【作者】 许铁岩；

【导师】 罗耀华；

【作者基本信息】 哈尔滨工程大学 ， 检测技术与自动化装置， 2013， 博士

【摘要】 随着社会和经济的发展，人类对电能的需求量迅速增长，利用传统的化石能源(如煤、石油、天然气等)发电不仅污染环境而且资源有限。潮流能作为一种无污染、可再生且蕴藏丰富的新型能源受到越来越多的重视。变流器是永磁直驱潮流能发电装置的关键设备，其性能直接关系到整个发电装置的性能。本文对永磁直驱潮流能发电装置中变流器的控制技术进行研究。由于潮流能发电装置所处环境恶劣，转子位置传感器不仅安装困难而且增加成本并降低装置可靠性。针对此问题，本文对无位置传感器永磁同步发电机的控制技术进行了研究。首先建立和分析了永磁同步发电机模型，分析和研究了基于锁相环的转子位置估计方法和基于状态观测器的反电势估计方法，并分别给出了基于两种估计方法的永磁同步发电机无位置传感器的控制策略。本文提出了一种基于比例谐振控制器的发电机反电势估计方法。随着潮流能发电装置容量的提高，变流器采用并联技术是一种提高系统容量和系统可靠性、降低开发成本的有效手段。潮流能发电变流器并联分为共直流母线并联和独立直流母线并联两种拓扑结构，针对这两种拓扑结构分别建立了变流器并联平均值模型。变流器零序环流降低装置效率、导致输出电流畸变甚至导致装置不稳定。通过分析变流器并联平均值模型，获得了零序环流平均值模型。为了改进抑制零序环流效果，首先分析了PWM死区时间、开关管管压降和PWM方法对输出零序电压的影响。通过分析变流器零序输出阻抗，提出了基于虚拟阻抗技术的零序环流抑制方法，该方法通过提高零序阻抗来抑制零序环流，并针对零序电压为周期性信号的特性着重提高了部分谐波频率处的阻抗来改善零序环流抑制效果。通过建立和分析零序环流闭环控制模型可知，零序调制电压为主要干扰。针对零序调制电压为三倍于基波频率的周期性信号的特点，提出一种基于快速重复控制的零序环流抑制方法，与传统重复控制相比该方法具有响应速度快的优点。当潮流能发电装置工作于孤岛模式时，需要网侧变流器提供三相四线制电源，三相四桥臂变流器具备该能力，所以针对该变流器控制技术进行了研究。本文提出一种三相四桥臂PWM方法，该方法具有直流电压利用率高、计算量小的突出优点。该方法将参考电压分为差模分量和共模分量两部分。差模分量用于abc相桥臂实现SVPWM；abc相调制电压的共模分量与参考电压的共模分量的差值作为第四桥臂d相的调制波。通过理论分析证明了采用该调制方法的四相桥臂输出电压平均值与参考电压相同。本文建立和分析了三相四桥臂变流器基于同步旋转坐标系的平均值模型，通过在控制器中增加电压和电流前馈实现d轴和q轴的解耦控制，解耦后三相四桥臂变流器相当于三套独立的直流变流器。通过分析同步旋转坐标系下负载电流的特性，提出控制器采用PI控制器和谐振控制器并联的控制策略。变流器采用LCL型滤波器可以降低装置重量和成本，所以首先对LCL型滤波器设计进行研究，然后针对LCL型滤波器固有的谐振问题进行了研究。本文从电压降、谐波抑制、无功比例、功耗、响应速度等方面分析了LCL型滤波器参数的限制条件。通过分析谐波频率处电压和电流分量的关系以及限制条件提出了一种LCL型滤波器设计方法，并分析了各个元器件与限制条件的关系。LCL型滤波器是三阶欠阻尼的系统，在谐振频率处增益大，这不仅增加电流闭环控制器设计难度而且容易引入谐波电流。针对LCL型滤波器的谐振问题进行了分析并给出了几种抑制滤波器谐振的可行控制方法。本文的研究成果可推广到UPS电源、有源电力滤波器、风力发电和太阳能发电等领域中去。更多还原

【Abstract】 With the development of society and economy，the demand for electric energy growsrapidly. Not only traditional power generation pollutes the environment, but also the fossilenergy resources are limited, such as coal, oil and natural gas. Tidal current energy hasreceived increasing attention, as pollution-free, renewable and rich resource. Convertor isone of the key equipments，and its performance directly affects the performance of theentire power generation device.The installation environment of the tidal current energy generation device is harsh andthe rotor position sensor is hard to installed, expensive and easy to damage. The sensorlesspermanent magnet synchronous generator control technology was studied in this paper. Themodel of the permanent magnet synchronous generator was constructed and analyzed. Therotor position estimation methods based on phase locked loop and state observer werestudied, and two rotor control strategies based on the two estimation methods wereintroduced. A novel rotor back electromotive force method was introduced.With the increase of tidal current energy generation device capacity, convertor paralleltechnology is an effective way to increase the capacity and reliability, to reduce thedevelopment cost. There are two kinds of convertor parallel topological structures, the firstone is the common dc bus parallel topology and the second one is the independent dc busparallel topology. The average value models of the two topology structures were constructed.The zero sequence circuit current reduces efficiency, causes current distortion and affectsthe stability of the system. The zero sequence circuit current average models wereconstructed by the analysis of the convertor parallel models. The effects of the dead time,switch pipe voltage drop and PWM method on the zero sequence voltage were analyzed. Anovel zero sequence circuit current suppression method based on virtual impedance wasintroduced, by the analysis of the convertor zero sequence impedance. The methodincreases the zero sequence impedance to suppress the zero sequence circuit current, andincreases some harmonic impedance to improve the performance, because of that the zerosequence voltage is periodic signal. The closed control model of the zero sequence circuitcurrent was constructed and analyzed. The zero sequence voltage of the convertor is themain disturb. A novel rapid repetitive control method was proposed, the response speed ofwhich is third times faster than the traditional repetitive control method. When tidal current generation device works in island mode, the convertor need tosupply three-phase four-wire power, and the three-phase four-leg convertor has the ability. Anovel three-phase four-leg PWM modulation method was proposed in this paper, and hasthe advantages of high dc voltage utilization ratio and small calculation volume. By themethod, reference voltage was divided into two components, the AC component and thecommon component. The AC component was used for abc-phase legs SVPWM; thedifference between common component of abc-phase modulation voltage and the commoncomponent of reference voltage was used for the fourth leg modulation. It was testified thatthe fourth leg output three-phase average voltage is same with the reference voltage, by thetheoretical analysis. The average model of the three-phase four-leg convertor wasconstructed and analyzed, which was in synchronous rotate coordinate. The voltage andcurrent feedforwards was added in the control loop to decouple the d-axis loop and theq-axis loop. The three-phase four-leg convertor is same to three dc buck convertors. A novelcontrol strategy that the PI controller was parallel with the resonant controller was proposed,by the analysis of the load current.The use of LCL filter in convertor can reduce the weight and cost of the device, so thedesign method and resonance suppression methods of LCL filter were studied. The LCLfilter design limited conditions of voltage drop, harmonic suppression, reactive power, lossand response speed is studied. The relationship between the limited conditions and thecomponents parameters was studied, and an LCL filter design method was introduced. TheLCL filter is third order under-damped, the large gain at the resonant frequency increasesthe design difficulty and reduces system stability. The resonant problem was analyzed andsome resonant suppression methods were introduced.The research results can be applied to UPS, active power filter, wind generator andsolar generator, et al.更多还原