the following aspects : 1 based on the multi - loop method , this paper describes the construction of a mathematical model of salient - pole synchronous generators suitable for analyzing the transient behavior of internal faults in stator windings 本文针对发电机定子绕组内部故障暂态分析中存在的一系列问题，开展了研究工作，主要内容有： ( 1 )建立了凸极同步发电机定子绕组内部故障暂态计算的多回路数学模型。
The distinguished contributions of this paper are listed in details as the following . 1 . the multi - loop mathematical models under the conditions that the squirrel cage asynchronous motor is healthy , faulty with broken rotor bars or with stator winding inter - turn shorts are deduced thoroughly , and improved necessarily 本文的主要研究成果如下： 1 .详细推导了yn接、 y接、 d接笼型异步电动机在正常、转子断条及定子绕组匝间短路故障情况下的多回路数学模型。
The mathematical model of multi - loop , which is improved through selecting new stator loops in this paper , can be used to simulate the transient behavior of external short circuit at machine ' s terminal and internal short circuit in the stator , not only under no - load condition with single machine but also under load condition connected to power network 本文改进了原来的多回路数学模型中对定子回路的选择，不仅可对同步发电机机端各种外部短路故障和单机空载下的各种定子内部故障进行暂态过程的仿真，还实现了负载时内部各种故障的暂态仿真。
The transient solution obtained from the multi - loop mathematical model are in agreement with experiment results approximately under the conditions that saturation is not severe . though the errors of currents in some non - fault branch seem a little large , the fundamental components of the simulation current are accurate 结果表明，多回路数学模型在电机饱和不严重的情况下，暂态仿真结果与实验结果大致吻合，虽然有时非故障分支电流与实验结果的差异比较大，但基波分量还比较准确，基本可以满足保护方案的灵敏度校验等工程需要。
In order to analyze the characteristics of stator ground fault and develop its protection schemes , a mathematical model for large - sized hydro - generators is established based on the multi - loop theory of ac machines and considering the capacitance to ground and actual construction of the stator windings 为了详细分析大型水轮发电机定子绕组单相接地故障特点，校验和开发相应的保护方案，本文建立了以交流电机多回路分析方法为基础、考虑定子绕组对地电容、采用实际绕组结构的发电机定子绕组单相接地故障仿真模型。
Most of practical design methods , including self tuning approaches for pid controllers , are based on the consideration of control systems with one closed loop , lower order process model and one pid controller . in the industrial engineering , however , some control systems are so complicated , for example more than one loops with many controllers , that it is very difficult to achieve desired properties of control systems by only making use of either engineer ' s experience or pure ana1ysis methods 二是现有的pid控制系统设计方法大多只考虑对低阶对象模型、单回路控制系统或一个pid控制器的设计和整定，而对于高阶对象模型、多回路或多个控制器的控制系统的整定往往十分复杂和繁锁，很难被工程技术人员掌握和使用。
For the first time , the transient simulation of rotor bar subsequent - breaking fault has been completed successfully . also , the corresponding experiments have been carried out . moreover , this paper systematically generalizes the rotor bar breaking fault features , and draws quite a few creative and interesting conclusions 2 .对笼型异步电动机转子断条故障特征做了机理分析，以笼型异步电动机多回路数学模型为基础，首次完成了转子导条持续断裂故障的暂态仿真，同时对转子断条故障进行了实验研究。
