Applied Mechanics and Materials Vols. 556-562

Abstract: Lighting is one of the important reasons of transmission line trip accident. For 330kV and above ultra high voltage transmission line, lighting flashover more frequently occur. To reduce tripping rate effectively and fundamentally, lightning over voltage level should be analyzed besides anti-pollution flashover. In this paper, a simplified equivalent circuit model of a 330kV overhead transmission lines is established. The lightning over voltage of the transmission is analyzed and calculated. Method to reduce the lightning overvoltage is discussed.

Abstract: With the number of private cars increasing, the problems such as the shortage of parking spaces, the disorder and congestion of parking are becoming serious, especially in a flourishing business street. So we do the research based on an underground parking lot at a commercial district. In this paper, we design a monitoring interface based on embedded cross-platform GUI system-Qt4 and embedded SQLite combining RFID and Zigbee technology on computer, and then transplant it to Intel PXA270 based on ARM-Linux. The designed system can realize automatic identification, charging of vehicles and displaying parking spaces. It can improve the efficiency of parking.

Abstract: As an important module in CMMB system, the performance of phase locked loop will directly determines the accuracy, purity and synchronization of system clock. In this paper, a high performance CPPLL circuit is designed to make each system clock of base station to get strict synchronization in frequency and phase. Test results show that the performance of this design meets the CMMB system requirements

Abstract: According to the number of users and the electricity measurement requirements for building, a novel intelligent system of single phase electric meter for building has been proposed in this paper. It is aiming at the application status and existing problems of watt-hour meter used in China. It has been designed by using the decentralized power parameter detection and centralized control method. The following designs of the intelligent system have been done in the study: the topological structure, hardware and software. According to the design of the intelligent system, the intelligent system of single phase electric meter for building can be developed. The electricity signal processing module, memory, GUI and the communication module are controlled by MCU. The intelligent system can easily measure various parameters, record data safety, calibrate meter with software, and it has more communication interface. The system can be realized functions, such as the monitoring, management, protection, wireless transmission and so on. It can be widely used in ordinary households, residential users, student apartments, office buildings, etc. to achieve the electricity detection, monitoring and controlling intelligently.

Abstract: In the need of intelligent multi-serial ports communication in smart home project, which ask for less consumption of resources. This paper introduces a NIOS II-based 6-way serial data communication, and it defines the corresponding data communication protocol.It makes PC could easily exchange data with FPGA and peripheral circuits. Experimental results show that the scheme has high reliability and stability. Serial number can be flexibly changed according to the actual needs, It could also be configured individually for each serial port, so it has good portability, flexibility and easy of implementation. At the same time reducing the hardware debugging time and saving hardware resources.

Abstract: The photovoltaic power generation system needed to be work at the maximum power point (MPP) to get the maximum efficiency. As the MPP can be influenced by environment condition, such as temperature and irradiation, it is necessary to optimize and control the PV system operation process. In this paper, a rough Fuzzy-PID control strategy is proposed to adjusting the PV operation to make the system working efficiency. Rough Fuzzy-PID control strategy is best in dealing with time-varying and non-linear system, it is much suitable for solving the MPPT of photovoltaic system through switching pulse generation to DC/DC buck converter. These control systems are modeled and simulated in Matlab/Simulink environment.

Abstract: This paper deeply researches on successive action zone and dead zone of transverse differential protection in parallel lines, and improves the existing analysis software for relay protection action. First determine which zone the fault point belongs to, and then analyze the protection action according to the different zone concretely. This improvement will greatly increase the accuracy to analyze the relay protection action, and will be significant to the safe and stable operation of regional networks.

Abstract: Most radar systems based on the structure that contains many DSP chips. The system structure is always complex, and it is difficult to update. Nowadays, multi-core processor develops very fast. Compared with DSP chips, multi-core processor has better performance in signal processing field. In this paper, we present a signal processing architecture which based on multi-core processor. Pulse compression algorithms and PCI-E bus are discussed as two important technologies. Adaptive beamforming test results show that multi-core processor is able to achieve radar signal processing.

Abstract: In this paper, a clock domains cross FIFO interface of multichannel continuous DDR2 read and write is designed. The interface provides continuous data stream from DDR2 to 12 different channels simultaneously. Four core issues are resolved: mismatch on bit width between DDR2 user interface and the channels, data stream conversion control from DDR2 to channels, clock domains difference between DDR2 and channels, Discontinuous process of DDR2 read and write. DDR2 storage spaces are partitioned for matching data width of the DDR2 user interface and the channels, and to achieve the maximum utilization of the DDR2 memory. Via state machine, data conversion and synchronization from DDR2 to channels are implemented, and the state machine can be applied to providing continuous DDR2 data to any numbers of channels simultaneously. Cross clock domains FIFO interface goes to solve the different clock domains problem between channels and DDR2. When bank or row addresses conversion occurs, or DDR2 auto-refresh cycle comes, DDR2 cannot be read or written, leading to data interruptedly in time aspect. To solve the problem, the FIFO interface is designed followed the full-mode handshake protocol. Through the interface caching, the 12 channels can continuously read data from the DDR2 simultaneously. The final design can achieve the goal that under the fastest case, DDR2 provides 12 channels data stream simultaneously at 61.538 MHz rate at the same time, and 90.566% efficiency in the reading and writing aspects.

Abstract: This paper presents about the implementation of monitoring program on PC and Android devices for the hybrid system conjugated with solar cell and fuel cell of 9kW class. In this paper, we show the information how to develop the system and monitoring program. The state of charge and information of cells must be monitored. For getting the result, the information of cells is simulated by LM3S9D96 and for the data is transmitted by using CAN communication. After that, the transmitted data is monitored by the programs of PC and Android.