Applied Mechanics and Materials Vols. 687-691

Abstract: Research on the conditions of solar photovoltaic grid connected power generation, research the form of converting solar energy into electrical energy generating.This paper introduces the solar photovoltaic system components, advantages and disadvantages as well as the current domestic solar photovoltaic power generation application status, prospect the development of the trend in the future, according to the analysis of the present problems. And relying on Tianjin CNOOC oil development group of Yingkou natural gas terminal 330KW solar photovoltaic power generation demonstration projects are introduced. For the photovoltaic CNOOC Yingkou terminal-station problems presents the feasibility scheme and suggestion.

Abstract: With the increasing application of Photovoltaic (PV) power system, it is important to make PV system always achieve its maximum power output, so maximum power point tracking (MPPT) technique develops. Based on Support Vector Regression (SVR) and Genetic Algorithm (GA), a novel MPPT method is proposed in this paper. The SVR model uses the solar radiation and temperature as two inputs, and uses the voltage at maximum power point (MPP) as output. Furthermore, GA is introduced to search the best parameters for SVR. Results validate the effectiveness of the proposed MPPT method.

Abstract: This design uses ATMEG8L as the master chip, real-time detection the state of the main power supply DC voltage, by controlling the MOSFET has the ability to quickly turn off the main power and backup power to achieve seamless switching, switching time of less than 1ms; by controlling the MOSFET with the fast turn-off capability to achieve the main power supply and backup power seamless switching, switching time of less than 1ms; Valley-fill PFC circuit is used in the main power supply to ensure the power factor > 0.9, DC-DC buck circuit is composed of LM2576T - ADJ, when great fluctuations in input voltage, output voltage 8 v is very stable, error < 1%, DC-DC boost circuit composed by LM2577T-ADJ, the battery voltage decay process, to achieve a stable output voltage of 8V, LED constant current drive circuit composed by PT4115, adjustable output current and high precision, and then adjust the brightness of LED. Master control chip, through detecting the change of photosensitive resistance, control the duty ratio of PWM wave, In order to achieve LED brightness can be adjusted automatically with ambient light, Protection of the power transformer is perfect, efficiency > 85%.

Abstract: Concerning the communication infrastructure pertinent construction guidelines, China South Power Grid (CSG) has clearly defined and detailed the data network equipment quality control, test and check. This paper proposes two indicators to monitor the power distribution automation in LTE private wireless network. The first one is the distribution online ratio (DoR), which evaluates the effect of distribution automation infrastructure construction. The second one is distribution tunnel integrity ratio (DiR), which reflects the availability of distribution automation communication tunnel. Furthermore, an indicator computing assistant (ICA) is developed to collect the data of two indicators transmitted by the large number of custom premise equipment (CPE) in LTE private wireless network in a computationally efficient way, which frees the conventionally demanding human and computing resources..

Abstract: The performance of the multicoil shimming is much better than that of the spherical harmonic coils in many aspects. The diameters and locations of the multicoil are optimized for the B0 shimming of the third order spherical harmonic field. And then every independent coil is decomposed into two series coils to take full advantage of a limited number of shim current supplies. The performance is improved by 16.7% when quantified by the surface root mean square.

Abstract: The message transmission reliability is very important for the design of the CAN (Controller Area Network) bus system, which is related to the normal operation of the bus control system. The bus message transmission time parameters are analyzed based on the CAN bus scheduling theory. The formula is a derived by means of probability analysis based on the fourth-moment method. An example is calculated to get its message reliability and the result is contrasted with the MONTE-CARLO method simulation, and then the bus message transmission reliability can be got. It has great practical significance.

Abstract: ComparedtobulkCMOStechnology,Silicon-on-Insulator (SOI) CMOS technology has many advantages, such as low power consumption, low leakage current, low parasitic capacitance and a low soft error rate from both alpha particles and cosmic rays. However,electrostatic discharge (ESD) protection in SOI technology is still a major substantial barrier to overcome for the poor thermal conductivity of isolation oxide and the absence of vertical diode and silicon controlled rectifier (SCR).

Abstract: With the wind power increasing quickly, its impact on power system becomes greater, thus the dynamic simulation study on grid-connected wind power generators has a significant importance. This paper focuses on introducing the quasi-steady-state approximation method into analyzing the operation characteristics of grid-connected doubly-fed wind power generators. Based on the detailed dynamic model of a variable-speed constant-frequency (VSCF) doubly-fed wind power generator, which consists of wind speed model, the integrated model of wind turbine and drive system, pitch angle control model, converter control model, and the integrated model of generator and converter, the quasi-steady-state approximation method is introduced and applied to simplify the detailed dynamic model to be an order-reduced model, that is, the quasi-steady-state (QSS) model. The accuracy of the QSS model is shown by comparing simulation results of QSS model and the detailed model.

Abstract: This objective of this work is to semi-physical simulate the power blackout of electrical propulsion marine. With the development of power electronics and variable frequency speed adjusting technology, electrical propulsion marine will be the most important aim of the marine research. Due to the high propulsion power and the adding of high new electrical load, more requirements about the management of marine power are needed. Power blackout is one of the most important technologies when managing the power of electrical propulsion marine. The semi-physical simulation research on power blackout of electrical propulsion marine is first proposed. The mathematical models of power generator equipment and main power consumption equipments are built and analyzed in this paper, and it is subsequently verified experimentally. After research and verification, the algorithms in this article can unload fast and black out the power.

Abstract: This paper proposes a hysteresis current control method for the grid-connected quasi Z source inverter with three states and constant frequency. The hysteresis band of the inverter is analyzed in detail, and the shoot-through is inserted into the zero state without affecting the grid-connected control. Moreover, the operating states of the switches are discussed. Finally, the feasibility of the proposed topology is verified by simulations and experiments results.