Applied Mechanics and Materials Vol. 590

Abstract: Transformer vibration research is an effective diagnosis of DC bias fault. The vibration signal acquired is actually the mix signal of vibration from both the core and windings, and this makes it difficult to analyze the above two separately. Therefore the paper presents a new approach to separate vibration signal of core and windings by Fast-ICA algorithm. The simulated results of core and windings vibration are given and compared with experiment test. Comparative analysis verify that transformer vibration in no-load is core vibration and vibration in short circuit is windings vibration. Transformer vibration signals under different DC bias are tested by experiment. Vibration signals are separated by Fast-ICA algorithm. Core vibration signal and windings vibration signal are respectively obtained. The research lays the groundwork for further research of transformer DC bias vibration.

Abstract: The present situation of the UHVDC (ultra high voltage direct current) power transmission project is introduced, based on ±800kV UHVDC power transmission project put into commercial operation, the function design and application of GWS-1 remote equipment are carried out, the communication capability on IEC61850 is supported, the temperature problem of HP rx2660 is resolved, the GWS-1 remote equipment could meet the requirement of the UHVDC power transmission project is approved, and there is guiding significance on the research of RCI of UHVDC power transmission project.

Abstract: The large scale photovoltaic plants have more effects on the stability of regional power grid with the rapid increase of photovoltaic generation ratio in some areas. According to the grid guideline, the photovoltaic inverter is required to maintain the running status even the grid voltage drops and needs to have the capability to contribute towards the stability of power grid voltage and to support the grid voltage ride through. To test the ability of photovoltaic inverter low voltage ride through (LVRT), the test platform to simulate all kinds of fault for voltage drop needs to be set up. By the low voltage through technical requirements, this paper puts forward three kinds of design for test platform and analyzes respective work principle and characteristics, in order to provide optimization solution for the low voltage ride through test work.

Abstract: This paper described new working mode of Power Factor Corrector (PFC), called Boundary Continuous Mode (BCM); studied the design parameters of the critical components for the BCM-PFC in the boost topology; proposed a method and a tool for designing an L6562A-based BCM-PFC Boost Converter. The method and tool was verified on an evaluation board emulating a PFC boost converter with an 80W output power, 400Vdc output voltage and a wide range main input from 85Vac to 264Vac; and it can be easily adapted for applications with higher output power around 400W.

Abstract: Current attenuation rate plays an important role for battery rapid charging.This paper studied the relation between state of charge (SOC) and rebound voltage. Then the fuzzy logic control system with single-input and single-tap has been designed based on SOC and initial charging current.The results showed the maximum current attenuation rate can be achieved when the relationship of initial current and SOC arrived at an optimal value.

Abstract: As the integrator of energy resources (DERs), a virtual power plant (VPP) would be able to control the amount of the power access to the distribution transformers such that energy efficiency can be improved. Battery energy storage system (BESS) and demand response (DR) as DERs can entrust the VPP with certain controllability to regulate the power supply of the distribution system. This paper aims to maximize the benefit of the supplied powers over the 24 hours under VPP operation. Combining an iterative dynamic programming optimal BESS schedule approach and a PSO-based DR scheme optimization approach, an optimal VPP operational method is proposed to minimize the total electricity cost with respect to the power supply limit of the distribution transformers and the system security constraints, especially, within the peak load hours. With the TOU rate given each hour, test results had confirmed the validity of the proposed method with the obviously decreased power supply in each peak-load hours and the largely reduced electricity cost accordingly.

Abstract: In this paper, an optimal strategy was presented to solve the operation dispatch of cogeneration systems in a deregulated market. With the load demand including steam and electricity, the operational model of cogeneration system was derived by considering the bi-lateral contracts and operation constraints. The objective function is formulated the profit-maximizing problem in the searching process. Sequential Quadratic Programming (SQP) was used to solve this problem. Test results verify that SQP can offer an efficient way for cogeneration plants to meet the load growth and promoted the competed ability of cogeneration plants.

Abstract: According to the national policy of energy conservation and emissions reduction, using renewable resources and new energy to reduce environmental pollution. Reforming power distribution network system for housing estate in taiyuan. Access to distributed power supply, researching the exact location and capacity. By analyzing the distributed generation of the impact of distribution network,the objective function including investment and operating maintenance cost, environmental factors, network loss costs; putting power flow , current, voltage, system capacity constraints as constraint conditions, Using particle swarm optimization (PSO) algorithm with inertia weight, determine the location and capacity of distributed power supply. The proposed method is testified on the IEEE-33 bus system,and get the reasonable installation position and capacity, the simulation results will be used in transformation housing estate in taiyuan.

Abstract: The development of a method training based on vibratory stimuli was used in Russia since the 80’s. In this training a change occurs in Tonic Vibration Reflex (TVR) determining a reflex muscle contraction, originated from a local stimulus in muscle and tendon by vibration. The application of vibratory stimulus produces a state of greater neuromuscular efficiency, which increases the income of voluntary movements. The aim of this study was develop a prototype of a vibratory treadmill to assist on the walking training with the benefits of vibration. The device was adapted in Athletic Advanced Treadmill. The evaluation of the prototype was performed through comparison of reference values of ISO standards with acquired values by measuring instruments, being: strength g, frequency, amplitude, structural stability and resistance. In the statistical analysis of equipment tests was used Anova one-way and was observed a low variation of strength g and maximum amplitude was of 3mm being acceptable based on the limits of research conducted. Finally, the walking can be practiced safely and there is not displacement of equipment during implementation of the vibration.

Abstract: For a truck rear guard device connections is weak, the height from the ground does not meet the national standard. Used CATIA to design the latest kind of swinging truck rear underrun protector. The size of the latest protective frame meet the requirements of Chinese standard GB1567.2-2001. Used the finite element simulation of analysis software LS-DYNA, make the simulation experiment of rear end collision between a car and the truck. Analysis of the curve about the transient dynamic response, displacement, velocity and acceleration of protective frame in the process of collision, Clearly show the deformation process in the rear-end collision process of the protection frame. it proved the effectiveness of the protective frame. Analysis and collision simulation research of the latest underrun protective device.