电励磁直驱风力发电机并网控制技术研究

发布时间：2018-03-19 02:26

本文选题：风力发电　切入点：电励磁同步发电机　出处：《北京交通大学》2014年博士论文　论文类型：学位论文

【摘要】：摘要：直驱型风力发电机组因其具有可靠性高、传动效率高、故障穿越能力强、发电机与电网无直接耦合等优点,成为了风电领域重要的发展趋势。近年来,永磁直驱型风电机组成本受永磁材料的价格、储量等因素影响较大,从而使电励磁直驱型风电机组成为直驱型风电机组的又一个发展方向。本文围绕电励磁直驱型风力发电机并网控制技术展开理论研究,对并网逆变器和电励磁同步发电机(electrically excited synchronous generator, EESG)的控制策略进行了研究,取得了以下成果。 1.围绕并网逆变器的建模和电流控制性能进行了研究。在并网逆变器静止坐标系和同步旋转坐标系下的动态数学模型的基础上,研究了并网逆变器在同步旋转坐标系下的解耦PI控制和静止坐标系下的PR控制两种典型电流控制策略的特点。利用复矢量分析法对采用不同电流调节器时系统的解耦性能、跟随性能、抗扰性能进行了对比分析。对静止坐标系下基于PR电流调节器时系统的功率解耦性能进行了理论分析,得到了系统的功率耦合关系,并提出了通过改进传统PR调节器实现功率解耦的方法。最后,通过并网逆变器的仿真和实验结果验证了静止坐标系下采用改进型PR电流调节器可以实现系统有功功率和无功功率的解耦控制,改善系统的动态性能。 2.对不平衡电网条件下并网逆变器的控制策略进行了研究。利用对称分量法建立了直驱风力发电机系统中并网逆变器在不平衡电网电压条件下的数学模型。针对不平衡电网电压条件下实现并网逆变器与电网同步的问题,提出了一种基于降阶谐振调节器的锁频环(frequency-locked loop based on reduced order resonant controller, ROR-FLL)技术实现电网频率检测及不平衡电压的正、负序分离等,通过仿真和实验验证了ROR-FLL实现正负序分离、谐波及频率检测的可行性。采用提出的ROR-FLL,引入了通用正负序电流指令计算方法,得到了并网逆变器静止坐标系下基于PR电流调节器的不平衡控制策略。最后,提出了一种新型的电流调节器——比例积分降阶谐振(proportion integral plus reduced order resonant, PI-ROR)调节器,并将其应用到不平衡控制系统中进行不平衡电流的控制,得到了一种正向同步旋转坐标系下基于PI-ROR电流调节器的不平衡控制策略,通过仿真和实验验证了系统的稳态和动态性能。 3.围绕EESG的建模和磁链观测技术展开研究。建立EESG在静止坐标系、dq同步旋转坐标系和MT轴系下的动态数学模型的基础上,研究了EESG的不同磁链定向方法,给出了气隙磁链定向控制的原理,并设计了矢量控制系统。对EESG矢量控制系统中的磁链观测技术进行了研究,针对基于电压模型磁链观测器中纯积分环节的初始值、直流偏置、积分饱和等问题,提出了一种改进型二阶广义积分器(improved second-order generalized integrator, ISOGI)代替纯积分器,得到了一种基于ISOGI的电压模型磁链观测技术,并对其实现方法及性能进行了分析。最后,通过Matlab仿真和电励磁直驱型风力发电系统实验平台验证了基于ISOGI磁链观测器是可行性,且此方案在风力发电系统要求的频率范围具有较好的稳态及动态性能。 4.对电励磁直驱型风力发电机在短时超速情况下的弱磁控制进行了研究。首先,介绍了EESG弱磁控制的原理,规划出了EESG在恒转矩区和高速弱磁区的电流轨迹。其次,对基于动态定子磁链电流补偿的EESG定、转子综合弱磁控制方法的性能进行了分析,并通过仿真和实验进行了验证。接着,针对传统弱磁控制方法存在动态响应慢的问题,提出了两种改进的弱磁控制方案：基于“虚拟阻抗”的定、转子综合弱磁控制方案和基于变M轴电压单电流调节器的定、转子综合弱磁控制方案。最后,通过仿真和实验验证了所提弱磁控制方案能够加快弱磁控制的动态响应,可以应用于电励磁直驱型风力发电系统的短时超速工况下,保证风力发电系统在更宽的速度范围内可靠运行。
[Abstract]:Abstract: direct drive wind turbine because of its high reliability, high transmission efficiency, fault crossing ability, the advantages of the generator and power system without direct coupling, has become an important trend of the development of wind power industry. In recent years, the permanent magnet direct drive wind turbine cost by permanent magnetic material prices, reserves and other factors a greater impact, so that the electrical excitation has become a development direction of direct drive wind turbine direct drive wind turbine. This paper focuses on the electric excitation direct drive wind generator control technology to conduct theoretical research, on the inverter and electric excitation synchronous generator (electrically excited synchronous generator, EESG) of the control strategy for the research, the following results have been achieved.
Around 1. of the grid connected inverter modeling and current control performance are studied. Based on the dynamic mathematical model of the inverter in the stationary coordinate and synchronous rotation coordinates on the research of grid inverter in synchronous rotating coordinate decoupling PI control and static coordinates PR control of two kinds of typical control strategies of current characteristics. By using the complex vector analysis method of decoupling performance, using different current regulator system tracking performance and anti disturbance performance are analyzed. The static coordinate power decoupling performance PR current regulator system based on the theoretical analysis, the coupling relationship between the power system, and put forward the improvement of traditional the PR regulator to achieve power decoupling method. Finally, through the simulation and experimental results verify the inverter static coordinates by using the improved PR current regulator can The decoupling control of the active power and reactive power of the system is realized, and the dynamic performance of the system is improved.
2. of the unbalanced control strategy of grid connected inverter grid conditions were studied. A direct drive wind generator system in grid connected inverter under unbalanced grid voltage conditions mathematical model using the symmetrical component method. Aiming at the problem of implementation of grid connected inverter and grid synchronization under unbalanced grid voltage, proposes a frequency locked loop reduced order resonant regulator based on (frequency-locked loop based on reduced order resonant controller ROR-FLL) technology to realize frequency detection and unbalanced voltage of positive and negative sequence separation, through simulation and experimental validation of the ROR-FLL to achieve the separation of positive and negative sequence, the feasibility of detecting harmonic and frequency. By using the proposed ROR-FLL, introduced the general positive and negative the instruction sequence current calculation method, the unbalanced control strategy of PR current regulator based on the inverter static coordinate system. Finally, put forward A new current regulator - reduced order proportional integral (proportion integral plus reduced order resonance resonant, PI-ROR) regulator, and its application to the unbalanced control system for unbalanced current control, unbalanced control strategy based on the PI-ROR current regulator has a positive synchronous rotating coordinate system system, steady and dynamic performance was verified by simulation and experiment.
Study 3. the EESG modeling and flux observation technology. The establishment of EESG in the static coordinate system, based on the dynamic mathematical model of DQ synchronous rotating coordinate and MT axis on the research methods of different flux oriented EESG, present the principle of air gap flux oriented control, and the design of the vector control system. EESG flux vector control technology system were studied, the initial pure integrator of the voltage model flux observer based on the value of DC bias, the problem of integral saturation, this paper proposes an improved Nikai Hiroyoshi integrator (improved second-order generalized integrator, ISOGI) instead of pure integrator, get a voltage model flux observer based on ISOGI, and the realization method and performance are analyzed. Finally, through Matlab simulation and electric excitation direct drive wind power system experimental platform is verified The ISOGI flux observer is feasible, and the scheme has good steady state and dynamic performance in the frequency range required by the wind power generation system.
Weak magnetic control 4. of electric excitation direct drive wind generator in the short time speeding has been investigated. Firstly, introduces the principle of EESG weak magnetic control, planning out the current track EESG in constant torque and high speed weakening region. Secondly, the dynamic current compensation based on stator flux EESG, rotor the comprehensive performance of weak magnetic control method is analyzed and verified by simulation and experiments. Then, aiming at the weak magnetic control method has the problem of slow dynamic response, this paper proposes two improved weak magnetic control scheme based on the "virtual impedance of the rotor, comprehensive weak magnetic control scheme and based on M the single shaft voltage current regulator, rotor comprehensive weak magnetic control scheme. Finally, through simulation and experimental verification of the proposed control scheme can accelerate the dynamic magnetic field weakening control response, can be applied to electric excitation direct drive wind power Under the short-time overspeed condition of the electric system, the wind power system is guaranteed to operate reliably within a wider range of speed.

【学位授予单位】：北京交通大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TM315

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