Monte Carlo Simulation of a Microgrid Harmonic Power Flow

2014 ◽  
Vol 15 (2) ◽  
pp. 129-140 ◽  
Author(s):  
Abdullahi Lanre Amoo ◽  
Usman O. Aliyu ◽  
Dalila Mat Said ◽  
Abdullah Asuhaimi Mohd Zin ◽  
Abubakar Sadiq Bappah

Abstract With the transformation of power utility companies from vertical structure to full deregulated entities, the need for the integration of distributed generation (DG) resource in the form of Microgrid (MG) system would soon become indispensable in most deregulated power systems. This is due to renewability of such generation systems. The power quality performance in terms of intermittent energy of these DG systems supply is the major limitation to their full integration as the sole generation entities that can propel rapid decentralization of electric power systems operation. Nonetheless, the acceptable standard is to operate them in an islanding mode or as a MG optimally dispatch among generation mix. This paper developed a total harmonic distortion models for a Microgrid bus in a Nigerian grid system and applied Monte Carlo technique to reliably predict the level of harmonic power flow in the system. The result shows that the distortion increases as the demand factor of the station decreases.

Author(s):  
Miloš Milovanović ◽  
Jordan Radosavljević ◽  
Bojan Perović ◽  
Milorad Dragičević

This paper presents the results of power flow calculations in the presence of harmonics in radial distribution systemsobtained using the decoupled harmonic power flow (DHPF) algorithm. In this algorithm, the interaction among the harmonicfrequencies is assumed to be negligible and hence the calculations are separately performed for every harmonic order of interest. Adetailed methodology for calculating current and voltage high order harmonics, harmonic losses and total harmonic distortion ofvoltage of the electrical distribution networks in the frequency domain is presented. The standard backward/forward sweep method isused for solving the power flow problem at the fundamental frequency. Furthermore, some practical and approximated models ofnetwork components in harmonic analysis are given. The performance of the DHPF approach is studied and evaluated on two standardtest systems with nonlinear loads, the distorted IEEE 18-bus and IEEE 33-bus. Nonlinear loads are treated as harmonic current sourcesthat inject harmonic currents into the system. The DHPF algorithm is verified by comparing its results with those generated bysoftware tools for the analysis of transmission, distribution and industrial power systems (i.g. ETAP and PCFLO). Simulation resultsshow the accuracy and efficiency of the applied procedure for solving the harmonic power flow problem.


1988 ◽  
Vol 3 (3) ◽  
pp. 949-955 ◽  
Author(s):  
J.P. Tamby ◽  
V.I. John

Energies ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2341
Author(s):  
Benjamin T. Gwynn ◽  
Raymond de Callafon

Load switches in power systems may cause oscillations in active and reactive power flow. Such oscillations can be damped by synthetic inertia provided by smart inverters providing power from DC sources such as photovoltaic or battery storage. However, AC current provided by inverters is inherently non-sinusoidal, making measurements of active and reactive power subject to harmonic distortion. As a result, transient effects due to load switching can be obscured by harmonic distortion. An RLC circuit serves as a reference load. The oscillation caused by switching in the load presents as a dual-sideband suppressed-carrier signal. The carrier frequency is available via voltage data but the phase is not. Given a group of candidate signals formed from phase voltages, an algorithm based on Costas Loop that can quickly quantify the phase difference between each candidate and carrier (thus identifying the best signal for demodulation) is presented. Algorithm functionality is demonstrated in the presence of inverter-induced distortion.


2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Aida Fazliana Abdul Kadir ◽  
Tamer Khatib ◽  
Wilfried Elmenreich

This paper is an overview of some of the main issues in photovoltaic based distributed generation (PVDG). A discussion of the harmonic distortion produced by PVDG units is presented. The maximum permissible penetration level of PVDG in distribution system is also considered. The general procedures of optimal planning for PVDG placement and sizing are also explained in this paper. The result of this review shows that there are different challenges for integrating PVDG in the power systems. One of these challenges is integrated system reliability whereas the amount of power produced by renewable energy source is consistent. Thus, the high penetration of PVDG into grid can decrease the reliability of the power system network. On the other hand, power quality is considered one of the challenges of PVDG whereas the high penetration of PVDGs can lead to more harmonic propagation into the power system network. In addition to that, voltage fluctuation of the integrated PVDG and reverse power flow are two important challenges to this technology. Finally, protection of power system with integrated PVDG is one of the most critical challenges to this technology as the current protection schemes are designed for unidirectional not bidirectional power flow pattern.


2016 ◽  
Vol 133 ◽  
pp. 355-364 ◽  
Author(s):  
Bo Liu ◽  
Zhengchun Du ◽  
Chongtao Li

Energies ◽  
2018 ◽  
Vol 11 (7) ◽  
pp. 1888
Author(s):  
Pedro A. Blasco ◽  
Rafael Montoya-Mira ◽  
José M. Diez ◽  
Rafael Montoya ◽  
Miguel J. Reig

In this work, the expression of the phasor of apparent power of harmonic distortion is formulated in the time domain. Applying this phasor along with the phasor of apparent unbalance power allows us to obtain a new set of phasors that include all of the inefficient power components appearing in the transfer of energy in non-linear and unbalanced systems. In this manner, a new model of inefficient power in electrical systems is developed. For each voltage harmonic of order ‘m’ and current harmonic of order ‘n’, a phasor of harmonic apparent power is obtained. Accuracy in the determination of the total apparent power of a system depends on the number of harmonics considered. Each phasor of apparent harmonic power is formed from six mutually orthogonal parameters or components that are calculated from the harmonic voltages at the nodes of the network and the circulating harmonic currents. To demonstrate the validity of the proposed formulation, a four-wire non-linear system formed by two nodes is assessed.


2011 ◽  
Vol 403-408 ◽  
pp. 3253-3257
Author(s):  
Yu Xu

Due to the rapid growth of non-linear loads in power systems, harmonic pollution is becoming more and more serious. Begin with the definition of harmonic power, the direction of power flow is analyzed from the sides of both fundamental and harmonic wave. Through a harmonic simulation circuit based on PSCAD/EMTDC, the conclusion that as a result of harmonic, harmonic-sources have their metered electric energy reduced, while non-harmonic-sources increased has been brought out. What's more, according to the result of simulation, the interactive influence of fundamental and harmonic wave on power measurement is proposed. Due to the above conclusion and the work principles of electromagnetic induction meter and electric meter, the reasons of measurement errors are found. And at the end of this paper, the development and current status of power definition which is a necessary key to the power measurement are discussed.


Sign in / Sign up

Export Citation Format

Share Document