Long-term voltage stability with large-scale solar-photovoltaic (PV) generation

2020 ◽  
Vol 117 ◽  
pp. 105663 ◽  
Author(s):  
Enkhtsetseg Munkhchuluun ◽  
Lasantha Meegahapola ◽  
Arash Vahidnia
Keyword(s):  
Large Scale ◽  
Voltage Stability ◽  
Solar Photovoltaic ◽  
Pv Generation

scholarly journals Application of large-scale grid-connected solar photovoltaic system for voltage stability improvement of weak national grids

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Bukola Babatunde Adetokun ◽  
Joseph Olorunfemi Ojo ◽  
Christopher Maina Muriithi
Keyword(s):  
Power System ◽  
Energy Demand ◽  
Large Scale ◽  
Voltage Stability ◽  
Reactive Power ◽  
Active Power ◽  
Photovoltaic System ◽  
Critical Voltage ◽  
Solar Photovoltaic ◽  
Solar Photovoltaic System

AbstractThis paper investigates the application of large-scale solar photovoltaic (SPV) system for voltage stability improvement of weak national grids. Large-scale SPV integration has been investigated on the Nigerian power system to enhance voltage stability and as a viable alternative to the aged shunt reactors currently being used in the Nigerian national grid to mitigate overvoltage issues in Northern Nigeria. Two scenarios of increasing SPV penetration level (PL) are investigated in this work, namely, centralized large-scale SPV at the critical bus and dispersed large-scale SPV across the weak buses. The voltage stability of the system is evaluated using the active power margin (APM) also called megawatt margin (MWM) derived from Active Power–Voltage (P–V) analysis, the reactive power margin (RPM) and the associated critical voltage–reactive power ratio (CVQR) index obtained from Reactive Power–Voltage (Q–V) analysis. All simulations are carried out in DIgSILENT PowerFactory software and result analyses done with MATLAB. The results show that with centralized SPV generation for the case study system, the highest bus voltage is able to fall within acceptable limits at 26.29% (1000 MW), while the dispersed SPV achieves this at 21.44% (800 MW). Also, the dispersed SPV scenario provides better voltage stability improvement for the system as indicated by the MWM, RPM and the CVQR index of the system. Therefore, this work provides a baseline insight on the potential application of large-scale SPV in weak grids such as the Nigerian case to address the voltage stability problems in the power system while utilizing the abundant solar resource to meet the increasing energy demand.

scholarly journals Investigation of Structural Voltage Stability in Tunisian Distribution Networks Integrating Large-Scale Solar Photovoltaic Power Plant

2020 ◽  
Vol 30 (13) ◽  
pp. 2050259
Author(s):  
Abdelaziz Salah Saidi
Keyword(s):  
Power Plant ◽  
Large Scale ◽  
Voltage Stability ◽  
Distribution Network ◽  
Differential Algebraic Equations ◽  
Load Flow ◽  
Transmission Network ◽  
Solar Photovoltaic ◽  
Dynamic Component ◽  
Photovoltaic Power

This research shows a structural voltage stability analysis of a distribution network incorporating large-scale solar photovoltaic power plant. Detailed modeling of the transmission network and photovoltaic systems is presented and a differential-algebraic equations model is developed. The resulting system state and load-flow Jacobian matrix are reorganized according to the type of the bus system in place of the standard injected complex power equations arrangement. The interactions among system buses for loading tests and solar photovoltaic power penetration are structurally scrutinized. Two-bus bifurcations are revealed to be a predecessor to system voltage collapse. The investigation is carried out by using bifurcation diagrams of photovoltaic generation margin, load-flow analysis, short-circuits, photovoltaic farm disconnections and loading conditions. Furthermore, evaluation of voltage stability reveals that the dynamic component of the voltage strongly depends on fault short-circuit capacity of the power system at the bus, where, the solar system is integrated. The overall result, which encompasses the views from the presented transmission network integration studies, is a positive outcome for future grid integration of solar photovoltaic in the Tunisian system. Tunisia’s utilities policies on integration of solar photovoltaic in distribution network is expected to benefit from the results of the presented study. Moreover, given the huge potential and need for solar photovoltaic penetration into the transmission network, the presented comprehensive analysis will be a valuable guide for evaluating and improving the performances of national transmission networks of other countries too.

Particle Swarm Optimization Solving Nonlinear Programming Problems in Power System

2013 ◽  
Vol 760-762 ◽  
pp. 1183-1186
Author(s):  
Li Kang ◽  
Xiao Guang Li
Keyword(s):  
Nonlinear Programming ◽  
Power System ◽  
Computational Efficiency ◽  
Optimization Model ◽  
Large Scale ◽  
Voltage Stability ◽  
Reactive Power ◽  
Voltage Control ◽  
Stability Control

In order to improve the control capability of the power system voltage stability and to enhance spatial and temporal coordination of voltage control means, it is essential to establish the model of emergency voltage control that can globally mobilize reactive power support and voltage control potential. Focus on the long-term voltage stability of power system, the paper introduce nonlinear programming into emergency voltage control, settle the problem that how to establish the model of emergency voltage control. Based on detailed models of power system, the receding optimization model of long-term voltage stability control is established under framework of model predictive control. In order to improve the computational efficiency and reduce feedback delays, nonlinear programming sensitivity algorithm is proposed to solve receding optimization model. The proposed method can improve computational efficiency significantly which creates the condition for the emergency voltage control application to large-scale systems.

Evolution of Large-Scale Coronal Structures

1994 ◽  
Vol 144 ◽  
pp. 29-33
Author(s):  
P. Ambrož
Keyword(s):  
Magnetic Field ◽  
Field Line ◽  
Large Scale ◽  
Coronal Magnetic Field ◽  
Source Surface ◽  
Solar Cycles ◽  
Characteristic Relationship ◽  
The Magnetic Field ◽  
Coronal Structures

AbstractThe large-scale coronal structures observed during the sporadically visible solar eclipses were compared with the numerically extrapolated field-line structures of coronal magnetic field. A characteristic relationship between the observed structures of coronal plasma and the magnetic field line configurations was determined. The long-term evolution of large scale coronal structures inferred from photospheric magnetic observations in the course of 11- and 22-year solar cycles is described.Some known parameters, such as the source surface radius, or coronal rotation rate are discussed and actually interpreted. A relation between the large-scale photospheric magnetic field evolution and the coronal structure rearrangement is demonstrated.

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