光伏电站无功补偿装置的交互影响及协调控制

发布时间：2018-08-04 15:51

【摘要】：当今大规模利用太阳能是优化能源结构和提升环境质量的重要途径之一。由于光伏电站地处偏僻,西部丰富的光照资源需要通过高压输电网传输至东部负荷中心,且并网逆变器通常采取单位功率因数的运行方式,所以光伏电站多选用在可控性、运行范围及响应速度等方面具有显著优势的FACTS装置以满足光伏电站正常运行的无功需求,抑制有功出力变化导致的并网点电压波动甚至越限,但许多不可避免的问题也随之而来。鉴于此,论文将从光伏站间及站内两个层面对无功补偿装置的交互影响及协调控制等问题展开研究。首先,针对光伏电站间不同类型的FACTS控制器在电网电压波动时会产生交互影响等问题,建立了系统数学模型,并利用Simulink和RGA理论进行了仿真试验及定量计算,证实了 FACTS控制器间确实存在交互影响,且影响程度与其间的电气距离有关。其次,针对交互影响产生的原因,从系统宏观的角度出发,统筹考虑各FACTS控制器间的关联作用,设计了一种全局协调控制器,有效削弱了光伏电站间FACTS控制器的交互影响,改善了系统的控制性能。再次,针对光伏电站内无功与电压的协调控制问题,基于光伏电站的拓扑结构,建立了其等效电路模型,给出了相关的技术参数,提出了并网逆变器的控制方案,并通过Simulink搭建了仿真模型,对上述各设计环节的正确性进行了验证。最后,针对光伏电源输出的随机性及不可控性,导致并网电能质量下降、稳定性较差等问题进行了理论分析,提出了一种并网逆变器与FACTS装置间的协调控制策略,优化了光伏电站内的无功分配方案,并利用Simulink进行了实例仿真,验证了该控制策略的正确性和可行性。
[Abstract]:Nowadays, large-scale utilization of solar energy is one of the important ways to optimize energy structure and improve environmental quality. Because the photovoltaic power station is located in the remote area, the abundant illumination resources in the west need to be transmitted to the eastern load center through the high-voltage transmission network, and the grid-connected inverter usually adopts the operation mode of unit power factor, so the photovoltaic power station is mostly chosen in controllability. The FACTS device, which has remarkable advantages in operation range and response speed, can meet the demand of reactive power of photovoltaic power plant in normal operation, and restrain the fluctuation or even overrun of the voltage of parallel dot caused by the change of active power output. But many inevitable problems followed. In view of this, this paper will study the interaction and coordinated control of reactive power compensator between and within photovoltaic stations. First of all, aiming at the problem that different types of FACTS controllers in photovoltaic power plants have interactive effects on the voltage fluctuation of the power system, the mathematical model of the system is established, and the simulation experiment and quantitative calculation are carried out by using Simulink and RGA theory. It is proved that there is interaction between FACTS controllers, and the degree of influence is related to the electrical distance between them. Secondly, aiming at the cause of interaction, considering the correlation between FACTS controllers, a global coordination controller is designed, which effectively weakens the interaction of FACTS controllers between photovoltaic power plants. The control performance of the system is improved. Thirdly, aiming at the coordination control of reactive power and voltage in photovoltaic power station, based on the topology of photovoltaic power station, the equivalent circuit model is established, the relevant technical parameters are given, and the control scheme of grid-connected inverter is put forward. The simulation model is built by Simulink, and the correctness of the above design links is verified. Finally, the random and uncontrollable output of photovoltaic power supply is analyzed theoretically, which leads to the decline of power quality and the poor stability of grid-connected power supply. A coordinated control strategy between grid-connected inverter and FACTS device is proposed. The reactive power distribution scheme in photovoltaic power plant is optimized, and the simulation results with Simulink are given to verify the correctness and feasibility of the control strategy.
【学位授予单位】：西安理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM615;TM761.12

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