微电网电压质量补偿控制策略研究

发布时间：2018-03-21 00:24

本文选题：电压质量　切入点：谐波畸变　出处：《兰州理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着新能源发电技术的不断兴起,新能源发电对电能质量带来了一些负面影响。为此,微电网作为一种解决问题的有效途径,得到了广泛的研究。作为一种新型的发电系统,微电网不仅可以解决偏远地区及紧急情况的供电问题,还可以通过并网来解决广大用户端的供电短缺问题。由于非线性及不平衡负载的接入,使得PCC点电压质量较差,在孤岛运行情况下,会造成本地设备的发热及损坏;在并网运行情况下,对大电网造成干扰,导致电网波动及不稳定。本文研究了电压不平衡和谐波补偿控制方法。该方法基于分布式分层控制,在两相静止αβ坐标下,结合本地控制器和二次控制器共同对PCC点的电压质量进行控制补偿。针对本地控制中出现的电压、频率和无功功率偏差问题,基于分布式分层控制策略,通过二次控制对电压、频率及无功功率进行了控制。仿真验证了二次控制器能很好的对本地控制器中的电压、频率、无功功率的偏差进行消除。针对电压不平衡情况,基于分布式分层控制策略,对电压质量问题进行研究。在二次控制器中设计电压不平衡补偿器,对PCC点的电压不平衡补偿值进行计算,然后将其送入本地控制器,进而对PCC点的电压进行补偿,最后通过仿真验证所提控制策略的有效性。针对电压不平衡和谐波情况,对PCC点的电压质量进行治理。当PCC点电压出现不平衡和谐波时,依据本文提出的SOGI-DSC谐波检测提取模块,对谐波进行提取,计算出谐波畸变率和电压不平衡度,从而得到谐波补偿值和电压不平衡补偿值,对PCC点的电压质量进行补偿;若DG补偿能力不足时,则采用APF来进行电压和电流的补偿,最后通过仿真验证了所提控制策略。
[Abstract]:With the rising of new energy generation technology, new energy generation has brought some negative effects on power quality. Therefore, as an effective way to solve the problem, micro-grid has been widely studied. As a new generation system, microgrid is a new type of power generation system. Microgrid can not only solve the problem of power supply in remote areas and emergency situations, but also solve the shortage of power supply for the vast number of users by grid connection. Because of the nonlinear and unbalanced load access, the quality of PCC point voltage is poor. Under the condition of isolated island operation, the local equipment will be heated and damaged. In the case of grid-connected operation, it will interfere with the large power grid. In this paper, the voltage imbalance and harmonic compensation control method is studied. The method is based on distributed hierarchical control, and under the two phase static 伪尾 coordinate, the control method of voltage imbalance and harmonic compensation is studied in this paper. Combined with local controller and secondary controller to control and compensate the voltage quality of PCC point, aiming at the voltage, frequency and reactive power deviation of local control, based on the distributed hierarchical control strategy, the voltage is controlled by quadratic control. The frequency and reactive power are controlled. The simulation results show that the quadratic controller can eliminate the bias of voltage, frequency and reactive power in the local controller. Voltage quality problem is studied. Voltage imbalance compensator is designed in the secondary controller. The voltage imbalance compensation value of PCC point is calculated, and then sent to the local controller to compensate the voltage of PCC point. Finally, the effectiveness of the proposed control strategy is verified by simulation. The voltage quality of PCC points is treated in the light of voltage imbalance and harmonic. When the voltage of PCC points is unbalanced and harmonic, the detection and extraction module of SOGI-DSC harmonics is proposed in this paper. By extracting harmonics and calculating the harmonic distortion rate and voltage imbalance, the harmonic compensation value and voltage imbalance compensation value are obtained, and the voltage quality of PCC point is compensated. If the compensation ability of DG is insufficient, APF is used to compensate the voltage and current. Finally, the proposed control strategy is verified by simulation.
【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】：TM727

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