摘要
针对三相大功率光伏并网逆变器在电网扰动或故障时突然脱网给电网带来的不利影响,基于电流平衡原则提出了一种基于正负序d-q坐标系的低穿控制策略。在研究了电网电压跌落对光伏并网逆变器运行性能影响的基础上,提出了采用前馈解耦的空间矢量PWM(SVPWM)控制算法,且为了获得最大转换效率,低穿过程中一直带着MPPT控制环运行。仿真和通过了国网电科院低穿认证表明该方法能够保证光伏逆变器在电网电压跌落时不过流,同时能保证在低穿过程中三相电流波形正弦且平衡,提高了系统运行性能。
Aiming to the performance of grid-connected inverters under the fault or unbalance circumstances of grid voltage, a control method on positive-negative dq rotate reference frame of grid-connected inverter is proposed for realizing low-voltage ride-through based on current balance rule. After the task that grid-connected inverter is influenced by voltage dips is researched, a forward back &decoupling control strategy is raised. In addition, for obtaining conversion efficiency, the Maximum Power Point Tracking( MPPT) loop is kept on in the LVRT process. Furthermore, the simulation model by Matlab/Simulink is established, and the LVRT test in State Grid Electric Power Research Institute is achieved. The results show that the LVRT control strategy which can ensure that the current wave is sinusoidal and balance is effective under voltage dips.
作者
闵泽生
李华银
杜睿
MIN Zesheng;LI Huayin;DU Rui(Sichuan Dongfang Electric Auto Control Engineering Co., Ltd., 618000, Deyang , Sichuan, China)
出处
《东方电气评论》
2017年第3期66-71,共6页
Dongfang Electric Review
关键词
光伏并网逆变器
低电压穿越
电流平衡
前馈解耦
grid-connected inverter
low voltage ride through ( LVRT )
current balance
forward back&decoupling
