Zhao B.,Tsinghua University |
Song Q.,Tsinghua University |
Liu W.,Tsinghua University |
Xiao Y.,Hubei Electric Power Company
IEEE Transactions on Industrial Electronics | Year: 2013
This paper analyzed the development trend of uninterruptible power supply (UPS) and presented a multi-functional modular intelligent UPS system for smart grid, which is composed of four identical H-bridge converters. It not only can realize all the basic functions of the traditional UPS system, but also can realize the cyclic use of the electrical power between the power grid and storage battery. Moreover, due to the modular construction, it can easily change into various power converters for other applications. The topology configuration and operating principle of the proposed UPS system are analyzed, and a distributed control management strategy and a distributed logic control algorithm are proposed. At last, experimental results verify the validity and effectiveness of the proposed system and its control strategy. The exploration of this study could provide some valuable references for the design of next-generation electrical equipment in smart grid. © 1982-2012 IEEE.
State Grid Corporation of China, Hubei Electric Power Company and CENTRAL CHINA GRID COMPANY Ltd | Date: 2016-05-10
The invention relates to a parallelization method for black-start subsystems of a power grid with external support, which includes, after power blackout, partitioning the power grid into subsystems, and respectively performing black-start on the subsystems based on a power grid black-start research scheme, performing stability check on each subsystem, performing voltage calculation on parallel lines between the subsystems, checking the parallelizing simulation of the subsystems, and determining a feasible parallelizing path and a recommendable charging direction. The method further includes, starting from the subsystems having external support and higher stability, networking them with an external power grid, parallelizing the networked subsystems having external support to obtain a subnet of the subsystems, parallelizing subsystems having no external support with the subnet of the subsystems to obtain a regional subnet, and finally parallelizing the remaining subsystems with the regional subnet to implement parallelization of black-start subsystems of the whole power grid.
State Grid Corporation of China and Hubei Electric Power Company | Date: 2016-05-11
The invention relates to a method for determining an integrated network loss rate in the UHV AC cross-regional electricity trading. The method includes fitting a curve relationship between integrated network loss rates and transmitting powers on the basis of theoretical calculations of the UHV AC transmission line loss, using a relational fitted curve between actual values of integrated network loss rates and transmitting powers calculated according to gateway power statistical data to perform geometrical average correction on the original curve, and making planned values of the integrated network loss rates to be closer to the actual values according to a method for determining UHV AC integrated network loss rates according to a correction curve function relation, which greatly increases fairness of the trading settlement. The method is simple and easy to implement with high accuracy, and applicable to planning and trading settlement of regular or real-time UHV AC electricity trading.
Cui Q.,Xi'an Jiaotong University |
Wang X.,Xi'an Jiaotong University |
Liu Z.,Hubei Electric Power Company
Zhongguo Dianji Gongcheng Xuebao/Proceedings of the Chinese Society of Electrical Engineering | Year: 2013
It is an ideal way to solve the bottlenecks of power source and grid construction that setting up large-scale battery energy storage systems on the demand sides. According to specific power market rules, a real-time price dynamic game linkage model considering power generation side, supply side, large-scale battery energy storage system and demand response was established. Based on electricity price signal, each participant adjusted their own game strategy until the equilibrium price was solved. The paper set up three cases to simulate the model. The simulation results showed that large-scale battery energy storage systems set up on the demand side could reduce the difference of valley-to-peak load and smooth the curve of real-time electricity price, the mean electricity price of user was reduced and the power generation and transmission cost was decreased, and some profits were shared by battery energy storage systems. At the same time, the utilization rate of generation and transmission equipments increased. © 2013 Chin. Soc. for Elec. Eng.
Shen Y.,Wuhan University |
Peng X.,Wuhan University |
Shi T.,Hubei Electric Power Company |
Mao X.,Wuhan University |
Sun Y.,Wuhan University
Dianli Xitong Zidonghua/Automation of Electric Power Systems | Year: 2012
According to the limitless of weighting according to the subjective principle or the objective principle and their combination, and to make the comprehensive evaluation more scientific, an integrated weighting method taking into account both the objective and subjective influencing factors is studied and presented. This method takes the decision-maker's subjective weights and objective weights as the standard, and the minimum sum between the integration weights and subjective and objective weights as the object. With the optimal combination model created on the moment estimation theory, the optimal combination weights can be arrived at by finding the best solution of the optimal combination model. On this basis, by referring to the grey relational degree, the grey comprehensive evaluation method of power quality based on the optimal combination weights is developed. The power quality of 10 kV buses in the regional power grid is evaluated with the grey comprehensive evaluation method. The evaluation results not only verify the reasonability of the proposed integrated weight method, but also show the validity of the grey comprehensive evaluation method for power quality. © 2012 State Grid Electric Power Research Institute Press.
Xiao D.-B.,Hubei Electric Power Company |
Zhang X.,Gansu Lanzhou EHV Power Transmission Company
Gaoya Dianqi/High Voltage Apparatus | Year: 2011
Several different polluted methods to conduct the insulator flashover performance research are recommended by IEC and China, but the differences between the polluted methods have not been pointed out. Based on the composite insulator, the quantitative brushing method, dipping method and spraying method were compared. The results indicate that, according to the AC pollution tests, the voltage achieved by the quantitative brushing method is about 4.02%~7.73% higher than spraying method, and quantitative brushing method is about 7.66%~13.19% higher than dipping method. It is found that the quantitative brushing method and dipping method have each's characteristic and the appropriate polluted methods should be chosen according to the specific circumstances of the test. The spraying method does not apply to the composite insulator.
Shu J.,North China Electrical Power University |
Li C.,Langfang Electrical Power Company |
Su J.,Hubei Electric Power Company |
Dong W.,Langfang Electrical Power Company
Zhongguo Dianji Gongcheng Xuebao/Proceedings of the Chinese Society of Electrical Engineering | Year: 2012
Due to the difficulty for traditional optimization methods to consider complicated contingency scenarios, an optimal reserve dispatch model considering contingency scenarios based on security constrained unit commitment (SCUC) was presented in this paper. Integrated with unit commitment, power dispatch, reserve capacity optimization and the reserve dispatch, the optimization model is to minimize the sum cost of the electricity and reserve while subjected to the security constraints of base case and contingency scenarios. By introducing scenarios classification and the scenarios set, the demand and dispatch of reserves with different response rates were decided by the requirement of different scenarios. This complicated mixed-integer linear programming problem was modeled by the GAMS and solved by the CPLEX. Numerical case studies illustrated the effectiveness of the proposed approach. © 2012 Chin. Soc. for Elec. Eng.
Wang J.,Hubei Electric Power Company
2013 IEEE International Conference on Signal Processing, Communications and Computing, ICSPCC 2013 | Year: 2013
The introduction of the concept of process level into smart substation makes protection and control of input and output values depend on the network communication. In order to ensure the stability and reliability of the smart substation process layer network, it must forecast the process level network traffic effectively and make early analysis warning. This paper proposed a smart substation process level network traffic prediction algorithm based on ARIMA model from the demand of smart substation process layer network traffic monitoring system. Our proposed algorithm introduces a dynamic error correction factor on the basis of Astrom algorithm based on the linear minimum variance prediction principle. It can solve the problem of stochastic effects in prediction, and the prediction precision is improved. The experimental results show that the algorithm can effectively predict the process level network traffic, reproduce the statistical properties of the real flow measurement, and guarantee the safe operation of power grid. © 2013 IEEE.
Xiao D.-B.,Hubei Electric Power Company
Gaoya Dianqi/High Voltage Apparatus | Year: 2010
Uniform increase voltage is an important test method of the artificial pollution test of insulator, According to the satistical characteristics analysis of pollution test times of composite insulator, under the certain accuracy standard and confidence level, the paper estimated the minimum sample amount of pollution tests needed for pollution flashover voltage of insulators by example calculation. The minimum effective sample size must be 10~12 times for d.c. composite insulator and 15~16 times for a.c. composite insulator.
Wang D.-Z.,Hubei Electric Power Company
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2010
This paper analyzes that the cause of a 330 kV circuit breaker's non-fault-trip is that the length of the cable in protection loop is too long and the distributing capacitance of the cable is too big when the situation of DC power supply is short to the ground. And it also puts forward that action power of starting middle relay should be increased and the action DC voltage is between 60% and 70% of the rated DC voltage in this situation, and the cable connected to operation box terminal R and Q for starting to make middle relay trip operation should be away from strongly interfering supply source when the directions of the cables are designed.