太阳能并网逆变电源变压器直流偏磁的抑制

Restraining of DC Bias Transformer Magnetization in Solar Energy Grid Inverter

设计太阳能并网逆变电源时必须考虑到直流偏磁对输出变压器的不良影响。导致变压器直流偏磁的因素包括控制系统引起的偏磁、驱动电路元件参数的分散性引起的偏磁以及主电路引起的偏磁。检测变压器的初级电流,通过DSP计算提取出初级电流的直流分量,再用闭环PI控制算法计算出抑制直流分量所需的补偿量,并将其加载到控制量中,可有效抑制变压器初级的直流偏磁。

When designing a solar energy grid inverter,the bad impact of DC bias transformer magnetization should be considered.The factors such as control system errors, driving circuit parameters dispersion and main circuit bias magnetization cause DC bias transformer magnetization.In this scheme,primary current of the transformer is detected and sent to DSP to calculate the DC component in it.The PI control algorithm is implemented to calculate the compensation value and the compensation value is added to the control output,in this way the DC bias transformer magnetization can be restrained.