scholarly journals Optimal Transient Search Algorithm-Based PI Controllers for Enhancing Low Voltage Ride-Through Ability of Grid-Linked PMSG-Based Wind Turbine

Electronics ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1807
Author(s):  
Mohammed H. Qais ◽  
Hany M. Hasanien ◽  
Saad Alghuwainem

This paper depicts a new attempt to apply a novel transient search optimization (TSO) algorithm to optimally design the proportional-integral (PI) controllers. Optimal PI controllers are utilized in all converters of a grid-linked permanent magnet synchronous generator (PMSG) powered by a variable-speed wind turbine. The converters of such wind energy systems contain a generator-side converter (GSC) and a grid-side inverter (GSI). Both of these converters are optimally controlled by the proposed TSO-based PI controllers using a vector control scheme. The GSC is responsible for regulating the maximum power point, the reactive generator power, and the generator currents. In addition, the GSI is essentially controlled to control the point of common coupling (PCC) voltage, DC link voltage, and the grid currents. The TSO is applied to minimize the fitness function, which has the sum of these variables’ squared error. The optimization problem’s constraints include the range of the proportional and integral gains of the PI controllers. All the simulation studies, including the TSO code, are implemented using PSCAD software. This represents a salient and new contribution of this study, where the TSO is coded using Fortran language within PSCAD software. The TSO-PI control scheme’s effectiveness is compared with that achieved by using a recent grey wolf optimization (GWO) algorithm–PI control scheme. The validity of the proposed TSO–PI controllers is tested under several network disturbances, such as subjecting the system to balanced and unbalanced faults. With the optimal TSO–PI controller, the low voltage ride-through ability of the grid-linked PMSG can be further improved.

Author(s):  
Sayyed Ali Akbar Shahriari ◽  
Mohammad Mohammadi ◽  
Mahdi Raoofat

Purpose The purpose of this study is to propose a control scheme based on state estimation algorithm to improve zero or low-voltage ride-through capability of permanent magnet synchronous generator (PMSG) wind turbine. Design/methodology/approach Based on the updated grid codes, during and after faults, it is necessary to ensure wind energy generation in the network. PMSG is a type of wind energy technology that is growing rapidly in the network. The control scheme based on extended Kalman filter (EKF) is proposed to improve the low voltage ride-through (LVRT) capability of the PMSG. In the control scheme, because the state estimation algorithm is applied, the requirement of DC link voltage measurement device and generator speed sensor is removed. Furthermore, by applying this technique, the extent of possible noise on measurement tools is reduced. Findings In the proposed control scheme, zero or low-voltage ride-through capability of PMSG is enhanced. Furthermore, the requirement of DC link voltage measurement device and generator speed sensor is removed and the amount of possible noise on the measurement tools is minimized. To evaluate the ability of the proposed method, four different cases, including short and long duration short circuit fault close to PMSG in the presence and absence of measurement noise are studied. The results confirm the superiority of the proposed method. Originality/value This study introduces EKF to enhance LVRT capability of a PMSG wind turbine.


Complexity ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Mojtaba Nasiri ◽  
Saleh Mobayen ◽  
Quan Min Zhu

In recent years, the complexities of wind turbine control are raised while implementing grid codes in voltage sag conditions. In fact, wind turbines should stay connected to the grid and inject reactive power according to the new grid codes. Accordingly, this paper presents a new control algorithm based on super-twisting sliding mode for a gearless wind turbine by a permanent magnet synchronous generator (PMSG). The PMSG is connected to the grid via the back-to-back converter. In the proposed method, the machine side converter regulates the DC-link voltage. This strategy improves low-voltage ride through (LVRT) capability. In addition, the grid side inverter provides the maximum power point tracking (MPPT) control. It should be noted that the super-twisting sliding mode (STSM) control is implemented to effectively deal with nonlinear relationship between DC-link voltage and the input control signal. The main features of the designed controller are being chattering-free and its robustness against external disturbances such as grid fault conditions. Simulations are performed on the MATLAB/Simulink platform. This controller is compared with Proportional-Integral (PI) and the first-order sliding mode (FOSM) controllers to illustrate the DC-link voltage regulation capability in the normal and grid fault conditions. Then, to show the MPPT implementation of the proposed controller, wind speed is changed with time. The simulation results show designed STSM controller better performance and robustness under different conditions.


Micromachines ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 39
Author(s):  
Chao-Tsung Ma ◽  
Zong-Hann Shi

As the penetration of renewable energy power generation, such as wind power generation, increases low-voltage ride-through (LVRT), control is necessary during grid faults to support wind turbine generators (WTGs) in compensating reactive current to restore nominal grid voltages, and maintain a desired system stability. In contrast to the commonly used centralized LVRT controller, this study proposes a distributed control scheme using a LVRT compensator (LVRTC) capable of simultaneously performing reactive current compensation for doubly-fed induction generator (DFIG)-, or permanent magnet synchronous generator (PMSG)-based WTGs. The proposed LVRTC using silicon carbide (SiC)-based inverters can achieve better system efficiency, and increase system reliability. The proposed LVRTC adopts a digital control scheme and dq-axis current decoupling algorithm to realize simultaneous active/reactive power control features. Theoretical analysis, derivation of mathematical models, and design of the control scheme are initially conducted, and simulation is then performed in a computer software environment to validate the feasibility of the system. Finally, a 2 kVA small-scale hardware system with TI’s digital signal processor (DSP) as the control core is implemented for experimental verification. Results from simulation and implementation are in close agreement, and validate the feasibility and effectiveness of the proposed control scheme.


Energies ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 5442
Author(s):  
Liang Yuan ◽  
Ke Meng ◽  
Jingjie Huang ◽  
Zhao Yang Dong ◽  
Wang Zhang ◽  
...  

Various challenges are acknowledged in practical cases with high wind power penetration. Fault ride-through (FRT) capability has become the most dominant grid integration requirements for the wind energy conversion system worldwide. The high voltage ride-through (HVRT) and low voltage ride-through (LVRT) performance play a vital role in the grid-friendly integration into the system. In this paper, a coordinated HVRT and LVRT control strategy is proposed to enhance the FRT capability of the permanent magnet synchronous generator (PMSG)-based wind turbine generators (WTG). A dual-mode chopper protection is developed to avoid DC-link overvoltage, and a deadband protection is proposed to prevent oscillations under edge voltage conditions. The proposed strategy can ride through different levels of voltage sags or swells and provide auxiliary dynamic reactive power support simultaneously. The performance of the proposed control scheme is validated through various comparison case tests in PSCAD/EMTDC.


2013 ◽  
Vol 732-733 ◽  
pp. 1184-1187
Author(s):  
Guo Liang Yang ◽  
Shuo Yang Liu ◽  
Xin Yan Chang ◽  
En Bei Zhang

The structure of the uncontrolled rectifier + Boost circuit + PWM inverter is taken for direct-drive permanent magnet synchronous generator (PMSG) wind-power system. on the basis of the analysis for two different traditional control strategies for the grid side converter, a new control strategy Based on active and reactive power for the low voltage ride through running is proposed and described in detail. The simulation results verify that the given control strategy can be better to provide a reliable guarantee for the system low voltage ride through capability and to provide some reference for the actual control system design.


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