适应畸变电网的双馈风力发电系统控制策略研究

发布时间：2018-06-19 14:26

本文选题：双馈风力发电 + 双馈变流器　；参考：《浙江大学》2014年博士论文

【摘要】：风力发电机组装机容量不断扩大,使得风力发电系统的输出电能质量和并网运行的安全可靠性受到越来越多的关注。我国的大型风电场大多安装在大电网的末端,所接入环境为弱电网环境,常存在电压不平衡、谐波畸变等非理想状况。为维持电网可靠性和稳定性、风力发电机组运行安全性,我国风电并网标准《风电场接入电力系统技术规定》和《风电场接入电网技术规定》均要求在电网不平衡及谐波畸变下,接入电网的风电系统能持续不脱网运行,且输出电能质量符合相关标准。考虑我国实际情况,本文对应用最为广泛的双馈异步感应(doubly fed induction generator, DFIG)风电机组在不平衡及谐波畸变电网下的增强运行控制展开研究。论文的研究重点为：1)谐波畸变电网下DFIG风电系统矢量控制性能评估及改进矢量控制方案；2)不平衡及谐波畸变电网下DFIG风电系统积分滑模控制性能评估及谐振滑模控制方案。主要研究内容和贡献有： 1)建立了谐波畸变电网下DFIG风电系统的数学模型,描述了该电网条件下DFIG风电系统的电流、功率、转矩等。分析了该电网下,传统矢量控制中滤波器参数及控制器参数对机侧变流器(rotor side converter, RSC)和网侧变流器(gridside converter, GSC)谐波抑制能力的影响,证明了DFIG风电系统传统矢量控制在谐波畸变电网下的局限性,并通过仿真和实验进行了验证。 2)提出了谐波畸变电网条件下包括GSC和RSC的DFIG风电系统的改进矢量控制策略。针对GSC,提出了基于比例-积分-谐振(proportional integral resonant,PIR)电流控制器的改进矢量控制方案,实现输出电流正弦或输出有功功率和无功功率平稳无脉动两个辅助控制目标。针对RSC,提出基于定子电流谐振闭环的改进矢量控制策略,实现转子电流正弦、定子电流正弦、消除定子有功功率和无功功率脉动、消除电机电磁转矩和定子无功功率脉动等4个辅助控制目标。进而提出基于改进矢量控制的DFIG风电系统协同控制方案,实现DFIG电磁转矩平稳、系统输出电流正弦或者系统输出功率平稳2个辅助控制目标。针对以上所提控制策略,进行了仿真和实验验证。 3)为了增强模型参数变化下DFIG风电系统的鲁棒性,分别设计GSC和RSC的积分滑模控制方案,并给出控制参数选取原则。然后对不平衡及谐波电网下积分滑模控制性能进行评估,证明了积分滑模控制在不平衡及谐波畸变电网下无法实现无静差控制。最后,通过仿真和实验进行了验证。 4)为消除积分滑模控制在不平衡及谐波电网下的跟踪误差,在滑动面方程中加入相应的谐振项,提出了GSC及DFIG谐振滑模控制策略。对GSC谐振滑模控制方案提出了输出电流正弦、输出有功功率和无功功率平稳无脉动两个辅助控制目标及其参考计算；对DFIG谐振滑模控制方案提出了定子电流正弦、定子有功功率和无功功率平稳无脉动、DFIG电磁转矩和定子无功功率平稳无脉动等三个辅助控制目标及其参考计算,并对所提谐振滑模控制策略进行了实验验证。
[Abstract]:The capacity of the wind generator assembly machine is expanding, which makes the output power quality of the wind power generation system and the safety and reliability of the grid connected operation more and more attention. Most of the large wind farms in our country are installed at the end of the large power grid, and the access environment is weak electric network environment, which often exists in the non ideal state of voltage imbalance, harmonic distortion and so on. In order to maintain the reliability and stability of the power grid and the safety of the wind turbine, the standard of the wind power grid connected to the power system of China, the technical regulations of the wind farm access to the power system and the provisions of the wind electric field access to the power grid require that the wind power system connected to the power grid can not be removed continuously and the output power quality is consistent with the power grid unbalance and harmonic distortion. Relevant standards. Considering the actual situation of our country, this paper studies the enhanced operation control of the doubly fed induction generator, DFIG (DFIG) wind turbine under unbalanced and harmonic distortion power grid. The focus of this paper is as follows: 1) the vector control performance evaluation of DFIG wind power system under the harmonic distortion power grid and the evaluation of the vector control performance. Improved vector control scheme; 2) integrated sliding mode control performance evaluation and resonant sliding mode control scheme for DFIG wind power system under unbalanced and harmonic distortion. The main research contents and contributions are as follows:
1) the mathematical model of the DFIG wind power system under the harmonic distortion power grid is established, and the current, power and torque of the DFIG wind power system under the power grid are described. The filter parameters and controller parameters in the traditional vector control are analyzed for the rotor side converter (RSC) and the network side converter (gridside converter, GSC). The influence of harmonic suppression capability proves the limitation of traditional vector control of DFIG wind power system under harmonic distortion power grid, and is verified by simulation and experiment.
2) an improved vector control strategy for DFIG wind power system with GSC and RSC is proposed under the harmonic distortion power grid. An improved vector control scheme based on proportional integral resonance (proportional integral resonant, PIR) current controller is proposed for GSC, and the output current sinusoidal or output active power and reactive power are smooth and non pulsating. Two auxiliary control targets. Based on the RSC, an improved vector control strategy based on the stator current resonance closed loop is proposed to realize the sinusoidal current of the rotor, the sinusoidal current of the stator, the elimination of the stator active power and the reactive power pulsation, the elimination of the motor electromagnetic torque and the stator reactive power pulsation, and the improvement of the vector control based on the improved vector control. The coordinated control scheme of the DFIG wind power system makes the DFIG electromagnetic torque smooth, the system output current sinusoidal or the system output power smooth 2 auxiliary control targets.
3) in order to enhance the robustness of DFIG wind power system under the change of model parameters, the integral sliding mode control scheme of GSC and RSC is designed respectively, and the principle of selecting control parameters is given. Then the performance of integral sliding mode control under unbalance and harmonic grid is evaluated. It is proved that the integral sliding mode control can not be realized under unbalance and harmonic distortion power grid. Finally, simulation and experiment are carried out to verify the static error control.
4) in order to eliminate the tracking error of the integral sliding mode control under the unbalanced and harmonic grid, the GSC and DFIG resonant sliding mode control strategy is put forward in the sliding surface equation. The output current sine, the output active power and the reactive power and the steady and unpulsating two auxiliary control targets are proposed for the GSC resonant sliding mode control scheme. The three auxiliary control targets, such as the stator current sinusoidal, the stator active power and the reactive power steady and non pulsating, the DFIG electromagnetic torque and the stator reactive power steady and non pulsating, are proposed for the DFIG resonant sliding mode control scheme, and the experimental verification of the proposed resonant sliding mode control strategy is also carried out.
【学位授予单位】：浙江大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TM614

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