多电压源型微源组网的微电网运行控制与能量管理策略研究

发布时间：2018-01-05 01:16

本文关键词：多电压源型微源组网的微电网运行控制与能量管理策略研究　出处：《中国电力科学研究院》2014年博士论文　论文类型：学位论文

【摘要】：当前,基于可再生能源的分布式发电技术在世界范围内得到了广泛的重视和发展。但同时,分布式发电的大规模接入也给电网尤其是配电网的运行控制、安全保护、调度管理等各方面带来了深刻的影响。微电网概念的提出为分布式电源的利用提出了一种新的模式,微电网通过有效协调系统内部的能量分配,能够实现分布式发电系统与传统电力系统之间的融合以及优势互补,为分布式可再生能源的开发与利用提供了广阔的发展空间。目前,微电网还基本处于实验室研究和小规模示范应用阶段,已经建立的微电网示范工程中,大多是由单台储能单元或者常规发电机组起平衡作用的小规模主从控制型微电网。随着经济和社会的发展,微电网组建的需求不断增加,微电网系统的规模不断扩大,尤其是偏远地区独立型微电网所需的供电容量己达兆瓦级,资源与电源种类也多种多样。由于组网单元的容量限制等因素,主从控制应用于规模较大的多能互补型微电网中具有一定的局限性,因此,微电网亟需解决多台微源的并联组网问题。本文对多电压源型微源组网的微电网的运行控制和能量管理技术进行了研究,包括基于混合储能的可调度型微源的控制策略、适用于微电网多种运行模式的微源换流器的模式自适应改进下垂控制、微电网的分层控制及独立型微电网的能量管理技术等。主要研究成果如下： (1)针对由蓄电池／超级电容器混合储能系统和可再生能源发电系统组成的共直流母线结构的可调度型分布式电源,制定了综合考虑各储能元件荷电状态(State of Charge, SOC)和蓄电池使用寿命的分布式电源控制策略。根据储能元件的SOC是否越限,分别提出了带滤波补偿系数的低通滤波算法与基于不同直流母线电压运行区间的多模式切换控制；为了预防系统控制模式频繁切换带来的暂态冲击以及对蓄电池使用寿命的影响,提出了超级电容端电压预控制法。通过上述控制,优化了分布式电源的运行性能。 (2)提出了微源换流器基于虚拟阻抗的模式自适应改进下垂控制。分析了虚拟阻抗法改变线路阻抗特性的控制原理,提出了一种dq旋转坐标系中复合虚拟阻抗的设计方法；提出了微源换流器基于复合虚拟阻抗的模式自适应改进下垂控制,实现了微电网在孤岛和并网运行状态下的稳定运行以及并离网运行状态的平滑切换。 (3)针对微源换流器采用下垂控制的微电网难以实现无功功率的准确分配及电压质量难以保证等问题,提出了一种基于不同时间尺度的微电网分层控制策略。利用较短时间尺度内增大下垂系数法的一级控制提高系统功率分配精度,利用较长时间尺度内的二级控制调整下垂特性曲线的空载频率和电压,保证系统的电能质量。搭建了基于NI-PXI (PCI Extensions for Instrumentation, PXI,面向仪器系统的PCI扩展)的微电网数字物理混合仿真实验平台,依托该平台对微电网的分层控制技术进行了验证。 (4)针对多电压源型微源组网的风光柴储结构的独立型微电网,提出了一种多时间尺度协调控制的能量管理策略。将微电网的能量管理划分为三个阶段,在日前机组优化启停阶段,综合考虑了储能元件的全生命周期折算费用、储能组网单元的功率调节裕度、需求响应或需求侧管理等因素,合理安排各元件的开停机计划；在日内经济优化调度阶段,提出了基于模型预测控制的在线滚动式能量管理策略,对日前调度结果进行修正；在调度计划实时调整阶段,采取一定的措施保证储能组网单元时刻保持足够的调节裕度。通过三个阶段的协调配合,最终能够实现微电网的安全经济运行。
[Abstract]:At present , the distributed power generation technology based on renewable energy has gained extensive attention and development in the world . At the same time , the large - scale access of distributed power generation has exerted a profound influence on the operation control , safety protection and dispatching management of the power grid , especially the distribution network . At present , the micro - grid is basically in the stage of laboratory research and small - scale demonstration application , and most of the micro - grid demonstration projects have been established . As the economic and social development , the demand of the micro - grid system increases continuously , the scale of the micro - grid system is expanding , especially the power supply capacity needed by the independent micro - grid in the remote area has reached the megawatt level , and the resource and the power supply type are various . This paper studies the operation control and energy management technology of the micro - grid of multi - voltage source type micro - grid , including the control strategy of the controllable micro - source based on hybrid energy storage , the mode adaptation of micro - source converter suitable for multiple operation modes of the micro - grid , the improved droop control , the hierarchical control of the micro - grid and the energy management technology of the independent micro - grid . The main research results are as follows : ( 1 ) A distributed power control strategy is developed for a common DC bus structure consisting of a storage battery / super capacitor hybrid energy storage system and a renewable energy power generation system . Based on whether the SOC of the energy storage element is over , a low pass filtering algorithm with a filter compensation coefficient and a multi - mode switching control based on different DC bus voltage operation intervals are respectively proposed . In order to prevent the transient impact caused by frequent switching of the system control mode and the influence on the service life of the battery , a super capacitor terminal voltage pre - control method is proposed . ( 2 ) The adaptive droop control based on the virtual impedance of the micro - source converter is proposed . The control principle of changing the impedance characteristic of the line is analyzed . A design method of the composite virtual impedance in the rotation coordinate system based on the virtual impedance method is presented . The adaptive modified droop control based on the composite virtual impedance is proposed . The stable operation of the micro - grid in the running state of the isolated island and the grid is realized , and the smooth switching of the off - network operation state is realized . ( 3 ) In order to solve the problems such as accurate distribution of reactive power and difficult guarantee of voltage quality , a micro - grid hierarchical control strategy based on different time scales is proposed for micro - power converter with droop control . ( 4 ) The energy management strategy of multi - time scale coordination control is put forward aiming at the independent micro - grid of multi - voltage source type micro - source networking . The energy management of the micro - grid is divided into three stages , the whole life cycle conversion cost of the energy storage element , the power regulation margin of the energy storage networking unit , the demand response or demand side management are comprehensively considered , and the prior scheduling result is corrected ;

【学位授予单位】：中国电力科学研究院
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TM732

【参考文献】