Applied Mechanics and Materials Vol. 681

Abstract: The Line Inspection Robot is used to detect the line's defects when it walks on the overhead lines. It will be swinging under its own vibration and the action of wind , due to the robot arms hanging on overhead line alone ,so the dynamic characteristics of robot arm cannot be ignored. In this paper, we establish three-dimensional models of the line inspection robot's manipulator with double manipulators of antisymmetric structure, and conduct solving and post-processing of statics and modal analysis after meshing and applying constraints. The manipulator's low frequencies and vibration modals are drawn, so we can provide a theoretical basis for the reasonable optimization improvements to the line inspection robot's manipulator with double manipulators of antisymmetric structure.

Abstract: As a new product of integration of mechanics and electrics, electric boiler is acomparatively environment-friendly and energy-saving heating equipment at the present time. For the electric boiler, the performance of intelligent temperature control will directly affect the effect of energy saving, satisfaction of consumers andthe competitive ability of products in the market. Temperature control with large timelag and disturbances is widely used in the production of industry and daily necessities.It is affected by many factors such as the control plant and production condition, so itis very difficult to build the accurate mathematical model. Thus, the conventionalcontrol method such as PID control can’t meet requirements. Fuzzy control instead of establishing a precise mathematical model by simulation comparison of electric boiler control objects have very good results

Abstract: The open, intelligent and integrated CNC systems have been increasingly demanded with the development of manufacturing. In this paper, derived from requirements analysis, the architecture for a novel open, intelligent and integrated CNC system based on STEP-NC and PMAC is proposed. In the architecture, STEP AP-238 is selected as the NC data, which meets the requirements of the openness of NC data. Then, the open master-slave hardware structure based on IPC+PMAC with double CPUs is designed, which meets the requirements of the flexible hardware. Also, the open and modular software structure is designed, which meets the intelligent function requirements. In addition, the work flow of the CNC system is discussed. It turns out that the architecture presented provides a feasible solution to implement the open, intelligent and integrated CNC system.

Abstract: A novel internal force decoupling control strategy of hyper-redundant shaking table based on stiffness matrix is proposed in this paper. The linear models of electro-hydraulic servo system and mechanical system are built by considering the shaking table moving in a small range around the zero point. Internal forces are given through a transformation of cylinder forces which can be acquired from the pressure sensors. By meshing top platform of the shaking table in different directions, the stiffness matrix between the redundancy displacements and internal forces are given through dynamics equations including inertia and shear parts. The IFDC controller is designed to feedback the redundancy displacement caused by internal forces to the input current of the servovalve. Simulation results show that the proposed method is capable to reduce internal forces effectively.

Abstract: In this paper, an increment-type multi-step predictive and multi-step control algorithm of single-variable systems based on Laguerre function approximate model is presented, and then the stability of this algorithm is analyzed. Additionally, simulation of this algorithm had been done to investigate performance, the results show that the controlling quality of this algorithm is fairly good.

Abstract: The problem of generalized power sources planning in distribution system is researched. Meanwhile, the active and reactive power of generalized power source are treated as control variables. In this paper a generalized index for probabilistic optimal planning is presented. Based on this, a new probabilistic assessment model being setted up, a new glowworm swarm optimization algorithm is used to optimize the generalized power source. Finally, the model and algorithm are tested and improved by modified IEEE 33-node example. The calculation result shows that the proposed model and algorithm are feasible and superior.

Abstract: Based on solving maximum income model of hydropower plant and forming original bidding strategy, this paper used price coefficient to amend the original bidding strategy. Then it used the fibonacci method to obtain. Finally, it found the best stragety. The proposed stragety can coordinate the consumption of water in various period、 the relationship between water and quotation, it meet the constraint of water availability of plant and realize its optimal operation in the form of output-bidding, it also avoided the waste of water, then it insured the maximum income of the plant. Finally, a concrete example is given in detail to validate the practicability of the model and algorithm

Abstract: In view of inherent insufficiency of traditional power grid fault diagnoses expert system inthe aspect of knowledge acquisition,together with the characteristics of decision tree algorithm andexpert system, this paper puts forward a new power gird fault diagnoses expert system model basedon multi-source information fusion with SCADA switch, fault wave recorder electric quantity andWAMS system of electric quantity.On this foundation,we discuss the reasoning mechanism forpower gird, the reasoning algorithm, and the method of knowledge acquisition of the model. Thepractice results show that this proposed new approach improves the diagnostic accuracy comparedwith the conventional way based merely on switching-time data,and has practical value and goodapplication prospects.

Abstract: In this paper, it uses PSCAD/EMTDC to build simulation system of STATCOM (Static Synchronous Compensator). According to the principle of coordinate transformation and the theory of instantaneous reactive power, it creates self-defined components in PSCAD/EMTDC. The working principle of the system is explained fistly.Then the theory of instantaneous reactive power and the diagram of simulation system is presented. Each functional module is also discussed in detail. Through the simulation test, it emphatically analyzes real-time tracking ability of the system when the capacitive and inductive loads are added. In this way, correctness and validity of the system has been proved.

Abstract: In this paper, an estimation of protection distance of 500kV arrester is given, and a simulation experiment is proceeded to study the protection distance of 500kV arrester. So far, there is no relevant standard reported on the protection distance of 500kV arrester at home and abroad . By the studying, recommended values of the protection distance of 500kV arrester can be suggested. The research in this paper can also provide references to installation of arresters and the data obtained is valuable for research in this field.