三相LCL并网逆变器改进型准比例谐振控制技术

Improved Quasi Proportional Resonance Control Technique Based On Three-Phase LCL Grid Connected Inverter

为提高并网逆变器在大规模新能源发电场合适应能力,提出一种改进型准PR控制技术。不同于PI控制,改进的控制器可以在两相静止坐标系下直接对谐波分量进行抑制,能够有效的消除并网电流中的谐波分量,同时在电流环中加入电网电压前馈控制,将进一步提高系统的动态性能和抗扰能力,有利于并网逆变器在复杂工作环境中的稳定。MATLAB仿真结果表明,在电网电压不对称及谐波情况下,三相LCL并网逆变器采用该控制策略能够得到高质量的并网电流,保证了逆变器高效稳定运行。

In order to improve the adaptability of grid-connected inverter in large-scale new energy generation field, an improved quasi-PR control technology is proposed. Different from the PI control, the controller can directly suppress the harmonic components in the two-phase stationary coordinate system, which can effectively eliminate the harmonic components in the grid current. While adding the grid voltage feed-forward control to current loop, it will not only further improve the system dynamic performance and anti disturbance ability, but also stabilize the grid connected inverter in complicated working environments. The results of MATLAB simulation show that the three-phase LCL grid-connected inverter can obtain high-quality grid-connected current and ensure the efficient and stable operation of the inverter under the condition of voltage asymmetry and harmonic.