摘要
在弱电网条件下,并网逆变器锁相环、电压环和电流环频带划分以及调制策略引起的振荡问题,影响着并网系统安全稳定的运行。为提高并网的稳定性,提出有源中点钳位型逆变器同步载波层叠调制技术以平衡内外管的电压应力、降低开关损耗和谐波,实时监测电流畸变率滞环切换控制模式以增强系统的稳定性。首先,采用三电平有源中点钳位型逆变器作为并网接口单元,优化了调制策略并分析了其谐波特性;接着,基于阻抗分析法建立阻抗模型,详细分析了锁相、电压和电流环频带分布规律及三者相互作用诱发并网系统失稳的机理;最后,通过实验验证了有源中点钳位型(active neutralpointclamp,ANPC)并网逆变器电流源控制模式和电压源控制模式根据谐波含量自适应切换控制策略,可以提高并网稳定性。有助于解决可再生能源大规模消纳的难题,对实现碳中和的目标和能源安全具有重要意义。
Under the condition of a weak grid,the frequency band division of the phase-locked loop,the voltage loop and the current loop,and the oscillation problem caused by the modulation strategy of the grid-connected inverter affect the safe and stable operation of the grid-connected system.To improve the grid-connected stability of the active midpoint clamp inverter,a synchronous carrier cascade modulation technology is proposed to balance the voltage stresses of the internal and external tubes and reduce the switching losses and harmonics,real-time monitoring the current distortion rate hysteresis switching control mode to enhance the stability of the system.Firstly,a three-level active midpoint clamp inverter is adopted as the grid-connected interface unit to optimize the modulation strategy and analyze its harmonic characteristics.Then,the impedance model is established based on the impedance analysis method,and the distribution of the phase locking,the voltage and current loop frequency band and the mechanism of the interaction of the three factors induced the instability of the grid-connected system are analyzed in detail.Finally,the experiment verifies that the current source control mode and the voltage source control mode of the active neutral point clamp(ANPC)grid-connected inverter adaptively switch the control strategies according to the harmonic content,which is able to improve the grid-connected stability,and help solve the issue of the large-scale uptaking of the renewable energy,having a great significance for achieving the goal of carbon neutrality and energy security.
作者
李鹏程
殷嘉棋
郭英军
李旭姗
杨江波
孙鹤旭
LI Pengcheng;YIN Jiaqi;GUO Yingjun;LI Xushan;YANG Jiangbo;SUN Hexu(School of Electrical Engineering,Hebei University of Science and Technology,Shijiazhuang 050018,Hebei Province,China;Abovosto Co.,Ltd.,Shijiazhuang 050018,Hebei Province,China)
出处
《电网技术》
EI
CSCD
北大核心
2023年第11期4521-4532,共12页
Power System Technology
基金
河北省教育厅项目(ZD2022030)
石家庄市科技局项目(211060321A)
河北省科技厅项目(20314501D,19214501D)。
关键词
同步调制
抑制振荡
滞环切换
弱电网
synchronous modulation
oscillation suppression
hysteresis switching control
weak grid
