scholarly journals Evaluation of Battery and Battery Charger Short-Circuit Current Contributions to a Fault on the DC Distribution System at a Nuclear Power Plant

2015 ◽  
Author(s):  
W. Gunther
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Distribution System ◽  
Nuclear Power ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Battery Charger ◽  
Dc Distribution

Comparison of Plant Response of Forsmark 3 Nuclear Power Plant to Forsmark 1 Type of Transient (25th July 2006), Using the HAMBO BWR Simulator: Thermal-Hydraulic Aspects

2008 ◽  
Author(s):  
Esko Pekkarinen
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Short Circuit ◽  
Complex Interplay ◽  
Operator Interface ◽  
Control Rooms ◽  
Hydraulic Process

Modernisation of control rooms of the nuclear power plants has been a major issue during the last few years. With this as a basis, the BWR plants in Sweden and Finland funded, in co-operation with the Halden Project, an experimental HAMBO BWR simulator project based on the Forsmark 3 plant in Sweden. VTT Energy in Finland developed the simulator models for HAMBO with the aid of their APROS tool, while the operator interface was developed by the Halden Project. The simulator and its performance have been described in other publications [1, 2]. On July 25th 2006 there was a short circuit at Forsmark 1 nuclear power plant when manoeuvring equipment in the 400kV-switch yard. Due to the short circuit, the plant suffered an electrical disturbance that led to scram and failure of two out of four diesel generators. The purpose of the study carried out at VTT in 2007 was to assess the capabilities of the HAMBO BWR simulator to handle Forsmark 1 type of events in different nuclear power plants (Forsmark 3 in this case). The Forsmark 1 incident showed (among other things) that the intention to protect certain components (in this case the UPS-system) can in certain situations affect negatively to the safety functions. It is concluded that most of this type of BWR transients may be simulated to a certain extent using the existing HAMBO- and APROS- models. A detailed modelling of the automation and electric systems is required sometimes if the complex interplay between these systems and the process is to be predicted reliably. The modelling should be plant specific and level of detail should be assessed case-by-case (i.e. what kind of transient is in question, what systems are available, what is the main purpose of the analyses etc.). The thermal-hydraulic models of the APROS-code seem to replicate well the real behaviour of thermal-hydraulic process provided that there is enough information about the transient in consideration.

scholarly journals Calculation of Short-Circuit Current in DC Distribution System Based on MMC Linearization

2021 ◽  
Vol 9 ◽  
Author(s):  
Peixiao Sun ◽  
Zaibin Jiao ◽  
Hanwen Gu
Keyword(s):  
Distribution System ◽  
Short Circuit ◽  
Analytical Calculation ◽  
Short Circuit Current ◽  
Modeling And Analysis ◽  
Dc Distribution ◽  
Proposed Model ◽  
Linearized Model ◽  
Comparison Of The Results ◽  
Important Basis

The calculation of the short-circuit current is an important basis for fault detection and equipment selection in the DC distribution system. This paper proposes a linearized model for modular multilevel converter (MMC) considering different grounding methods and different failure scenarios. This model can be used in different fault conditions before MMC’s block. Under different fault forms, the model has different manifestations. This paper analyzes and models the DC distribution network with two types of faults: inter-pole short circuit and single-pole grounding short circuit. Among them, the modeling and analysis of single-pole grounding short-circuit uses the method of common- and differential-mode (CDM) transformation. To solve such a model, an analytical calculation method is proposed. As a mean of evaluating the effectiveness and accuracy of the proposed model, the analytical calculation solution is compared to the solution produced by PSCAD/EMTDC. A comparison of the results reveals the efficacy of the proposed model.

Study on Power Transmission Plan of the Nuclear Power Base in Shandong Peninsula

2016 ◽  
Author(s):  
Chengzhu Yin ◽  
Miao Wang
Keyword(s):  
Power Plant ◽  
Nuclear Power ◽  
Large Scale ◽  
Power Transmission ◽  
Short Circuit ◽  
Power Grid ◽  
Short Circuit Current ◽  
Jiaodong Peninsula ◽  
Power Load ◽  
Power Base

The nuclear power site resource is very rich in Jiaodong Peninsula of Shandong Province. It is suitable for construction of the large nuclear power base. The transmission scope and direction of Jiaodong Peninsula nuclear power base is analyzed, and optional transmission plans of Plant 1, Plant 2, Plant 3 and Plant 4 are proposed. The transmission plans are recommended based on technical and economic comparison, which provide good references for construction of the large-scale nuclear power base and power grid development planning. Jiaodong Peninsula nuclear power base is planned to be built in the year of 2016–2030, planning capacity of which is 30500MW. The site of nuclear power base is 100∼400km away from the power load center. The nuclear power will use AC transmission and mainly meet the demand of local power load. The early 15500MW gensets will be accessed to the power grid at 500kV, as the following 15000MW gensets will be accessed at 1000kV UHV (Ultra-high voltage) grid. As the accessing of many large-capacity gensets will produce huge impact to the short-circuit current, sectionalized double-bus configuration is recommended in the 500kV main electrical wiring to reduce the short-circuit current of 500kV bus of nuclear power plant. Double bus section cross wire connection is presented to make sure that every two generators on each bus will be connected to different substations on two transmission lines which are set up on different poles and in different paths, to improve the reliability of the power plant. Through analysis and provement, the construction of large nuclear power base must be based on large and stronge power grid, especially the UHV (Ultra-high voltage) AC grid, to meet the demand of huge nuclear power transmission, and to improve the ability of power exchange and ensure the safety of regional power supply. Also, as the nuclear power plant should better be in base-load operation, the construction of large-scale nuclear power base, would make the system load-control demands increase, which leads to more prominent problems. In order to avoid adding additional depth of peaking power operation and reducing the overall economic operation of power system, power grid should have the necessary means to load-control. Namely the construction of peaking units, such as pumped storage units or gas-fired units at about 5000MW. By analyzing and demonstration, large-scale nuclear power base must rely on large-scale power grid, particularly the support of UHV power grid in order to meet the demond of large-scale power transmission and electricity exchange, and also to ensure regional security of electricity supply.

scholarly journals Current Protection Applicability Analysis of Flexible DC Power Supply Network

2021 ◽  
Author(s):  
Yuan Gao ◽  
Bingyuan Yang ◽  
Dongsheng Li
Keyword(s):  
Distribution System ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Operation Performance ◽  
Performance Simulation ◽  
Backup Protection ◽  
Dc Distribution ◽  
Passive Network ◽  
Current Characteristics ◽  
Level Converter

In the flexible AC/DC distribution system supplying passive network, when the modular multi-level converter (MMC) inverter AC line fault occurs, the MMC short-circuit current amplitude is greatly affected by the control strategy, which may affect the operation performance of three-stage current protection. In view of this, a flexible AC/DC distribution network system supplying power to the passive network is built on the RTDS platform, and then the AC fault traverse strategy is designed in the MMC controller. Based on the thinking of coordinated control and protection of the fault through the strategy into two cases with no input to higher current protections performance simulation contrast, the simulation results show that asymmetric fault occurred when MMC inverter AC line, under the effect of communication failure through the strategy, the current main protection I, II period of refusing action, only by this line nearly backup protection current section III delay removal of fault. The three-stage current protection based on the fault current characteristics of pure AC system has poor action performance and is no longer suitable for the AC line of MMC inverter station.

Sign in / Sign up

Export Citation Format

Share Document