【作者】 华明；

【导师】 邢岩；

【作者基本信息】 南京航空航天大学 ， 电力电子与电力传动， 2011， 博士

【摘要】 逆变器冗余并联技术是实现高可靠性、大容量、可扩展性电源系统的基础，也是电力电子领域的研究热点和难点。本文基于恒频、恒压（Constant Voltage Constant Frequency，CVCF）逆变器电源分布式并联控制方法，针对变频、变压（Variable Voltage Variable Frequency，VVVF）逆变器（变频器）提出了一种由数字控制实现的分布式有互联线并联控制方法。将变频器的并联控制解耦成为频率变化的正弦基准信号的同步控制和均流控制。首先利用方波信号来表示各模块的基准相位及频率，并据此生成所有并联运行的变频器共享的同步信号，各台变频器根据共享的同步信号，控制各台之间同频、同相；然后采样计算环流信号对各模块正弦电压基准信号微调，实现负载均分。同时分析了并联系统同步控制和均流控制的稳定性，进行了仿真和实验验证。参考电力系统中用于功率调度的分层控制方法，提出了一种基于多层控制技术的无互联线并联控制，以实现多层控制的解耦，提高系统稳定性和可靠性。控制包含三层：第一层为改进的PQ下垂算法，在传统算法中引入正比于有功功率的初始相位调节量，在并联模块相位差较小的前提下，精准调节输出电压，实现良好的动态及稳态均流性能；第二层控制为负载调整率校正，检测并联系统输出交流母线电压的频率及幅值，据此对由下垂调节和均流电感造成的输出电压偏差进行补偿，以改善负载调整率；第三层控制称为准同步控制，各逆变器模块检测交流母线电压相位，在本模块与交流母线相位差超过允许范围时，粗略但快速的调节本模块相位，使相位差回落到第一层控制可以有效工作的区间内，以便实施第一层控制，并有效实现无冲击热投入及避免逆变器的动态相位失步，提高了系统的可靠性和稳定性。提出了多层控制协调策略，给出了关键参数设计准则。提出了基于无互联线并联的逆变器准同步控制方法。结合逆变器基于空间矢量控制的特性及检测交流母线电压相位，调节基准电压与交流母线之间的相位偏差在一定小的范围内，在热投入过程中保证逆变器与交流母线基本上同频、同相后再投入并联运行，有效抑制并联瞬间的电流冲击，改善并联系统的热插拔性能，在动态过程中，保证逆变器与交流母线之间的相位差不超过允许的范围。研究了准同步控制方法和下垂同步控制方法之间的关系，并分析了两者之间的稳定性。将提出的无线并联控制技术应用于大功率、模块化的电力机车辅助电源系统中。提出了电力机车辅助电源系统架构、工作模式和建网逻辑，建立了由两台35kVA逆变器构成的实验系统，验证了理论分析和设计的正确性和可行性，为实现高可靠性、高可维护性和高冗余性的机车辅助电源系统提供了理论和技术基础。更多还原

【Abstract】 Paralleled control for inverters is one of most key and challenging techniques to achieve power supply systems featuring high reliability, high capacity as well as high expansibility. Paralleled control technique has been for many decades and is still a hot topic and one technique challenging in the power electronics field.Based on the paralleled control strategy for constant voltage constant frequency inverters (CVCF), a distributed control strategy with wired connection, implemented by a digital signal processor (DSP), is proposed for variable voltage variable frequency paralleled inverters feeding an asynchronous motor. The system is decoupled into two independent subsystems for synchronization regulation and current sharing control respectively by introducing the local feedback technique. A square waveform, containing information of both frequency and phase angle, is used to generate a synchronization signal for all the inverter in parallel operation, which is shared by all the inverters to keep them in phase. Then the voltage references for current sharing control are regulated through sensing the circulating currents, aiming at equally sharing the load currents. The stability issue for synchronization control and current sharing control is analyzed and the control strategy is verified both in simulation and experimentally.Referring to the well-known hierarchical control applied to power dispatching in large AC power system, a multilayer control for inverters in parallel operation with wireless connection is proposed in this paper to enhance the stability and reliability of the paralleled system. A controller, embedded in each inverter, consists of three layers:The first layer is based on an improved droop method, based on which the paralleled operation can be achieved under conditions with small phase angle difference through regulating reactive power and active power to fine adjust system frequency and initial phase angle. As a result, good steady state performance and dynamic response are obtained. The second layer is designed for compensating the droop control and thus improving the load regulation performance of the inverter. The third layer, called quasi-synchronization control, aims to limit the phase deviation between the inverter and the shared ac bus. If the phase difference is out of limit, the phase of the inverter is regulated immediately in order to ensure the phase difference to be kept within the appropriate range within which the first layer can take effect. And the paralleled inverters can keep in phase with each other and the inrush currents among the inverters are suppressed at hot plug-in. The coordinated control for all layers is proposed and analyzed in detail, and the stability of the control is analyzed as well.A quasi-synchronization control scheme is proposed for the inverters in wireless connection parallel operation. Combining the features of the inverters with the space vector control and the phase angle of the shared ac bus, the phase differences of the reference voltage and the shared ac bus are regulated within a certain small range to keep the frequency and phase angle of the inverters as same as those of the shared ac bus, which will effectively suppress the inrush currents and improve the performance of the hot swap when the inverters start to put into parallel operation. During the transients in parallel operation, the control scheme makes sure that the phase angle differences of the inverters and the shared ac bus are kept within a certain range to avoid the out-of-synchronization. The relationship between the quasi-synchronization control and the droop synchronization control is studied and the stability between them is analyzed as well.The proposed wireless parallel control technique is applied to high power and modularized train’s auxiliary power system. A system architecture and its operation mode are proposed for train’s auxiliary power system and the logic in the establishment of auxiliary power system is set according to the principle of the multilayer control. A prototype, configured by two paralleled35kVA inverters, is set up. And the experimental results verify the validility and feasibility of the proposed control. The theoretical and technical bases for realizing the train’s auxiliary power system with high reliability, high maintainability and high redundancy are provided.更多还原