低压微电网采用坐标旋转的虚拟功率V/f下垂控制策略  

A Coordinate Rotational Transformation Based Virtual Power V/f Droop Control Method for Low Voltage Microgrid

作　　者：周贤正[1] 荣飞[1] 吕志鹏[1] 罗安[1] 彭双剑[1] 

机构地区：[1]湖南大学电气与信息工程学院,湖南省长沙市410082

出　　处：《电力系统自动化》2012年第2期47-51,63,共6页Automation of Electric Power Systems

基　　金：国家自然科学基金资助项目(50907017);湖南省科技计划资助项目(2010RS4017);中国博士后科学基金资助项目(20100471212)~~

摘　　要：针对低压微电网线路与传统高压输电线路阻抗比的不同而引起的功率耦合问题,提出一种采用坐标旋转的虚拟功率控制策略。该方法通过坐标旋转正交变换矩阵,实现了功率的解耦控制,对采用下垂控制特性的电压/频率控制进行了改进,提出了新的下垂限幅控制算法。此外专门设计了低通滤波器,以有效降低谐波影响和增加控制精确性。考虑低压微电网孤网时负荷扰动和孤网至联网运行状态的切换,仿真验证了所提出的低压微电网控制器具有良好的适应能力。实验结果表明,该方法在低压微电网环境下能有效实现负荷变化时不同微电源间变化功率的共享,且频率和幅值较为稳定、动态效果好、工程实现简单,提高了系统功率分担的精确性和稳定性。Power coupling is a common problem in a microgrid because of the differences in impedance ratios between low voltage microgrid lines and traditional high voltage transmission lines. A virtual power V/f droop control method based on coordinate rotational transformation is proposed to handle this problem. The method achieves the decoupled real and reactive power control through orthogonaI transformation matrix. By improving the voltage frequency droop control, a new drooping restriction control algorithm is also introduced. Furthermore, a low pass filter is designed specifically to reduce the harmonic effect and improve the control accuracy. Taking the load disturbance of microgrid in the islanded mode and its transformation from islanded mode to interconnected mode into consideration, the good adaptability of low-voltage microgrid controller is proved by simulation results. Experimental results indicate that the proposed method can achieve the load power sharing effectively in the low-voltage microgrid, with relatively stable frequency and amplitude, good dynamic effect, and enhanced accuracy and stability of system power sharing.

关 键 词：微电网 微电源 坐标旋转 下垂控制 低通滤波器 

分 类 号：TM727[电气工程—电力系统及自动化] TM76