Applied Mechanics and Materials Vols. 644-650

Abstract: This paper designed a new band-gap voltage reference circuit with two-stage temperature compensation.It realizes non-linear temperature compensation by using NMOS-pipe leakage current and increases the power supply rejection ratio of the band-gap voltage reference source by introducing negative feedback between the operational amplifier and the power supply. What is more, the paper simulates the band-gap voltage reference source based on CSMC 0.5μm CMOS technique. The result as follow: the band-gap voltage reference source has the temperature coefficient of 8.2ppm/oC among-40-120oC with the supply voltage of 3V, the low-frequency power supply rejection ratio is 83dBat 27oC and the power supply rejection ratio is 71dB in 1KHz, the output voltage regulation is 1.05mV/V in the supply voltage range from 2.4V to 5V.

Abstract: Aiming at multiple attribute in electric power system black start scheme evaluation, the characteristics of the subjective and objective weights are difficult to determine; Entropy weight method can not ensure independence; DEA model can't completely sorted and judgment matrix all of 1 problem may come up, this paper puts forward improved DEA/AHP model. According to the index of evaluation index focus type optimal selection, the worst plan to join the group evaluation schemes for evaluation. This method not only can guarantee the independence of the scheme can achieve full sort again, avoid the process of calculating the weight at the same time, to enhance the objectivity. The method is simple in calculation and reliable results, tianjin power grid black start scheme evaluation results prove the effectiveness of this method.

Abstract: This paper presents a time-to-digital converter (TDC) based built-in self-test (BIST) scheme for operational amplifier (Op Amp). The propagation delay exiting in the transient response of the Op Amp is monitored by the inverter based TDC, and converted into a digital code based on the referenced delay interval of the inverter used in the TDC, as a result, the digital code is finally employed to determine the test rsults. The circuit-level simualtion results of the proposed BIST syetem for a two-stage Op Amp are presented to demonstrated the feasility of the proposed BIST scheme with high fault coverage.

Abstract: Arrayed waveguide grating (AWG) is a very popular dense wavelength division multiplexing (DWDM) device, which is produced in the field of optical communication technology. Instead of traditional grating and lens spectral system, AWG is used as the spectral chip in miniature Raman spectrometer. It’s quite important for miniature Raman spectrometer in miniaturization and low cost. This paper analyzed the basic principles of AWG device, and introduces the insertion loss, crosstalk and phase error performance parameters, also focuses on the specific technical requirements about wavelength, optical channel number, phase error, wavelength resolution and bandwidth, which are applied in miniature Raman spectrometer. Some new researches and a series of related simulation have been made, finally won the 1 * 40 channels AWG spectral chips, with wavelength range of 880-920 nm, insertion loss of center wavelengths is better than-0.9 dB.

Abstract: This paper studies electromagnetic parameters' impact of λ/4 type dielectric absorber on absorbing properties. Calculation shows that the maximum absorption amount is corresponding to specific values of K and R when absorber's permittivity is stable, when the thickness of material is determined and the real part permittivity is increased, the absorption peaks move to lower frequency and reduce the distance between adjacent peaks, while the imaginary part of permittivity and resistance of membrane resistance only affect absorption peaks' amount but have no effect on the peaks' position. Accordingly, it is reasonable to adjust the material's electromagnetic parameters according to the above rule when the high-performance λ/4 dielectric-type absorber is prepared.

Abstract: With manufacturing technology innovation and progress of electronic devices of semiconductors, dimensions of electronic devices get smaller nowadays. There has been processing of 90nm and 20nm in production. With in-depth research, scientists are more and more interested in molecular devices. Since the size of molecular devices is small, electrons transfer by ballistic transport. In semiconductor devices, when the transport distance is at micrometer or smaller sizes, the ballistic transport phenomena of electrons and holes of carriers occur. This transfer form is not affected by lattice defects, doping, and interaction of crystal interfaces. Since there is no interference of these interactions, carrier’s velocity can be faster several times than common electronic devices, resulting in the doubled operating speed of these devices. Although it is difficult to achieve pure ballistic transport, when the size of semiconductor devices is close to the mean free path of carriers, the speed of carriers will still be greatly improved.

Abstract: This paper designed a DC programmable power-supply system based on ARM Cortex-M3 as the main controller. The main power module is supplied with PAF600 from TDK-lambda. This system uses 12 bit serial high speed chip analog-to-digital conversion from TI (Texas Instruments) and 12 bit parallel high resolution analog-to-digital conversion chip from AD (Analog Devices) for the signal of the power supply system of acquisition and adjustment. The system not only can use the encoder and the keyboard to adjust and control, but also can through the RS-232 interface apply the PC software to send command to do that. The signal of power supply system can realize software over-voltage protection and over-current protection function by high speed DAQ (Data Acquisition) ,the rapid data processing of ARM and the least squares curve fitting. This system runs steadily and reliably and also has high adjusting precision and simple operation. The best is to read these instructions and follow the outline of this text.

Abstract: The development of Operation &Maintenance Automation System of CSG EHV Power Transmission Company needs to integrate some automation systems being in use, in order to build effective connections among different data and business process. This paper introduced several system integration technologies, and analyzed the applicability of these technologies referring to the automation systems used in power Grid Company, and proposed system integration solutions for typical automation systems in details.

Abstract: In this work, an adaptive sliding mode control method is presented to achieve output synchronization tracking for the uncertain hyper-chaotic Lü system. An adaptive piecewise linear (PWL) filter is used to identify the uncertain hyper-chaotic system. Base on the identification results, an adaptive sliding mode controller is designed to obtain output synchronization tracking for the hyper-chaotic Lü system. The convergence condition of the adaptive PWL filter is derived based on the Lyapunov theorem. Simulation is done to verify the effectiveness and correction of the proposed identification and synchronization tracking control method.

Abstract: Water level control of the steam generator is an important indicator of the safe operation of nuclear power plant. The traditional PID controller system has the disadvantages of large amount of overshoot, long adjusting time, etc. Steam generator has complex, nonlinear and time-varying characteristics. This article proposes the adopting the BP neural network intelligent control algorithm. The simulation experiments results indicated that: Comparing with traditional PID control it has smaller overshoot and shorter adjustment time, more ideal control effect c.