共直流母线并网逆变器并联系统运行方式

为使共直流母线并网逆变器并联系统(GIPS)实现理想无环流运行状态,各并联单元输出的脉宽调制电压波形需要保持一致,也就是各并联单元驱动信号需保持同步。借助并联系统各单元驱动信号的同步约束规律,可容易将被提出的H桥死区消除正弦脉宽调制应用于共直流母线GIPS,从而避免死区效应对并网电流的影响。由数字信号处理器与现场可编程门阵列结合的数字控制系统易于实现所提出的并联运行方式。实验结果验证了所提控制方法的运行特点与有效性,GIPS基本能够实现无环流运行状态并且在整个运行阶段无需设置死区时间。

Operation method for grid-connected inverter parallel system with common DC link

Keeping no difference in the instantaneous output pulse width modulation ( PWM) voltages of parallel inverters was the ideal operation status of a grid-connected inverter parallel system ( GIPS) to a-chieve no circulating current among parallel inverters .In other words , the gate control signals for swit-ches in parallel inverters should be synchronized .By means of the uniform constraint of the gate control signals for switches , the H-bridge dead-time elimination sinusoidal pulse width modulation ( SPWM ) presented can be easily applied to GIPS with common DC link .Thereby , the influence of the current by dead time can be avoided .The proposed operation method is easy to be implemented on the digital con-trol board using digital signal processing ( DSP) and field-programmable gate array ( FPGA) .The experi-mental results are presented to demonstrate the validity and features of the proposed operation method . GIPS can basically achieve no circulating current among parallel inverters , and the dead-time isn't neces-sary within the entire running time .