基于NCP1252光伏逆变器辅助电源的应用

Application of Photovoltaic Inverter Auxiliary Power Supply Based on NCP1252

提出了一种宽输入电压范围的双管反激式开关电源作为光伏逆变器辅助电源方案。该开关电源具有多路直流输出,通过调节控制芯片输出脉冲的频率以适应直流输入在较大范围内变化,为光伏并网逆变器的开关器件驱动及控制电路提供稳定的直流电压。介绍了具有功能集成度高、价格低的NCP1252 PWM控制芯片的特性。分析了双管反激拓扑原理及优点,设计了变压器以及各关键电路。试验表明,辅助电源适应光伏逆变器输入直流电压的大范围波动,输出直流电压纹波在可以接受的范围内,可为光伏逆变器长期运行可靠供电。

This paper proposed a design that a dual flyback switching power supply with wide input voltage is used for photovoltaic inverter auxiliary power supply. By adjusting the frequency of the pulse outputted by control chip,this switching power supply adapts to the DC input variation and has lots of outputs to provide stable voltage for the switching device and control circuit of photovoltaic inverter. The paper illustrated the feature of the control chip NCP1252 which is cheap and is highly integrated,analyzed the principle of dual flyback topology and designed the transformer as well as some critical circuits. The test result shows that this design of assistant power supply can provide long-term reliable DC voltage with acceptable ripples and adapt to a wide fluctuation of input DC voltage.