Ningxia Electrical Power Company

Yinchuan, China

Ningxia Electrical Power Company

Yinchuan, China
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Zheng T.,North China Electrical Power University | Zhang J.,North China Electrical Power University | Wu D.,NARI Group | Huang S.,North China Electrical Power University | Wang X.,Ningxia Electrical Power Company
IET Generation, Transmission and Distribution | Year: 2017

Cross-voltage faults, i.e. multi-circuit faults that occur between different voltage level systems, in mixed-voltage quadruple-circuit transmission lines occur at times. The short-circuit calculations, which are the basis of the relay protection settings, for different faults are required. This study proposes a new method based on the theory of multiple fault analysis. First, the cross-voltage fault is regarded as a double multiple fault of the system. By retaining the fault nodes and the ground node, while eliminating all the intermediate nodes, the equivalent impedance of each sequence is obtained. Next, the fault reference phase is selected and the two-port network of each sequence that belongs to the reference phase is formed. Further, the port voltages of each sequence are transferred to a special phase using phase-shifting transformers. Then, a unified composite sequence network is formed according to the boundary conditions of the special phase. Finally, a set of equations are listed based on the composite sequence network in order to determine the fault currents and voltages. The simulation results in PSCAD agree well with the results calculated using the above algorithm, verifying the accuracy of this method. © The Institution of Engineering and Technology.

Shi H.,Beifang University of Nationalities | Yang J.,Beifang University of Nationalities | Ding M.,Ningxia Electrical Power Company | Wang J.,Ningxia University
Dianli Xitong Zidonghua/Automation of Electric Power Systems | Year: 2011

Establishing the wind power prediction system and improving the prediction accuracy is one of the key techniques for exploiting wind power. Based on numerical weather prediction, a wind power prediction model using the back propagation (BP) neural network is proposed. Factors that affect the prediction accuracy are analyzed using actual data of a certain wind farm. In the light of inconspicuous day characteristic of the original wind speed and the failure of the BP neural network to completely map its power sequence, a prediction model based on wavelet-BP neural network is proposed. With the wavelet-BP neural network model, the wind speed and power sequence are decomposed into different scales. Then the sub-sequences of different frequency components are predicted using multiple BP neural networks. Finally, the output data of BP neural networks are reconstructed to obtain the complete wind power predicting results. It is shown by the research results that the prediction accuracy of wavelet-BP neural network is effectively improved. © 2011 State Grid Electric Power Research Institute Press.

Chang K.,State Grid Electric Power Research Institute of China | Ding M.-S.,Ningxia Electrical Power Co. | Xue F.,State Grid Electric Power Research Institute of China | Zhang J.,Ningxia Electrical Power Co. | And 2 more authors.
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2012

With the growth of wind power penetration rate, the study and application of ultra-short-term wind power forecasting which is suitable for on-line early-warning system is of great importance, which could improve the grids receptiveness, security and stability. Firstly, an ultra-short-term wind power forecasting model is established based on autoregressive integrated moving average (ARIMA) time series model. Secondly, considering the requirements of on-line early-warning system, a technique of on-line computing white noise sequence is discussed. And then the way of improving the adaptability is proposed. Thirdly, the applications of the proposed forecasting method in on-line early-warning system are discussed. Finally, taking Ningxia wind farms operation data as example, a comparison between persistence forecasting method and the proposed method is made in three kinds of operation conditions. And the validity of the proposed method is proved.

Xu R.,NARI Group | Teng X.,NARI Group | Zhang X.,NARI Group | Pang T.,NARI Group | And 2 more authors.
Dianli Xitong Zidonghua/Automation of Electric Power Systems | Year: 2013

The uncertainty of large-scale grid connected photovoltaic (PV) active power output increases the difficulties of power system control. The influence of large-scale PV power integration on the main system operation and control is analyzed. Considering the current status of PV stations and dispatching stations, the framework and design logic of active power control system is then proposed for large-scale PV power integration. PV data collection and communication, PV control mode for multi-objective control requirement and control performance evaluation method are studied and formulated. Furthermore, a PV integrated control system is constructed with functions of supervisory control and data acquisition, active power control, and of dispatching center and PV station. It implements closed-loop control of dispatching center to control the PV station. The proposed integrated control system has been implemented in a provincial grid and validated. © 2013 State Grid Electric Power Research Institute Press.

Wei W.,Xi'an Jiaotong University | Hao M.,Ningxia Electrical Power Company
Applied Mechanics and Materials | Year: 2012

This article discusses some of the linear regression model from the modeling theory, focusing on the modeling method of selecting the optimal model, choose the best bandwidth criteria. Then, given some of the partial linear regression model from the estimates and the partial residual nuclear smooth estimates, and estimate the model using the partial residual in the unknown parameters and to estimate the unknown function. Finally, the establishment of the Shanghai Index and Shenzhen Component Index Partially linear regression model.

Wei W.,Xi'an Jiaotong University | Hao M.,Ningxia Electrical Power Company
Applied Mechanics and Materials | Year: 2012

The theoretical properties of the ARMA model and the modeling process, then, the Shanghai power network and Shenzhen power network in China were established ARMA model and wavelet-based ARMA model fitting, prediction, and finally, to fit forecast The results were compared. It can be seen, combined with relatively good forecasting effect after wavelet.

Wu W.-C.,Ningxia Electrical Power Company | Nie H.-J.,Ningxia Electrical Power Company | Bian J.,Ningxia Electrical Power Company
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2011

This paper introduces a single-phase grounding breakdown caused by a bird damage that occurs in the 110 kV line in Hongsipu substation of Ningxia Power Grid, which led to the wrong action of the line end main transformer zero-sequence overvoltage protection. Based upon the practical protection setting value situation, and by analyzing the accident in detail, we find that the weak selectivity and sensitivity of practical protection and the improper coordination of relay settings are the main reasons. After the reason is clear, aiming at the problems of bird damage and main transformer protection and line protection setting inspection, this paper puts forward the corresponding improvement scheme and countermeasure.

Xia J.-K.,Ningxia Electrical Power Corporation
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2010

This paper indicates a number of factors which affect the normal action of current differential protection for transmission line in power system in actual operation. And it takes the principle and certain operating mode of differential protection for optical fiber as a view and the RCS-931 differential protection for optical fiber as an example to discuss and analyze intensively the influence over the differential protection for optical fiber from the line capacitance and current, high-impedance grounding fault under heavy load, CT saturation on the transmission line, disparity of CT on two sides of the transmission line, and the data sampling in step of the optical fiber line. Then it brings in some solutions in detail from the operational guidance, selection of design, and protection of software algorithm to remove the adverse effect brought by those problems above for the differential protection for optical fiber.

Chen H.,Ningxia Electrical Power Company
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2015

The optimal configuration of location and capacity of the distributed generation (DG) can ensure its better technical and economic utility. Based on the detailed analysis on peculiarity of DG, this paper establishes a model of DG which takes the minimal active network loss of DG and the least cost into consideration. A bacterial colony optimization (BCO) algorithm based on the basic growth law of bacterial colony is presented. An information sharing method is built for the colony. This BCO algorithm provides a new type of termination; it will terminate the iteration when the colony vanishes, regardless of the iteration number or the precision value. Finally, the effectiveness of the proposed algorithm is illustrated by experiments. © 2015, Power System Protection and Control Press. All right reserved.

Wang S.H.,Ningxia Electrical Power Company | Zhang H.,NingXia Electrical Power Company | He R.,Ningxia Electrical Power Company | Xiao Q.M.,NingXia Electrical Power Company | And 2 more authors.
Energy Procedia | Year: 2012

The reactive power planning involved in the scenario of uncertainty, by processing the scene, several scenes with the state to represent the dynamic process of system development. Traditional reactive planning for a lack of flexibility of the lack of a scene made more flexible reactive power planning ideas, its objective function will split the cost for the initial investment and volatility in two parts, pre-planning to increase by a small amount of reactive power investments, planning program more flexible, can adapt to future changes in the environment. The standard test system is used to validated the effectiveness and practicality. © 2011 Published by Elsevier Ltd.

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