Applied Mechanics and Materials Vols. 229-231

Abstract: Study on TOU (Time-of-Use) power price in our country almost treats power users as a unified whole, but different categories of users have the different power consumption and way in the actual condition. Therefore, they have different responses to TOU power price. According to the power load features of all kinds of users, the paper presents a solution to reclassify the users using fuzzy clustering algorithm, and provides theoretical basis for implementing categorized TOU power price. Finally comparatively perfect effect is obtained by simulation analysis, and it has great reference value to perfect TOU power price and improve load curve.

Abstract: The solar wireless charging circuit system based on resonance coupling power wireless transmission is aimed at addressing long wire, complex manual operation of wire charging type and short-distance, low efficiency of general electromagnetic induction-type power wireless transmission. Solar is conversed to electricity by photoelectric conversion then the electricity passes the following processing circuit: solar power supply circuit, power wireless transmission circuit and lithium battery charging circuit to complete lithium battery charging finally. The proposed circuit system owns perfect long-distance transmission, safe-operation, automotive rechargeable, flexible and efficient etc basic features and preventing over charge and over discharge double protection performance.

Abstract: In view of the coal mine neutral point ungrounded system when single-phase ground fault occurs, the grounding capacitance current is too big affect the security of coal mine powe supply.The paper analyzed testing data of capacitance current of coal mine network, established a treating scheme of capacitance current according to evaluating results, namely automatic tracking compensation arc suppression coil devices. The running results show that the scheme limits the size of the ground current and decreases rate of accidents of arc grounding over-voltage, which is good for improving the power supply safety.

Abstract: Diesel engine for automobile mainly adopts diesel particulate filter (DPF) method to deal with the exhaust particulate. In order to eliminate the particulate in the filter and complete DPF regeneration, the burner needs to be set at the entrance of DPF. This paper designs the evaporation-type DPF regenerative burner, and makes the bench and the real vehicle test. The test shows that the burner can complete DPF regeneration well within the working scope of the larger engine.

Abstract: The reactive power compensation optimization in distribution network has the important meaning in maintaining system voltage stability, decreasing network loss and reducing operation costs. In order to meet factual conditions, we assume the system operates in minimum, normal and maximum three load modes and the objective function of problem includes the costs of power loss and the dynamic reactive power compensation devices allocated. In this paper we use Artificial Immune Algorithm(AIA) and Particle Swarm Optimization Algorithm(PSO) to determine compensate nodes and use the back/forward sweep algorithm calculate load flows. After applied into 28-nodes system, the result demonstrates the method is feasible and effective.

Abstract: In this work, the cell performance of high temperature PEM fuel cells based on ABPBI membranes was experimentally measured in details. The ABPBI-based high PEM fuel cell was fabricated by using ABPBI-based gas diffusion electrodewith directly adding carbon-supported- catalyst to a homogeneous ABPBI solution prior to deposition and its membrane electrode assembly. The effects of various Pt loading of the catalyst layer, as well as the effect of different operating conditions were studied. The cell performance was evaluated using dry hydrogen/oxygen gases, which added advantage of eliminating the complicated humidification system of nafion cells. The measured results reveal that a catalyst layer with the higher Pt loading has a higher cell performance. In addition, better cell performance is noted for a case with higher cell temperature or higher cathode flowrate.

Abstract: The brushless doubly-fed machine (BDFM) is a new type of induction machine with good application in wind power generation. In this paper, the design method for the stator winding and rotor winding of BDFM in detail on the basis of operation principle of the machine is introduced. As an example, The performance simulation for a 480kW cage rotor BDFM with 8-pole stator power winding and 4-pole control winding can be considered under the condition of no-load, rated load and variable speed constant frequency operation based on field-circuit coupled finite element analysis. Simulation results show that the design method has good performance and is feasible in variable speed constant frequency wind generation systems.

Abstract: The purpose of this paper is to improve the transient stability of wind power system. This paper presents a new DFIG control strategy, The strategy achieve the decoupling of reactive power and active power. In order to improve the transient stability of wind power, here lead STATCOM into wind power system. Then put forward the STATCOM'S control strategy according it's mathematical model. The simulation result shows that, the proposed scheme can greatly improve the wind power system's transient stability.

Abstract: The purpose of this paper is to compare three power-feedback maximum power point tracking (MPPT) algorithms used in photovoltaic systems. The Matlab/Simulink is used in this paper to establish a model of photovoltaic system with MPPT function. This system is developed by combining the models of established PV module and DC-DC boost converter with the power-feedback MPPT algorithms of perturbation and observation, incremental conductance and hill climbing, respectively. The system will be simulated under different weather conditions and MPPT algorithms. According to the comparisons of the simulation results, it can be observed that the photovoltaic simulation system can track the maximum power accurately using the three MPPT algorithms discussed in this paper. HC algorithm possesses fast dynamic response, but P&O algorithm is well regulated PV output voltage and power than HC algorithm. The tracking time spent by INC algorithm is a little longer than the other two algorithms. The HC algorithm is suitable for the cases of battery charging which doesn't need extremely stable voltage, and the P&O algorithm is more suitable for the system with precision electric instruments. Furthermore, the INC algorithm is adaptable to the cases of fast changing weather conditions owing to its advantage of no misjudgment.

Abstract: This paper firstly describes magnetohydrodynamic (MHD) generator, which makes use of liquid metal and provide an excellent match to the mechanical impedance of an ocean wave. Then a new power converting system especially for LMMHD generator is designed and simulated, the results show that the power converting system can meet the requirement of LMMHD generator and has the advantage of lower cost.