scholarly journals Instantaneous Power Control Strategy for Voltage Improvement in Power Network Equipped by Wind Generator

2021 ◽  
Vol 54 (1) ◽  
pp. 147-154
Author(s):  
Issam Griche ◽  
Sabir Messalti ◽  
Kamel Saoudi

The uncertainty of wind power brings great challenges to large-scale wind power integration. The conventional integration of wind power is difficult to adapt the demand of power grid planning and operation. This paper proposes an instantaneous power control strategy for voltage improvement in power networks using wind turbine improving the dynamical response of power systems performances (voltage and transient stability) after fault. In which the proposed control algorithm based on a new advanced control strategy to control the injected wind power into power system. The efficiency of developed control strategy has been tested using IEEE 9 Bus. Simulation results have showed that the proposed method perform better to preserve optimal performances over wide range of disturbances for both considered scenarios studied short circuit and variable loads.

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2287
Author(s):  
Kaina Qin ◽  
Shanshan Wang ◽  
Zhongjian Kang

With the rapid increase in the proportion of the installed wind power capacity in the total grid capacity, the state has put forward higher and higher requirements for wind power integration into the grid, among which the most difficult requirement is the zero-voltage ride through (ZVRT) capability of the wind turbine. When the voltage drops deeply, a series of transient processes, such as serious overvoltage, overcurrent, or speed rise, will occur in the motor, which will seriously endanger the safe operation of the wind turbine itself and its control system, and cause large-scale off-grid accident of wind generator. Therefore, it is of great significance to improve the uninterrupted operation ability of the wind turbine. Doubly fed induction generator (DFIG) can achieve the best wind energy tracking control in a wide range of wind speed and has the advantage of flexible power regulation. It is widely used at present, but it is sensitive to the grid voltage. In the current study, the DFIG is taken as the research object. The transient process of the DFIG during a fault is analyzed in detail. The mechanism of the rotor overcurrent and DC bus overvoltage of the DFIG during fault is studied. Additionally, the simulation model is built in DIgSILENT. The active crowbar hardware protection circuit is put into the rotor side of the wind turbine, and the extended state observer and terminal sliding mode control are added to the grid side converter control. Through the cooperative control technology, the rotor overcurrent and DC bus overvoltage can be suppressed to realize the zero-voltage ride-through of the doubly fed wind turbine, and ensure the safe and stable operation of the wind farm. Finally, the simulation results are presented to verify the theoretical analysis and the proposed control strategy.


Energies ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3174
Author(s):  
Qiufang Zhang ◽  
Zheng Shi ◽  
Ying Wang ◽  
Jinghan He ◽  
Yin Xu ◽  
...  

Short-circuit faults in a receiving-end power system can lead to blocking events of the feed-in high-voltage direct-current (HVDC) systems, which may further result in system instability. However, security assessment methods based on the transient stability (TS) simulation can hardly catch the fault propagation phenomena between AC and DC subsystems. Moreover, effective emergency control strategies are needed to prevent such undesired cascading events. This paper focuses on power systems with multi-infeed HVDCs. An on-line security assessment method based on the electromagnetic transient (EMT)-TS hybrid simulation is proposed. DC and AC subsystems are modeled in EMTDC/PSCAD and PSS/E, respectively. In this way, interactions between AC and DC subsystems can be well reflected. Meanwhile, high computational efficiency is maintained for the on-line application. In addition, an emergency control strategy is developed, which coordinates multiple control resources, including HVDCs, pumped storages, and interruptible loads, to maintain the security and stability of the receiving-end system. The effectiveness of the proposed methods is verified by numerical simulations on two actual power systems in China. The simulation results indicate that the EMT-TS hybrid simulation can accurately reflect the fault propagation phenomena between AC and DC subsystems, and the coordinated emergency control strategy can work effectively to maintain the security and stability of systems.


Author(s):  
Li Yunwei ◽  
Yujun Zhang ◽  
Hua Liu

Aiming at a wide range and high-frequency reactive voltage fluctuation problem in 750kV power grid which due to large-scale wind power, a coordinated control strategy of a multiple FACTS (Flexible Alternative Current Transmission Systems) configuration is investigated in the paper. System-level and electromagnetic transient level control method of multiple FACTS devices are proposed in the small wind power fluctuation, big disturbance and off-grid level, and the priorities and the principles are determined. The strategy is applied to “Xinjiang and Northwest 750kV main grid interconnection second channel project”, and the correctness and effectiveness is proved.


2013 ◽  
Vol 448-453 ◽  
pp. 2185-2190 ◽  
Author(s):  
He Nan Dong ◽  
Yun Dong Song ◽  
Gang Wang ◽  
Zuo Xia Xing

The proportion of wind power in power systems is increasing year by year. Large-scale wind turbine off the grid when grid system failures. So the wind turbine needs to low voltage ride through (LVRT) function of wind turbine. Aiming at this problem, which in this article by DIgSILENT simulation software build 1.5MW doubly-fed wind turbine(DFIG) model, using active Crowbar and series grid side converter (SGSC) control strategy to realize the simulation of low voltage ride through of wind turbine. The control strategy of active Crowbar is mainly through the short circuit of rotor side converter to realize LVRT, and needs to be matched with the active and reactive power control strategy. SGSC is a novel converter structure, which mainly through compensating stator flux drop to realize LVRT. Finally this two kinds of control strategies were compared, demonstrated SGSC control strategy can achieve the low voltage ride through capabilities of the doubly-fed wind turbine.


Electricity ◽  
2020 ◽  
Vol 1 (1) ◽  
pp. 62-86
Author(s):  
Nikhil Kalloe ◽  
Jorrit Bos ◽  
Jose Rueda Torres ◽  
Mart van der Meijden ◽  
Peter Palensky

The last decade has seen an immense growth in renewable energy sources such as solar photovoltaic (PV) plants due to environmental concerns. Due to this rapid growth, solar PV plants are starting to have a larger influence on power system stability and thus their dynamic behavior cannot be ignored in stability studies. The lack of well-established models and parameter sets is the primary reason solar PV plants are not modeled with dynamic characteristics. This paper presents a method to define a standard parameter set for representing large-scale and aggregated solar PV plants in stability studies from the perspective of the transmission system operator (TSO). The method takes into account primarily the conditions provided in the grid connection requirements; for illustrative purposes, the connection requirements of the Netherlands are used. Additionally, a relationship defined as short-circuit current (SCC) PV ratio is proposed to estimate the effect of solar PV plants on transient stability. To illustrate the workings of the proposed ratio, the transmission network of the TenneT TSO B.V. in the Netherlands is used. The analysis demonstrated that high values of SCC PV ratio are an indicator that solar PV plants affect the transient stability while low values of SCC PV ratio showed that solar PV plants have minimal effect on the transient stability. Additionally, methods to improve the transient stability are provided which include limiting the operation regions of critical generators, increasing short-circuit ratio by adding a synchronous condenser or static compensator (STATCOM) and decreasing the reactance between the critical synchronous generator and faulted bus.


2021 ◽  
Vol 8 (1) ◽  
pp. 81-88
Author(s):  
Issam Griche ◽  
Sabir Messalti ◽  
Kamel Saoudi ◽  
Mohamed Yaakoub Touafek ◽  
Fares Zitouni

This paper proposes a new controller for stability and voltage improvement of power networks equipped by wind turbine which optimize the dynamical response of power systems performances (voltage and transient stability) after fault. The proposed control algorithm based on new Adaptive Neuro-Fuzzy Inference System (ANFIS) controller to enhance the mechanical power of the synchronous machine into power system. The efficiency of developed control strategy has been tested using IEEE 9 Bus. Simulation results have showed that the proposed method perform better performances over wide range of disturbances for three considered scenarios studied.


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