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1.
《Energy Conversion, IEEE Transaction on》2009,24(3):650-660
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《Energy Conversion, IEEE Transaction on》2008,23(4):1073-1081
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An input‐output linearization–based control strategy for wind energy conversion system to enhance stability 下载免费PDF全文
This paper proposes a novel control strategy for doubly fed induction generator (DFIG)‐based wind energy conversion system to investigate the potential of enhancing the stability of wind energy transmission system, a synchronous generator weakly integrated to a power system with a DFIG‐based wind farm. The proposed approach uses state feedback to exactly linearize the nonlinear wind energy transmission system from control actions (active power and reactive power control order of DFIG) to selected outputs (power angle and voltage behind transient resistance of synchronous generator) at first. Then, on account of the linearized subsystem, the stability enhancement controller is designed based on linear quadratic regulator algorithm to contribute adequate damping characteristics to oscillations of the synchronous generator system under various operation points. The proposed control strategy successfully deals with the nonlinear behaviors exist from the inputs to outputs and improve the robustness with respect to the variation of system operation points. Furthermore, not only the rotor angle stability but also the voltage stability is enhanced by using the proposed control strategy. The simulation results carried on the studied system verify the effectiveness of the proposed control strategy of wind energy conversion system for system stability enhancement and the robustness against various system operation points. 相似文献
4.
A new control strategy is investigated for Doubly Fed Induction Generators (DFIGs). It exercises control over the generator terminal voltage and output power by adjusting the magnitude and angle of the rotor flux vector. It is shown that this control strategy leads to low interaction between the power and voltage control loop, better system damping and voltage recovery following faults, and it also provides enhanced frequency regulation capability compared with that achieved with existing DFIG controllers described in the open literature. The dynamic performance of the proposed DFIG control is tested for small and large disturbances using a generic network that combines wind and conventional synchronous generation. Simulation results are presented and discussed that demonstrate the capabilities of the new strategy to enhance DFIG performance and its contribution to network operation. 相似文献
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To mitigate subsynchronous control interaction (SSCI) in doubly fed induction generator (DFIG)‐based wind farm, this paper proposes a robust controller for rotor‐side converter (RSC) using fractional‐order sliding mode controller (FOSMC). The proposed FOSMC can improve robustness and convergence properties of the controlled system, thus achieving SSCI damping under various operating conditions. Impedance‐based analysis and time‐domain simulation are performed to check the capability of the designed FOSMC as compared with conventional sliding mode control (SMC) and subsynchronous damping control (SSDC). Simulation results demonstrate that FOSMC can mitigate SSCI within shorter time and effectively reduce the fluctuation range of system transient responses under various operating conditions of wind speeds and compensation levels. Moreover, FOSMC also improves system robustness against parameter uncertainties and external disturbances, which is important for safe operation of realistic wind farms. 相似文献
6.
Coordinated Reactive Power Control of a Large Wind Farm and a STATCOM Using Heuristic Dynamic Programming 总被引:1,自引:0,他引:1
《Energy Conversion, IEEE Transaction on》2009,24(2):493-503
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《Energy Conversion, IEEE Transaction on》2009,24(4):905-915
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Mohamed S. El‐Moursi 《风能》2010,13(7):633-655
This paper addresses the design and implementation of the line drop secondary voltage control (LDSVC) for the doubly fed induction generator‐wind turbine (DFIG‐WT) complemented with reactive power allocation algorithm to achieve more efficient voltage regulation, reactive power compensation and to enhance the transient stability margin of the electric power system. The LDSVC is used to generate the local voltage reference, providing an improvement for overall voltage profile. The paper presents the influence of the integration of variable speed wind turbines‐based doubly fed induction generator (DFIG) while employing LDSVC for increasing the transient stability margin. This paper proposes an improved voltage control scheme, based on a secondary voltage controller complemented with an automatic gain controller (AGC). The scheme is applied to a wind energy system incorporating DFIG‐based wind turbines. The controller structure is developed and the performance of the self‐tuning AGC scheme is developed and analysed. The proposed controller is tested in response to system contingencies for different short circuit ratios. The performance of the secondary voltage control without and with AGC is verified. The influence of the AGC in improving the transient response and damping of voltage oscillations is verified. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
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The stability of a doubly-fed induction generator (DFIG) under vector control in stator voltage orientation (SVO) is investigated. Prior art has tended to assume that the inner current loop dynamics can be neglected when an SVO is employed. As a result, the poorly damped poles of the DFIG system were considered unaffected by the inner current loop tuning. The state-space model of the machine including the inner current closed loop dynamics is developed for schemes where different feed-forward compensation terms are used. The interaction between inner current loop dynamics and damping of the critical poles of the system is illustrated through analysis and simulation. The main outcome of the analysis is that the stability of the machine system in an SVO depends solely on the parameters of the proportional-integral controllers. Erroneous tuning can lead to instability, irrespective of the particular feed-forward compensation scheme, which could cause the disconnection of the machine as a result of rotor current oscillations of unacceptable magnitude in an actual case. The main contribution is to provide the necessary methodology in order to ensure the stable operation of a DFIG under SVO vector control. 相似文献
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The results of a comparative study on the application of two countermeasures, i.e. the excitation controller and the static VAr compensator (SVC), for damping of subsynchronous resonance (SSR) are presented. To stabilize all the SSR modes, a unified approach based on modal control theory is proposed for the design of the excitation controller and the SVC, which are essentially dynamic output feedback compensators. The two damping schemes differ in the way they modulate the reactive power flow in the system to damp out the subsynchronous oscillations. To demonstrate the effectiveness of the proposed damping schemes under disturbance conditions, time-domain simulations based on a nonlinear system model are also performed. The relative merits of the two countermeasures are compared with respect to their validities under various loading conditions and different degrees of series compensations and their capabilities to expand the stable region on the real-capacitive reactance plane 相似文献
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DFIG sliding mode control fed by back-to-back PWM converter with DC-link voltage control for variable speed wind turbine 总被引:1,自引:1,他引:0
This paper proposes an indirect power control of doubly fed induction generator (DFIG) with the rotor connected to the electric grid through a back-to-back pulse width modulation (PWM) converter for variable speed wind power generation. Appropriate state space model of the DFIG is deduced. An original control strategy based on a variable structure control theory, also called sliding mode control, is applied to achieve the control of the active and reactive power exchanged between the stator of the DFIG and the grid. A proportional-integral-(PI) controller is used to keep the DC-link voltage constant for a back-to-back PWM converter. Simulations are conducted for validation of the digital controller operation using Matlab/Simulink software. 相似文献
13.
着重研究双馈感应电机在电网电压不平衡条件下的不间断运行控制问题。利用对称分量法将三相不对称向量分解成正序、负序、零序分量给出的电网电压不平衡情况下的双馈感应电机数学模型,使用非线性自适应控制技术综合设计了电机转子电压的鲁棒自适应控制器。理论分析和仿真研究表明,即使在系统参数和外部干扰存在的情况下,设计的控制器仍可以保证:系统安全可靠的运行、最大风能跟踪、输出恒压恒频的电流以及电网电压不平衡情况下的电机不间断运行。 相似文献
14.
Influence of Tower Shadow and Wind Turbulence on the Performance of Power System Stabilizers for DFIG-Based Wind Farms 总被引:1,自引:0,他引:1
Hughes F.M. Anaya-Lara O. Ramtharan G. Jenkins N. Strbac G. 《Energy Conversion, IEEE Transaction on》2008,23(2):519-528
The aim of the paper is to demonstrate the way in which mechanical power variations, due to tower shadow and wind turbulence, influence control performance of power system stabilizer (PSS) loops for doubly-fed induction generators (DFIGs). The PSS auxiliary loops are applied on a specific DFIG control scheme, the flux magnitude and angle controller (FMAC). However, since the PSS signal is applied at the output of the basic controller, the PSS performance characteristics displayed are deemed typical for DFIG control schemes in general. The relative capabilities of PSS controllers based on stator power, rotor speed, and network frequency, when the DFIG turbine is subjected to aerodynamic torque variations, are investigated via simulation studies. A two-generator aggregate model of a wind farm is introduced, which enables the influence of tower shadow and wind turbulence on both an individual turbine and on the overall wind farm itself to be assessed. 相似文献
15.
张廷营 《电网与水力发电进展》2013,29(11):49-54
针对静止同步补偿器(STATCOM)在抑制次同步谐振(SSR)方面的理论与应用进行了研究。分析了STATCOM抑制SSR的基本工作原理;提出了STATCOM抑制SSR的控制策略,并设计了相应的控制器,以IEEE第一标准模型为例,采用特征值分析和时域仿真分析2种方法验证STATCOM对SSR的抑制效果。此外,利用PSCAD/EMTDC电磁暂态仿真软件,建立了锦界电厂串补送出系统的电磁暂态仿真平台,并进行了相应的仿真分析。仿真结果表明,STATCOM~有效抑制SSR的发生,为解决国内外交流串补输电工程中的SSR问题提供了参考,也为STATCOM装置的应用提供了依据。 相似文献
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Inertia emulation methods exist to compensate for the reduced inertial support provided by doubly fed induction generator (DFIG) based wind turbines. Instead of emulating inertia, this paper proposes to temporarily convert DFIGs to synchronous generators, enabling supply of real inertia to the system. In order to achieve this, the voltage supplied to the DFIG rotor needs to be made independent of the grid frequency. Feeding the rotor with a fixed dc voltage while it is rotating at synchronous speed enables the DFIG to operate in synchronism with the grid and couple the inertia of its rotating mass to the power system. The rotor side converter of a DFIG can be controlled to function as the dc voltage source, allowing convenient switching between the two operation modes according to system requirements. 相似文献
17.
Quantitative and qualitative behavior analysis of a DFIG wind energy conversion system by a wind gust and converter faults 下载免费PDF全文
A wind gust can cause severe dynamic conditions that affect the operational behavior of the whole doubly fed induction generator (DFIG) wind energy conversion system and, as a result, the quality of power exchanged with the grid. In addition, it can cause great disturbances to critical system's variables with possible damages to the system's construction—to mechanical or electrical part. The knowledge of DFIG reaction in such conditions is useful for both protection issues and the risk assessment concerning system's tolerance, maintenance costs and revenue losses, because of the disconnection from the grid. In this paper, a quantitative and qualitative behavior analysis of a 2 MW DFIG wind energy conversion system under a wind gust and converter faults, which has been carried out via simulation, is presented. The pitch controller parameters impact to its behavior, when a gust appears, has been investigated. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
18.
《Energy Conversion, IEEE Transaction on》2009,24(1):137-145
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Wang Li Lee Ching-Huei 《Energy Conversion, IEEE Transaction on》1991,6(3):373-380
Results of a study on the application of shunt reactors for the damping of torsional oscillations that occur in a power system containing series-capacitor compensation are presented. The IEEE Second Benchmark Model, system-1 is used to investigate the benefits of the utilization of modulated reactive power in suppressing unstable subsynchronous resonance (SSR) modal interactions. A set of shunt reactors is connected to the generator bus of the affected synchronous machine whose shaft is directly coupled to the turbine system of the benchmark model. In order to stabilize all the torsional modes, a unified approach based on modal control theory is proposed for the design of a shunt reactor controller, which is essentially a dynamic output compensator. To demonstrate the effectiveness of the damping enhanced by the proposed scheme, eigenvalue analysis for different loading conditions and sensitivity analysis for controller parameters are performed 相似文献
20.
《Energy Conversion, IEEE Transaction on》2009,24(4):875-883