Applied Mechanics and Materials Vols. 130-134

Abstract: Three phase double mode inverter system was researched in this paper, whose input was battery bank system with PV generation. This system can be operated in stand-alone mode by connecting to local load and also in grid-connected mode by paralleling with grid. When in stand-alone mode, system worked as voltage source, while when in grid-connected mode, the output current of inverter was controlled following with grid. A transition algorithm to restrain current inrush and fast detection of switch and grid status make sure the seamless transition between grid-connected and stand-alone. This inverter system has advantage of simple structure and easy to implement, so that it was appropriate for micro-grid. .

Abstract: When dealing with such complex systems such as the software package of a smart mobile phone, it is necessary to apply powerful methods to detect and report errors when they occur. This paper probes and analyzes a powerful debug method called trap and exception handling, which is supported by the ARM platforms. The method can easily capture some valuable debug information. When a fatal error occurs during runtime or system detects an abnormal, a trap or an exception shall be logged and stored in the non-volatile random access memory (NVRAM). The information must be enough and easy for engineer to analyze the software error.

Abstract: The paper designs digital PI controller based on VHDL, which achieves closed-loop speed control of the submerged arc welding. And the controller has passed the compilation and simulation using MATLAB. The simulation validates that the design accords with the request of PI controller.

Abstract: Optimal allocation of reactive power compensation plays an important role in power system planning and design. However, as a non-linear, large scale combinatorial optimization problem, Conventional methods are not normally appropriate for it . A mathematical model is firstly presented in this paper for comprehensive optimal configuration in distribution feeders based on the analysis of engineering factors of reactive power compensation, whose objective is to minimize the annual expenditure involving the devices investment and the income of energy saving, and satisfy all sorts of operation，fixing and maintenance constrains. The control variables include the capacitor banks’ number and capacity of various compensation schemes. RARW-GA algorithm is adopted to solve this problem. The result of calculation and analysis of BenXi Steel group corporation power system shows that the proposed method is feasible and effective.

Abstract: Edge detection is one of the most important techniques in image processing. A new image edge detection approach is presented by wavelet scale multiplication, which has the advantage of magnifying the edge structures and suppressing the noise. The dyadic wavelet transforms at tow adjacent scales are multiplied as product function and image edge is detected by wavelet model maximum. It need not link edge points, realize simply and is usually applied to noisy, low contrast image.

Abstract: In this paper, a long sequence length, reduced complexity MASH 1-1-1 digital delta-sigma modulator (DDSM) suitable for fractional-N frequency synthesizer applications is presented. Good shaping of quantization noise is achieved by using the state of art MASH structure for a digital third-order delta-sigma modulator, meanwhile, the hardware required for this modulator is considerably reduced by recoding all carry output signal from accumulators. The functional operation of the modulator is confirmed by simulation.