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Power-flow study

About: Power-flow study is a research topic. Over the lifetime, 8091 publications have been published within this topic receiving 155053 citations. The topic is also known as: load-flow study.


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Journal ArticleDOI
TL;DR: In this paper, an optimized reactive power compensation algorithm (RPCA) is proposed to improve the system operation stability and reliability, and facilitate MPPT implementation for each converter module simultaneously.
Abstract: Cascaded multilevel converter structure can be appealing for high-power solar photovoltaic (PV) systems thanks to its modularity, scalability, and distributed maximum power point tracking (MPPT). However, the power mismatch from cascaded individual PV converter modules can bring in voltage and system operation issues. This paper addresses these issues, explores the effects of reactive power compensation and optimization on system reliability and power quality, and proposes coordinated active and reactive power distribution to mitigate this issue. A vector method is first developed to illustrate the principle of power distribution. Accordingly, the relationship between power and voltage is analyzed with a wide operation range. Then, an optimized reactive power compensation algorithm (RPCA) is proposed to improve the system operation stability and reliability, and facilitate MPPT implementation for each converter module simultaneously. Furthermore, a comprehensive control system with the RPCA is designed to achieve effective power distribution and dynamic voltage regulation. Simulation and experimental results are presented to demonstrate the effectiveness of the proposed reactive power compensation approach in grid-interactive cascaded PV systems.

169 citations

Proceedings ArticleDOI
25 Jul 2010
TL;DR: A sequential AC/DC power flow algorithm is proposed to solve networks containing Multi-terminal Voltage Source Converter High Voltage Direct Current systems, and it is shown that correctly defining the power setpoints with respect to the system bus instead of the converter bus requires additional iterative calculations.
Abstract: In this paper, a sequential AC/DC power flow algorithm is proposed to solve networks containing Multi-terminal Voltage Source Converter High Voltage Direct Current (VSC MTDC) systems. In VSC HVDC technology, the converter losses add up to a significant fraction of the overall system losses. However, they are often neglected or not taken into account in a proper manner in VSC HVDC power flows. The algorithm put forward in this paper takes the converter losses into account using a generalized converter loss model. The converter steady state equations are derived in their most general format, with the AC network power injections as controlled quantities. It is shown that correctly defining the power setpoints with respect to the system bus instead of the converter bus, as is often done to simplify calculations, requires additional iterative calculations. The DC system modelling method proposed in this paper does not impose any restriction on the HVDC grid topology. A VSC MTDC power flow solver is incorporated into MATPOWER to show the validity of the proposed algorithm.

169 citations

Journal ArticleDOI
Jen-Hao Teng1
TL;DR: The mathematical models of distributed generations (DGs) are integrated into three-phase distribution load flow program to analyse and simulate the penetrations of DGs for distribution systems.
Abstract: The mathematical models of distributed generations (DGs) are integrated into three-phase distribution load flow program to analyse and simulate the penetrations of DGs for distribution systems. DGs can utilise the traditional energy sources such as oil and coal or renewable energy sources such as wind, solar and fuel cell and use rotating generators or converters to transfer energy to power grids. According to the characteristics of output power, DGs can be specified as constant power factor model, constant voltage model or variable reactive power model in the load flow analysis. These three models are all derived and integrated into the proposed load flow method. Test results demonstrate the validity and capability of the proposed method.

168 citations

Journal ArticleDOI
TL;DR: In this paper, an approach for probabilistic load flow (PLF) evaluation using the unscented transformation (UT) method is presented. And the results are compared with those of the Monte Carlo simulation as well as two-point estimation method with regards to both accuracy and execution time criteria.
Abstract: As a matter of course, the unprecedented ascending penetration of distributed energy resources, mainly harvesting renewable energies, is a direct consequence of environmental concerns. This type of energy resource brings about more uncertainties in power system operation and planning; consequently, it necessitates probabilistic analyses of the system performance. This paper develops a new approach for probabilistic load flow (PLF) evaluation using the unscented transformation (UT) method. The UT method is recognized as a powerful approach in assessing stochastic problems with/without correlated uncertain variables. The capability of the UT method in modeling correlated uncertain variables is very appealing in the power system context, in which noticeable inherent correlation exists. The salient features of the UT method in probabilistic applications have been well proven in other engineering aspects. Following adaptation of the UT method for the PLF problem, three dimensionally different case studies are examined in order to inspect the performance of the proposed methodology. The obtained results are then compared with those of the Monte Carlo simulation as well as two-point estimation method with regards to both accuracy and execution time criteria.

168 citations

Journal ArticleDOI
TL;DR: The result of laboratory experiments revealed that amplitudes and phases of ac output voltage were well regulated in the proposed hybrid system, and will contribute to global environmental protection on isolated islands and in rural locations without any dependence on commercial power systems.
Abstract: This paper proposes a unique standalone hybrid power generation system, applying advanced power control techniques, fed by four power sources: wind power, solar power, storage battery, and diesel engine generator, and which is not connected to a commercial power system. Considerable effort was put into the development of active-reactive power and dump power controls. The result of laboratory experiments revealed that amplitudes and phases of ac output voltage were well regulated in the proposed hybrid system. Different power sources can be interconnected anywhere on the same power line, leading to flexible system expansion. It is anticipated that this hybrid power generation system, into which natural energy is incorporated, will contribute to global environmental protection on isolated islands and in rural locations without any dependence on commercial power systems.

168 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202325
202283
2021162
2020179
2019228
2018221