Xu Y.,Qiongzhou University |
Wang Z.,Northeast Dianli University |
Zheng Q.,Chengdu University of Technology |
Han Z.,Taizhou Power Supply Company
Proceedings of the 2012 4th International Conference on Intelligent Human-Machine Systems and Cybernetics, IHMSC 2012 | Year: 2012
As to the major building in the city currently ,the traditional fixed signs of the fire evacuation system can't meet people's security needs any longer and the intelligent fire evacuation system has been the current development direction.This article combined the Dijkstra's algorithm with intelligent fire evacuation system self-developed which identified the fires by analyzing the fire linkage signal received and thereby determine the best route to evacuate the people in the fire region safely. Copyright © 2012 by The Institute of Electrical and Electronics Engineers, Inc.
Xu K.,Shanghai JiaoTong University |
Xu K.,Shanghai Municipal Electric Power Company |
Fan C.-J.,Shanghai JiaoTong University |
Xu J.-X.,Taizhou Power Supply Company
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2014
The calculation methods of ground fault through transition resistance are studied. Firstly, single-line ground fault through transition resistance is analyzed by symmetrical component method. The six-sequence component theory is used to analyze two parallel lines on the same tower when the parameters are exactly the same. Secondly, a method is presented to analyze two parallel lines of asymmetry parameter on the same tower. According to symmetrical component method, impedance matrix of the lines is decoupled to positive sequence, negative sequence and zero sequence. It comes to a conclusion that positive sequence and negative sequence have already been decoupled, but zero sequence is still coupling. Then, the coupling zero sequence is decoupled to the same directional zero component and the circumfluence zero component based on six sequence component theory in which the zero sequence is divided into the same directional component and the circumfluence component. And system impedance is modified. Finally, the new decoupling method is applied to do fault analysis and figure up the correction coefficient of transition resistance. The PSCAD results prove that the new decoupling method is correct.
You J.,Nanjing Southeast University |
You J.,Suzhou Key Laboratory of Electrical Equipment and Automation |
Wang C.,Nanjing Southeast University |
Wang C.,Suzhou Key Laboratory of Electrical Equipment and Automation |
And 3 more authors.
Dianli Xitong Zidonghua/Automation of Electric Power Systems | Year: 2012
A voltage space vector based regular-time hysteresis current control scheme for the photovoltaic grid connection system with Z source inverter is presented. The regular-time hysteresis current control has been designed to realize the zero control error and fixed switching frequency. It also achieved high power factors, which indicated the synchronization between the inverter output current and the grid voltage. Meanwhile, the zero space vector acts at the beginning of each control interval. By calculating the minimal duration possible for the zero space vector, the duty ratio can be obtained. The corresponding shoot-through duration is added to the minimal duration to boost the DC side voltage successfully. The system and control scheme proposed offer the advantages of fast response, high accuracy, high immunity of perturbations, low switching actions, and easy implementation. Both simulation and experiments have verified the correctness of the method. © 2012 State Grid Electric Power Research Institute Press.
Yang Z.,Changzhou Power Supply Company |
Xu X.,Taizhou Power Supply Company |
Xu S.,Nanjing Southeast University |
Zhao J.,Nanjing Southeast University
Asia-Pacific Power and Energy Engineering Conference, APPEEC | Year: 2010
To eliminate common-mode voltage (CMV) of cascaded multi-level inverter, a novel strategy is carried out respectively in the point of 2-level SVM and 3-level SVM, which can be easily applied in cascaded high voltage (HV) inverters by sampling time staggered technique. The concept of left-and-right leg groups is proposed for the special structure of 2-level SVM, and the phase difference between two reference vectors is set to be 2π/3 to suppress the CMV. On 3-level SVM mode, as each one cascade can generate three levels, only zero-CMV vectors are selected for modulation in order to decrease the CMV. Applying the above two SVM strategies to cascaded HV inverters by sampling time staggered (STS) technique, the CMV can be completely eliminated theoretically. Experimental results testified the effectiveness of the above two methods. ©2010 IEEE.
Xu S.,Nanjing Southeast University |
Zhao J.,Nanjing Southeast University |
Xu X.,Taizhou Power Supply Company
Dianli Zidonghua Shebei/Electric Power Automation Equipment | Year: 2010
Based on the DC-side voltage equilibrium control method for the unity-power-factor 4-quadrant H-bridge rectifier, an improved n + 1 redundant fault-tolerant control strategy is proposed for the cascaded H-bridge DSTATCOM, which adjusts the DC-side voltage of the healthy cells in the faulty phase to ensure the normal operation of the faulty device. Its main feature is that, the DC-side voltage of faulty phase is raised according to the capacity requirement when fault occurs, which increases the utilization efficiency of DC-side voltage and decreases the switching loss, du/dt and fault rate when device is in normal operation. In order to preserve the good harmonic characteristics of CPS-SPWM output voltage after device fault, the CPS-SPWM pulse generation sequence of the healthy cells in the faulty phase is regulated by modulating the carrier wave frequency of faulty phase. Simulative and experimental results show that, when the quantity of faulty cell is not beyond redundancy, the device with the proposed control strategy can adjust the output power in time, without any influence on the compensation performance.
Shi L.,Hohai University |
Zhang L.,Jiangsu Electric Power Company |
Chen S.,Taizhou Power Supply Company |
Zhuang M.,Danyang Power Supply Company
Dongnan Daxue Xuebao (Ziran Kexue Ban)/Journal of Southeast University (Natural Science Edition) | Year: 2012
The linearized model of multi-machine power systems with a flywheel energy storage system(FESS) is derived, and the feasibility of damping multi-mode oscillations with a single FESS is proved by application of damping torque analysis (DTA). Two FESS-based stabilizers are superposed on two independent control loops of the FESS, the active power control loop and the voltage control loop, to damp multi-mode oscillations. The control loops and the feedback signals are selected for each mode based on the controllability and observability of the modern control theory. And the parameters of the FESS-based stabilizers are tuned by the improved particle swarm optimization (IPSO) algorithm. Taking a four-machine power system as an example, the damping ratios of the two oscillation modes are improved from -0.013 and 0.052 to 0.106 and 0.102 by a single FESS with two additional stabilizers, indicating that the single FESS has the ability of damping power system multi-mode oscillations.
Yang Z.-Y.,Changzhou Power Supply Company |
Xu S.,Jiangnan University |
Xu X.-T.,Taizhou Power Supply Company
2010 China International Conference on Electricity Distribution, CICED 2010 | Year: 2010
In view of analysis and comparison of present high-voltage large-capacity D-STATCOM circuit structure, especially advantages and disadvantages of Δ-cascaded structure and Y-cascaded structure, then it proposes and describes a Y-cascaded structure, the link of which is composed of two back-to-back H converters. Current compensation algorithm based on coordinate αβ conversion, fault links bypass tolerance, and its correlative CPS-SPWM are proposed respectively, the experimental results of 1.14kV/100kVA prototype testify the validity and the effectivity of the proposed structure and algorithm. © 2010 Chinese Soc for Elec Eng.
Han X.,Wuhan University |
Liu J.,Taizhou Power Supply Company |
Liu D.,Wuhan University |
Liao Q.,Wuhan University |
And 2 more authors.
Asia-Pacific Power and Energy Engineering Conference, APPEEC | Year: 2014
The traditional methods used for distribution network planning are challenged because of the access of the stochastic distributed generation. A new distribution network planning model is proposed by converting the distribution network planning with distributed generation into solving the Steiner tree problem. Moreover, in order to solve the problem that the time of calculation multiplied along with the increase in the amount of Steiner nodes, an improved particle swarm optimization algorithm is proposed to solve the Steiner tree Non-deterministic Polynomial problem. In this algorithm the problem of premature convergence is solved by applying a small disturbance to the global optimum and the searching results are more reliable and accurate by improve the search ability for global optimum. Typical results of the proposed algorithm and the traditional algorithm are further illustrated and compared through an actual 54 nodes system to prove the validity of the methods in this paper. © 2014 IEEE.
Liu Y.,Nanjing Power Engineering Design Co. |
Wu N.,Nanjing Power Engineering Design Co. |
Yin J.,Taizhou Power Supply Company
Dianli Zidonghua Shebei/Electric Power Automation Equipment | Year: 2010
Jubao 220 kV substation has to adopt all-indoor layout because of area restriction, which applies the B-3 and B-4 schemes of the power transmission & substation engineering typical designs of State Grid (the 220 kV substation section). The compact layout design should meet the requirements of safety distance among equipments and building, and carefully arrange the cable pathways for different voltage levels. Its influencing factors, equipment disposal and cable arrangement are analyzed and the cooperation among different departments is discussed.
Zhao H.,North China Electrical Power University |
Guo W.,Taizhou Power Supply Company |
Shao L.,North China Electrical Power University |
Zhang X.,North China Electrical Power University
Dianli Zidonghua Shebei/Electric Power Automation Equipment | Year: 2015
A gearbox fault prediction algorithm based on the stochastic subspace identification is proposed to reduce the serious faults of wind turbine. A stochastic state space model of gearbox is built and the vibration monitoring data in normal operation are applied to calculate the eigenvalues of its parameter matrix, which are taken as the references. The eigenvalues calculated based on the actual vibration monitoring data are compared with the references and their differences are used to detect the gearbox fault. The RMSE(Root-Mean-Square Error) is introduced as a fault detection criterion to reduce the calculation load and its threshold is defined by SPC(Statistical Process Control) principle. Simulation is carried out with the vibration monitoring data of an actual wind turbine and the simulative results verify the effectiveness of the proposed algorithm. ©, 2015, Electric Power Automation Equipment Press. All right reserved.