Load Power Quality Characteristics of Trains With Switch-Type Converters and the Impact to AC Electrified Traction Power Systems

2014 ◽  
Author(s):  
Bih-Yuan Ku ◽  
Yen-Chun Chen ◽  
Guan-Ru Chen ◽  
Ming-Jan Ko
Keyword(s):  
Power Systems ◽  
Power Quality ◽  
Power Flow ◽  
Reactive Power ◽  
Measurement Data ◽  
Quality Characteristics ◽  
Load Power ◽  
Switch Type ◽  
The Impact ◽  
Traction Power

In this paper we present our study on load power quality characteristics of new trains with switch-type converters using field measurement data. We apply these data to perform power flow and harmonic power flow computations to examine the impacts of new train loads to existing ac traction power network with filters designed for old train loads. Our simulation results show that existing filters can result in over-compensation of reactive power and ineffective filtering of load current harmonic components. It is recommended that filter designs be modified to suit the load power characteristics of new-generation trains.

Research and Application of SVC Technology in Grid

2014 ◽  
Vol 543-547 ◽  
pp. 878-883
Author(s):  
Jun Dong ◽  
Jian Guo Xu ◽  
Hao Zhang ◽  
Yu Jie Pei ◽  
Xian Feng Li
Keyword(s):  
Power Systems ◽  
Power Quality ◽  
Distribution System ◽  
Power Flow ◽  
Reactive Power ◽  
Control Strategies ◽  
Load Capacity ◽  
Flow Distribution ◽  
Nonlinear Load ◽  
The Impact

The cause serious deterioration in power quality problems for the growing impact and nonlinear load capacity, introduced SVC device in the role of modern power systems and applications. According to the lack of adequate regional dynamic reactive power regulation means to cause voltage fluctuations, harmonics exceeded the actual situation, through analysis and simulation of the existing 66kV grid power quality conditions, refers to the necessity of application of SVC, the compensation capacity for SVC, filter capacitor system parameters and control strategies were designed, the results show improved 220kV SVC reactive power flow distribution system, reducing the system once or twice a net loss, reducing the impact and harmonic interference voltage caused by nonlinear loads, system security, economic operation of great significance.

scholarly journals UPFC Location and Performance Analysis in Deregulated Power Systems

2009 ◽  
Vol 2009 ◽  
pp. 1-20 ◽  
Author(s):  
Seyed Abbas Taher ◽  
Ali Akbar Abrishami
Keyword(s):  
Power Systems ◽  
Objective Function ◽  
Electricity Market ◽  
Power Flow ◽  
Reactive Power ◽  
Unified Power Flow Controller ◽  
Test Case ◽  
Spot Prices ◽  
Sensitivity Approach ◽  
The Impact

We deal with the effect of Unified Power Flow Controller (UPFC) installation on the objective function of an electricity market. Also this paper proposes a Novel UPFC modelling in OPF which facilities the consideration of the impact of four factors on power market. These include the series transformer impedance addition, the shunt reactive power injection, the in-phase component of the series voltage and the quadrature component of the series voltage. The impact of each factor on the electricity market objective function is measured and then compared with the results from a sensitivity approach. The proposed sensitivity approach is fast so it does not need to repeat OPF solutions. The total impacts of the factors are used to offer UPFC insertion candidate points. It is shown that there is a clear match between the candidate points of the sensitivity method and those proposed by the introduced UPFC modelling in our test case. Furthermore, based on the proposed method, the relation between settings of UPFC series part and active and reactive power spot prices is presented.

scholarly journals Reliability Evaluation of Bulk Power Systems Incorporating UPFC

2021 ◽  
Vol 9 (VI) ◽  
pp. 2339-2347
Author(s):  
Mr. B. Madhu
Keyword(s):  
Power Systems ◽  
Power Flow ◽  
Reactive Power ◽  
Reliability Evaluation ◽  
Test System ◽  
Operating Modes ◽  
Reactive Power Flow ◽  
Proposed Model ◽  
State Models ◽  
The Impact

Unified power flow controller (UPFC) is one of the most advanced flexible AC transmission system (FACTS) devices that can simultaneously and independently control both the real and reactive power flow in a transmission line. The utilization of UPFC can result in significant reliability benefits in modern power systems. This paper proposes a novel reliability network model for a UPFC, which incorporates the logical structure and the distinct operating modes of a UPFC. Two-state or three-state models have been used for UPFC by previous researchers. The proposed model divides the UPFC operating modes into four states, namely the UPFC up state, STATCOM state, SSSC state and UPFC down state, in order to improve the accuracy of the model by recognizing the practical operating states of a UPFC. The new model also incorporates an AC flow-based optimal load shedding approach to assess the impact of bus voltages and reactive power flow on UPFC in order to decide appropriate load curtailment in the reliability evaluation process. The performance of the proposed model is verified using a test system, and compared with different reliability models of UPFC. Various operating schemes, such as different placement locations of UPFC, and different capacities of UPFC are used to illustrate the advantages of the developed models, and to examine the impacts of UPFC on the system reliability.

Optimal Capacitors Placement of Distribution Systems Using 2nd Order Power Loss Sensitivity Analysis and Hierarchical Clustering

2014 ◽  
Vol 986-987 ◽  
pp. 377-382 ◽  
Author(s):  
Hui Min Gao ◽  
Jian Min Zhang ◽  
Chen Xi Wu
Keyword(s):  
Sensitivity Analysis ◽  
Hierarchical Clustering ◽  
Distribution System ◽  
Power Flow ◽  
Distribution Systems ◽  
Reactive Power ◽  
Digital Simulation ◽  
Second Order ◽  
First Order ◽  
The Impact

Heuristic methods by first order sensitivity analysis are often used to determine location of capacitors of distribution power system. The selected nodes by first order sensitivity analysis often have virtual high by first order sensitivities, which could not obtain the optimal results. This paper presents an effective method to optimally determine the location and capacities of capacitors of distribution systems, based on an innovative approach by the second order sensitivity analysis and hierarchical clustering. The approach determines the location by the second order sensitivity analysis. Comparing with the traditional method, the new method considers the nonlinear factor of power flow equation and the impact of the latter selected compensation nodes on the previously selected compensation location. This method is tested on a 28-bus distribution system. Digital simulation results show that the reactive power optimization plan with the proposed method is more economic while maintaining the same level of effectiveness.

Sensitivity Based Approach for Transmission Congestion Management Utilizing Bids for Generation Rescheduling and Load Curtailment

2006 ◽  
Vol 7 (4) ◽  
Author(s):  
Himanshu Kumar Singh ◽  
S.C. Srivastava ◽  
Ashwani Kumar Sharma
Keyword(s):  
Electricity Markets ◽  
Power Flow ◽  
Reactive Power ◽  
Congestion Management ◽  
Test System ◽  
Hyperbolic Function ◽  
Flow Sensitivity ◽  
Fair Competition ◽  
Load Curtailment ◽  
The Impact

One of the most important tasks of System Operator (SO) is to manage congestion as it threatens system security and may cause rise in electricity price resulting in market inefficiency. In corrective action congestion management schemes, it is crucial for SO to select the most sensitive generators to re-schedule their real and reactive powers and the loads to curtail in extreme congestion management. This paper proposed the selection of most sensitive generators and loads to re-schedule their generation and load curtailment based on the improved line flow sensitivity indices to manage congestion. The impact of slack bus on power flow sensitivity factors has been determined to encourage fair competition in the electricity markets. Effect of bilateral and multilateral transactions, and impact of multi-line congestion on congestion cost has also been studied. The generators’ reactive power bid has been modeled by a continuous differentiable tangent hyperbolic function. The proposed concept of congestion management has been tested on a practical 75-bus Indian system and IEEE-118-bus test system.

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