Applied Mechanics and Materials Vols. 341-342

Abstract: With the increasing development of clean energy technologies, the application of new energy and carbon capture technology would have a positive effect for CO2 emissions reduction. In this paper, planning of power system model including clean energy technology facing low carbon targets established, considering the carbon emission rights allocation and carbon trading. By studying coal-fired power plant planning model with wind power and carbon capture technology for the future planning period, establish the multi-objective model of minimum comprehensive cost and biggest carbon trading gains, considering constraint conditions of power generating capacity, wind power integrated capacity and carbon emissions reduction targets. Use the bacterial colony chemotaxis algorithm for optimization calculation of the power planning, to give a planning scheme that can meet the requirements of economic development trend and emission reducing requirements.

Abstract: Distribution network supervisory terminal unit is widely used in the smart distribution grid construction. To solve the problem that the means of communication is short, a multi-mode communication distribution network supervisory terminal is proposed which can be contactless operated and can collect and transfer local data remotely.

Abstract: Two results were obtained by analysing electromagnetism transition condition: firstly, when the initial phase angle of fault is larger, the characteristic of travelling wave is obvious, and the polarity of the first travelling wave head is consistent with the overall trend of zero sequence current in preliminary stage; secondly, when the initial phase angle of fault is smaller, the characteristic of travelling wave is not obvious, but the fault lines and perfect lines can be recognized through the direction of decaying direct current component in zero sequence current, and the direction of decaying direct current component is consistent with the overall trend of zero sequence current in preliminary stage. Research suggests that it is feasible to make the overall trend of zero sequence current in preliminary stage as characteristic for line selection.

Abstract: Based on the analysis of combustion conditions of the experimental grate-fired furnaces with a capacity of 2t/h, a low-NOx combustion transformation program was proposed. The effects of influencing factors including fuel staged combustion, air staged combustion and circulating flue gas on NOx emissions were investigated. The results show that when air-staged combustion based on separate room air distribution and fuel staged combustion, NOx emissions decreased from 260-359 mg/Nm³ to 137-182 mg/Nm³. And when circulating flue gas rate reached 10-15%, NOx emissions decreased 3-5%. These results indicate that the NOx concentration in the flue gas of the grate-fired furnaces with low-NOx combustion technology was below 200 mg/Nm³, which has great application prospects.

Abstract: A novel apparatus is introduced in this paper used to measure high voltage electric energy based on three-phase four-wire virtual-ground theory. The virtual-ground design, Faraday shielding technique and Warner DC (Direct Current) self-supply method are integrated in this apparatus based on new I/V, V/V techniques to realize high accuracy, reliability and wide-linear range measuring. The effectiveness of the apparatus has been proved by in-house calibration and on-site test . The test result shows that it can be used in high voltage grid on-site calibration . Its measurement uncertainty can be limited to 0.1% under the condition of PF=1.0~0.8, and can reach 0.15% as PF=0.5. In summary, the apparatus discussed in this paper can be applied as high voltage electric energy measurement instrument to meet the requirement of online metrological verification and calibration. Furthermore, it is very useful for building the system of Advanced Metering Infrastructure (AMI) in smart grid.

Abstract: The indirect air-cooling system is usually optimized for minimum annual cost. Domestic designing departments take different views on incremental power generation method and coal consumption method in calculation of operating cost. This paper analyzed the two different methods by using the optimization software of indirect air-cooling system, and modified the main parameters of indirect air-cooling system in practical engineering. In this paper, annual cost is in 10 thousand Yuan.

Abstract: HVDC transmission lines can generate an effect on the environment nearby due to the electric field and the ion current density after the corona occurs, so the calculation of ionic flow field is significant to transmission lines design and electromagnetic analysis. However, there is no effective method to calculate the characteristic parameters of ionic flow field under rainy condition. Based on Deutschs assumption, a calculational method is proposed with considering the effects of raindrops on ionic flow field. In the method, the space-charge-free electric field distortion caused by raindrops is especially considered, and the charged raindrops are seen as a charge background of transmission lines. The field strengths and ion current densities calculated using this method are compared with the experimental results in the published literature, it shows that the method is effective and accurate enough under fair and rainy conditions.

Abstract: Switch power supply is a power supply of maintaining the stable output voltage by the use of modern electronic technology, controlling the time ratio (duty cycle) of on and off of switching transistors . Push-pull switch power supply is a form of switching power supply family, which is divided into an independent-excited push-pull switch power supply and self-excited push-pull switch power supply. This paper will put forward an design scheme of the independent-excited push-pull switch power supply based on the design requirements, and the driving integrated circuit selection according to the design scheme of the push-pull switch power, at the same time, the switching transistors and rectifier diode selection through the calculation. The number of turns on a switch transformer is calculated according to the input and output voltage. Considering the skin effect and the proximity effect, switch transformer winding method is selected and the power supply meets the requirements of design according to the saber2007 simulation and implementation.

Abstract: the push-pull switch power is a kind of form in the family. It has the characteristics of good voltage output, high efficiency, the simple circuit and so on. On the design of the push-pull switch power supply, the key and difficult point is the design of switch transformer. Taking the switch transformer of a push-pull switching power supply as the research object and based on the design requirements, this paper aims to realize the calculation of the coil turns in switching transformer. Meanwhile, under the consideration of the skin effect and the proximity effect and the choices of switch transformers wires and the methods of wires winding, the design of switch transformer of the push-pull switch power supply has been completed by circuit simulation and implementation.

Abstract: Taking advantage of advanced sensor technique, wireless network technology, multi-sensor information synthesize, general information progressing technology and computer technology, based on wireless sensor network, foundation platform hardware and the software architecture of the monitoring and warning system of high voltage transmission line are set up, which is used as the unified platform of high voltage transmission line monitoring for data collecting, data transmission, data display and warning, thus real-time online monitoring of high voltage transmission line is realized.