基于多微源的直流微电网协调控制策略研究

发布时间：2018-03-07 10:03

本文选题：直流微电网　切入点：混合储能系统　出处：《上海电力学院》2017年硕士论文　论文类型：学位论文

【摘要】：能源是人类赖以生存、经济发展和社会进步的基础,电力作为最清洁便利的能源形式,是国民经济发展的命脉,而传统的化石能源已经日益走向枯竭,且造成了巨大的环境污染。直流微电网以无需考虑频率、相位、无功功率以及控制结构简单等优点得到了各国专家学者的关注。本文研究了含风光混合储能的直流微电网系统,提出了基于实时功率控制的能量管理控制策略,主要内容包括:首先,本文以含光伏电池、永磁同步风力发电机组、超级电容器、蓄电池及本地负荷组成的直流微电网为研究对象,根据直流微电网运行状态的不同,将其分为并网运行和孤岛运行两种运行模态。设计了分布式电源、超级电容器和蓄电池组成的混合储能、本地负荷及大电网不同工作状态间的切换逻辑,使得各模块通过本地控制系统在不同运行模式间平滑的切换,确保微电源、储能装置、负荷、大电网之间的功率实时平衡。其次,针对传统的光伏电池MPPT控制策略跟踪速度慢、稳态功率波动大的缺点,本文提出了一种基于变功率扰动观察法的光伏MPPT控制策略,扰动步长根据光伏电池输出功率的变化而改变,通过仿真分析验证了该控制策略的控制性能优于常规的扰动观察法。最后,针对常规的基于母线电压信号(DBS)的直流微电网协调控制策略中母线电压波动频繁且稳态波动范围大,一方面降低了电网的电能质量,另一方面可能造成系统不同运行模式间的频繁切换,使系统的稳定性和可靠性降低的问题,本文提出了基于实时功率控制的协调控制策略,以分布式电源输出功率和负荷功率的差值为控制信号,来控制混合储能的充放电功率大小及微网的运行模式,同时结合超级电容荷电状态SOC大小来决定混合储能的控制策略,使得微网内的功率实时达到平衡。通过搭建的基于Matlab/Simulink模型,验证了本文提出的控制策略的有效性和可靠性。
[Abstract]:Energy is the basis of human survival, economic development and social progress. As the cleanest and most convenient form of energy, electricity is the lifeblood of national economic development, and the traditional fossil energy has been increasingly depleted. The DC microgrid has attracted the attention of experts and scholars from all over the world because of its advantages of not considering frequency, phase, reactive power and simple control structure. In this paper, the DC microgrid system with mixed solar energy storage is studied. An energy management control strategy based on real-time power control is proposed. The main contents are as follows: firstly, this paper uses photovoltaic cells, permanent magnet synchronous wind turbines and supercapacitors. The DC microgrid composed of storage battery and local load is studied. According to the different operation state of DC microgrid, it is divided into two operation modes: grid-connected operation and isolated island operation. The hybrid energy storage composed of supercapacitor and battery, local load and switching logic between different working states of large power grid make each module switch smoothly between different operation modes through local control system, so as to ensure micro-power supply and energy storage device. Secondly, aiming at the disadvantages of the traditional MPPT control strategy of photovoltaic cells, such as slow tracking speed and large fluctuation of steady-state power, a photovoltaic MPPT control strategy based on variable power disturbance observation method is proposed in this paper. The disturbance step size is changed according to the output power of photovoltaic cell. Simulation results show that the control performance of the proposed control strategy is better than that of the conventional disturbance observation method. In the conventional coordinated control strategy of DC microgrid based on bus voltage signal (DBS), the bus voltage fluctuates frequently and the range of steady state fluctuation is large, on the one hand, it reduces the power quality of the power network. On the other hand, it may cause frequent switching between different operation modes of the system, and reduce the stability and reliability of the system. In this paper, a coordinated control strategy based on real-time power control is proposed. The difference between output power and load power of distributed power supply is used as the control signal to control the charge and discharge power of hybrid energy storage and the operation mode of microgrid. At the same time, the control strategy of hybrid energy storage is determined by combining the SOC size of supercapacitor charge state. The power balance in the microgrid is achieved in real time. The validity and reliability of the proposed control strategy are verified by building the Matlab/Simulink model.
【学位授予单位】：上海电力学院
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM727

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