Advanced Materials Research Vols. 614-615

Abstract: Estimation of Signal Parameters via Rotational Invariance Techniques (ESPRIT) is applied to analyze the interharmonics in Electric Power System (EPS). First, the signal received by one A/D convertor forms a signal vector through time shift; second, the number of sinusoidal components which compose the analyzed signal is estimated by calculating Minimum Descriptive Length (MDL), and then ESPRIT utilizes the rotational invariance of two sampling linear arrays to obtain frequency information by Total Least Squares (TLS) algorithm; and finally the rest amplitudes and phase angles are estimated by a simplified Support Vector Regression Machine (SVRM). TLS-ESPRIT aided by MDL as a super-resolution algorithm can overcome resolution limit and achieve better results compared with FFT and PRONY algorithms. Computer simulations prove that the proposed method is feasible and applicable.

Abstract: The electrostatic discharge (ESD) failure of power drain-extended MOS (DEMOS) devices, the protection circuit SCR, and a DEMOS with SCR protection circuit will be investigated in this paper. The ESD immunity of the DEMOS was very poor under the human-body model (HBM) testing. Here we discuss how to design an ESD good SCR device. Eventually, the ESD immunity of DEMOS test sample with an SCR circuit can significantly improve device ESD performance.

Abstract: Mathematical model of tension servo system drived by two induction motor is analyzed in this paper. Then, structure optimized of first-order active disturbance rejection control (ADRC) of tension servo system is designed. Double channels compensation of extended state observer is used to estimate and compensate the total disturbance of system, and approximate linear and determined treatment is done to the tension control system. S7-300 PLC is used as lower computer controller, while WinCC is used as upper computer monitor software, realizing all-digital control of the system. The experiments is carried on based on S7-300 PLC experimental platform and the results prove that the decoupling control of speed and tension is realized, and the control system has higher dynamic, static status and robustness performances.

Abstract: When general PID controller appllied into multi-variable decoupling control system, its parameters are difficult to set and self-adaptability is poor. A neural network decoupling controller composed of self-adaptive PID controller and compensated decoupling network is presented, which is based on the analysis of the system model. Simulation results show that the controller designed basically eliminates the coupling effect of the tension control system and improves the dynamic and static performances.

Abstract: With putting forward to construct strong power gird, safe operation of electrical equipment is an important part of power system,especially fault detection of electrical equipment. At present the infrared technology is used widely in power system, because it can discover abnormal temperature in time and accurately which caused by the fault of electric equipment. The article introduces how to measure the temperature of electric using the infrared measuring temperature module, and revises the parameters to get more accurate temperature data, then analyses and judges whether the electrical equipment is in failure.

Abstract: Current source converter (CSC) configuration tailored to high-power grid-connected wind energy conversion system (WECS) has been an attractive solution for direct drive of permanent magnet synchronous generators (PMSGs). A maximum power point tracking (MPPT) scheme for a PMSG-based WECS is presented in this paper. On the generator side, a fully controlled current source converter is inserted as a circuit interface to handle a wide range of the variable wind speeds. Rectifier side controller extracts maximum power through closed-loop regulation of generator speed. The available maximum power fed to the grid is adjusted by regulating dc-link output current of CSC according to the variable wind speed. Simulation results obtained from a megawatt PSIM model are provided to verify the proposed concepts.

Abstract: An efficient SRAM power modeling method based on two formula techniques is proposed, which contains a mathematical method called two-dimensional bilinear interpolation function and a segment analysis on the basis of MUX. This scheme allows us to reach the accurate modeling of SRAM power consumption without complicated calculation and specific circuit analysis. Hsim simulation in 65 nm CMOS process shows our proposed method error is closed to 5%.

Abstract: Retracted paper: Stable epistemologies and Internet QoS have garnered minimal interest from both cyberneticists and physicists in the last several years. Given the current status of semantic communication, scholars obviously desire the emulation of model checking. In this position paper, we concentrate our efforts on proving that suffix trees can be made homogeneous, scalable, and low-energy. Results showed that the well-known constant-time algorithm for the evaluation of DHCP is optimal, and ShernCod is no exception to that rule. Furthermore, our application successfully analyzed many flip-flop gates at once. This paper also disconfirmed not only that multi-processors and Smalltalk can collude to fulfill this objective, but that the same is true for model checking. Finally, this study provided evidences that the well-known pseudorandom algorithm for the improvement of 802.11b is in Co-NP.

Abstract: Be aimed at the difficulty problems that entrance variation in thickness and hardness variation change a lot、back-up roll deflection、roller thermal expansion、the variation of lubricating fluid and flow compensation indeterminacy of servo mechanism in the system of steel plate strip, anti-interference controller is applied to rolling mill AGC control system for the first time in this paper. Theory analysis and simulation experiment demonstrate that rolling mill AGC based on Auto Disturbance Rejection controller can solve the above difficulty problems which convention rolling mill AGC control system can’t solve, the proposed system possess excellent dynamic property and static state property.

Abstract: The Characteristics of FSC (Fixed Series Compensation) and TCSC (Thyristor Controlled Series Capacitor) damping power-angle oscillation and increasing the limit of power transmission were analyzed. FSC can damp the power-angle in a certain extent. Based on the linear control combined with Bang-bang control strategy, TCSC can damp power-angle effectively. In the cases of only FSC, only TCSC and their combinations, simulation results demonstrate that TCSC is more effective than FSC in damping power-angle oscillation. A conclusion is made that taking effect and cost into consideration, TCSC and FSC in a certain percentage is appropriate.