基于瞬时功率理论的电力系统谐波检测及抑制方法研究

发布时间：2018-06-12 23:13

本文选题：谐波电流 + 瞬时功率理论　；参考：《兰州交通大学》2014年硕士论文

【摘要】：随着电力电子技术的发展，电网中的非线性负荷越来越多，电流波形畸变也日益严重，如果不加以治理将严重影响电力系统的安全、稳定运行。因此，对电力系统谐波电流采取实时检测和必要地抑制措施，是保证电力系统安全、稳定运行亟待解决的重要课题之一。为了系统地研究基于瞬时功率理论的谐波电流检测及抑制方法，论文首先分析了电力系统谐波的概念、表示形式、衡量指标、危害以及电网中的主要谐波源。在此基础上，引入瞬时功率理论的定义和相关结论，并将瞬时功率理论应用于谐波电流检测法，从而得到p-q检测法和ip-iq检测法。论文分别采用理论推导和仿真实验的方法研究了p-q检测法在电网电压有、无畸变的三相三线制系统和ip-iq检测法在电网电压有畸变的三相三线制系统、三相四线制系统和单相系统中的应用。其中，p-q检测法只能在电网电压无畸变时准确地检测出电网中的谐波电流，当电网电压有畸变时检测结果是有误差的；而ip-iq检测法在电路的各种运行状态下都能获得令人满意的检测效果，因此ip-iq检测法比p-q检测法具有更加广阔的应用空间。另外，无论是基于p-q检测法还是ip-iq检测法构造的谐波电流检测电路，其中的低通滤波器都是影响谐波电流检测效果的重要因素，因此，论文详细分析了低通滤波器的类型、阶数和截止频率对ip-iq检测法检测效果的影响，为选择低通滤波器提供了依据和参考。采用基于瞬时功率理论的有源电力滤波器检测和抑制谐波电流是治理电力系统谐波电流的最有效方法之一。论文在分析了有源电力滤波器的基本原理和接入方式的基础上，对并联型有源电力滤波器的主电路结构进行了较详细地研究。最后，论文提出了一种基于瞬时功率理论的并联型三相三线制有源电力滤波器设计方案，并重点研究了硬件设计和控制策略两个方面的问题，为基于瞬时功率理论的有源电力滤波器实用化奠定了一定的基础。在硬件设计方面，重点研究了电流、电压检测电路，过零检测电路，采样周期信号产生电路，AD转换电路及主电路等关键性环节。在控制策略方面，，重点研究了补偿电流滞环控制和直流侧电压控制的具体工作过程。
[Abstract]:With the development of power electronics technology, there are more and more nonlinear loads in the power network, and the distortion of current waveform is becoming more and more serious. If not treated, the safety and stability of power system will be seriously affected. Therefore, it is an important task to ensure the safety and stability of power system to take real-time detection and necessary suppression measures for harmonic current in power system. In order to systematically study the harmonic current detection and suppression method based on instantaneous power theory, this paper first analyzes the concept, representation, measurement index, harm and main harmonic sources of power system harmonics. On this basis, the definition and relevant conclusions of instantaneous power theory are introduced, and the instantaneous power theory is applied to the harmonic current detection method to obtain p-q detection method and ip-iq detection method. In this paper, the method of theoretical derivation and simulation experiment are used to study the three-phase three-wire system with p-q detection method and three-phase three-wire system with no distortion in the grid voltage, and the three-phase three-wire system with ip-iq detection method with voltage distortion in the power network. Application of three-phase four-wire system and single-phase system. The p-q detection method can only accurately detect the harmonic current in the power network when the voltage is not distorted, and there are errors in the detection results when the voltage is distorted. However, the ip-iq detection method can obtain satisfactory detection results under various operating states of the circuit, so the ip-iq detection method has a wider application space than the p-q detection method. In addition, whether based on p-q detection method or ip-iq detection method, the low pass filter is an important factor that affects the harmonic current detection effect. Therefore, the type of low pass filter is analyzed in detail. The influence of order and cutoff frequency on the detection effect of ip-iq detection method provides the basis and reference for selecting low pass filter. Detection and suppression of harmonic current by active power filter based on instantaneous power theory is one of the most effective methods to control harmonic current in power system. On the basis of analyzing the basic principle and access mode of active power filter, the main circuit structure of shunt active power filter is studied in detail in this paper. Finally, a design scheme of shunt three-phase three-wire active power filter based on instantaneous power theory is proposed, and two aspects of hardware design and control strategy are studied. It lays a foundation for the practical application of active power filter based on instantaneous power theory. In the aspect of hardware design, the key links such as current, voltage detection circuit, zero-crossing detection circuit, sampling period signal generation circuit, AD conversion circuit and main circuit are studied. In the aspect of control strategy, the detailed working process of compensation current hysteresis control and DC side voltage control is studied.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM711

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