Study on Online Dispatching Defensive Strategy for Power Grid Considering Expected Circuit Breaker Fault Set

With the construction of smart grid and smart substation, influences of the main electrical connection on the reliability of the entire power gird have become more and more important. Therefore, coordinated development between power grid and substation is a key to the design and optimization of main electrical connection. In this paper, the entire equipment in power grid including the main electrical connection is simulated simultaneously, and then the index of power gird with the main electrical connection optimization by disconnecting circuit breaker is calculated. Optimization schemes are sorted by the method of TOPSIS, realizing the evaluation of main electrical connection based on coordinated development between power grid and substation.

Download Full-text

Analysis of capacitor cells failure due to circuit breaker pole discrepancy in RRVPNL power grid

2014 IEEE Students' Conference on Electrical, Electronics and Computer Science ◽

10.1109/sceecs.2014.6804424 ◽

2014 ◽

Cited By ~ 1

Author(s):

Om Prakash Mahela ◽

Neeraj Gupta ◽

Sheesh Ram Ola

Keyword(s):

Power Grid ◽

Circuit Breaker

Download Full-text

Electrical Network Modeling and Electrical Transfer Simulation of C.N. Asco´ I and C.N. Asco´ II, to Obtain Voltage and Frequency Limit Values Allowing the Electrical Transfer From the Main Generator to the External 110 kV Power Grid

Volume 2: Structural Integrity; Safety and Security; Advanced Applications of Nuclear Technology; Balance of Plant for Nuclear Applications ◽

10.1115/icone17-75546 ◽

2009 ◽

Author(s):

Alberto Ban˜o´ Azco´n ◽

Jose´ Mollera Barriga

Keyword(s):

Power Supply ◽

Power Grid ◽

Circuit Breaker ◽

Operating Mode ◽

Electrical Network ◽

Limit Values ◽

Electric System ◽

Future Design ◽

Turbo Generator ◽

Protective Relays

Broadly speaking, a simple electrical diagram of Asco´ I and Asco´ II power nuclear plants could be two power supply bus bars for general equipment classified No-1E, three power supply bus bars class No-1E for the Reactor Coolant Pumps (RCP) and two more bus bars classified 1E for safety related equipment. In normal operating mode, all the five power supply bus bars class No-1E are connected to the main generator (GP1) through two unit transformers (TAG1/2), while the two class 1E power supply bus bars are always connected to an external 110 kV power grid through two auxiliary transformer (TAA1/2). The main generator supplies power to an external 400 kV grid through the main transformer (TP1). The main circuit breaker is placed between the high voltage side of the main transformer and the 400 kV grid. With this configuration, the appearance of an abnormal condition that originates the trip of the main generator and the opening of the main circuit breaker from the external network, involves an electric transfer of the supply bus bars connected to the turbo generator to the external 110 kV power grid. The electric transfer to the external 110 kV power grid will be only possible if the frequency and voltage values are within the allowed range allowed by the grid’s protective relays. Two kinds of electrical transfers are possible: fast transfers and slow transfers. It will be necessary then to evaluate the limit values of voltage and frequency of the power grid that makes the electrical transfer possible in each case. In order to obtain the limit values previously mentioned, the electric system of the plant has been modeled. Different scenarios have been analyzed, taking into account the dynamic behavior of the system components and the delay of the protective relays actuation, verifying the electrical transfer for those situations. This analysis will give enough information to take the correct decisions for future design modifications, and it will assure that the electrical transfer will be done always with success.

Download Full-text

A Power Grid Fault Diagnosis Method in the Case of Alarm Information Loss Based on the Top-k Skyline Query Algorithm

Energies ◽

10.3390/en14196223 ◽

2021 ◽

Vol 14 (19) ◽

pp. 6223

Author(s):

Lei Jin ◽

Qing Chen ◽

Jinjie Ji ◽

Xiaotong Zhou

Keyword(s):

Fault Diagnosis ◽

Power Grid ◽

Circuit Breaker ◽

Information Loss ◽

Uncertain Information ◽

Skyline Query ◽

Data Set ◽

Information Set ◽

Diagnosis Method ◽

Query Algorithm

After the failure of the power system, a large amount of alarm information will flood into the dispatching terminal instantly. At the same time, there are inevitable problems, such as the abnormal operation of the protection and the circuit breaker, the lack of alarm information, and so on. This kind of uncertainty problem brings great trouble to the fault diagnosis algorithm. As a data processing algorithm for an uncertain information set, Top-k Skyline query algorithm can eliminate the data points that do not meet the requirements in the information set, and then output the final K results in order. Based on this background, this paper proposes a power grid fault diagnosis method based on the Top-k Skyline query algorithm considering alarm information loss. Firstly, the fault area is determined by using the information of the electrical quantity and switching value. Then, backward reasoning Petri nets are established for the nodes in the fault area to form the data set of fault hypotheses. Then, the Top-k Skyline query algorithm is used to sort the hypotheses and choose the hypothesis with higher reliability. Finally, an IEEE 39-bus system example is given to verify the reliability of the proposed method.

Download Full-text

A multiport superconducting fault‐current‐limiting circuit breaker for a flexible DC power grid

IET Energy Systems Integration ◽

10.1049/esi2.12032 ◽

2021 ◽

Author(s):

Weiru Wang ◽

Limeng Wang ◽

Zhiyuan He ◽

Yechun Xin ◽

Guoqing Li

Keyword(s):

Power Grid ◽

Circuit Breaker ◽

Fault Current ◽

Dc Power ◽

Current Limiting

Download Full-text

Operation Characteristics of Mechanical DC Circuit Breaker Combined with LC Divergence Oscillation Circuit for High Reliability of LVDC System

Energies ◽

10.3390/en14165097 ◽

2021 ◽

Vol 14 (16) ◽

pp. 5097

Author(s):

Sang-Yong Park ◽

Hyo-Sang Choi

Keyword(s):

Simulation Analysis ◽

High Reliability ◽

Power Grid ◽

Circuit Breaker ◽

Zero Point ◽

Power Semiconductor ◽

Dc Power ◽

Oscillation Circuit ◽

Dc Circuit Breaker ◽

Superconducting Current

DC systems are modernly starting to come into the spotlight again due to the carbon-neutral policy, the development of semiconductor devices for power, and the increase in digital loads. We need to prepare in advance solutions to problems that may arise from fault currents due to transients for future DC power grid models. In the case of DC, there is no current zero-point because there is no frequency. Therefore, a large switching surge is generated when the circuit breaker cuts off the fault current. The possibility of insulation breakdown is greater than that of AC in severe cases. We consider power semiconductors or superconducting current limiters as an alternative. However, DC breaking cannot be safely achieved by itself. For reliable DC breaking, mechanical circuit breakers must be used with them. Among the mechanical shut-off methods, we adopted the divergence oscillation method. It has the biggest advantage compared to other methods in that it has a simple structure by composing passive elements and can artificially create zero current. In addition, it can be applied to a power semiconductor and a superconducting current limiter to perform a high-reliability cut-off operation. In this paper, we conducted simulation analysis by configuring the DC power grid and DC cut-off system through the PSCAD/EMTDC program. Results confirmed that the application of the LC divergence oscillation circuit can reduce the cut-off time and reduce the power burden of the mechanical DC circuit breaker (MCB).

Download Full-text