【作者】 郭以贺；

【导师】 石新春； 谢志远；

【作者基本信息】 华北电力大学 ， 电力电子与电力传动， 2014， 博士

【摘要】 近年来我国智能配电网发展迅速,对通信平台也提出了越来越高的要求。鉴于我国配电网覆盖面广、结构复杂的特点,需要因地制宜地选取合适的通信技术。其中,中压电力线通信技术具有自身独特的优势和广阔的应用前景,同时也面临着诸多技术难点需要进一步完善和解决。本文结合国家自然科学基金面上项目“面向智能电网的中压电力线通信关键技术研究”(61172075),重点研究了中压电力线信道模型和相关通信技术,在此基础上,设计实现了基于中压电力线通信的馈线自动化系统。本文主要研究成果如下：1.基于多导体传输线理论建立了中压三相架空电力线路的传输和输入阻抗模型。结合典型的线路结构分析了各模量信号在三相线路上的传播特性,指出了Clarke矩阵在整个频段内可以作为相模变换矩阵,降低了信道建模的难度。分析了相地和相相输入阻抗的特性。提出了一段均匀三相线路在相地和相相耦合方式下传输衰减的简化计算公式,揭示了不同模量间相互耦合的规律,得出了相相耦合方式下终端匹配电阻的计算方法。2.基于对多台配电变压器的测量数据,分析了电力线通信频段内变压器高压端口的阻抗特性。利用其输入阻抗矩阵的对称性,提出了一种简化的变压器端口建模方法。3.建立了中压电力线通信信道的整体模型。典型现场实测的阻抗和衰减数据证明了模型的正确性。分析了主要模型参数对建模结果的影响,进一步简化了模型的复杂度。建立了中压电力线路输入阻抗的宽频宏模型,可以用于实验室环境下研究阻抗匹配电路的设计。4.基于直接优化法和简化实频法提出了中压电力线路宽带阻抗匹配的方法,利用这些方法可以有效地提高注入电力线的信号功率。设计了基于锁相放大器的电力线阻抗在线测量系统,具有较强噪声抑制能力,并同时测量阻抗的实部和虚部。为了验证阻抗匹配的效果,设计了通过测量直流电源供给功放的电流,从而间接检测功放输出电流的方案。5.设计了基于10kV一体化智能柱上开关的馈线自动化系统,并首次应用于配电网。分析了其中具有自主知识产权的电力线通信、测控和保护等关键技术。为了应对电力线通信信道的恶劣环境,提出了一种自适应通道选择策略,设计了相应的通信规约。结合某实际馈线自动化系统的运行情况,证明了中压电力线通信技术可以为配电自动化系统提供稳定可靠的通信服务。根据系统的通信信号强度数据,分析了信道衰减和噪声的一般规律,总结了中压电力线路的信道特性,进一步验证了建模方法的可行性,这些数据可以为相关科研工作者提供设计帮助。更多还原

【Abstract】 In recent years, with the rapid development of smart distribution network, there are more and more demands for communication system. Since distribution network in China has the characteristics of wide coverage and complex structure, the appropriate communication technologies must be chose to suit the local conditions. Among them, the medium voltage power line communication (MVPLC) technology has its own unique advantages and broad prospects. Whereas there are still a number of technical problems need to be further improved and solved. The thesis is combined with the subject ’Research on key technologies of medium voltage power line communication oriented to smart grid’which is supported by the National Natural Science Foundation of China (Grant No.61172075). The modeling of MVPLC channel and related communication technologies are studied and a feeder automation system which is based on MVPLC is designed and implemented. The main innovative achievements are presented as follows:1. Based on the theory of multi-conductor transmission lines, the transmission and impedance models of overhead medium voltage power lines are proposed. Combined with a typical line structure the signal propagation characteristics of each mode in the three-phase line are analyzed, which shows that the Clarke matrix can be used as phase mode transformation matrix in the whole frequency band. This method reduces the difficulty of channel modeling. The characteristics of phase to ground and phase to phase impedance are analyzed. The simplified calculation formulas are proposed for calculating the transmission attenuation of a uniform three-phase power lines in the manner of phase to ground and phase to phase coupling, which revel the relationship of mutual coupling of different modes, then the calculation method of matching resistor in the manner of phase to phase coupling is proposed.2. Based on measured data of several distribution transformers, the impedance characteristics of MV terminals are analyzed in the power line communication frequency band. Applying the symmetry of input impedance matrix, a simplified transformer port modeling is proposed.3. The systematic model of MVPLC channel is proposed. The field test of impedance and attenuation data proves the validity of the model. The effects of modeling parameters on the results are discussed, which further simplifies the complexity of the model. A wideband macromodel of medium voltage power line input impedance is proposed, which can be employed to the design of impedance matching circuit in the laboratory.4. The wideband impedance matching method of medium voltage power line is proposed by direct optimization and simplified real frequency techniques, which can effectively improve the signal power into the power line. The online power line impedance detection system is proposed by lock-in amplifier, which has strong ability of noise suppression and measurement of the real and imaginary part of the input impedance. In order to verify the effect of impedance matching, a scheme is designed that replaced the detection object of amplifier output current by DC power supply current.5. A feeder automation system based on integrated intelligent10kV switch is designed, which is applied to distribution network firstly. The key technologies with the independent intellectual property of MVPLC, measurement and protection are analyzed. Aiming at the hostile channel environments of power line communication, an adaptive channel selection strategy is employed and the corresponding communication protocol is designed. The field operation data of a feeder automation system has proved that the MVPLC technologies can achieve stable and reliable communication service for distribution automation system. According to the data of communication signal strength, the general law of channel attenuation and noise are analyzed. Then the channel characteristics of distribution network are summarized, which verified the feasibility of modeling method. These data can be referenced by the related researchers.更多还原