scholarly journals Study on generation capacity of small hydropower stations in distribution network

2021 ◽  
Vol 71 (1&2) ◽  
pp. 5
Author(s):  
Genghuang Yang ◽  
Wenbin Sun ◽  
Xiayi Hao ◽  
Yingmei Zhang ◽  
Li Yang ◽  
...  
Keyword(s):  
Power System ◽  
Distribution Network ◽  
Relay Protection ◽  
Hydropower Station ◽  
Small Hydropower ◽  
Current Variation ◽  
Generation Capacity ◽  
The Difference ◽  
Hydropower Stations

Small hydropower station, when producing power energy to power system through the distribution network, may lead to the change of the detected current in relay protection and the protection coverage. In this paper, IEEE7 based network is formed in the platform of PSCAD/EMTDC to analyze the effects of distribution network in current protection when a small hydropower station is linked in. The running of relay protection in Section I and II is simulated to obtain the difference of current variation of network with or without small hydropower station. Also the key parameters are calculated to point out the maximum generation capacity of the small hydropower station in case of reliable and sensitive current protection.

Application of Fuzzy Recognition Model for the Diversion Structures Safety Evaluation at Small Hydropower Stations

2014 ◽  
Vol 687-691 ◽  
pp. 3686-3690
Author(s):  
Ming Li ◽  
Xue Feng Yu ◽  
Yuan Dong Wei
Keyword(s):  
Safety Evaluation ◽  
Hydropower Station ◽  
Hydroelectric Power Station ◽  
Hydroelectric Power ◽  
Power Station ◽  
Small Hydropower ◽  
Recognition Model ◽  
Fuzzy Recognition ◽  
Hydropower Stations

In this passage is about the safety evaluation on the conveyance structure of small hydroelectric power station. Applying Binary comparative indicators to determine the weights and fuzzy recognition model on the conveyance structure of small hydroelectric power station’s assessment. Compared other models with fuzzy recognition model which will be explained in detail in the next section on a specific small hydropower station. The results show that the fuzzy recognition model is feasible and effective on safety evaluation on the conveyance structure of the hydroelectric power station.

The Application of Monte Carlo Simulation in Present Earning Value Method — Case Study of a Medium Hydropower Station

2013 ◽  
Vol 732-733 ◽  
pp. 731-737
Author(s):  
Ai Lan Zhang ◽  
Song Jiang Wang
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Hydropower Station ◽  
Small Hydropower ◽  
Hydropower Stations ◽  
Personnel Control ◽  
Assessment Results

Processing the parameters overly simplistic will leave space for overestimating or underestimating artificially when we assess the assets of medium and small hydropower stations using present earning value method. And absolute assumptions often affect the adequacy of the assessment results, also the persuasive and credibility. Monte Carlo simulation can determine the wave of parameters in present earning value method, so as to improve the persuasion and credibility of assessment results and reduce the personnel control.

The Study on Configuration and Setting of Relay Protection when Distributed Generation Accesses to Distribution Network

2012 ◽  
Vol 433-440 ◽  
pp. 1950-1956
Author(s):  
Xiao Ming Li ◽  
Sha Li ◽  
Peng Lu ◽  
Shu Qiong Liu
Keyword(s):  
Power System ◽  
Distributed Generation ◽  
Theoretical Basis ◽  
Distribution Network ◽  
Relay Protection ◽  
Power Capacity ◽  
System Reconfiguration ◽  
Protective Devices ◽  
Protection Devices

When distributed generation (DG) accesses to non-system bus , and the power capacity increases to a certain extent, it will cause malfunction of protective devices, as a result of which ,protective devices lose selectivity. This paper analyzes influence to relay protection of power system as a result of the access of DG, establishes a model of the access of DG, and proposes principles of reconfiguration of protection devices, and re-setting of relay protection when DG accesses to power system. This method provides a theoretical basis for designing of DG accessing to power system, reconfiguration of protection devices and re-setting of relay protection.

A Harmonic Source Location Method Based on PMU Measurements in Distribution Network

2015 ◽  
Vol 775 ◽  
pp. 409-414
Author(s):  
Bing Jun Li ◽  
Su Quan Zhou ◽  
Xiao Xiang Lun
Keyword(s):  
Power System ◽  
State Estimation ◽  
Distribution Network ◽  
Measured Data ◽  
Optimal Measurement ◽  
Location Method ◽  
Measurement Placement ◽  
Minimum Number ◽  
Harmonic Source ◽  
The Cost

It is of great importance to identify the location of the harmonic sources for the harmonic governance in the power system. Applied with optimal measurement placement (OMP) and harmonic state estimation (HSE), this paper presents a novel process based on PMU measurements to locate the harmonic sources in the distribution network. Considering the cost and the observability, the OMP can provide a scheme of the measurement placement with the minimum number of PMU measurements. In order to simplify the HSE equation, the measured data are converted to the form of voltage by the method proposed in this paper.By solving the HSE equation, the location and magnitude of the harmonic source are evaluated. The methodology is applied to the IEEE 33-bus system, and the obtained results are properly analyzed.

Numerical Simulation on Rupture Behavior and Selection of Safety Membranes

2014 ◽  
Author(s):  
Chen Sheng ◽  
Zhang Jian ◽  
Xiaodong Yu
Keyword(s):  
Present Theory ◽  
Large Fluctuation ◽  
Surge Tank ◽  
Small Hydropower ◽  
Weak Points ◽  
Maximum Water ◽  
Safety Operation ◽  
Hydropower Stations ◽  
Selection Of ◽  
Rupture Behavior

This present study deals with a new mechanical device consisting of a set of safety membranes, which has been successfully applied in several middle and small hydropower stations in China instead of a surge tank. Safety membranes are installed on the penstock near the powerhouse as controlled weak points. When the pressure caused by load rejection rises to the preset explosive value, one or more membranes rupture, protecting the penstock and the unit from damage. The device is simple, reliable and economical. The method of characteristics is employed to establish numerical model of safety membranes to simulate their rupture behavior, which is then introduced to investigate how to determine the number and diameter of membranes from two aspects, large fluctuation and hydraulic disturbance. The results show that the diameter of the membranes depends on the negative pressure along pipeline under hydraulic disturbance while the number of the membrane depends on the maximum water hammer pressure under large fluctuation during load rejection of the unit. The conclusion of membrane selection can perfect the present theory of safety membranes, and provide the theoretical guidance and practical basis for membrane device design and safety operation.

Protection Coordination of 33/11 kV Power Distribution Substation in Iraq

2021 ◽  
Vol 39 (5A) ◽  
pp. 723-737
Author(s):  
Yamur M. Obied ◽  
Thamir M. Abdul Wahhab
Keyword(s):  
Time Delay ◽  
Power System ◽  
Power Distribution ◽  
Software Package ◽  
Short Circuit ◽  
Distribution Network ◽  
Circuit Breaker ◽  
Short Circuit Current ◽  
Earth Fault ◽  
Current Characteristics

The coordination between protective devices is the process of determining the most appropriate timing of power interruption during abnormal conditions in the power system. The aim of this work is to coordinate the protection of the 33/11 kV power distribution substation in Iraq using the CYME 7.1 software package. In this paper overcurrent and earth fault relays are simulated in two cases, with time delay setting and instantaneous setting, to obtain the Time Current Characteristics (TCC) curves for each Circuit Breaker (CB) relay of Al-Karama substation (2×31.5 MVA, 33/11 kV) in Babil distribution network. The short circuit current at each CB is calculated and accordingly, the protection coordination for Al-Karama substation has been simulated. The TCC curves have been obtained in two cases for overcurrent and earth fault relays; in a case with time delay setting and in the case with the instantaneous setting. The setting takes into consideration the short circuit current at the furthest point of the longest outgoing feeder and the shortest outgoing feeder.

Influence of Surge Tank and Relief Valve on Transient Flow Behaviour in Hydropower Stations

2011 ◽  
Author(s):  
Alireza Riasi ◽  
Ahmad Nourbakhsh
Keyword(s):  
Power Plants ◽  
Transient Flow ◽  
Flow Analysis ◽  
Internal Boundary ◽  
Transient Condition ◽  
Maximum Pressure ◽  
Surge Tank ◽  
Small Hydropower ◽  
Relief Valve ◽  
Hydropower Stations

Unsteady flow analysis in water power stations is one of the most important issues in order to predict undesirable pressure variations in waterways and also probable changes in rotor speed for the power plants safe operation. Installation of surge tank and relief valve is the two main methods for controlling of hydraulic transient. The relief valve is used in several medium and small hydropower stations instead of the surge tank and mounted on the penstock near the powerhouse. The recent generation of relief valves are reliable and beneficial and consist of fully control system that directly conducted by governor. This paper presents a numerical method for transient flow in hydropower stations using surge tank and relief valve. For this purpose the governing equations of transient flow in closed conduit are solved using the method of characteristics (MOC) using unsteady friction. Hydraulic turbine, surge tank and relief valve are considered as internal boundary conditions. The influence of surge tank and also relief valve on the maximum pressure in spiral case and turbine over speed has been studied for a real case. The results show that the transient condition is considerably improved by using a relief valve and this device can be mounted in lieu of an expensive surge tank.

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