根据光伏并网逆变系统的供电需求,设计了一种120 ～ 850 V宽输入的辅助电源.为防止在输入电压过高时丢失开通脉冲,在传统的单端反激式拓扑电路的基础上加入了变频电路.输入电压升高时,降低开关频率,保证导通时间大于开关管的最小导通时间,实现了宽输入范围电压的要求.采用DCM工作模式,峰值电流控制,在反馈电路中加入了2型补偿网络,保证了输出电压快速调节性和稳定性.样机实验结果表明,该电源能够适应输入电压在大范围波动,可靠地为光伏并网实验系统供电.%According to the requirement of the PV grid-connected inverter system, an auxiliary power supply with an input voltage of 120 -850 V is designed. To avoid losing the opening pulse at a high input voltage, a circuit that can change switching frequency based on the input voltage is introduced. The peak current control and DCM work mode is used, and the type-2 compensation circuit in the feedback loop guarantees the rapid adjustment of output voltage and stability of the system. Experimental results show that this auxiliary power supply can adapt to a wide fluctuation of input voltage and provide long-term reliable DC voltage to the PV system.
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