微源逆变器串联型微网中功率协调控制策略研究

发布时间：2018-05-01 04:22

本文选题：串联型微电网 + 功率分配　；参考：《兰州理工大学》2017年硕士论文

【摘要】：微源逆变器串联型微电网(Series micro power grids,SMPGs)从逆变器连接的结构形式入手解决了普通并联型微电网存在的一些较难解决的问题,或使某些问题的解决变得相对简单,但结构形式的变化使得其在实际运行中的控制策略需要重新被考虑。为了满足SMPGs系统内部功率平衡,并让系统中各部分能量按其出力能力发挥各自的优势,本文研究了一种SMPGs的功率协调控制策略。首先,介绍了单相、三相串联型微电网系统的具体结构以及系统中的主要微源;研究了孤岛系统、并网系统、系统中储能单元的功率协调运行策略与能量平衡机理,为SMPGs中控制策略的设计奠定了基础。其次,孤岛模式下,建立了系统串联逆变环节的小信号模型,据此分析了各参量对系统性能的影响,在满足系统稳定的前提下,研究了一种“能者多劳”的分配方法;并网模式下,分析了三相SMPGs系统在各相输入功率不相同状况下的运行机理,研究了三相系统的功率分配方法,解决了系统输出电流对称控制问题。据此,分别设计了孤岛、并网模式下系统的功率协调控制策略,前者主要包括滤波电容电压、电流控制和功率协调控制;后者主要包括并网电流控制、功率协调控制、直流链电压控制。通过仿真验证了它们各自控制方法的有效性。最后,对于SMPGs中的混合储能系统,从上层能量优化调度的角度出发,基于混合储能系统的平均荷电状态、超级电容器组和蓄电池组各自的荷电状态,研究了SMPGs中储能系统间、储能系统内部的功率协调分配方法。此外,对混合储能系统进行了小信号模型分析,据此研究了一种双层结构的前馈协调控制方法,主要包括直流链电压控制、电感电流的二次协调控制,仿真分析验证了控制策略的有效性。
[Abstract]:Series micro power griddsSMPGs of microsource inverter solves some difficult problems existing in ordinary parallel microgrid from the structure of inverter connection, or makes the solution of some problems relatively simple. However, the change of structure makes its control strategy need to be reconsidered in practice. In order to meet the internal power balance of SMPGs system and to give full play to each part of the system according to its power capacity, a coordinated power control strategy for SMPGs is studied in this paper. Firstly, the specific structure of single-phase and three-phase series microgrid system and the main microsources in the system are introduced, and the coordinated power operation strategy and energy balance mechanism of the isolated island system, grid-connected system and energy storage unit in the system are studied. It lays a foundation for the design of control strategy in SMPGs. Secondly, in the isolated island mode, the small signal model of the series inverter is established, according to which the influence of the parameters on the performance of the system is analyzed. On the premise of satisfying the stability of the system, a distribution method of "the more skilled and the more laborious" is studied. In grid-connected mode, the operation mechanism of three-phase SMPGs system with different input power is analyzed, the power allocation method of three-phase system is studied, and the problem of symmetrical control of system output current is solved. Based on this, the power coordination control strategies of isolated island and grid-connected system are designed respectively. The former includes filter capacitor voltage, current control and power coordination control, the latter includes grid-connected current control and power coordinated control, the former includes grid-connected current control and power coordinated control, and the latter includes grid-connected current control and power coordinated control. DC chain voltage control. The effectiveness of their respective control methods is verified by simulation. Finally, for the hybrid energy storage system in SMPGs, based on the average charge state of the hybrid energy storage system and the charge state of the supercapacitor bank and the battery bank, the energy storage system in SMPGs is studied from the point of view of energy optimal scheduling. A coordinated power allocation method within the energy storage system. In addition, the small signal model analysis of hybrid energy storage system is carried out. Based on this, a two-layer feedforward coordinated control method is studied, which mainly includes DC link voltage control, inductance current secondary coordinated control. Simulation results show the effectiveness of the control strategy.
【学位授予单位】：兰州理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM464;TM727

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