Applied Mechanics and Materials Vols. 278-280

Abstract: This paper proposes a new optimization fault location algorithm. Based on distributed model, this algorithm builds frequency spectrum equation of faulty network with transmission line parameters to identify, extracts transient frequency spectrum, gives each error of harmonic corresponding weight to construct optimal objective function and finally solves the equations through simulated annealing (SA) algorithm. The algorithm will not be affected by the inaccurate parameters and makes full use of the extracted frequency spectrum. Simulation on EMTP shows high accuracy of the algorithm.

Abstract: Strapdown three-axis magnetometer is becoming increasingly used in navigation systems and in biomedical applications. A calibration must be performed before the magnetometer can be used, because its outputs are often corrupted by various magnetic field sources. This paper presents a new calibration algorithm based on constrained total least squares (CTLS) to determine different calibration parameters such as sensor non-orthogonality, scale factors, offsets, hard iron and soft iron errors. The basic idea is to convert the calibration problem into an unconstrained nonlinear optimization problem. An iterative technique based on Newton’s method is applied to give a numerical solution. Simulation results show that the proposed CTLS algorithm gives more accurate solutions than compared algorithms.

Abstract: Intensive Aquaculture Wireless Sensor Network (WSN) for water quality monitoring has specific requirements such as limited energy availability, low memory. Ant Colony Optimization (ACO) routing algorithm can maximize the lifetime of the network. A modified routing algorithm for Intensive Aquaculture WSN based on the ACO meta-heuristic is presented in this paper. Functions of basic ACO-based algorithm are modified to update the pheromone trail. The performance of Intensive Aquaculture WSN is improved on reducing memory used in monitor nodes and energy spent with communications. The modified routing algorithm was simulated for Intensive Aquaculture WSN scenarios and the results show that it maximizes energy savings.

Abstract: In recent years, wireless body area sensor network (WBASN) has gained a lot of attention from researchers for its potential application in medical care and health care fields. However, previous studies are typically involved in performance of WBASN, and most research has barely considered the details of system design. This paper presents a health care monitoring system. The design of the system is detailedly described. The evaluation result shows that the system can be easily deployed and suitable for health care monitoring.

Abstract: Carbon dioxide is one of the important signature gases in spontaneous combustion forecasting of coal goaf area. In the mine limited ventilation environment, concentration of CO2 directly affects the health of coal mines. So a new application of the least squares fitting method in Coal Mine gas monitoring was introduced. The optical fiber CO2 monitoring system which based on this method and tunable diode laser absorption spectroscopy (TDLAS) technology was used in Coal Mine beam tube system, and selected a near-infrared wavelength 1609.117nm fiber-coupled distributed feedback laser (DFB) as light source. Goaf area gas concentrations were directly calculated by the least squares fitting method which also simplified the calibration operation that used only one point to calibrate. Compared to electronic CO2 detector, this improved system has very high detection accuracy and stability. In the condition of 1.4m gas cell, the minimum detectable concentration is 0.05%, and the minimum detectable spectral absorption rate can up to , response time≤60s.

Abstract: Multi-level human motion tracking and analysis is still an open question in person surveillance, especially with constrained computational and communication resources. In this paper, we propose a sensing paradigm which could address this challenge efficiently and effectively. The proposed paradigm mainly includes two components. First, we design a compressive infrared sensing model, which can sample and encode multi-level human motion into low-level sensor data directly, without the mediate process of scene recovery. Second, we employ lightweight data processing algorithms to detect and segment human motion at different levels, and decode the location information adaptively. We used self-developed pyroelectric infrared (PIR) sensor nodes to construct a wireless distributed network, and conducted experiments in real office environment. The experimental results showed that the proposed paradigm could track human motion at two levels robustly, and the computational and communication burden is low (5×1 sensor data stream at 5 Hz for processing). Our paradigm bridges the gap between the low-level sensor data and the high-level analysis for large-scale automated surveillance, and could serve as useful guidance for system design if needed.

Abstract: With the progress of science and technology, electronic type electric energy meter is widely used in electric energy metering and charging in China, especially in rural power network reform, investment, electronic type electric energy meter with its linearity, stability is good, the power consumption of small, voltage and frequency response speed, high measurement precision, to further improve the market share, but how to test electronic type electric energy meter, but has been puzzling the test technical staff, according to the practical experience on the above problem undertakes a few discuss. This paper analyzes the electronic type electric energy meter principle, characteristics, focus on the research of the electric energy meter calibration method, the electronic type electric energy meter calibrating idea and train of thought.

Abstract: For the sake of real-time online monitoring the operating state and parameters of electric energy metering devices, detecting the abnormal states of devices, predicting the trend of electric energy metering device error, and changing the traditional management mode for electric energy metering devices, which adopts the cycle test rotation mechanism, this paper has proposed a state management system of electric energy metering device based on NI CompactRIO platform. The proposed system can implement real-time online management for monitoring the measurement error of electric energy meter, data acquisition of electric energy meter, test of Secondary Voltage Drop and Secondary Load of PT, test of Secondary Load of CT, video monitoring, measurement of temperature humidity, measurement of space magnetic, etc. The system combines CompactRIO platform and electric energy metering devices to acquire, monitor and analyze the real-time online data corresponding to electric energy meter, CT, PT and secondary loop. And the Energy metering error and the evaluation of parameters of electric energy metering device are calculated by the CPU, and the data is exchanged with the remote station by communication network. So the system improves the management efficiency and benefits of electric energy metering devices.

Abstract: The development of smart grid puts higher requirement on the intelligentization of high-voltage equipment including transformers. At present, the intelligentization of transformers is mainly realized through intelligent components. The combination of intelligent components and transformer can realize the measurement, control, calculation, inspection and protection of the transformer. This paper detailedly described the hardware design framework and software function modules of transformer intelligent components, as well as the expert diagnosis system applied to transformer intelligent components. The intelligent components designed by this paper have been successfully applied to 220kV intelligent substation, which is operating stably and reliably. This can promote the development of intelligentized primary power equipment and smart grid as well.

Abstract: According to the electricity metering of civil airports covered bridge equipment, the smart meter is presented based on ATT7022A and AT89C52. The smart meter has the interface of RS485 bus, so it can achieve network control function. Based on the hardware system’s general structure, the design of the three-phase voltage and current measuring circuits and some precautions, we designed the SPI communication interface of ATT7022A and AT89C52, and we gave the software correction flowchart of smart meter. Finally we know that the design of smart meter based on this scheme is simple and effective.