Time filter

Source Type

Liu H.,Tianjin Polytechnic University | Zhang H.,Tianjin Polytechnic University | Wang J.,Tianjin Polytechnic University | Wei J.,Tianjin Polytechnic University | Zhang Y.,Tianjin Electric Power Research Institute
Journal of Chemical Technology and Biotechnology | Year: 2017

BACKGROUND: Biological synthesis of platinum nanoparticles (PtNPs) with Cacumen platycladi (C. platycladi) in a microfluidic chip and numerical simulation of formation processes were studied. The effect of volumetric flow rate on PtNPs' size distribution was investigated in detail not only by experimental methods but also by means of numerical simulation. Computational fluid dynamics (CFD) and a population balance model (PBM) combined with reactive kinetics were employed to simulate PtNPs' formation and to calculate the particle size distributions (PSD). RESULTS: The experimental results confirmed the validity of the model and its practicality in predicting the formation of PtNPs and PSD evolution in the microfluidic chip. In addition, the numerical simulation results also tested and verified the accuracy of the results and conclusions acquired from the experiment. CONCLUSION: It is concluded that PSD was influenced not only by mixing efficiency but also by residence time in the microfluidic chip, and that the two factors were determined by volumetric flow rate. There is a specific volumetric flow rate to achieve equilibrium (optimal mixing and residence time) that results in the average particle size reaching its maximum value. This work provides useful insight into the microfluidic biological synthesis of PtNPs and the influence of volumetric flow rate on size distribution in a microfluidic chip. © 2017 Society of Chemical Industry.

Qi Y.,Tianjin Electric Power Research Institute | Wang F.,Shanghai Municipal Electric Power Company | Wang D.,Shanghai University
China International Conference on Electricity Distribution, CICED | Year: 2016

Operation homogeneity is a basic state property of distribution system with DG. It is related to the active power of bus and DG in the distribution system with DG. Load, network and element parameters are the influencing factors too. High-reliability supplying for power users is a very important feature of distribution system with DG, and it is the material basis for the high satisfaction of power users. In this paper, the operation homogeneity index, reliability indices and the line loose which is the characteristic of economy are calculated and analyzed based on the modified IEEE-33 system. The results show that these reliability index demand bigger DG active power, while these homogeneity indices, security index, economy index needing moderate DG active power. Operation and planning department will decide the operation scheme in practical work. © 2016 IEEE.

Wang F.,Shanghai JiaoTong University | Qi Y.,Tianjin Electric Power Research Institute | Fu Z.,Shanghai JiaoTong University
Dianli Xitong Zidonghua/Automation of Electric Power Systems | Year: 2012

The reliability of the distribution system with a microgrid (DSM) is evaluated using the modified minimal path searching algorithm based on the network space topology in which the power control mode, network configuration and operation characteristics of the microgrid are fully considered. The positive effect of the microgrid on the distribution system reliability is analyzed from the reliability aspect. The results of the IEEE RBTS bus 6 using this model have verified the validity of the model showing the remarkable effect of the microgrid on increasing the reliability of the distribution system. © State Grid Electric Power Research Institute Press.

Wang X.,Tianjin Electric Power Research Institute | Lin J.,Tongji University | Li S.,Shanxi Electric Power Research Institute | Zheng W.,State Grid Corporation of China
Dianli Xitong Zidonghua/Automation of Electric Power Systems | Year: 2013

Islanding operation is a special operation mode in the smart grid. For a power transmission system, if a connected system is split into several stable islanding sub-systems in time in the optimal islanding operation mode in case of extreme emergency, not only will enormous losses due to large area blackout or even system collapse caused by the spread of the local fault be avoided, but the amount of load shedding and generator tripping might be minimized as well. For a distributed system with distributed generator (DG), optimum islanding operation can bring the potential of DG into full play, while improving the reliability of power supply. The influencing factors of the optimal island partitioning in the smart grid are summed up and all the relevant methods and strategies available at home and abroad are thoroughly analyzed and classified. And the advantages and disadvantages along with key issues of each method are also discussed. Finally, the development tendency and the problems demanding prompt solution are treated. © right.

Dong Wang X.,Tianjin Electric Power Research Institute | Lin J.,Tianjin University
China International Conference on Electricity Distribution, CICED | Year: 2014

As one of effective emergency control measures that are taken to keep the interconnected power grids from collapse caused by cascading failure, controlled splitting received broad recognition and approbation from engineering field and academic circle. The optimal controlled splitting problem is essentially an optimal graph splitting problem subjected to complicated topology constraints and large-scale, nonlinear constraints. In this paper, a complete model of the optimal controlled splitting of the power system is proposed, and a new decomposition algorithm searching for optimal splitting strategy was proposed. The complete model was converted into coupling sub-problems: graph partition problems and optimal power flow problem. The graph partition problem is solved by CGKP(Connected Graph Constrained Knapsack Problem) algorithm. Load and generation power adjustment variables are taken as transfer variables between the sub-problems. The results of the samples demonstrate the validity of the new model and method. © 2014 IEEE.

Tao L.,Tianjin Electric Power Research Institute
Applied Mechanics and Materials | Year: 2014

This paper designs and discusses black-start scheme based on a gas-steam combined cycle power plant (CCPP) in Tianjin power grid of China. First, considering the structure characteristics and station service power connection mode of the gas-steam unit, the diesel generator is chosen as fast self-starting unit. Also two self-starting schemes of direct starting and variable frequency starting are designed. Second, the technical feasibility of two schemes is determined through first loading capability test and bus voltage level test. After investment estimation comparison, the scheme II is chosen as recommended scheme. The research process proposed in this paper has certain reference significance to power grid black-start. © (2014) Trans Tech Publications, Switzerland.

Wang J.,Tianjin University | Zhang X.,Tianjin University | Du X.,Tianjin University | Li G.,Tianjin Electric Power Research Institute
Dianli Zidonghua Shebei/Electric Power Automation Equipment | Year: 2011

The standards of grid-connection technology commonly used at home and abroad for photovoltaic and wind power generations are compared. The grid-connection mode, the power quality indicators including voltage deviation, voltage fluctuation and flicker, frequency, harmonics and DC injection, the protection and control and the low-voltage ride-through of wind farm are analyzed in detail. The inadequacies of existing domestic standards are pointed out and it is suggested that the output capacity of grid-connected system, the voltage level of grid and other factors should be considered during the development of grid-connection technology standards.

Gan Z.,Tianjin Electric Power Research Institute
IEEE Transportation Electrification Conference and Expo, ITEC Asia-Pacific 2014 - Conference Proceedings | Year: 2014

The advanced smart grid sensing measurement technology, information and communication technology, analysis and decision technology, automatic control technology and grid technology, and a high degree of integration with grid infrastructure, the power grid is the future direction of development. Through the use of advanced smart grid technology, electric vehicle charging behavior of a reasonable adjustment to achieve fully meet electric vehicle charging, while reducing the impact of electric vehicle charging on the grid, so as to realize the coordinated development of electric vehicles and smart grid. © 2014 IEEE.

Ge S.,Tianjin University | Wang H.,Tianjin Electric Power Research Institute
Dianli Xitong Zidonghua/Automation of Electric Power Systems | Year: 2013

Based on the system state transition sampling approach, this paper presents a sequential Monte Carlo simulation method for the reliability evaluation of the distribution system including distributed generations (DGs) with high penetration rate. The proposed method can be used to calculate both the generation and the distribution reliability indices. The state transition models of non-power components and DGs are established respectively. The chronological output of wind turbines, photovoltaic arrays and the time varying load as well as the utility grid capacity are all taken into account. The state of charge of battery is simulated by the Kinetic Battery Model (KiBaM) incorporating different battery dispatch strategies. The state space of the system is divided into two categories of the generation states and the distribution states. The system is treated as a distribution system when some non-power component is in its down state, and treated as generation system when all the non-power components are in up states. The validity of the proposed method was demonstrated by a study case. This method can be used for the optimal planning of distribution networks including DGs. © State Grid Electric Power Research Institute Press.

Wang X.D.,Tianjin Electric Power Research Institute | Liang W.,Tianjin Electric Power Research Institute
Applied Mechanics and Materials | Year: 2013

Island operation is a special operation mode for service restoration for the smart distribution system with distributed generation. In this paper, a model of island reconfiguration of the smart distribution system is proposed. The objection of this model is maximizing the total power supply profit. Meanwhile, load priority, controllable and uncontrollable load, and the restrictions of power balance, voltage and equipment capability are all taken into account. The island configuration problem is first simplified as a special knapsack problem, and based on the solution of this knapsack problem an initial island scheme is gained. By feasibility checking and adjusting, a island configuration is finally proposed. The results of the samples demonstrate that the model and method presented in this paper is feasible and valid. © (2013) Trans Tech Publications, Switzerland.

Loading Tianjin Electric Power Research Institute collaborators
Loading Tianjin Electric Power Research Institute collaborators