两级式并网变换器级联稳定性及控制策略研究  

Cascade Stability and Control Strategy Research on Two Stage Bidirectional Converter

作　　者：支娜[1] 张辉[1] 肖曦[2] 魏亚龙[1] 

机构地区：[1]西安理工大学自动化与信息工程学院,陕西西安710048 [2]清华大学电机工程与应用电子技术系,北京100084

出　　处：《电气传动》2015年第6期32-36,共5页Electric Drive

基　　金：国家自然科学基金(51277150/51307140);陕西省工业攻关项目(2013K07-05);陕西省教育厅专项科研基金(13JK0994);陕西省教育厅产业化培育项目(14JF020);电力设备电气绝缘国家重点实验室开放基金(EIPE12209);西安市科技计划项目(CX1256);西安市碑林区科技计划项目(GX1210);陕西省重点学科建设专项资金(105-5X1201)

摘　　要：直流微电网通过并网变换器与交流电网相连,实现功率的双向流动及直流母线电压的稳定,两级式并网变换器以其直流侧电压调节范围大、动态响应快等优点被用于低压直流微电网中。以母线电压为400 V的直流微电网为背景,研究两级式并网变换器的控制策略及其级联稳定性。提出以直流母线电压为控制信号的两级式并网变换器均流策略,实现直流微电网功率的自动平衡及并网变换器功率的双向流动。建立两级式并网变换器的小信号模型,设计控制器参数,并根据阻抗比判据分析了两级式变换器的级联稳定性。仿真和实验结果表明,所提出的控制策略能够跟踪直流母线电压的变化,平衡直流微电网功率,稳定直流母线电压,并实现并网变换器功率的双向控制,具有良好的动态响应。Bidirectional converter is used to interface a DC microgrid to utility grid, realize the bidirectional power flow control and DC bus voltage regulation, two stage bidirectional converter has the advantages of larger voltage regulation range and fastter dynamic response which can be used to low voltage I）C microgrid. Studied the control strategy and cascaded instability of two stage bidirectional converter based on DC microgrid which has bus voltage of 400 V. Proposed a current sharing schemes of two stage bidirectional converter based on DC bus voltage, and realized self-balancing and bidirectional power of the DC microgrid. Through established small signal model of two stage bidirectional converter, the controller parameters were designed, and analyzed the cascaded stability of two stage bidirectional converter based on impedance criterion. Simulation and experimental results show that the proposed control strategy can track the change of the DC bus vohage, stabilize DC bus voltage and achieve bidirectional power control, has the good dynamic response.

关 键 词：直流微电网 两级式变换器 级联稳定性 功率双向控制 

分 类 号：TM615[电气工程—电力系统及自动化]