Abstract:A symmetric successive over ralaxation preconditioned conjugate gradient method is used to calculate nonlinear electromagnetic field. The storage and the computer time of the method discussed hfire are compared with those of Newton's iteration.

Abstract:This paper reports on the application of "Out-of-Kilter Algorithm" (OKA) to the real power economic dispatch with security constraints. The network flow programming is characterized by simple manipulation, fast and reliable convergence, while the OKA can treat nonzero lower bounds and may initiate with any set of flows (including infeasible flow) which satisfies Conservation of flow. The major procedure and numerical example of OKA are given in this paper. The calculating results for economic dispatch on test systems have shown that the method is feasible and effective.

Abstract:The eigenvalue sensitivity methods is very useful not only in analysis of electric power system stability but also in design of the controllers. In this paper a new optimal method is proposed to design the parameters of PSS. Using this method the PSS is designed for a single machine-infinite bus system, and the results of digital simulation show that this method is very effective and useful.

Abstract:In this paper, a new microcomputer distance protection scheme with high property-cost ratio has been approached. The paper presents the performance equations based on the symmetrical components of current and voltage, proposes a new (1,a) coordinate plane and derives a Fourier symmetrical component algorithem with high accuracy and less calculation amount on the (1,a) plane. The protection program is debugged on the developing system of single chip computer. The digital imitation tests indicate that the proposed relaying system is satisfactory.

Abstract:If generator capacity were not graded, the error in reliability evaluation would increase along with the large-capacity generators put into use.In this paper, the method for calculating LNS Index of generators is analyzed and studied using piecewise "algorithm by capacity, it can be used in reliability evaluating of unspecified under loaded generators.

Abstract:This paper discusses about maximum power tranrfer from the active resistive network to the passive reactive network, and derives the condition that the load network must satisfy when the power transfer is maximum, and gives some examples about its application.

Abstract:The forces acted on a polar coordinate measuring instrument have been analysed in this paper. According to the, characteristics of friction, a friction reducing principle, which is by motion and with rolling in place of sliding, has been put forward, with the princple we can improve the frietional state effectively and make it possible to measure large presurc angle curved parts automatically with low cost.

Abstract:The theoretical analysis and testing result indicate that, a hydrodynamic effect will be taken under place the condition of a turning spindle which will rise the rigidily of the spindle system and strengthen its antivibration ability as well. Below a critical turning, speed, itis discivered that the high the turning speed is, the more obvious hyrodynamic effect and the letter static and dynamic characteristic would be.

Abstract:It is known that cylinder heads, exhaust manifoids, ingot molds, etc. are often failed resulting from thermal fatigue. For this reason, the influence of RE on the thermal fatigue behavior of cast iron was studied by measn of a thermal fatigue test unit with completely constrained strain developed by ourselves. The test results shown that RE can improve the thermal fatigue resistance of cast iron greatly when residual RE contents surpass a critical value. This value is 0.04-0.045% for light Rare-Earth, and 0.045-0.05%; for heavy Rare-Earth. Further more, the relationship between RE and the thermophysical and mechanical properties of cast iron which have influence on thermal fatigue resisteance was also discussed.

Abstract:Using the flaw-detecting with ultrasonic wave one may know the equivalant area of a crack that burys in the member. If the crack is ellipse shaped, the equivalant area is constant, and the distribution function of its major semiaxle and the plane strain fracture toughness of the material are given, then we would get the probability of reliability of the member under the uniform tension. In this condition, a formula of calculating the probability would be provided in this paper. Because a simple and enough precise approximate function has been introduced the formula in the paper is simple in shape and easy to use.

Abstract:This paper presents the equal theory of the sine wave voltage and PWM waveform in the integration of time. Using the graphic method as well as the comparison method of sequential integration the PWM control pattern is calculated. Depending on an example for PWM circuit inverter the microcomputer is investi-gated. The method is simple and effective. It is specially adeguate to the engineering control.

Abstract:In this paper, two different concepts of apparent vicosity are theoretically distinguished. The necessity fordeveloping a new apparent-viscometer. is shown. A new idea for this aim is described. The main points of the design of the main body, control circuit and software are given.

Abstract:This paper describes the research work of analyzing vibration signal to monitor and diagnose on line the ball bearing fatique. Carrying out a large mumber of life test on ball bearing test machine, it is discovered that in the so called "second effect" vibration signal as the bearing fatique occurs, apart from the two widely used spetrum charactersof "fraverse frequency" and "high frequency shock pulse" , there is another important but rarely known opcctrum characteristic of high frequency peaks existing in the middle-to-high frequency band.The generating mechanism, effect factors and test method of those high frequency peaks are researched tentativ tentatively. Two binds of device for monitoring abnd diagnos sing ball learing fatique on line are developed based ion this new type spectrum characteristic. One consists of a bandpass filter, the other is based on the spetrum characters which corns from the DDS ( Dynamic Data System ) modeling

Abstract:This paper introduces imitation of the expert experence, whole procedures for establishing mathematical model and clinical effects. The system has higher level and clinical effects in diagnosis.

Abstract:In this paper,we have studied the change law of the structural parameter of coal in Nan Tong Coal Mine with the increasing the temperature. At the same time, we explore the cause of the changes with the electron microscope and of infrared spectrum.

Abstract:高速钢回火过程中组织变化十分复杂,本文用透射电子显微镜对低合金高速钢W3Mo2Cr4V的回火过程进行了研究。结果表明:该钢560℃回火时主要析出MC型和M_3C型碳化物,其中MC呈盘状,M_3C呈微细粒状,钢中加入硅,显著抑制了合金渗碳体的形成,并加速其向MC和M_7C_3碳化物的转变。

Abstract:Based on the physical processes of regenerative heating systems, the mathematical models of regenerative system,reheat system and steam turbine for a 200MW reheating steam turbine are presented, and the digital simulation of them on IBM-PC is also provided in this paper. The present work is a part of the study of the dynamic characteristics of all power systems. The mathematical model is expressed into state space form ,and its matrix is standardized to avoid the repeatation of establishing the models of heat exchangers.

Abstract:In this article metallic iron in vanadium-slag tread with sodium is separated by abrading and leaching with CuSO4 solution. The residual copper sulfate is scrubed with ammonium citrate, and the quanity of metallic iron is determinated by indirecting electro-weight analysis. Corpper whinh is replaced out during the process can be solved selectedly by NH2OH-H2SO4 Solution, and its result is satisfactory. This method's reliability is proved by returning test, metallogrrphic assay and X-ray diffraction cerification.