Short-circuit protecting circuit of high-power photovoltaic inverter

Disclosed in the utility model is a short-circuit protecting circuit of a high-power photovoltaic inverter, wherein the short-circuit protecting circuit comprises a high-power photovoltaic inverter, an alternating current sampling circuit, a signal conditioning circuit, an absolute value and maximum value solving circuit, a reference voltage generating circuit, a current threshold detection circuit, an optical coupling isolation circuit, a DSP control module, and a switch tube driving module. The current sampling device includes hall current sensors and sampling resistors; and the reference voltage generating circuit includes a plurality of reference voltage divider resistors. According to the utility model, the hall current sensors with fast responding speeds and high measuring precision are utilized to carry out sampling on output instantaneous current values of the inverter. The whole protecting circuit is formed by conventional hardware circuits; the motion speed is fast and secure and reliable performances are realized; the utilization of a general integrated current protection module can be avoided. The short-circuit protecting circuit can be used for photovoltaic inverters with different power grades and can be used to solve short-circuit faults of different types; and the circuit has advantages of high detection sensitivity, fast protection motion and reliable execution.