scholarly journals To study the voltage stability limits of distributed generation using induction machine in distribution networks

2013 ◽  
Vol 16 (2) ◽  
pp. 43-53
Author(s):  
Chuong Trong Trinh ◽  
Anh Viet Truong ◽  
Tu Phan Vu

There are now a lot of distributed generation (DG) using asynchronous machines are connected to power distribution grid. These machines do not usually generate reactive power, even consume reactive power, so they generally affect the voltage stability of whole power grid, and can cause instability in itself it is no longer balanced by the torque to work. In this paper, we investigate the voltage stability problem of the asynchronous machine of wind turbines used in power distribution networks. From the static model of the asynchronous machine, this paper will apply the pragmatic criteria to analysis the voltage stability of the asynchronous machine based on the results of the power flow in power distribution network.

2012 ◽  
Vol 16 (suppl. 1) ◽  
pp. 189-203 ◽  
Author(s):  
Vladimir Strezoski ◽  
Dragan Popovic ◽  
Dusko Bekut ◽  
Goran Svenda

Modern (electric power) distribution utilities are faced with high penetration of distributed (electric) generation. Renewable generation is of prime interest. Within this generation, the green one incorporating solar (photovoltaic) and wind generation is the most important. Consequently, the following two imperatives are established in modern distribution utilities: 1) absorption of as much of available (connected to network) green generation as possible and 2) increasing of the limit of green distributed generation penetration. This generation is a significant basis of Smart Distribution Grid Concept. Distributed generation transfers passive distribution network into active one. The active distribution network analysis, control, operation management and planning become significantly complex. This complexity radically hinders the achievement of two above stated imperatives referring to the distributed generation penetration. This paper proves that Distribution Management System is a unique powerful system that integrates all tools necessary for surpassing main difficulties in the achievement of the both imperatives. The proof is obtained by the elaboration of a set of power applications (mathematical calculations) integrated in the Distribution Management System. The most important power applications, which deal with voltage / reactive power control, are specially stressed.


Author(s):  
Mahesh Kumar ◽  
Perumal Nallagownden ◽  
Irraivan Elamvazuthi ◽  
Pandian Vasant ◽  
Luqman Hakim Rahman

In the distribution system, distributed generation (DG) are getting more important because of the electricity demands, fossil fuel depletion and environment concerns. The placement and sizing of DGs have greatly impact on the voltage stability and losses in the distribution network. In this chapter, a particle swarm optimization (PSO) algorithm has been proposed for optimal placement and sizing of DG to improve voltage stability index in the radial distribution system. The two i.e. active power and combination of active and reactive power types of DGs are proposed to realize the effect of DG integration. A specific analysis has been applied on IEEE 33 bus system radial distribution networks using MATLAB 2015a software.


2014 ◽  
Vol 668-669 ◽  
pp. 749-752 ◽  
Author(s):  
Xiao Yi Zhou ◽  
Ling Yun Wang ◽  
Wen Yue Liang ◽  
Li Zhou

Distributed generation (DG) has an important influence on the voltage of active distribution networks. A unidirectional power distribution network will be transformed into a bidirectional, multiple power supply distribution network after DGs access to the distribution network and the direction of power flow is also changed. Considering the traditional forward and backward substitution algorithm can only deal with the equilibrium node and PQ nodes, so the other types of DGs should be transformed into PQ nodes, then its impact on active distribution network can be analyzed via the forward and backward substitution algorithm. In this paper, the characteristics of active distribution networks are analyzed firstly and a novel approach is proposed to convert PI nodes into PQ nodes. Finally, a novel forward and backward substitution algorithm is adopted to calculate the power flow of the active distribution network with DGs. Extensive validation of IEEE 18 and 33 nodes distribution system indicates that this method is feasible. Numerical results show that when DG is accessed to the appropriate location with proper capacity, it has a significant capability to support the voltages level of distribution system.


Author(s):  
GOPIYA NAIK. S ◽  
D. K. KHATOD ◽  
M. P. SHARMA

The concept of traditional distribution networks with unidirectional power flow is weakening due to large penetration of Distributed Generation (DG). The penetration of DG may impact the operation of a distribution network in both beneficial and detrimental ways. Some of the positive impacts of DG are voltage support, power loss reduction, support of ancillary services and improved reliability, whereas negative ones include protection coordination, dynamic stability and islanding. Therefore, proper planning methods that evaluate the composite impacts, i.e. technical, economical and environmental impacts of DG integration to existing distribution networks are very much essential. This paper presents a critical review of various impacts of DG on power distribution system. For ease of reference and to facilitate better understanding this literature is categorized and discussed under five major headings.


Energies ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1960 ◽  
Author(s):  
Majid Ghaffarianfar ◽  
Amin Hajizadeh

Voltage stability analysis of power distribution systems with high photovoltaic (PV) penetration is a challenging problem due to the stochastic generation of a solar power system. Voltage stability is an important benchmark for defining PV’s penetration level in active distribution networks considering loading capacity. The massive integration of PV power units, the effect of distribution system characteristics, like high ratio of R/X, and the reported collapses in power networks come up in serious studies that investigate their impact and upcoming problems on distribution networks. Therefore, this paper proposes analytical voltage stability and it is implemented on IEEE 34 nodes radial distribution systems with 24.9 kV and 4.16 kV voltage levels. In this regard, in addition to given properties in stability and power loss analysis, a penetration coefficient for PVs is considered. Simulation results prove that the applied method can illustrate the positive and negative effects of PV in distribution networks.


2021 ◽  
Vol 13 (10) ◽  
pp. 5752
Author(s):  
Reza Sabzehgar ◽  
Diba Zia Amirhosseini ◽  
Saeed D. Manshadi ◽  
Poria Fajri

This work aims to minimize the cost of installing renewable energy resources (photovoltaic systems) as well as energy storage systems (batteries), in addition to the cost of operation over a period of 20 years, which will include the cost of operating the power grid and the charging and discharging of the batteries. To this end, we propose a long-term planning optimization and expansion framework for a smart distribution network. A second order cone programming (SOCP) algorithm is utilized in this work to model the power flow equations. The minimization is computed in accordance to the years (y), seasons (s), days of the week (d), time of the day (t), and different scenarios based on the usage of energy and its production (c). An IEEE 33-bus balanced distribution test bench is utilized to evaluate the performance, effectiveness, and reliability of the proposed optimization and forecasting model. The numerical studies are conducted on two of the highest performing batteries in the current market, i.e., Lithium-ion (Li-ion) and redox flow batteries (RFBs). In addition, the pros and cons of distributed Li-ion batteries are compared with centralized RFBs. The results are presented to showcase the economic profits of utilizing these battery technologies.


Author(s):  
Mostafa Elshahed ◽  
Mahmoud Dawod ◽  
Zeinab H. Osman

Integrating Distributed Generation (DG) units into distribution systems can have an impact on the voltage profile, power flow, power losses, and voltage stability. In this paper, a new methodology for DG location and sizing are developed to minimize system losses and maximize voltage stability index (VSI). A proper allocation of DG has to be determined using the fuzzy ranking method to verify best compromised solutions and achieve maximum benefits. Synchronous machines are utilized and its power factor is optimally determined via genetic optimization to inject reactive power to decrease system losses and improve voltage profile and VSI. The Augmented Lagrangian Genetic Algorithm with nonlinear mixed-integer variables and Non-dominated Sorting Genetic Algorithm have been implemented to solve both single/multi-objective function optimization problems. For proposed methodology effectiveness verification, it is tested on 33-bus and 69-bus radial distribution systems then compared with previous works.


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