Advanced Materials Research Vols. 516-517

Abstract: Abstract. Transmission planning is a complex optimization problem with multiple deciding variables and restrictions. The mathematical model is non-linear, discrete, multi-objective and dynamic. It becomes complicated as the system grows. So the algorithm adopted affects the results of planning directly. In this paper, a fast non-dominated sorting genetic algorithm (NSGA-II) is employed. The results indicate that NSGA-II has some advantages compared to the traditional genetic algorithms. In transmission planning, NSGA-II is feasible, flexible and effective.

Abstract: Load density index method is one of widely used spatial load forecasting techniques in distribution planning. The determination of load density is a key task for this method. In order to overcome the drawback of traditional method which adopts analogy method to obtain load density and is hard to meet the demand of precision, a new approach based on intuitionistic fuzzy entropy and fuzzy clustering is proposed. The fuzzy clustering analysis is adopted to classify the set of load density and impacting factors into several grades. Then the intuitionistic fuzzy theory is utilized to describe the uncertainty that would appear in the load density selection. According to the intuitionistic fuzzy entropy the grade of load density can be selected, and the load density interval is available by the fuzzy clustering from the grade selected. An example is used to demonstrate the validity of the proposed method.

Abstract: At present, the rate of energy utilization is low for the transit regenerative braking on urban rail; most of the energy is consumed by the resistance heating. In this paper, a regenerative braking energy injected-grid device is designed, which makes use of regenerative braking energy and effectively reduce the temperature rise caused by the resistance in the tunnel. The paper describes the composition and the design procedure of regenerative braking energy injected-grid device and presents a control strategy of device. The simulation of the single train model verifies that the stability of DC-bus voltage can be maintained and more power can be feedback to the grid by the proposed device when the train is braking. The feasibility and effectiveness of the proposed control method are validated by the experimental results.

Abstract: In distribution network, there are multiple constraint condition on the capacity allocation of distributed generation, this text takes the maximization of power generation benefit as the premise, and adopts genetic algorithm to implement the optimal allocation of distributed generation’s capacity. The algorithm uses the minimum distribution network power consumption as objective function, the admissible deviation of supply voltage and capacity accessed to common point not more than 10MVA are taken as the constraint condition, and the Newton-Raphson method is adopted to carry out power flow calculation. Based on the algorithm, the specific planning program flow diagram is given, and combining Jiangxi Gongqing city distribution case, capacity planning design is carried out to conclude the optimal node access capacity. The conclusion of the study can play a better guiding role for the planning and design of distribution network including distributed generation.

Abstract: There might be dynamic stability problems with multiple low frequency oscillation modes in power system with long distance and large capacity power stations, especially with clean energy stations, which may cause ” seesaw effect” between every power base, and restrict the power transmission capability. Considering this problem, an appropriate integrated solution is put forward according to the factors and measures for each mode. It is proved effective from the view of oscillation suppression and power transmission capability increasing by time domain simulation and frequency domain simulation.

Abstract: VSC-Multi-Terminal Direct Current(VSC-MTDC) system is much more controllable and economic. In this paper, the mathematical model for the VSC-MTDC system is set up. Base on this model, the multi-terminal constant DC voltage control scheme with an offset component was developed for MTDC system in the distribute network. Decoupling linear PI controllers are applied for the independent control of active and reactive power. Constant DC and AC voltage controller is implemented respectively for source side and loads side for the high quality power supply. Simulation results show that the control scheme is very effective. With the proposed control strategies, dynamic process of the system can be controlled effectively. What is more, the control law is not complex and it is in the local mode. All of these merits make the control strategy very practical.

Abstract: In 110kV railway traction the V/V connection transformers are common used. The distance protection performance for 110kV line connects to V/V traction transformer is analyzed in detail. Then some new advices on setting method for such kind of line protection calculation are proposed. This method is applied to several protection devices in Shandong power supply system. The operating result shows the accuracy of this method.

Abstract: On the basis of analysis on difficulty of a single phase grounding fault locating in distribution network, a fault location method using C-type of traveling wave is put forward. The C-type of traveling wave location method is off-line. This location method can not be affected by the signal intensity of traveling wave when the fault is taking place and would be used repeatedly. As a result, the measure accuracy is guaranteed. Through the simulation to traveling wave’s process of reflection and refraction by ATP, the result what simulation experiment shows by putting up model of 10kV line with 3 branches single phase grounding fault, we can compare waveform of the normal phase and the fault phase to find the first waveform distortion point and determine the fault location. The fault location precision meets accuracy requirements, so it is feasible to locate the fault by using C-type of traveling wave location method.

Abstract: Nowadays, the world population and economic development are increasing. Followed by this resulted in a bigger amount of energy.Majority of the energy use of fossil raw materials and the using of fossil releases greenhouse gases to the atmosphere. These greenhouse gases cause Global warming. The way to reduce greenhouse gases is planting trees. Because a tree absorbs carbon dioxide through photosynthesis process and to sequestrate in different parts of a tree to reduce the amount of carbon dioxide in the atmosphere.To reduce the Global warming. The current crude oil prices tend to be increasing. Need to study and research for the new energy sources to replace the suitable and consistent with national energy policy. One option is very easy. Biomass (Biomass Energy) which uses a wood as raw materials in stead of petroleum. The research purpose is to look for the amount of carbon sequestration in a part of biomass in the from of fast growing, 5 forms, of 3 types of woods are Anthocephalus Chinensis , Eucalyptus K7 Leucaena salvadore And to estimate the size of areas for planting fast growing. For use as fuel to generate power in the community . To study of carbon sequestration of fast growing trees 3 types are Anthocephalus Chinensis , Eucalyptus K7 Leucaena Salvadore By design, 5 forms (Pattern 1 Planted Leuceana Salvador, Pattern 2 Planted Leuceana Salvador and Anthocephalus Chinensis (Planted from the beginning of every shift.), Pattern 3 Planted Anthocephalus Chinensis, Pattern 4 Planted Anthocephalus Chinensis and Eucalyptus K7 (Planted from the beginning of every shift.), Pattern 5 Planted Eucalyptus K7) of planting and the area planted is Ban Sub Moo 4 Tumbon Serng Sang , Amper Serng Sang Nakhonratchasima Province. Soil is a sandy loam soil. Planted by the rainfall, on the average more than 1,000 mm / year. The sample area size is 20 x 75 square meters and spacing of 2.5 m x 2.5 m and a biomass conversion plant of fast growing 5 forms of 3 types of woods at the age of 2.5 years. And to measure carbon in a part of trees. The study found that the trees grow faster at 2.5 years. Average of biomass of fast growing plants as a form of 1,2,3,4 and 5 are equal to 1.3309,4.5935,4.1237,6.3673 and 8.3273 tons/rai. (rai.=1,600 m2.) by order. Statistical tests found the average value of this biomass was difference and important (p<0.05) from the biomass measure. From the above, to mention about the amount of biomass carbon storage in biomass of fast growing trees pattern 1,2,3,4 and 5 are equal to a 0.6486,2.12945.1.9618,3.8994 and 4.1205 tonC / rai. The mass of carbon sequestered and the amount of carbon dioxide in biomass of fast growing trees pattern 1,2,3,4 and 5 are equal to 2.3782, 8.0466, 7.1933, 14.2979 and 15.1086 tonCO2 / rai. and followed by forest planting projects in order to obtain quantities of carbon about 16,000 tons of CO2/ year the plot 5 (Eucalyptus) using least fast growing trees areas equal to 2,647.50 rai. To use as a basis for calculating of carbon sequestered quantities. Planting fast growing trees are able to absorb carbon dioxide in the air. To reduce global warming. Planting fast growing trees are capable use as fuel for biomass power products. The size of the fast growing trees areas for biomass energy production in power plants that use gas, 100 KW. Space for planting fast growing circulation (Eucalyptus 4.2 tons/ rai /year) at least 426.42 rai. To accommodate the use of community size from 480 to 576 families this helps to reduce power of fossil in producing electricity. To reduce Global warming in another hand.

Abstract: This paper first introduced the harm of discard-oil and the state quo of its reuse development, and then put forward an idea of co-firing discard-oil for power generation and analyzed its feasibility. It was concluded that this idea is completely feasible with appropriate process design, reasonable mxing ratio and proper environmental protection measures.