Design And Implementation Of Surge Suppression Circuit Based On Embedded Controller

With the rapid development of power supply technology,switching DC power supplies are widely used in industrial control,automotive electronics and avionics fields due to their high efficiency,small size,and good performance.The complex and diverse working environment puts forward higher requirements on the reliability and stability of the switching power supply.The switching power supply often encounters unexpected voltage transients and inrush current during the switching process.If it is not suppressed,it will damage the internal components of the circuit,affect the back-end load and power supply bus,and cause the whole machine to fail.In order to keep the power supply working safely and reliably in the event of a surge or sudden failure,it is necessary to design a surge protection circuit for the switching power supply.On the basis of analyzing the types,causes and common protective measures of surges,this paper proposes a design scheme of surge suppression circuit based on embedded controller.The circuit can suppress surge voltage and surge current while taking into account the functions of overcurrent protection,output power limit,reverse polarity protection of input power supply and anti-backflow.According to the design scheme,the sample was trial-produced and the circuit was testedThe normal working voltage range of this surge suppressor is 16 V～40 V.When the voltage between-40 V～16 V is applied to the device,the circuit cannot work normally,but it will not be damaged.The output current of the device can reach 30 A,and the maximum output power is 480 W.The surge suppressor is tested with three typical surge voltages（60 V/550 ms,80 V/100 ms,100 V/80 ms）.The test results show that the output voltage of the device is clamped within 50 V during the overvoltage period,and the circuit can work normally after the surge is removed.The protection function of the surge suppressor is tested,mainly including reverse polarity of the input power supply and antibackflow protection,power limit protection and overcurrent protection.The test shows that the device startup time is about 5 ms,the fault restart time is less than 500 ms,and the maximum load startup capacity of the circuit is 1.5 A～1.6 A.