Power electronic interfaced DG units: impact of control strategy on power system transient stability

Author(s):  
M. Reza
Energies ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1995 ◽  
Author(s):  
Peng Shen ◽  
Lin Guan ◽  
Zhenlin Huang ◽  
Liang Wu ◽  
Zetao Jiang

This paper proposes an active-current control strategy for large-scale wind turbines (WTs) to improve the transient stability of power systems based on a perturbation estimation (PE) approach. The main idea of this control strategy is to mitigate the generator imbalance of mechanical and electrical powers by controlling the active-current of WTs. The effective mutual couplings of synchronous generators and WTs are identified using a Kron-reduction technique first. Then, the control object of each WT is assigned based on the identified mutual couplings. Finally, an individual controller is developed for each WT using a PE approach. In the control algorithm, a perturbation state (PS) is introduced for each WT to represent the comprehensive effect of the nonlinearities and parameter variations of the power system, and then it is estimated by a designed perturbation observer. The estimated PS is employed to compensate the actual perturbation, and to finally achieve the adaptive control design without requiring an accurate system model. The effectiveness of the proposed control approach on improving the system transient stability is validated in the modified IEEE 39-bus system.


2014 ◽  
Vol 1008-1009 ◽  
pp. 197-201
Author(s):  
Jian Ping Liu ◽  
Chun Liu ◽  
Ting Rui Lu ◽  
Hai Yan Tang ◽  
Xin Shou Tian ◽  
...  

On the basic of deeply analyzing the characteristic of circulation economy power system with high penetration of wind power, and researching the model and transient characteristics of DFIG, the problem on transient stability of circulation economy power grid was given through simulating and analyzing the huolinhe circulation economy demonstration project on wind power consumed in the local in the paper. At last, an optimal control strategy of wind turbine based on circulation economy power system with high penetration of wind power was proposed.


Author(s):  
Antonio Griffo ◽  
Davide Lauria

Transient stability is recognized as a critical problem for modern electrical power systems, since the deregulation could involve more and more restricted margins. Continuous improvements in power electronics technology gives the possibility to improve significantly the dynamic behaviour. Recently, a great attention in the relevant literature has been paid to Superconducting Magnetic Energy Storage (SMES) devices, showing their intrinsic ability to improve power transmission capability. In the paper, a control strategy for these devices is derived starting from a Control Lyapunov function, thus determining reference values for SMES active and reactive powers injections, able to counteract the effects of large disturbances. Hence, a new topology of the power conditioning system for interfacing SMES device with a power system is proposed. Finally, a control law based upon quasi-sliding technique is employed for tracking the required active and reactive powers. In the last part of the paper an application is presented, with reference to a test system, allowing to outline the flexibility and the goodness of the proposed control strategy.


2013 ◽  
Vol 385-386 ◽  
pp. 1082-1085 ◽  
Author(s):  
Yan Juan Wu ◽  
Lin Chuan Li ◽  
Fang Zhang

In view of a serious threat for the transient stability of the power system being caused by the large-scale wind farms integration, and combining with advantages of STATCOM which can quickly restore the fault voltage and fastly, flexibly and smoothly compensate the reactive power, a method is proposed using STATCOM controller of to improve transient stability of the power system integrated by large-scale wind farms. The control strategy of the STATCOM controller uses adaptive double loop control. The role of the device to improvement transient stability of the power system is studied under the condition of serious fault. by simulation comparison with the condition without STATCOM controller installed at the same place. The simulation results show that the STATCOM controller can clearly improve transient stability of the power system integrated by large-scale wind farms.


2011 ◽  
Vol 48-49 ◽  
pp. 335-344
Author(s):  
Meng Zeng Cheng ◽  
Zhen Lan Dou ◽  
Xu Cai

In this paper, a control strategy for operation of rotor side converter (RSC) of Doubly Fed Induction Generators (DFIG) is developed by injecting reactive power into the grid in order to support the grid voltage during and after grid fault events. The novel nonlinear control method is based on differential geometry theory, and exact feedback linearization is applied for control system design of DFIG. Then the optimal control for the linearized system is obtained through introducing the linear quadratic regulator (LQR) design method. Simulation results on a single machine infinite bus power system show that the proposed nonlinear control method can inject reactive power to fault grid rapidly, reduce the oscillation of active power and improve the transient stability of power system.


Electronics ◽  
2021 ◽  
Vol 10 (19) ◽  
pp. 2437
Author(s):  
Md. Rifat Hazari ◽  
Effat Jahan ◽  
Mohammad Abdul Mannan ◽  
Narottam Das

This paper presents a new intelligent control strategy to augment the low-voltage ride-through (LVRT) potential of photovoltaic (PV) plants, and the transient stability of a complete grid system. Modern grid codes demand that a PV plant should be connected to the main power system during network disturbance, providing voltage support. Therefore, in this paper, a novel fuzzy logic controller (FLC) using the controlled cascaded strategy is proposed for the grid side converter (GSC) of a PV plant to guarantee voltage recovery. The proposed FLC offers variable gains based upon the system requirements, which can inject a useful amount of reactive power after a severe network disturbance. Therefore, the terminal voltage dip will be low, restoring its pre-fault value and resuming its operation quickly. To make it realistic, the PV system is linked to the well-known IEEE nine bus system. Comparative analysis is shown—using power system computer-aided design/electromagnetic transients including DC (PSCAD/EMTDC) software—between the conventional proportional–integral (PI) controller-based cascaded strategy and the proposed control strategy to authenticate the usefulness of the proposed strategy. The comparative simulation results indicate that the transient stability and the LVRT capability of a grid-tied PV system can be augmented against severe fault using the proposed FLC-based cascaded GSC controller.


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