基于虚拟谐波电阻的微网同步定频电流控制法

孤岛微网同步定频电流控制法具有逆变器间功率均分效果受系统运行参数影响小,抗电压扰动能力强,实现方法简单等优势.但是,其应用于含非线性不平衡负荷的微网时存在电压畸变及不平衡问题.为此,文中提出基于虚拟谐波电阻的同步定频电流控制法,通过引入虚拟谐波电阻,降低逆变器低次谐波频域的输出阻抗,抑制电压畸变及电压不平衡.同时,在并...

Virtual harmonic resistance based constant-frequency synchronous current phasor control method for microgrid

The constant-frequency synchronous current control method for island micro-grid has many advantages,such as the effect of power sharing between inverters is less affected by system operation parameters,strong resistance to voltage disturbance and simple implementation method.However,when it is applied to the micro-grid with nonlinear unbalanced loads,there is the problem of voltage distortion and voltage unbalance.Therefore,a virtual harmonic resistance based constant-frequency synchronous current control method is proposed in this paper.By introducing virtual harmonic resistors,the output impedance of the inverter in the low harmonic frequency domain is reduced,and the voltage distortion and voltage unbalance is suppressed.In the meantime,the harmonic current is evenly distributed among parallel inverters.The output impedance model of the inverter is established.According to the model analysis,it is found that the virtual harmonic resistance would cause resonance and amplify the high-order voltage harmonics.Therefore,active damping control is used to suppress resonance generation.The simulation and experimental results show that the proposed control method can effectively improve the voltage waveform quality and realize the reasonable averaging of harmonic current among inverters.