锁相同步并网变换器电流控制内电势幅值/频率形成机制分析  

Analysis of Formation Mechanism of Internal Voltage Amplitude/Frequency in Current Control of Phase-locked Synchronous Grid-connected Converter

作　　者：洪宇 袁小明[1,2] 龚轩 HONG Yu;YUAN Xiaoming;GONG Xuan(School of Electrical and Electronic Engineering,Huazhong University of Science and Technology,Wuhan 430074,China;CPSS)

机构地区：[1]华中科技大学电气与电子工程学院,武汉430074 [2]中国电源学会

出　　处：《电源学报》2024年第4期112-120,共9页Journal of Power Supply

基　　金：国家自然科学基金智能电网联合基金资助项目(U1866601)。

摘　　要：传统电力系统中,同步发电机独立形成内电势幅值/频率,接入电网建立系统电压。然而目前电网电压的建立越来越依赖于可再生能源设备,在锁相同步下并网变换器形成内电势需检测电网电压,看似与同步机独立形成内电势并建立系统电压不同。针对此问题,研究锁相同步下变换器电流控制形成内电势幅值/频率的机制,明确内电势幅值/频率由电流唯一确定,阐明锁相同步设备在本质上与同步发电机独立形成内电势建立电压相同。首先,基于控制结构与交流瞬时值形成的本质,说明变换器的输出实质上为内电势幅值/频率。然后,从设备与网络闭环动态过程出发,明确端电压与电流的冗余关系,在输入电流确定后内电势幅值/频率即可相应地唯一确定。最后,结合仿真分析,说明输入电流唯一确定内电势幅值/频率的正确性。In the traditional power system,the synchronous generator independently forms the internal voltage amplitude/frequency,which is connected to grid to establish the system voltage.However,the establishment of grid voltage at present is increasingly dependent on renewable energy equipment.Under the phase-locked synchronization,the grid-connected converter needs to detect the grid voltage to form the internal voltage,which seems to be different from the synchronous machine that independently forms the internal voltage and further establishes the system voltage.On this basis,the mechanism of internal voltage amplitude/frequency formed by the current control of the phase-locked synchronous converter is studied,and it is explicitly stated that the internal voltage amplitude/frequency is uniquely determined by current,which is essentially the same as the synchronous generator independently forming the internal voltage to establish the system voltage.In this paper,based on the control structure and the nature of forming the AC instantaneous value,it is explained that the converter output is essentially the internal voltage amplitude/frequency.Then,starting from the closed-loop dynamic process of equipment and network,the redundant relationship between terminal voltage and current is clarified.After the input current is determined,the internal voltage amplitude/frequency can be uniquely determined accordingly.Finally,combined with the simulation analysis,the correctness of uniquely determining the internal voltage amplitude/frequency by input current is demonstrated.

关 键 词：并网变换器 电流控制 内电势幅值/频率 形成机制 

分 类 号：TM711[电气工程—电力系统及自动化]