三相负载不平衡有源补偿装置研究
发布时间：2018-11-20 14:54
【摘要】：在低压配电网中,系统用户侧大多都是单相负荷,且用电具有不同时性,配电系统极易出现三相不平衡问题,对电能质量产生了严重影响。目前针对不平衡补偿的有源装置的研究大多为三相三线制,只能消除负序电流,而不治理零序电流。因此对三相四线制负载不平衡补偿装置研究,对改善电能质量及配电网的安全稳定运行有重大现实意义。本文以三相四线制负载不平衡有源调节装置为研究对象,针对不平衡电流检测、电网同步算法、调制算法、电流跟踪控制算法等关键问题进行了研究。针对三相四线制负载不平衡的特点,实现补偿负序电流的同时也能补偿中性线上的零序电流,选择了四桥臂的变流器作为装置的拓扑结构,滤波器使用四支路的LCL滤波器,并对此模型进行了数学建模和分析,给出了LCL滤波器参数的设计方法。为了解决负载不平衡电流解耦问题,本文从抗干扰能力的角度分析比较了陷波器法、延时信号法和基于二阶广义积分器的解耦法三种方法,证明了基于二阶广义积分的解耦法抗干扰能力较强、稳定性较好,适用于补偿装置。仿真结果表明该方法能实现负载不平衡电流基波正序、负序和零序分量的快速零误差解耦。针对电网不平衡工况下传统锁相环性能不佳的问题,本文从锁相精度和动态响应速度的角度研究了基于双同步坐标系解耦的电网同步算法和基于二阶广义积分的电网同步算法。针对系统动态响应速度慢的缺点,本文进行了改进,即SOGI-αβ混合电网同步算法。分析了锁相环的线性模型及系统的稳定性,并对系统进行了参数设计。仿真和试验结果表明改进的算法,能快速准确锁定电网电压相位,且有较强的抗干扰能力。针对四桥臂变流器有开关状态多,电压调制算法复杂的特点,本文设计了三维空间矢量脉宽调制算法,仿真结果表明该算法调制得到的输出电压与参考电压一致。补偿装置的控制策略是本文的研究重点,为了提高控制系统的性能,本文在满足系统稳定性前提下,针对传统重复控制器动态响应速度慢的缺点提出改进方案,在传统重复控制器上加了比例控制器,经过改进后的重复控制器有很好的指令电流跟踪能力,可以在含有谐波的指令信号中准确的跟踪基波信号。此外还设计了电压环控制器参数,直流母线电容参数及系统的硬件。最后通过仿真和实验验证了系统的正确性和有效性。
[Abstract]:In the low-voltage distribution network, most of the system users are single-phase load, and the power consumption is different, distribution system is easy to appear three-phase imbalance problem, which has a serious impact on the power quality. At present, most of the researches on unbalanced compensator are three-phase three-wire system, which can only eliminate the negative sequence current, but not the zero sequence current. Therefore, it is of great practical significance to study the three-phase four-wire load imbalance compensation device to improve the power quality and the safe and stable operation of the distribution network. In this paper, the three-phase four-wire load unbalanced active regulating device is taken as the research object. The key problems such as unbalanced current detection, power grid synchronization algorithm, modulation algorithm and current tracking control algorithm are studied. In view of the unbalanced load of three-phase four-wire system, the negative sequence current can be compensated and the zero sequence current on the neutral line can be compensated. The converter of the four-arm is chosen as the topology of the device. The filter uses four-branch LCL filter. The model is modeled and analyzed, and the design method of LCL filter parameters is given. In order to solve the problem of load unbalance current decoupling, this paper analyzes and compares three methods: notch method, delay signal method and decoupling method based on second-order generalized integrator from the point of view of anti-jamming ability. It is proved that the decoupling method based on the second order generalized integral has strong anti-interference ability and good stability. It is suitable for the compensator. The simulation results show that the proposed method can decouple the zero error of the fundamental sequence, the negative sequence and the zero sequence component of the load unbalance current. In order to solve the problem of poor performance of traditional phase-locked loop (PLL) under unbalanced condition, this paper studies the synchronization algorithm based on the decoupling of double synchronous coordinate system and the power system synchronization algorithm based on second-order generalized integral from the point of view of phase-locked precision and dynamic response speed. Aiming at the shortcoming of slow dynamic response, this paper improves the synchronization algorithm of SOGI- 伪 尾 hybrid power system. The linear model of PLL and the stability of the system are analyzed, and the system parameters are designed. The simulation and experimental results show that the improved algorithm can lock the voltage phase of the power system quickly and accurately, and has strong anti-interference ability. In view of the multi-switching state and complex voltage modulation algorithm of the four-arm converter, a three-dimension space vector pulse width modulation algorithm is designed in this paper. The simulation results show that the output voltage obtained by the algorithm is consistent with the reference voltage. The control strategy of the compensator is the focus of this paper. In order to improve the performance of the control system, in order to improve the performance of the control system, this paper, on the premise of satisfying the stability of the system, puts forward an improved scheme aiming at the shortcoming of the slow dynamic response speed of the traditional repetitive controller. A proportional controller is added to the traditional repetitive controller. The improved repetitive controller has a good command current tracking ability and can accurately track the fundamental signal in the instruction signal containing harmonics. In addition, the parameters of voltage loop controller, DC bus capacitance and the hardware of the system are also designed. Finally, the correctness and validity of the system are verified by simulation and experiment.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM761.12
本文编号：2345206
[Abstract]:In the low-voltage distribution network, most of the system users are single-phase load, and the power consumption is different, distribution system is easy to appear three-phase imbalance problem, which has a serious impact on the power quality. At present, most of the researches on unbalanced compensator are three-phase three-wire system, which can only eliminate the negative sequence current, but not the zero sequence current. Therefore, it is of great practical significance to study the three-phase four-wire load imbalance compensation device to improve the power quality and the safe and stable operation of the distribution network. In this paper, the three-phase four-wire load unbalanced active regulating device is taken as the research object. The key problems such as unbalanced current detection, power grid synchronization algorithm, modulation algorithm and current tracking control algorithm are studied. In view of the unbalanced load of three-phase four-wire system, the negative sequence current can be compensated and the zero sequence current on the neutral line can be compensated. The converter of the four-arm is chosen as the topology of the device. The filter uses four-branch LCL filter. The model is modeled and analyzed, and the design method of LCL filter parameters is given. In order to solve the problem of load unbalance current decoupling, this paper analyzes and compares three methods: notch method, delay signal method and decoupling method based on second-order generalized integrator from the point of view of anti-jamming ability. It is proved that the decoupling method based on the second order generalized integral has strong anti-interference ability and good stability. It is suitable for the compensator. The simulation results show that the proposed method can decouple the zero error of the fundamental sequence, the negative sequence and the zero sequence component of the load unbalance current. In order to solve the problem of poor performance of traditional phase-locked loop (PLL) under unbalanced condition, this paper studies the synchronization algorithm based on the decoupling of double synchronous coordinate system and the power system synchronization algorithm based on second-order generalized integral from the point of view of phase-locked precision and dynamic response speed. Aiming at the shortcoming of slow dynamic response, this paper improves the synchronization algorithm of SOGI- 伪 尾 hybrid power system. The linear model of PLL and the stability of the system are analyzed, and the system parameters are designed. The simulation and experimental results show that the improved algorithm can lock the voltage phase of the power system quickly and accurately, and has strong anti-interference ability. In view of the multi-switching state and complex voltage modulation algorithm of the four-arm converter, a three-dimension space vector pulse width modulation algorithm is designed in this paper. The simulation results show that the output voltage obtained by the algorithm is consistent with the reference voltage. The control strategy of the compensator is the focus of this paper. In order to improve the performance of the control system, in order to improve the performance of the control system, this paper, on the premise of satisfying the stability of the system, puts forward an improved scheme aiming at the shortcoming of the slow dynamic response speed of the traditional repetitive controller. A proportional controller is added to the traditional repetitive controller. The improved repetitive controller has a good command current tracking ability and can accurately track the fundamental signal in the instruction signal containing harmonics. In addition, the parameters of voltage loop controller, DC bus capacitance and the hardware of the system are also designed. Finally, the correctness and validity of the system are verified by simulation and experiment.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM761.12
【参考文献】
相关期刊论文 前10条
1 曾祥君;胡京莹;王媛媛;熊婷婷;;基于柔性接地技术的配电网三相不平衡过电压抑制方法[J];中国电机工程学报;2014年04期
2 刘伟增;周洪伟;张磊;郭磊;梁欢迎;;电网不平衡条件下光伏并网控制策略研究[J];太阳能学报;2013年04期
3 王宝诚;伞国成;郭小强;邬伟扬;;分布式发电系统电网同步锁相技术[J];中国电机工程学报;2013年01期
4 胡鑫;韩崇伟;马捷;任海波;;参数辨识法与卡尔曼滤波法精对准实验研究[J];火炮发射与控制学报;2010年03期
5 李子欣;李耀华;王平;朱海滨;陈峻岭;谈龙成;刘丛伟;;PWM整流器在静止坐标系下的准直接功率控制[J];中国电机工程学报;2010年09期
6 许胜;赵剑锋;唐国庆;;一种DSTATCOM补偿指令电流的实时检测方法[J];电力电子技术;2009年11期
7 武健;何娜;徐殿国;;重复控制在并联有源滤波器中的应用[J];中国电机工程学报;2008年18期
8 魏学良;戴珂;方昕;康勇;;三相并联型有源电力滤波器补偿电流性能分析与改进[J];中国电机工程学报;2007年28期
9 娄奇鹤,高仕斌;三相变四相变压器在AT供电系统中的应用研究[J];中国电机工程学报;2005年01期
10 游小杰,李永东,Victor Valouch,郝瑞祥;并联型有源电力滤波器在非理想电源电压下的控制[J];中国电机工程学报;2004年02期
相关博士学位论文 前2条
1 周娟;四桥臂有源电力滤波器关键技术研究[D];中国矿业大学;2011年
2 邹振宇;多灵活交流输电控制器间交互影响分析及其协调控制研究[D];浙江大学;2006年
相关硕士学位论文 前2条
1 李王敏;电网不对称时静止无功发生器的控制策略的研究[D];合肥工业大学;2015年
2 杨静;不平衡电网下三相光伏并网逆变器控制策略研究[D];电子科技大学;2013年
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