Study of Voltage Stability in Grid-Connected Large Wind Farms

2012 ◽  
Vol 433-440 ◽  
pp. 1794-1801 ◽  
Author(s):  
Jian Dong Duan ◽  
Rui Li ◽  
Lin An

Squirrel-cage induction generator (SCIG), as its structural and economic advantages, has been widely utilized in large wind farms in China. However, the large wind farm composed of induction generators will cause obvious problems to the power system stability due to the dependency on reactive power. At the same time, Doubly-fed induction generator (DFIG), as a new type of wind turbine generator, has excellent dynamic characteristics for operation of wind farms. With the increase in penetration of wind power in power systems, more and more wind farms will use both SCIG and DFIG. In this case, the dynamic characteristic of wind farm on power systems is becoming an important issue especially in terms of the voltage stability. This article is to show by means of simulations the dynamic performance of wind farm linked to power system under the circumstances of network disturbances. Furthermore, the interaction between the SCIGs and DFIGs has also been investigated. A detailed model of wind farms is presented through the plat root of MATLAB/SIMULINK. The simulation results demonstrate that the DFIG applications will largely improve the dynamic performance of wind farm in certain conditions, if the DFIGs could be applied reasonably, the voltage stability of the wind farm will be largely improved and even low voltage ride through(LVRT) characteristic of SCIGs, which may be a good solution to reduce the high dependence of costly reactive power compensation equipment(Some flexible AC transmission systems devices like SVC, STATCOM) to some extent.

2011 ◽  
Vol 354-355 ◽  
pp. 989-992
Author(s):  
An Lin

Squirrel-cage induction generator (SCIG) has been widely utilized in large wind farms in China. However, the large wind farm composed of induction generators will cause obvious power system stability problems due to the dependency on reactive power. Doubly-fed induction generator (DFIG) has excellent dynamic characteristics of wind farm operations. With the increasing of wind power penetration in power systems, more and more wind farms use both SCIG and DFIG. This paper firstly analyzes the the dynamic characteristic of wind farm on power systems, especially in terms of the voltage stability. Then the interaction between the SCIGs and DFIGs is also investigated. A detailed simulation model of wind farms is presented by means of MATLAB. The simulation results demonstrate that the DFIG applications will improve the voltage stability of the wind farm largely and the low voltage ride through characteristics of SCIG to some extend.


Nowadays, many countries have started to implement and installed solar photovoltaic (PV). The initial designs of existing power systems were not integrating with any renewable energy (RE) including PV. So, the small scale PV may not have any effect on these power systems. However, integrating large scale PV might raise several power quality issues including power system stability. Power system stability has become major attention where the main focus is on voltage stability.Voltage stability is related on electrical grid capacity to balance the Total Power of Demand (PD) and Total Power generated by Generator (Pgtt). Instability of the voltage can cause inability of the power system to meet the demand of reactive power. The lack of reactive power will cause instability in the power system.This paper present optimal placement and sizing of PV for stability enhancement and operating cost minimization. In this research, reactive power has gradually increased and Fast Voltage Stability Index (FVSI) is applied to analyze voltage stability. PV is applied to stabilize voltage stability of the power system. Economic Load Dispatch (ELD) is conducted to determine the optimal cost and loss. DEIANT is conducted to optimize the total cost and the total loss after solar PV implementation. Simulation result indicates the effectiveness of the proposed technique for stability enhancement and operating cost minimization.


Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Xiao-ling Su ◽  
Lai-jun Chen ◽  
Jun Yang ◽  
Zhengxi Li ◽  
Peng Zhou ◽  
...  

Power systems have developed significantly because of the increasing share of renewable energy sources (RESs). Despite the advantages, they also bring inevitable challenges to power system stability, especially under extreme fault conditions. This paper presents a practical active support control strategy for RESs to support the power grid under extreme fault conditions. The proof process is taken in an AC-DC hybrid power grid integrated with large capacity of PV stations and wind farms. The on-site engineering test results reflect that RESs bring potential risks in the AC-DC hybrid power grid operation and validate the excellent engineering practical features of the proposed control strategy. In addition, test results also reveal predisposing factors of power system instability which are missing in the simulation and fault simulation device-based testing results. They prove the outstanding advantages of on-site engineering tests.


2013 ◽  
Vol 391 ◽  
pp. 291-294
Author(s):  
Xiao Ning Xu ◽  
Xue Song Zhou

In recent years, wind power in China developed rappidly. More and more problems occurred with the integration of large-scale wind power. Arounding the issues of power system stability which are resulted from the integration of wind power and ite relevant technology, this paper mainly introduced the voltage stability from the angle of the definition and the classification, and analyzed power systems which contains wind farms from the angle of the research contents and methods of static and dynamic voltage stability, especially emphasizing the necessity of the bifurcation theory used in power system contains wind power.


2014 ◽  
Vol 25 (4) ◽  
pp. 128-135 ◽  
Author(s):  
Othman Hasnaoui ◽  
Mehdi Allagui

The main causes of wind farms disconnection from the grid is the three-phase grid faults at the point common coupling (PCC) e.g. the voltage dip. The use of a Static Synchronous Compensator (STATCOM) which is from the family of Flexible AC Transmission System (FACTS) devices can be used effectively in a wind park based on FSIG to provide transient voltage and to improve wind system stability. Due to the asynchronous operation nature, system instability of wind farms based on FSIG (Fixed Speed Induction Generator) is largely caused by the reactive power absorption by FSIG because due to the large rotor slip during grid fault. STATCOM contributes to control the grid voltage at PCC and maintain wind farm connection to the grid during some severe conditions of grid faults and used for power flow control and for damping power system oscillations. The evaluation of this control strategy using (STATCOM) is investigated in terms of regulation reactive power and transient stability of the wind farm during grid disturbances.


2020 ◽  
Vol 10 (24) ◽  
pp. 9034
Author(s):  
Junji Tamura ◽  
Atsushi Umemura ◽  
Rion Takahashi ◽  
Atsushi Sakahara ◽  
Fumihito Tosaka ◽  
...  

The penetration level of large-scale wind farms into power systems has been increasing significantly, and the frequency stability and transient stability of the power systems during and after a network fault can be negatively affected. This paper proposes a new control method to improve the stability of power systems that are composed of large wind farms, as well as usual synchronous generators. The new method is a coordinated controlling method between an adjustable-speed pumping generator (ASG) and a battery. The coordinated system is designed to improve power system stability during a disconnection in a fixed-rotor-speed wind turbine with a squirrel cage-type induction generator (FSWT-SCIG)-based wind farm due to a network fault, in which a battery first responds quickly to the system frequency deviation due to a grid fault and improves the frequency nadir, and then the ASG starts to supply compensatory power to recover the grid frequency to the rated frequency. The performance of the proposed system was confirmed through simulation studies on a power system model consisting of usual synchronous generators (SGs), an ASG, a battery, and an SCIG-based wind farm. Simulation results demonstrated that the proposed control system can enhance the stability of the power system effectively.


2021 ◽  
Vol 16 (3) ◽  
pp. 245-250
Author(s):  
Giulio Lorenzini ◽  
Mehrdad Ahmadi Kamarposhti ◽  
Ahmed Amin Ahmed Solyman

Current methods to determine the wind farms maximum size do not consider the effect of new wind generation on the Voltage Stability Margins (VSMs). Installing wind power in one area may affect VSMs in other areas of the power system. Buses with high VSMs before wind power injection may be converted into weak buses after wind power injections in other parts of power systems, which may lead to limited future wind farms expansion in other areas. In this paper, two methods are proposed to determine two new wind farms maximum size in order to maximize wind power penetration level. In both methods, the size of any new wind farm is determined using an iterative process which is increased by a constant value. Proposed methods were used in the IEEE 14-bus power system. The results of applying these new methods indicate that the second method results in higher maximum sizes than the first method.


2011 ◽  
Vol 347-353 ◽  
pp. 791-794 ◽  
Author(s):  
Xiao Yan Bian ◽  
Guang Yue Li ◽  
Yang Fu

It’s a new challenge to power system stability with large wind farm’s integration. Taking the wind farm which consist of GE1.5MW double fed induction generators that has been modeled in the software PSS/E as the research object, The difference between the impact of wind farm and conventional generators integrated to grid in power system transient progress is analyzed. Besides, the impact on transient progress of increasing wind farm penetration and differnet interconnection with wind farm to power system is investigated.


Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 382
Author(s):  
Ronglin Ma ◽  
Yaozhen Han ◽  
Weigang Pan

Subsynchronous oscillation, caused by the interaction between the rotor side converter (RSC) control of the doubly fed induction generator (DFIG) and series-compensated transmission line, is an alleged subsynchronous control interaction (SSCI). SSCI can cause DFIGs to go offline and crowbar circuit breakdown, and then deteriorate power system stability. This paper proposes a novel adaptive super-twisting sliding mode SSCI mitigation method for series-compensated DFIG-based wind power systems. Rotor currents were constrained to track the reference values which are determined by maximum power point tracking (MPPT) and reactive power demand. Super-twisting control laws were designed to generate RSC control signals. True adaptive and non-overestimated control gains were conceived with the aid of barrier function, without need of upper bound of uncertainty derivatives. Stability proof of the studied closed-loop power system was demonstrated in detail with the help of the Lyapunov method. Time-domain simulation for 100 MW aggregated DFIG wind farm was executed on MATLAB/Simulink platform. Some comparative simulation results with conventional PI control, partial feedback linearization control, and first-order sliding mode were also obtained, which verify the validity, robustness, and superiority of the proposed control strategy.


Author(s):  
Xu Pei-Zhen ◽  
Lu Yong-Geng ◽  
Cao Xi-Min

Background: Over the past few years, the subsynchronous oscillation (SSO) caused by the grid-connected wind farm had a bad influence on the stable operation of the system and has now become a bottleneck factor restricting the efficient utilization of wind power. How to mitigate and suppress the phenomenon of SSO of wind farms has become the focus of power system research. Methods: This paper first analyzes the SSO of different types of wind turbines, including squirrelcage induction generator based wind turbine (SCIG-WT), permanent magnet synchronous generator- based wind turbine (PMSG-WT), and doubly-fed induction generator based wind turbine (DFIG-WT). Then, the mechanisms of different types of SSO are proposed with the aim to better understand SSO in large-scale wind integrated power systems, and the main analytical methods suitable for studying the SSO of wind farms are summarized. Results: On the basis of results, using additional damping control suppression methods to solve SSO caused by the flexible power transmission devices and the wind turbine converter is recommended. Conclusion: The current development direction of the SSO of large-scale wind farm grid-connected systems is summarized and the current challenges and recommendations for future research and development are discussed.


Sign in / Sign up

Export Citation Format

Share Document